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Sample records for binding protein-1 induces

  1. Hyperactivation of 4E-binding protein 1 as a mediator of biguanide-induced cytotoxicity during glucose deprivation.

    Science.gov (United States)

    Matsuo, Junichi; Tsukumo, Yoshinori; Saito, Sakae; Tsukahara, Satomi; Sakurai, Junko; Sato, Shigeo; Kondo, Hiromichi; Ushijima, Masaru; Matsuura, Masaaki; Watanabe, Toshiki; Tomida, Akihiro

    2012-05-01

    Biguanides, including metformin, buformin, and phenformin, are potential antitumorigenic agents and induce cell death during glucose deprivation, a cell condition that occurs in the tumor microenvironment. Here, we show that this selective killing of glucose-deprived cells is coupled with hyperactivation of eukaryotic initiation factor 4E-binding protein 1 (4E-BP1), a negative regulator of translation initiation. We found, in fact, that the 4E-BP1 hyperactivation led to failure of the unfolded protein response (UPR), an endoplasmic reticulum-originated stress signaling pathway for cell survival. We also found that the 4E-BP1-mediated UPR inhibition occurred through a strong inhibition of the mTOR signaling pathway, a proven antitumor target. Importantly, the 4E-BP1 hyperactivation can be also seen in xenografted cancer cells through an in vivo biguanide treatment. Our findings indicate that antitumor action of biguanides can be mediated by 4E-BP1 hyperactivation, which results in UPR inhibition and selective cell killing when glucose is withdrawn.

  2. Functional characterization of the ER stress induced X-box-binding protein-1 (Xbp-1 in the porcine system

    Directory of Open Access Journals (Sweden)

    Jin Dong-Il

    2011-05-01

    Full Text Available Abstract Background The unfolded protein response (UPR is an evolutionary conserved adaptive reaction for increasing cell survival under endoplasmic reticulum (ER stress conditions. X-box-binding protein-1 (Xbp1 is a key transcription factor of UPR that activates genes involved in protein folding, secretion, and degradation to restore ER function. The UPR induced by ER stress was extensively studied in diseases linked to protein misfolding and aggregations. However, in the porcine system, genes in the UPR pathway were not investigated. In this study, we isolated and characterized the porcine Xbp1 (pXbp1 gene in ER stress using porcine embryonic fibroblast (PEF cells and porcine organs. ER stress was induced by the treatment of tunicamycin and cell viability was investigated by the MTT assay. For cloning and analyzing the expression pattern of pXbp1, RT-PCR analysis and Western blot were used. Knock-down of pXbp1 was performed by the siRNA-mediated gene silencing. Results We found that the pXbp1 mRNA was the subject of the IRE1α-mediated unconventional splicing by ER stress. Knock-down of pXbp1 enhanced ER stress-mediated cell death in PEF cells. In adult organs, pXbp1 mRNA and protein were expressed and the spliced forms were detected. Conclusions It was first found that the UPR mechanisms and the function of pXbp1 in the porcine system. These results indicate that pXbp1 plays an important role during the ER stress response like other animal systems and open a new opportunity for examining the UPR pathway in the porcine model system.

  3. Airway epithelial inflammation-induced endoplasmic reticulum Ca2+ store expansion is mediated by X-box binding protein-1.

    Science.gov (United States)

    Martino, Mary E B; Olsen, John C; Fulcher, Nanette B; Wolfgang, Matthew C; O'Neal, Wanda K; Ribeiro, Carla M P

    2009-05-29

    Inflamed cystic fibrosis (CF) human bronchial epithelia (HBE), or normal HBE exposed to supernatant from mucopurulent material (SMM) from CF airways, exhibit endoplasmic reticulum (ER)/Ca(2+) store expansion and amplified Ca(2+)-mediated inflammation. HBE inflammation triggers an unfolded protein response (UPR) coupled to mRNA splicing of X-box binding protein-1 (XBP-1). Because spliced XBP-1 (XBP-1s) promotes ER expansion in other cellular models, we hypothesized that XBP-1s is responsible for the ER/Ca(2+) store expansion in inflamed HBE. XBP-1s was increased in freshly isolated infected/inflamed CF in comparison with normal HBE. The link between airway epithelial inflammation, XBP-1s, and ER/Ca(2+) store expansion was then addressed in murine airways challenged with phosphate-buffered saline or Pseudomonas aeruginosa. P. aeruginosa-challenged mice exhibited airway epithelial ER/Ca(2+) store expansion, which correlated with airway inflammation. P. aeruginosa-induced airway inflammation triggered XBP-1s in ER stress-activated indicator (ERAI) mice. To evaluate the functional role of XBP-1s in airway inflammation linked to ER/Ca(2+) store expansion, control, XBP-1s, or dominant negative XBP-1 (DN-XBP-1) stably expressing 16HBE14o(-) cell lines were used. Studies with cells transfected with an unfolded protein response element (UPRE) luciferase reporter plasmid confirmed that the UPRE was activated or inhibited by expression of XBP-1s or DN-XBP-1, respectively. Expression of XBP-1s induced ER/Ca(2+) store expansion and potentiated bradykinin-increased interleukin (IL)-8 secretion, whereas expression of DN-XBP-1 inhibited bradykinin-dependent IL-8 secretion. In addition, expression of DN-XBP-1 blunted SMM-induced ER/Ca(2+) store expansion and SMM-induced IL-8 secretion. These findings suggest that, in inflamed HBE, XBP-1s is responsible for the ER/Ca(2+) store expansion that confers amplification of Ca(2+)-dependent inflammatory responses.

  4. La Autoantigen Induces Ribosome Binding Protein 1 (RRBP1) Expression through Internal Ribosome Entry Site (IRES)-Mediated Translation during Cellular Stress Condition.

    Science.gov (United States)

    Gao, Wenqing; Li, Qi; Zhu, Ruiyu; Jin, Jian

    2016-07-20

    The function of ribosome binding protein 1 (RRBP1) is regulating the transportation and secretion of some intracellular proteins in mammalian cells. Transcription of RRBP1 is induced by various cytokines. However, few studies focused on the process of RRPB1 mRNA translation. The RRBP1 mRNA has a long 5' untranslated region that potentially formed a stable secondary structure. In this study, we show that the 5' UTR of RRBP1 mRNA contains an internal ribosome entry site (IRES). Moreover, the RRBP1 expression is induced by chemotherapeutic drug paclitaxel or adriamycin in human hepatocellular carcinoma cells and accompanied with the increased expression of La autoantigen (La), which binds to RRBP1 IRES element and facilitates translation initiation. Interestingly, we found IRES-mediated RRBP1 translation is also activated during serum-starvation condition which can induce cytoplasmic localization of La. After mapping the entire RRBP1 5' UTR, we determine the core IRES activity is located between nt-237 and -58. Furthermore, two apical GARR loops within the functional RRBP1 IRES elements may be important for La binding. These results strongly suggest an important role for IRES-dependent translation of RRBP1 mRNA in hepatocellular carcinoma cells during cellular stress conditions.

  5. Effects of glutathione depletion by 2-cyclohexen-1-one on excitatory amino acids-induced enhancement of activator protein-1 DNA binding in murine hippocampus.

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    Ogita, K; Kitayama, T; Okuda, H; Yoneda, Y

    2001-03-01

    We have investigated the role of glutathione in mechanisms associated with excitatory amino acid signaling to the nuclear transcription factor activator protein-1 (AP1) in the brain using mice depleted of endogenous glutathione by prior treatment with 2-cyclohexen-1-one (CHX). In the hippocampus of animals treated with CHX 2 h before, a significant increase was seen in enhancement of AP1 DNA binding when determined 2 h after the injection of kainic acid (KA) at low doses. The sensitization to KA was not seen in animals injected with CHX 24 h before, in coincidence with the recovery of glutathione contents to the normal levels. By contrast, CHX did not significantly affect the potentiation by NMDA of AP1 binding under any experimental conditions. Prior treatment with CHX resulted in facilitation of behavioral changes induced by KA without affecting those induced by NMDA. These results suggest that endogenous glutathione may be at least in part involved in molecular mechanisms underlying transcriptional control by KA, but not by NMDA, signals of cellular functions.

  6. Guanylate-Binding Protein 1, an Interferon-Induced GTPase, Exerts an Antiviral Activity against Classical Swine Fever Virus Depending on Its GTPase Activity

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    Li, Lian-Feng; Yu, Jiahui; Li, Yongfeng; Wang, Jinghan; Li, Su; Zhang, Lingkai; Xia, Shui-Li; Yang, Qian; Wang, Xiao; Yu, Shaoxiong; Luo, Yuzi; Sun, Yuan; Zhu, Yan; Munir, Muhammad

    2016-01-01

    ABSTRACT Many viruses trigger the type I interferon (IFN) pathway upon infection, resulting in the transcription of hundreds of interferon-stimulated genes (ISGs), which define the antiviral state of the host. Classical swine fever virus (CSFV) is the causative agent of classical swine fever (CSF), a highly contagious viral disease endangering the pig industry in many countries. However, anti-CSFV ISGs are poorly documented. Here we screened 20 ISGs that are commonly induced by type I IFNs against CSFV in lentivirus-delivered cell lines, resulting in the identification of guanylate-binding protein 1 (GBP1) as a potent anti-CSFV ISG. We observed that overexpression of GBP1, an IFN-induced GTPase, remarkably suppressed CSFV replication, whereas knockdown of endogenous GBP1 expression by small interfering RNAs significantly promoted CSFV growth. Furthermore, we demonstrated that GBP1 acted mainly on the early phase of CSFV replication and inhibited the translation efficiency of the internal ribosome entry site of CSFV. In addition, we found that GBP1 was upregulated at the transcriptional level in CSFV-infected PK-15 cells and in various organs of CSFV-infected pigs. Coimmunoprecipitation and glutathione S-transferase (GST) pulldown assays revealed that GBP1 interacted with the NS5A protein of CSFV, and this interaction was mapped in the N-terminal globular GTPase domain of GBP1. Interestingly, the K51 of GBP1, which is crucial for its GTPase activity, was essential for the inhibition of CSFV replication. We showed further that the NS5A-GBP1 interaction inhibited GTPase activity, which was critical for its antiviral effect. Taking our findings together, GBP1 is an anti-CSFV ISG whose action depends on its GTPase activity. IMPORTANCE Classical swine fever virus (CSFV) is the causative agent of classical swine fever (CSF), an economically important viral disease affecting the pig industry in many countries. To date, only a few host restriction factors against CSFV

  7. Regulation of Insulin-Response Element Binding Protein-1 in Obesity and Diabetes: Potential Role in Impaired Insulin-Induced Gene Transcription

    OpenAIRE

    2008-01-01

    One of the major mechanisms by which insulin modulates glucose homeostasis is through regulation of gene expression. Therefore, reduced expression of transcription factors that are required for insulin-regulated gene expression may contribute to insulin resistance. We recently identified insulin response element-binding protein-1 (IRE-BP1) as a transcription factor that binds and transactivates multiple insulin-responsive genes, but the regulation of IRE-BP1 in vivo is largely unknown. In thi...

  8. X-box-binding protein 1-modified neural stem cells for treatment of Parkinson's disease.

    Science.gov (United States)

    Si, Lihui; Xu, Tianmin; Wang, Fengzhang; Liu, Qun; Cui, Manhua

    2012-04-01

    X-box-binding protein 1-transfected neural stem cells were transplanted into the right lateral ventricles of rats with rotenone-induced Parkinson's disease. The survival capacities and differentiation rates of cells expressing the dopaminergic marker tyrosine hydroxylase were higher in X-box-binding protein 1-transfected neural stem cells compared to non-transfected cells. Moreover, dopamine and 3,4-dihydroxyphenylacetic acid levels in the substantia nigra were significantly increased, α-synuclein expression was decreased, and neurological behaviors were significantly ameliorated in rats following transplantation of X-box-binding protein 1-transfected neural stem cells. These results indicate that transplantation of X-box-binding protein 1-transfected neural stem cells can promote stem cell survival and differentiation into dopaminergic neurons, increase dopamine and 3,4-dihydroxyphenylacetic acid levels, reduce α-synuclein aggregation in the substantia nigra, and improve the symptoms of Parkinson's disease in rats.

  9. X-box-binding protein 1-modified neural stem cells for treatment of Parkinson's disease

    Institute of Scientific and Technical Information of China (English)

    Lihui Si; Tianmin Xu; Fengzhang Wang; Qun Liu; Manhua Cui

    2012-01-01

    X-box-binding protein 1-transfected neural stem cells were transplanted into the right lateral ventricles of rats with rotenone-induced Parkinson's disease. The survival capacities and differentiation rates of cells expressing the dopaminergic marker tyrosine hydroxylase were higher in X-box-binding protein 1-transfected neural stem cells compared to non-transfected cells. Moreover, dopamine and 3,4-dihydroxyphenylacetic acid levels in the substantia nigra were significantly increased, α-synuclein expression was decreased, and neurological behaviors were significantly ameliorated in rats following transplantation of X-box-binding protein 1-transfected neural stem cells. These results indicate that transplantation of X-box-binding protein 1-transfected neural stem cells can promote stem cell survival and differentiation into dopaminergic neurons, increase dopamine and 3,4-dihydroxyphenylacetic acid levels, reduce α-synuclein aggregation in the substantia nigra, and improve the symptoms of Parkinson's disease in rats.

  10. Revisiting Apoplastic Auxin Signaling Mediated by AUXIN BINDING PROTEIN 1.

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    Feng, Mingxiao; Kim, Jae-Yean

    2015-10-01

    It has been suggested that AUXIN BINDING PROTEIN 1 (ABP1) functions as an apoplastic auxin receptor, and is known to be involved in the post-transcriptional process, and largely independent of the already well-known SKP-cullin-F-box-transport inhibitor response (TIR1) /auxin signaling F-box (AFB) (SCF(TIR1/AFB)) pathway. In the past 10 years, several key components downstream of ABP1 have been reported. After perceiving the auxin signal, ABP1 interacts, directly or indirectly, with plasma membrane (PM)-localized transmembrane proteins, transmembrane kinase (TMK) or SPIKE1 (SPK1), or other unidentified proteins, which transfer the signal into the cell to the Rho of plants (ROP). ROPs interact with their effectors, such as the ROP interactive CRIB motif-containing protein (RIC), to regulate the endocytosis/exocytosis of the auxin efflux carrier PIN-FORMED (PIN) proteins to mediate polar auxin transport across the PM. Additionally, ABP1 is a negative regulator of the traditional SCF(TIR1/AFB) auxin signaling pathway. However, Gao et al. (2015) very recently reported that ABP1 is not a key component in auxin signaling, and the famous abp1-1 and abp1-5 mutant Arabidopsis lines are being called into question because of possible additional mutantion sites, making it necessary to reevaluate ABP1. In this review, we will provide a brief overview of the history of ABP1 research.

  11. Penicillin Binding Protein 1 Is Important in the Compensatory Response of Staphylococcus aureus to Daptomycin-Induced Membrane Damage and Is a Potential Target for β-Lactam–Daptomycin Synergy

    Science.gov (United States)

    Berti, Andrew D.; Theisen, Erin; Sauer, John-Demian; Nonejuie, Poochit; Olson, Joshua; Pogliano, Joseph; Sakoulas, George; Nizet, Victor; Proctor, Richard A.

    2015-01-01

    The activity of daptomycin (DAP) against methicillin-resistant Staphylococcus aureus (MRSA) is enhanced in the presence of β-lactam antibiotics. This effect is more pronounced with β-lactam antibiotics that exhibit avid binding to penicillin binding protein 1 (PBP1). Here, we present evidence that PBP1 has a significant role in responding to DAP-induced stress on the cell. Expression of the pbpA transcript, encoding PBP1, was specifically induced by DAP exposure whereas expression of pbpB, pbpC, and pbpD, encoding PBP2, PBP3, and PBP4, respectively, remained unchanged. Using a MRSA COL strain with pbpA under an inducible promoter, increased pbpA transcription was accompanied by reduced susceptibility to, and killing by, DAP in vitro. Exposure to β-lactams that preferentially inactivate PBP1 was not associated with increased DAP binding, suggesting that synergy in the setting of anti-PBP1 pharmacotherapy results from increased DAP potency on a per-molecule basis. Combination exposure in an in vitro pharmacokinetic/pharmacodynamic model system with β-lactams that preferentially inactivate PBP1 (DAP-meropenem [MEM] or DAP-imipenem [IPM]) resulted in more-rapid killing than did combination exposure with DAP-nafcillin (NAF) (nonselective), DAP-ceftriaxone (CRO) or DAP-cefotaxime (CTX) (PBP2 selective), DAP-cefaclor (CEC) (PBP3 selective), or DAP-cefoxitin (FOX) (PBP4 selective). Compared to β-lactams with poor PBP1 binding specificity, exposure of S. aureus to DAP plus PBP1-selective β-lactams resulted in an increased frequency of septation and cell wall abnormalities. These data suggest that PBP1 activity may contribute to survival during DAP-induced metabolic stress. Therefore, targeted inactivation of PBP1 may enhance the antimicrobial efficiency of DAP, supporting the use of DAP–β-lactam combination therapy for serious MRSA infections, particularly when the β-lactam undermines the PBP1-mediated compensatory response. PMID:26525797

  12. Retinoblastoma-binding protein 1 has an interdigitated double Tudor domain with DNA binding activity.

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    Gong, Weibin; Wang, Jinfeng; Perrett, Sarah; Feng, Yingang

    2014-02-21

    Retinoblastoma-binding protein 1 (RBBP1) is a tumor and leukemia suppressor that binds both methylated histone tails and DNA. Our previous studies indicated that RBBP1 possesses a Tudor domain, which cannot bind histone marks. In order to clarify the function of the Tudor domain, the solution structure of the RBBP1 Tudor domain was determined by NMR and is presented here. Although the proteins are unrelated, the RBBP1 Tudor domain forms an interdigitated double Tudor structure similar to the Tudor domain of JMJD2A, which is an epigenetic mark reader. This indicates the functional diversity of Tudor domains. The RBBP1 Tudor domain structure has a significant area of positively charged surface, which reveals a capability of the RBBP1 Tudor domain to bind nucleic acids. NMR titration and isothermal titration calorimetry experiments indicate that the RBBP1 Tudor domain binds both double- and single-stranded DNA with an affinity of 10-100 μM; no apparent DNA sequence specificity was detected. The DNA binding mode and key interaction residues were analyzed in detail based on a model structure of the Tudor domain-dsDNA complex, built by HADDOCK docking using the NMR data. Electrostatic interactions mediate the binding of the Tudor domain with DNA, which is consistent with NMR experiments performed at high salt concentration. The DNA-binding residues are conserved in Tudor domains of the RBBP1 protein family, resulting in conservation of the DNA-binding function in the RBBP1 Tudor domains. Our results provide further insights into the structure and function of RBBP1.

  13. The expression of selenium-binding protein 1 is decreased in uterine leiomyoma

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    Quddus M Ruhul

    2010-12-01

    Full Text Available Abstract Background Selenium has been shown to inhibit cancer development and growth through the mediation of selenium-binding proteins. Decreased expression of selenium-binding protein 1 has been reported in cancers of the prostate, stomach, colon, and lungs. No information, however, is available concerning the roles of selenium-binding protein 1 in uterine leiomyoma. Methods Using Western Blot analysis and immunohistochemistry, we examined the expression of selenium-binding protein 1 in uterine leiomyoma and normal myometrium in 20 patients who had undergone hysterectomy for uterine leiomyoma. Results and Discussion The patient age ranged from 34 to 58 years with a mean of 44.3 years. Proliferative endometrium was seen in 8 patients, secretory endometrium in 7 patients, and atrophic endometrium in 5 patients. Two patients showed solitary leiomyoma, and eighteen patients revealed 2 to 5 tumors. Tumor size ranged from 1 to 15.5 cm with a mean of 4.3 cm. Both Western Blot analysis and immunohistochemistry showed a significant lower level of selenium-binding protein 1 in leiomyoma than in normal myometrium. Larger tumors had a tendency to show a lower level of selenium-binding protein 1 than smaller ones, but the difference did not reach a statistical significance. The expression of selenium-binding protein 1 was the same among patients with proliferative, secretory, and atrophic endometrium in either leiomyoma or normal myometrium. Also, we did not find a difference of selenium-binding protein 1 level between patients younger than 45 years and older patients in either leiomyoma or normal myometrium. Conclusions Decreased expression of selenium-binding protein 1 in uterine leiomyoma may indicate a role of the protein in tumorigenesis. Our findings may provide a basis for future studies concerning the molecular mechanisms of selenium-binding protein 1 in tumorigenesis as well as the possible use of selenium in prevention and treatment of uterine

  14. Epilepsy, Behavioral Abnormalities, and Physiological Comorbidities in Syntaxin-Binding Protein 1 (STXBP1 Mutant Zebrafish.

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    Brian P Grone

    Full Text Available Mutations in the synaptic machinery gene syntaxin-binding protein 1, STXBP1 (also known as MUNC18-1, are linked to childhood epilepsies and other neurodevelopmental disorders. Zebrafish STXBP1 homologs (stxbp1a and stxbp1b have highly conserved sequence and are prominently expressed in the larval zebrafish brain. To understand the functions of stxbp1a and stxbp1b, we generated loss-of-function mutations using CRISPR/Cas9 gene editing and studied brain electrical activity, behavior, development, heart physiology, metabolism, and survival in larval zebrafish. Homozygous stxbp1a mutants exhibited a profound lack of movement, low electrical brain activity, low heart rate, decreased glucose and mitochondrial metabolism, and early fatality compared to controls. On the other hand, homozygous stxbp1b mutants had spontaneous electrographic seizures, and reduced locomotor activity response to a movement-inducing "dark-flash" visual stimulus, despite showing normal metabolism, heart rate, survival, and baseline locomotor activity. Our findings in these newly generated mutant lines of zebrafish suggest that zebrafish recapitulate clinical phenotypes associated with human syntaxin-binding protein 1 mutations.

  15. Sonic Hedgehog Guides Axons via Zipcode Binding Protein 1-Mediated Local Translation.

    Science.gov (United States)

    Lepelletier, Léa; Langlois, Sébastien D; Kent, Christopher B; Welshhans, Kristy; Morin, Steves; Bassell, Gary J; Yam, Patricia T; Charron, Frédéric

    2017-02-15

    Sonic hedgehog (Shh) attracts spinal cord commissural axons toward the floorplate. How Shh elicits changes in the growth cone cytoskeleton that drive growth cone turning is unknown. We find that the turning of rat commissural axons up a Shh gradient requires protein synthesis. In particular, Shh stimulation increases β-actin protein at the growth cone even when the cell bodies have been removed. Therefore, Shh induces the local translation of β-actin at the growth cone. We hypothesized that this requires zipcode binding protein 1 (ZBP1), an mRNA-binding protein that transports β-actin mRNA and releases it for local translation upon phosphorylation. We found that Shh stimulation increases phospho-ZBP1 levels in the growth cone. Disruption of ZBP1 phosphorylation in vitro abolished the turning of commissural axons toward a Shh gradient. Disruption of ZBP1 function in vivo in mouse and chick resulted in commissural axon guidance errors. Therefore, ZBP1 is required for Shh to guide commissural axons. This identifies ZBP1 as a new mediator of noncanonical Shh signaling in axon guidance.SIGNIFICANCE STATEMENT Sonic hedgehog (Shh) guides axons via a noncanonical signaling pathway that is distinct from the canonical Hedgehog signaling pathway that specifies cell fate and morphogenesis. Axon guidance is driven by changes in the growth cone in response to gradients of guidance molecules. Little is known about the molecular mechanism of how Shh orchestrates changes in the growth cone cytoskeleton that are required for growth cone turning. Here, we show that the guidance of axons by Shh requires protein synthesis. Zipcode binding protein 1 (ZBP1) is an mRNA-binding protein that regulates the local translation of proteins, including actin, in the growth cone. We demonstrate that ZBP1 is required for Shh-mediated axon guidance, identifying a new member of the noncanonical Shh signaling pathway.

  16. X-Box Binding Protein-1 in Breast Cancer

    Science.gov (United States)

    2005-08-01

    inhibitors can induce aromatase such that there is suYcient estrogen biosyn- thesis to overcome the eVects of the drug (Goss et al., 2003). Other potential... doxorubicin , 5‐fluorouracil, or methotrexate. In a study of BCAR1 in material from 937 primary human breast tumors, almost 10% exhibited strong staining... Impact of tamoxifen on the pharmacokinetics and endocrine eVects of the aromatase inhibitor letrozole in postmeno- pausal women with breast cancer

  17. Specific T-cell recognition of the merozoite proteins rhoptry-associated protein 1 and erythrocyte-binding antigen 1 of Plasmodium falciparum

    DEFF Research Database (Denmark)

    Jakobsen, P H; Hviid, L; Theander, T G;

    1993-01-01

    The merozoite proteins merozoite surface protein 1 (MSP-1) and rhoptry-associated protein 1 (RAP-1) and synthetic peptides containing sequences of MSP-1, RAP-1, and erythrocyte-binding antigen 1, induced in vitro proliferative responses of lymphocytes collected from Ghanaian blood donors living...

  18. Poly(C)-binding protein 1 (PCBP1) mediates housekeeping degradation of mitochondrial antiviral signaling (MAVS)

    Institute of Scientific and Technical Information of China (English)

    Xiang Zhou; Fuping You; Huihui Chen; Zhengfan Jiang

    2012-01-01

    Mitochondrial antiviral signaling (MAVS) is a key adaptor in cellular antiviral innate immunity.We previously identified poly(C)-binding protein 2 (PCBP2) as a feedback inhibitor of MAVS that facilitates its degradation after viral infection,but little is known about the regulatory potential of poly(C)-binding protein 1 (PCBP1),which highly resembles PCBP2.Here we report that PCBP1 mediates housekeeping degradation of MAVS using the same mechanism as PCBP2 employs.Overexpression of PCBP1 impairs MAVS-mediated antiviral responses,while knockdown of PCBP1 exerts the opposite effect.The suppression is due to PCBP1-induced MAVS degradation.We observe that PCBP1 and PCBP2 show synergy in MAVS inhibition,but their expression patterns are distinct:PCBP1 is stably and abundantly expressed,while PCBP2 shows low basal expression with rapid induction after infection.Individual knockdown and subcellular fractionation analyses reveal that unlike the postinfection inhibitor PCBP2,PCBP1 continuously eliminates cellular MAVS.Our findings unravel a critical role of PCBP1 in regulating MAVS for both finetuning the antivirai immunity and preventing inflammation.

  19. PTPRT regulates the interaction of Syntaxin-binding protein 1 with Syntaxin 1 through dephosphorylation of specific tyrosine residue

    Energy Technology Data Exchange (ETDEWEB)

    Lim, So-Hee; Moon, Jeonghee [Biomedical Proteomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806 (Korea, Republic of); Lee, Myungkyu [Bionanotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806 (Korea, Republic of); Lee, Jae-Ran, E-mail: leejr@kribb.re.kr [Biomedical Proteomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806 (Korea, Republic of)

    2013-09-13

    Highlights: •PTPRT is a brain-specific, expressed, protein tyrosine phosphatase. •PTPRT regulated the interaction of Syntaxin-binding protein 1 with Syntaxin 1. •PTPRT dephosphorylated the specific tyrosine residue of Syntaxin-binding protein 1. •Dephosphorylation of Syntaxin-binding protein 1 enhanced the interaction with Syntaxin 1. •PTPRT appears to regulate the fusion of synaptic vesicle through dephosphorylation. -- Abstract: PTPRT (protein tyrosine phosphatase receptor T), a brain-specific tyrosine phosphatase, has been found to regulate synaptic formation and development of hippocampal neurons, but its regulation mechanism is not yet fully understood. Here, Syntaxin-binding protein 1, a key component of synaptic vesicle fusion machinery, was identified as a possible interaction partner and an endogenous substrate of PTPRT. PTPRT interacted with Syntaxin-binding protein 1 in rat synaptosome, and co-localized with Syntaxin-binding protein 1 in cultured hippocampal neurons. PTPRT dephosphorylated tyrosine 145 located around the linker between domain 1 and 2 of Syntaxin-binding protein 1. Syntaxin-binding protein 1 directly binds to Syntaxin 1, a t-SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) protein, and plays a role as catalysts of SNARE complex formation. Syntaxin-binding protein 1 mutant mimicking non-phosphorylation (Y145F) enhanced the interaction with Syntaxin 1 compared to wild type, and therefore, dephosphorylation of Syntaxin-binding protein 1 appeared to be important for SNARE-complex formation. In conclusion, PTPRT could regulate the interaction of Syntaxin-binding protein 1 with Syntaxin 1, and as a result, the synaptic vesicle fusion appeared to be controlled through dephosphorylation of Syntaxin-binding protein 1.

  20. Oleanolic Acid Diminishes Liquid Fructose-Induced Fatty Liver in Rats: Role of Modulation of Hepatic Sterol Regulatory Element-Binding Protein-1c-Mediated Expression of Genes Responsible for De Novo Fatty Acid Synthesis

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    Changjin Liu

    2013-01-01

    Full Text Available Oleanolic acid (OA, contained in more than 1620 plants and as an aglycone precursor for naturally occurred and synthesized triterpenoid saponins, is used in China for liver disorders in humans. However, the underlying liver-protecting mechanisms remain largely unknown. Here, we found that treatment of rats with OA (25 mg/kg/day, gavage, once daily over 10 weeks diminished liquid fructose-induced excess hepatic triglyceride accumulation without effect on total energy intake. Attenuation of the increased vacuolization and Oil Red O staining area was evident on histological examination of liver in OA-treated rats. Hepatic gene expression profile demonstrated that OA suppressed fructose-stimulated overexpression of sterol regulatory element-binding protein-(SREBP- 1/1c mRNA and nuclear protein. In accord, overexpression of SREBP-1c-responsive genes responsible for fatty acid synthesis was also downregulated. In contrast, overexpressed nuclear protein of carbohydrate response element-binding protein and its target genes liver pyruvate kinase and microsomal triglyceride transfer protein were not altered. Additionally, OA did not affect expression of peroxisome proliferator-activated receptor-gamma- and -alpha and their target genes. It is concluded that modulation of hepatic SREBP-1c-mediated expression of the genes responsible for de novo fatty acid synthesis plays a pivotal role in OA-elicited diminishment of fructose-induced fatty liver in rats.

  1. Disruption of genes encoding eIF4E binding proteins-1 and -2 does not alter basal or sepsis-induced changes in skeletal muscle protein synthesis in male or female mice.

    Science.gov (United States)

    Steiner, Jennifer L; Pruznak, Anne M; Deiter, Gina; Navaratnarajah, Maithili; Kutzler, Lydia; Kimball, Scot R; Lang, Charles H

    2014-01-01

    Sepsis decreases skeletal muscle protein synthesis in part by impairing mTOR activity and the subsequent phosphorylation of 4E-BP1 and S6K1 thereby controlling translation initiation; however, the relative importance of changes in these two downstream substrates is unknown. The role of 4E-BP1 (and -BP2) in regulating muscle protein synthesis was assessed in wild-type (WT) and 4E-BP1/BP2 double knockout (DKO) male mice under basal conditions and in response to sepsis. At 12 months of age, body weight, lean body mass and energy expenditure did not differ between WT and DKO mice. Moreover, in vivo rates of protein synthesis in gastrocnemius, heart and liver did not differ between DKO and WT mice. Sepsis decreased skeletal muscle protein synthesis and S6K1 phosphorylation in WT and DKO male mice to a similar extent. Sepsis only decreased 4E-BP1 phosphorylation in WT mice as no 4E-BP1/BP2 protein was detected in muscle from DKO mice. Sepsis decreased the binding of eIF4G to eIF4E in WT mice; however, eIF4E•eIF4G binding was not altered in DKO mice under either basal or septic conditions. A comparable sepsis-induced increase in eIF4B phosphorylation was seen in both WT and DKO mice. eEF2 phosphorylation was similarly increased in muscle from WT septic mice and both control and septic DKO mice, compared to WT control values. The sepsis-induced increase in muscle MuRF1 and atrogin-1 (markers of proteolysis) as well as TNFα and IL-6 (inflammatory cytokines) mRNA was greater in DKO than WT mice. The sepsis-induced decrease in myocardial and hepatic protein synthesis did not differ between WT and DKO mice. These data suggest overall basal protein balance and synthesis is maintained in muscle of mice lacking both 4E-BP1/BP2 and that sepsis-induced changes in mTOR signaling may be mediated by a down-stream mechanism independent of 4E-BP1 phosphorylation and eIF4E•eIF4G binding.

  2. Evidence that selenium binding protein 1 is a tumor suppressor in prostate cancer.

    Directory of Open Access Journals (Sweden)

    Emmanuel Ansong

    Full Text Available Selenium-Binding Protein 1 (SBP1, SELENBP1, hSP56 is a selenium-associated protein shown to be at lower levels in tumors, and its lower levels are frequently predictive of a poor clinical outcome. Distinguishing indolent from aggressive prostate cancer is a major challenge in disease management. Associations between SBP1 levels, tumor grade, and disease recurrence following prostatectomy were investigated by duplex immunofluorescence imaging using a tissue microarray containing tissue from 202 prostate cancer patients who experienced biochemical (PSA recurrence after prostatectomy and 202 matched control patients whose cancer did not recur. Samples were matched by age, ethnicity, pathological stage and Gleason grade, and images were quantified using the Vectra multispectral imaging system. Fluorescent labels were targeted for SBP1 and cytokeratins 8/18 to restrict scoring to tumor cells, and cell-by-cell quantification of SBP1 in the nucleus and cytoplasm was performed. Nuclear SBP1 levels and the nuclear to cytoplasm ratio were inversely associated with tumor grade using linear regression analysis. Following classification of samples into quartiles based on the SBP1 levels among controls, tumors in the lowest quartile were more than twice as likely to recur compared to those in any other quartile. Inducible ectopic SBP1 expression reduced the ability of HCT-116 human tumor cells to grow in soft agar, a measure of transformation, without affecting proliferation. Cells expressing SBP1 also demonstrated a robust induction in the phosphorylation of the p53 tumor suppressor at serine 15. These data indicate that loss of SBP1 may play an independent contributing role in prostate cancer progression and its levels might be useful in distinguishing indolent from aggressive disease.

  3. Insight into temperature dependence of GTPase activity in human guanylate binding protein-1.

    Directory of Open Access Journals (Sweden)

    Anjana Rani

    Full Text Available Interferon-γ induced human guanylate binding protein-1(hGBP1 belongs to a family of dynamin related large GTPases. Unlike all other GTPases, hGBP1 hydrolyzes GTP to a mixture of GDP and GMP with GMP being the major product at 37°C but GDP became significant when the hydrolysis reaction was carried out at 15°C. The hydrolysis reaction in hGBP1 is believed to involve with a number of catalytic steps. To investigate the effect of temperature in the product formation and on the different catalytic complexes of hGBP1, we carried out temperature dependent GTPase assays, mutational analysis, chemical and thermal denaturation studies. The Arrhenius plot for both GDP and GMP interestingly showed nonlinear behaviour, suggesting that the product formation from the GTP-bound enzyme complex is associated with at least more than one step. The negative activation energy for GDP formation and GTPase assay with external GDP together indicate that GDP formation occurs through the reversible dissociation of GDP-bound enzyme dimer to monomer, which further reversibly dissociates to give the product. Denaturation studies of different catalytic complexes show that unlike other complexes the free energy of GDP-bound hGBP1 decreases significantly at lower temperature. GDP formation is found to be dependent on the free energy of the GDP-bound enzyme complex. The decrease in the free energy of this complex at low temperature compared to at high is the reason for higher GDP formation at low temperature. Thermal denaturation studies also suggest that the difference in the free energy of the GTP-bound enzyme dimer compared to its monomer plays a crucial role in the product formation; higher stability favours GMP but lower favours GDP. Thus, this study provides the first thermodynamic insight into the effect of temperature in the product formation of hGBP1.

  4. A Critical Role for Cysteine 57 in the Biological Functions of Selenium Binding Protein-1

    Directory of Open Access Journals (Sweden)

    Qi Ying

    2015-11-01

    Full Text Available The concentration of selenium-binding protein1 (SBP1 is often lower in tumors than in the corresponding tissue and lower levels have been associated with poor clinical outcomes. SBP1 binds tightly selenium although what role selenium plays in its biological functions remains unknown. Previous studies indicated that cysteine 57 is the most likely candidate amino acid for selenium binding. In order to investigate the role of cysteine 57 in SBP1, this amino acid was altered to a glycine and the mutated protein was expressed in human cancer cells. The SBP1 half-life, as well as the cellular response to selenite cytotoxicity, was altered by this change. The ectopic expression of SBP1GLY also caused mitochondrial damage in HCT116 cells. Taken together, these results indicated that cysteine 57 is a critical determinant of SBP1 function and may play a significant role in mitochondrial function.

  5. Arabidopsis dynamin-related protein 1A polymers bind, but do not tubulate, liposomes

    Energy Technology Data Exchange (ETDEWEB)

    Backues, Steven K. [Department of Biochemistry, University of Wisconsin - Madison, 433 Babcock Dr., Madison, WI 53706 (United States); Bednarek, Sebastian Y., E-mail: sybednar@wisc.edu [Department of Biochemistry, University of Wisconsin - Madison, 433 Babcock Dr., Madison, WI 53706 (United States)

    2010-03-19

    The Arabidopsis dynamin-related protein 1A (AtDRP1A) is involved in endocytosis and cell plate maturation in Arabidopsis. Unlike dynamin, AtDRP1A does not have any recognized membrane binding or protein-protein interaction domains. We report that GTPase active AtDRP1A purified from Escherichia coli as a fusion to maltose binding protein forms homopolymers visible by negative staining electron microscopy. These polymers interact with protein-free liposomes whose lipid composition mimics that of the inner leaflet of the Arabidopsis plasma membrane, suggesting that lipid-binding may play a role in AtDRP1A function. However, AtDRP1A polymers do not appear to assemble and disassemble in a dynamic fashion and do not have the ability to tubulate liposomes in vitro, suggesting that additional factors or modifications are necessary for AtDRP1A's in vivo function.

  6. AMYLOID-β PEPTIDE BINDS TO MICROTUBULE-ASSOCIATED PROTEIN 1B (MAP1B)

    Science.gov (United States)

    Gevorkian, Goar; Gonzalez-Noriega, Alfonso; Acero, Gonzalo; Ordoñez, Jorge; Michalak, Colette; Munguia, Maria Elena; Govezensky, Tzipe; Cribbs, David H.; Manoutcharian, Karen

    2008-01-01

    Extracellular and intraneuronal formation of amyloid-beta aggregates have been demonstrated to be involved in the pathogenesis of Alzheimer’s disease. However, the precise mechanism of amyloid-beta neurotoxicity is not completely understood. Previous studies suggest that binding of amyloid-beta to a number of targets have deleterious effects on cellular functions. In the present study we have shown for the first time that amyloid-beta 1-42 bound to a peptide comprising the microtubule binding domain of the heavy chain of microtubule-associated protein 1B by the screening of a human brain cDNA library expressed on M13 phage. This interaction may explain, in part, the loss of neuronal cytoskeletal integrity, impairment of microtubule-dependent transport and synaptic dysfunction observed previously in Alzheimer’s disease. PMID:18079022

  7. Role of Plasmodium vivax Duffy-binding protein 1 in invasion of Duffy-null Africans.

    Science.gov (United States)

    Gunalan, Karthigayan; Lo, Eugenia; Hostetler, Jessica B; Yewhalaw, Delenasaw; Mu, Jianbing; Neafsey, Daniel E; Yan, Guiyun; Miller, Louis H

    2016-05-31

    The ability of the malaria parasite Plasmodium vivax to invade erythrocytes is dependent on the expression of the Duffy blood group antigen on erythrocytes. Consequently, Africans who are null for the Duffy antigen are not susceptible to P. vivax infections. Recently, P. vivax infections in Duffy-null Africans have been documented, raising the possibility that P. vivax, a virulent pathogen in other parts of the world, may expand malarial disease in Africa. P. vivax binds the Duffy blood group antigen through its Duffy-binding protein 1 (DBP1). To determine if mutations in DBP1 resulted in the ability of P. vivax to bind Duffy-null erythrocytes, we analyzed P. vivax parasites obtained from two Duffy-null individuals living in Ethiopia where Duffy-null and -positive Africans live side-by-side. We determined that, although the DBP1s from these parasites contained unique sequences, they failed to bind Duffy-null erythrocytes, indicating that mutations in DBP1 did not account for the ability of P. vivax to infect Duffy-null Africans. However, an unusual DNA expansion of DBP1 (three and eight copies) in the two Duffy-null P. vivax infections suggests that an expansion of DBP1 may have been selected to allow low-affinity binding to another receptor on Duffy-null erythrocytes. Indeed, we show that Salvador (Sal) I P. vivax infects Squirrel monkeys independently of DBP1 binding to Squirrel monkey erythrocytes. We conclude that P. vivax Sal I and perhaps P. vivax in Duffy-null patients may have adapted to use new ligand-receptor pairs for invasion.

  8. Rotavirus nonstructural protein 1 antagonizes innate immune response by interacting with retinoic acid inducible gene I

    Directory of Open Access Journals (Sweden)

    Qin Lan

    2011-12-01

    Full Text Available Abstract Background The nonstructural protein 1 (NSP1 of rotavirus has been reported to block interferon (IFN signaling by mediating proteasome-dependent degradation of IFN-regulatory factors (IRFs and (or the β-transducin repeat containing protein (β-TrCP. However, in addition to these targets, NSP1 may subvert innate immune responses via other mechanisms. Results The NSP1 of rotavirus OSU strain as well as the IRF3 binding domain truncated NSP1 of rotavirus SA11 strain are unable to degrade IRFs, but can still inhibit host IFN response, indicating that NSP1 may target alternative host factor(s other than IRFs. Overexpression of NSP1 can block IFN-β promoter activation induced by the retinoic acid inducible gene I (RIG-I, but does not inhibit IFN-β activation induced by the mitochondrial antiviral-signaling protein (MAVS, indicating that NSP1 may target RIG-I. Immunoprecipitation experiments show that NSP1 interacts with RIG-I independent of IRF3 binding domain. In addition, NSP1 induces down-regulation of RIG-I in a proteasome-independent way. Conclusions Our findings demonstrate that inhibition of RIG-I mediated type I IFN responses by NSP1 may contribute to the immune evasion of rotavirus.

  9. Differential expression of serum glycodelin and insulin-like growth factor binding protein 1 in early pregnancy.

    Science.gov (United States)

    Douglas, Nataki C; Thornton, Melvin H; Nurudeen, Sahadat K; Bucur, Maria; Lobo, Rogerio A; Sauer, Mark V

    2013-11-01

    This prospective study evaluated whether serum glycodelin and insulin-like growth factor binding protein 1 (IGFBP-1) predict the likelihood of embryo implantation in recipients undergoing donor egg in vitro fertilization. We measured glycodelin and IGFBP-1 at 6 points from lining check to lutenizing hormone (LH) + 31. β-Human chorionic gonadotropin levels were first measured at LH + 17. The recipients were divided into those without embryo implantation (group 1, n = 6) and those with successful implantation (group 2, n = 30). Although this is a negative study in that neither glycodelin nor IGFBP-1 alone reflected endometrial (EM) receptivity, the glycodelin/IGFBP-1 ratio on the day of blastocyst transfer was higher in recipients who achieved pregnancy (P = .05). At LH + 17, glycodelin was higher (P = .04), and IGFBP-1 was lower (P = .004) in recipients who achieved pregnancy when compared to those who did not. These observations are likely due to EM changes induced by successful embryo implantation.

  10. Loss of selenium-binding protein 1 decreases sensitivity to clastogens and intracellular selenium content in HeLa cells

    Science.gov (United States)

    Selenium-binding protein 1 (SBP1) is not a selenoprotein but structurally binds selenium. Loss of SBP1 during carcinogenesis usually predicts poor prognosis. Because genome instability is a hallmark of cancer, we hypothesized that loss of SBP1 modulates cellular selenium content and the response of ...

  11. The Y-Box Binding Protein 1 Suppresses Alzheimer's Disease Progression in Two Animal Models.

    Directory of Open Access Journals (Sweden)

    N V Bobkova

    Full Text Available The Y-box binding protein 1 (YB-1 is a member of the family of DNA- and RNA binding proteins. It is involved in a wide variety of DNA/RNA-dependent events including cell proliferation and differentiation, stress response, and malignant cell transformation. Previously, YB-1 was detected in neurons of the neocortex and hippocampus, but its precise role in the brain remains undefined. Here we show that subchronic intranasal injections of recombinant YB-1, as well as its fragment YB-11-219, suppress impairment of spatial memory in olfactory bulbectomized (OBX mice with Alzheimer's type degeneration and improve learning in transgenic 5XFAD mice used as a model of cerebral amyloidosis. YB-1-treated OBX and 5XFAD mice showed a decreased level of brain β-amyloid. In OBX animals, an improved morphological state of neurons was revealed in the neocortex and hippocampus; in 5XFAD mice, a delay in amyloid plaque progression was observed. Intranasally administered YB-1 penetrated into the brain and could enter neurons. In vitro co-incubation of YB-1 with monomeric β-amyloid (1-42 inhibited formation of β-amyloid fibrils, as confirmed by electron microscopy. This suggests that YB-1 interaction with β-amyloid prevents formation of filaments that are responsible for neurotoxicity and neuronal death. Our data are the first evidence for a potential therapeutic benefit of YB-1 for treatment of Alzheimer's disease.

  12. Structural Insights into RNA Recognition by the Alternate-Splicing Regulator CUG-Binding Protein 1

    Energy Technology Data Exchange (ETDEWEB)

    M Teplova; J Song; H Gaw; A Teplov; D Patel

    2011-12-31

    CUG-binding protein 1 (CUGBP1) regulates multiple aspects of nuclear and cytoplasmic mRNA processing, with implications for onset of myotonic dystrophy. CUGBP1 harbors three RRM domains and preferentially targets UGU-rich mRNA elements. We describe crystal structures of CUGBP1 RRM1 and tandem RRM1/2 domains bound to RNAs containing tandem UGU(U/G) elements. Both RRM1 in RRM1-RNA and RRM2 in RRM1/2-RNA complexes use similar principles to target UGU(U/G) elements, with recognition mediated by face-to-edge stacking and water-mediated hydrogen-bonding networks. The UG step adopts a left-handed Z-RNA conformation, with the syn guanine recognized through Hoogsteen edge-protein backbone hydrogen-bonding interactions. NMR studies on the RRM1/2-RNA complex establish that both RRM domains target tandem UGUU motifs in solution, whereas filter-binding assays identify a preference for recognition of GU over AU or GC steps. We discuss the implications of CUGBP1-mediated targeting and sequestration of UGU(U/G) elements on pre-mRNA alternative-splicing regulation, translational regulation, and mRNA decay.

  13. Molecular cloning and subcellular localization of Tektin2-binding protein 1 (Ccdc 172) in rat spermatozoa.

    Science.gov (United States)

    Yamaguchi, Airi; Kaneko, Takane; Inai, Tetsuichiro; Iida, Hiroshi

    2014-04-01

    Tektins (TEKTs) are composed of a family of filament-forming proteins localized in cilia and flagella. Five types of mammalian TEKTs have been reported, all of which have been verified to be present in sperm flagella. TEKT2, which is indispensable for sperm structure, mobility, and fertilization, was present at the periphery of the outer dense fiber (ODF) in the sperm flagella. By yeast two-hybrid screening, we intended to isolate flagellar proteins that could interact with TEKT2, which resulted in the isolation of novel two genes from the mouse testis library, referred as a TEKT2-binding protein 1 (TEKT2BP1) and -protein 2 (TEKT2BP2). In this study, we characterized TEKT2BP1, which is registered as a coiled-coil domain-containing protein 172 (Ccdc172) in the latest database. RT-PCR analysis indicated that TEKT2BP1 was predominantly expressed in rat testis and that its expression was increased after 3 weeks of postnatal development. Immunocytochemical studies discovered that TEKT2BP1 localized in the middle piece of rat spermatozoa, predominantly concentrated at the mitochondria sheath of the flagella. We hypothesize that the TEKT2-TEKT2BP1 complex might be involved in the structural linkage between the ODF and mitochondria in the middle piece of the sperm flagella.

  14. Spliced X-box binding protein 1 couples the unfolded protein response to hexosamine biosynthetic pathway.

    Science.gov (United States)

    Wang, Zhao V; Deng, Yingfeng; Gao, Ningguo; Pedrozo, Zully; Li, Dan L; Morales, Cyndi R; Criollo, Alfredo; Luo, Xiang; Tan, Wei; Jiang, Nan; Lehrman, Mark A; Rothermel, Beverly A; Lee, Ann-Hwee; Lavandero, Sergio; Mammen, Pradeep P A; Ferdous, Anwarul; Gillette, Thomas G; Scherer, Philipp E; Hill, Joseph A

    2014-03-13

    The hexosamine biosynthetic pathway (HBP) generates uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) for glycan synthesis and O-linked GlcNAc (O-GlcNAc) protein modifications. Despite the established role of the HBP in metabolism and multiple diseases, regulation of the HBP remains largely undefined. Here, we show that spliced X-box binding protein 1 (Xbp1s), the most conserved signal transducer of the unfolded protein response (UPR), is a direct transcriptional activator of the HBP. We demonstrate that the UPR triggers HBP activation via Xbp1s-dependent transcription of genes coding for key, rate-limiting enzymes. We further establish that this previously unrecognized UPR-HBP axis is triggered in a variety of stress conditions. Finally, we demonstrate a physiologic role for the UPR-HBP axis by showing that acute stimulation of Xbp1s in heart by ischemia/reperfusion confers robust cardioprotection in part through induction of the HBP. Collectively, these studies reveal that Xbp1s couples the UPR to the HBP to protect cells under stress.

  15. Insulin-like growth factor binding protein-1 activates integrin-mediated intracellular signaling and migration in oligodendrocytes

    NARCIS (Netherlands)

    Chesik, Daniel; De Keyser, Jacques; Bron, Reinier; Fuhler, Gwenny M.

    2010-01-01

    P>In multiple sclerosis (MS), oligodendrocytes in lesions are lost, leaving damaged tissue virtually devoid of these myelin-producing cells. Our group has recently demonstrated enhanced expression of insulin-like growth factor (IGF) binding protein-1 (IGFBP-1) in oligodendrocytes (CNPase+) localized

  16. Single strand DNA binding proteins 1 and 2 protect newly replicated telomeres

    Institute of Scientific and Technical Information of China (English)

    Peili Gu; Wei Deng; Ming Lei; Sandy Chang

    2013-01-01

    Human single-strand (ss) DNA binding proteins 1 and 2 (hSSB1 and 2) are components of the hSSB1/2-INTS3-C9orf80 heterotrimeric protein complex shown to participate in DNA damage response and maintenance of genome stability.However,their roles at telomeres remain unknown.Here,we generated murine SSB1 conditional knockout mice and cells and found that mSSB1 plays a critical role in telomere end protection.Both mSSB1 and mSSB2 localize to a subset of telomeres and are required to repair TRF2-deficient telomeres.Deletion of mSSB1 resulted in increased chromatid-type fusions involving both leading-and lagging-strand telomeric DNA,suggesting that it is required for the protection of G-overhangs.mSSB1's interaction with INTS3 is required for its localization to damaged DNA.mSSB1 interacts with Potla,but not Potlb,and its association with telomeric ssDNA requires Potla.mSSB1△/△ mice die at birth with developmental abnormalities,while mice with the hypomorphic mSSB1F/F allele are born alive and display increased sensitivity to ionizing radiation (IR).Our results suggest that mSSB1 is required to maintain genome stability,and document a previously unrecognized role for mSSB1/2 in the protection of newly replicated leading-and lagging-strand telomeres.

  17. Phyllostachys edulis compounds inhibit palmitic acid-induced monocyte chemoattractant protein 1 (MCP-1 production.

    Directory of Open Access Journals (Sweden)

    Jason K Higa

    Full Text Available BACKGROUND: Phyllostachys edulis Carriere (Poaceae is a bamboo species that is part of the traditional Chinese medicine pharmacopoeia. Compounds and extracts from this species have shown potential applications towards several diseases. One of many complications found in obesity and diabetes is the link between elevated circulatory free fatty acids (FFAs and chronic inflammation. This study aims to present a possible application of P. edulis extract in relieving inflammation caused by FFAs. Monocyte chemoattractant protein 1 (MCP-1/CCL2 is a pro-inflammatory cytokine implicated in chronic inflammation. Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB and activator protein 1 (AP-1 are transcription factors activated in response to inflammatory stimuli, and upregulate pro-inflammatory cytokines such as MCP-1. This study examines the effect of P. edulis extract on cellular production of MCP-1 and on the NF-κB and AP-1 pathways in response to treatment with palmitic acid (PA, a FFA. METHODOLOGY/PRINCIPAL FINDINGS: MCP-1 protein was measured by cytometric bead assay. NF-κB and AP-1 nuclear localization was detected by colorimetric DNA-binding ELISA. Relative MCP-1 mRNA was measured by real-time quantitative PCR. Murine cells were treated with PA to induce inflammation. PA increased expression of MCP-1 mRNA and protein, and increased nuclear localization of NF-κB and AP-1. Adding bamboo extract (BEX inhibited the effects of PA, reduced MCP-1 production, and inhibited nuclear translocation of NF-κB and AP-1 subunits. Compounds isolated from BEX inhibited MCP-1 secretion with different potencies. CONCLUSIONS/SIGNIFICANCE: PA induced MCP-1 production in murine adipose, muscle, and liver cells. BEX ameliorated PA-induced production of MCP-1 by inhibiting nuclear translocation of NF-κB and AP-1. Two O-methylated flavones were isolated from BEX with functional effects on MCP-1 production. These results may represent a possible

  18. Improved crystallization and diffraction of caffeine-induced death suppressor protein 1 (Cid1)

    Energy Technology Data Exchange (ETDEWEB)

    Yates, Luke A., E-mail: luke@strubi.ox.ac.uk; Durrant, Benjamin P.; Barber, Michael; Harlos, Karl [University of Oxford, Roosevelt Drive, Oxford OX3 7BN (United Kingdom); Fleurdépine, Sophie; Norbury, Chris J. [University of Oxford, South Parks Road, Oxford OX1 3RE (United Kingdom); Gilbert, Robert J. C., E-mail: luke@strubi.ox.ac.uk [University of Oxford, Roosevelt Drive, Oxford OX3 7BN (United Kingdom)

    2015-02-21

    The use of truncation and RNA-binding mutations of caffeine induced death suppressor protein 1 (Cid1) as a means to enhance crystallogenesis leading to an improvement of X-ray diffraction resolution by 1.5 Å is reported. The post-transcriptional addition of uridines to the 3′-end of RNAs is an important regulatory process that is critical for coding and noncoding RNA stability. In fission yeast and metazoans this untemplated 3′-uridylylation is catalysed by a single family of terminal uridylyltransferases (TUTs) whose members are adapted to specific RNA targets. In Schizosaccharomyces pombe the TUT Cid1 is responsible for the uridylylation of polyadenylated mRNAs, targeting them for destruction. In metazoans, the Cid1 orthologues ZCCHC6 and ZCCHC11 uridylate histone mRNAs, targeting them for degradation, but also uridylate microRNAs, altering their maturation. Cid1 has been studied as a model TUT that has provided insights into the larger and more complex metazoan enzyme system. In this paper, two strategies are described that led to improvements both in the crystallogenesis of Cid1 and in the resolution of diffraction by ∼1.5 Å. These advances have allowed high-resolution crystallo@@graphic studies of this TUT system to be initiated.

  19. A temporal switch in the insulin-signalling pathway that regulates hepatic IGF-binding protein-1 gene expression

    OpenAIRE

    2006-01-01

    PUBLISHED Insulin regulation of hepatic gene transcription is a vital component of glucose homeostasis. Understanding the molecular regulationof thisprocess aids the searchfor the defect(s) that promotesinsulin-resistant states, such asdiabetesmellitus. We havepreviously shownthat the insulin regulationof hepatic IGF-binding protein-1 (IGFBP1) expression requiresthe signalling proteins phosphatidylinositol 3-kinase (PI 3-kinase) and mammalian target of rapamycin (mTOR). In this report, we ...

  20. Changes in circulating level of IGF-I and IGF-binding protein-1 from the first to second trimester as predictors of preeclampsia

    DEFF Research Database (Denmark)

    Vatten, Lars J; Nilsen, Tom I L; Juul, Anders;

    2008-01-01

    To assess whether circulating IGF-I and IGF-binding protein-1 (IGFBP-1) in the first and second trimester are associated with subsequent risk of preterm and term preeclampsia.......To assess whether circulating IGF-I and IGF-binding protein-1 (IGFBP-1) in the first and second trimester are associated with subsequent risk of preterm and term preeclampsia....

  1. Characterization of the in vitro binding and inhibition kinetics of primary amine oxidase/vascular adhesion protein-1 by glucosamine.

    LENUS (Irish Health Repository)

    Olivieri, Aldo

    2012-04-01

    Primary-amine oxidase (PrAO) catalyzes the oxidative deamination of endogenous and exogenous primary amines and also functions, in some tissues, as an inflammation-inducible endothelial factor, known as vascular adhesion protein-1. VAP-1 mediates the slow rolling and adhesion of lymphocytes to endothelial cells in a number of inflammatory conditions, including inflammation of the synovium.

  2. Cycle modulation of insulin-like growth factor-binding protein 1 in human endometrium

    Directory of Open Access Journals (Sweden)

    Corleta H.

    2000-01-01

    Full Text Available Endometrium is one of the fastest growing human tissues. Sex hormones, estrogen and progesterone, in interaction with several growth factors, control its growth and differentiation. Insulin-like growth factor 1 (IGF-1 interacts with cell surface receptors and also with specific soluble binding proteins. IGF-binding proteins (IGF-BP have been shown to modulate IGF-1 action. Of six known isoforms, IGF-BP-1 has been characterized as a marker produced by endometrial stromal cells in the late secretory phase and in the decidua. In the current study, IGF-1-BP concentration and affinity in the proliferative and secretory phase of the menstrual cycle were measured. Endometrial samples were from patients of reproductive age with regular menstrual cycles and taking no steroid hormones. Cytosolic fractions were prepared and binding of 125I-labeled IGF-1 performed. Cross-linking reaction products were analyzed by SDS-polyacrylamide gel electrophoresis (7.5% followed by autoradiography. 125I-IGF-1 affinity to cytosolic proteins was not statistically different between the proliferative and secretory endometrium. An approximately 35-kDa binding protein was identified when 125I-IGF-1 was cross-linked to cytosol proteins. Secretory endometrium had significantly more IGF-1-BP when compared to proliferative endometrium. The specificity of the cross-linking process was evaluated by the addition of 100 nM unlabeled IGF-1 or insulin. Unlabeled IGF-1 totally abolished the radioactivity from the band, indicating specific binding. Insulin had no apparent effect on the intensity of the labeled band. These results suggest that IGF-BP could modulate the action of IGF-1 throughout the menstrual cycle. It would be interesting to study this binding protein in other pathologic conditions of the endometrium such as adenocarcinomas and hyperplasia.

  3. Distal Interleukin-1β (IL-1β) Response Element of Human Matrix Metalloproteinase-13 (MMP-13) Binds Activator Protein 1 (AP-1) Transcription Factors and Regulates Gene Expression*

    Science.gov (United States)

    Schmucker, Adam C.; Wright, Jason B.; Cole, Michael D.; Brinckerhoff, Constance E.

    2012-01-01

    The collagenase matrix metalloproteinase-13 (MMP-13) plays an important role in the destruction of cartilage in arthritic joints. MMP-13 expression is strongly up-regulated in arthritis, largely because of stimulation by inflammatory cytokines such as IL-1β. Treatment of chondrocytes with IL-1β induces transcription of MMP-13 in vitro. IL-1β signaling converges upon the activator protein-1 transcription factors, which have been shown to be required for IL-1β-induced MMP-13 gene expression. Using chromatin immunoprecipitation (ChIP), we detected activator protein-1 binding within an evolutionarily conserved DNA sequence ∼20 kb 5′ relative to the MMP-13 transcription start site (TSS). Also using ChIP, we detected histone modifications and binding of RNA polymerase II within this conserved region, all of which are consistent with transcriptional activation. Chromosome conformation capture indicates that chromosome looping brings this region in close proximity with the MMP-13 TSS. Finally, a luciferase reporter construct driven by a component of the conserved region demonstrated an expression pattern similar to that of endogenous MMP-13. These data suggest that a conserved region at 20 kb upstream from the MMP-13 TSS includes a distal transcriptional response element of MMP-13, which contributes to MMP-13 gene expression. PMID:22102411

  4. Flexibility of EF-hand motifs: structural and thermodynamic studies of Calcium Binding Protein-1 from Entamoeba histolytica with Pb2+, Ba2+, and Sr2+

    Directory of Open Access Journals (Sweden)

    Kumar Shivesh

    2012-08-01

    Full Text Available Abstract Background EF-hand proteins can be activated by the binding of various heavy metals other than calcium, and such complexes can disturb the calcium-signaling pathway and cause toxicity and disease causing state. So far, no comprehensive study has been done to understand different heavy metals binding to calcium signaling proteins. Results In this work, the flexibility of the EF-hand motifs are examined by crystallographic and thermodynamic studies of binding of Pb2+, Ba2+ and Sr2+ to Calcium Binding Protein-1 from Entamoeba histolytica (EhCaBP1. The structures of the EhCaBP1- heavy metal complexes are found to be overall similar, nevertheless specific differences in metal coordination, and small differences in the coordination distances between the metal and the ligands in the metal binding loop. The largest such distances occur for the Ba2+- EhCaBP1 complex, where two bariums are bound with partial occupancy at the EF2 motif. Thermodynamic studies confirm that EhCaBP1 has five binding sites for Ba2+ compared to four binding sites for the other metals. These structures and thermodynamic studies reveal that the EF-hand motifs can accommodate several heavy atoms with similar binding affinities. The binding of Ca2+ to the 1st, 2nd and 4th sites and the binding of Ba2+ to the 1st, 2nd, 4th and 5th sites are both enthalpically and entropically driven, whereas the binding of Sr2+ to the 1st, 2nd and 4th sites are simply enthalpy driven, interestingly in agreement with ITC data, Sr2+ do not coordinate with water in this structure. For all the metals, binding to the 3rd site is only entropy driven. Conclusion Energetically, Ca2+ is preferred in three sites, while in one site Ba2+ has better binding energy. The Sr2+-coordination in the EF hand motifs is similar to that of the native Ca2+ bound structure, except for the lack of water coordination. Sr2+ coordination seems to be a pre-formed in nature since all seven coordinating atoms are from the

  5. Sterol Regulatory Element Binding Protein 1a Regulates Hepatic Fatty Acid Partitioning by Activating Acetyl Coenzyme A Carboxylase 2

    OpenAIRE

    Im, Seung-Soon; Hammond, Linda E.; Yousef, Leyla; Nugas-Selby, Cherryl; Shin, Dong-Ju; Seo, Young-Kyo; Fong, Loren G.; Young, Stephen G.; Osborne, Timothy F.

    2009-01-01

    We generated a line of mice in which sterol regulatory element binding protein 1a (SREBP-1a) was specifically inactivated by insertional mutagenesis. Homozygous mutant mice were completely viable despite expressing SREBP-1a mRNA below 5% of normal, and there were minimal effects on expression of either SREBP-1c or -2. Microarray expression studies in liver, where SREBP-1a mRNA is 1/10 the level of the highly similar SREBP-1c, demonstrated that only a few genes were affected. The only downregu...

  6. Recent insights into the biological functions of liver fatty acid binding protein 1.

    Science.gov (United States)

    Wang, GuQi; Bonkovsky, Herbert L; de Lemos, Andrew; Burczynski, Frank J

    2015-12-01

    Over four decades have passed since liver fatty acid binding protein (FABP)1 was first isolated. There are few protein families for which most of the complete tertiary structures, binding properties, and tissue occurrences are described in such detail and yet new functions are being uncovered for this protein. FABP1 is known to be critical for fatty acid uptake and intracellular transport and also has an important role in regulating lipid metabolism and cellular signaling pathways. FABP1 is an important endogenous cytoprotectant, minimizing hepatocyte oxidative damage and interfering with ischemia-reperfusion and other hepatic injuries. The protein may be targeted for metabolic activation through the cross-talk among many transcriptional factors and their activating ligands. Deficiency or malfunction of FABP1 has been reported in several diseases. FABP1 also influences cell proliferation during liver regeneration and may be considered as a prognostic factor for hepatic surgery. FABP1 binds and modulates the action of many molecules such as fatty acids, heme, and other metalloporphyrins. The ability to bind heme is another cytoprotective property and one that deserves closer investigation. The role of FABP1 in substrate availability and in protection from oxidative stress suggests that FABP1 plays a pivotal role during intracellular bacterial/viral infections by reducing inflammation and the adverse effects of starvation (energy deficiency).

  7. Human Sterol Regulatory Element-Binding Protein 1a Contributes Significantly to Hepatic Lipogenic Gene Expression

    OpenAIRE

    Andreas Bitter; Nüssler, Andreas K.; Thasler, Wolfgang E.; Kathrin Klein; Zanger, Ulrich M.; Matthias Schwab; Oliver Burk

    2015-01-01

    Background/Aims: Sterol regulatory element-binding protein (SREBP) 1, the master regulator of lipogenesis, was shown to be associated with non-alcoholic fatty liver disease, which is attributed to its major isoform SREBP1c. Based on studies in mice, the minor isoform SREBP1a is regarded as negligible for hepatic lipogenesis. This study aims to elucidate the expression and functional role of SREBP1a in human liver. Methods: mRNA expression of both isoforms was quantified in cohorts of human li...

  8. Neuronal low-density lipoprotein receptor-related protein 1 binds and endocytoses prion fibrils via receptor cluster 4

    DEFF Research Database (Denmark)

    Jen, Angela; Parkyn, Celia J; Mootoosamy, Roy C;

    2010-01-01

    For infectious prion protein (designated PrP(Sc)) to act as a template to convert normal cellular protein (PrP(C)) to its distinctive pathogenic conformation, the two forms of prion protein (PrP) must interact closely. The neuronal receptor that rapidly endocytoses PrP(C) is the low-density lipop......For infectious prion protein (designated PrP(Sc)) to act as a template to convert normal cellular protein (PrP(C)) to its distinctive pathogenic conformation, the two forms of prion protein (PrP) must interact closely. The neuronal receptor that rapidly endocytoses PrP(C) is the low......-density lipoprotein receptor-related protein 1 (LRP1). We show here that on sensory neurons LRP1 is also the receptor that binds and rapidly endocytoses smaller oligomeric forms of infectious prion fibrils, and recombinant PrP fibrils. Although LRP1 binds two molecules of most ligands independently to its receptor...... clusters 2 and 4, PrP(C) and PrP(Sc) fibrils bind only to receptor cluster 4. PrP(Sc) fibrils out-compete PrP(C) for internalization. When endocytosed, PrP(Sc) fibrils are routed to lysosomes, rather than recycled to the cell surface with PrP(C). Thus, although LRP1 binds both forms of PrP, it traffics...

  9. Role of Fibroblast Growth Factor Binding Protein-1 in Mammary Development and Tumorigenesis

    Science.gov (United States)

    2009-10-01

    2002) and parathyroid related hormone (Wysolmerski et al. 1998). Here we have focused on the effects that FGF may have on the mammary gland and...mammary gland development, reduced tertiary branching, apoptosis, HER2/neu mice 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18...inducible system. Preliminary data indicate a striking decrease in the lateral budding of mammary glands in animals expressing BP1. Matrigel plug assays

  10. Membrane steroid-binding protein 1 (MSBP1) negatively regulates brassinosteroid signaling by enhancing the endocytosis of BAK1

    Institute of Scientific and Technical Information of China (English)

    Li Song; Qiu-Ming Shi; Xiao-Hua Yang; Zhi-Hong Xu; Hong-Wei Xue

    2009-01-01

    Brassinosteroids (BRs) are perceived by transmembrane receptors and play vital roles in plant growth and devel-opment, as well as cell in responses to environmental stimuli. The transmembrane receptor BRI1 can directly bind to brassinolide (BL), and BAK1 interacts with BRI1 to enhance the BRll-mediated BR signaling. Our previous studies indicated that a membrane steroid-binding protein 1 (MSBP1) could bind to BL in vitro and is negatively involved in BR signaling. To further elucidate the underlying mechanism, we here show that MSBP1 specifically interacts with the extracellular domain of BAKI in vivo in a BL-independent manner. Suppressed cell expansion and BR responses by increased expression of MSBPI can be recovered by overexpressing BAKI or its intracellular kinase domain, sug-gesting that MSBPI may suppress BR signaling through interacting with BAK1. Subcellular localization studies re-vealed that both MSBPI and BAKI are localized to plasma membrane and endocytic vesicles and MSBPI accelerates BAKI endocytosis, which results in suppressed BR signaling by shifting the equilibrium of BAKI toward endosomes. Indeed, enhanced MSBPI expression reduces the interaction between BRI1 and BAK1 in vivo, demonstrating that MSBPI acts as a negative factor at an early step of the BR signaling pathway.

  11. Quantitative Proteomics Identifies Serum Response Factor Binding Protein 1 as a Host Factor for Hepatitis C Virus Entry

    Directory of Open Access Journals (Sweden)

    Gisa Gerold

    2015-08-01

    Full Text Available Hepatitis C virus (HCV enters human hepatocytes through a multistep mechanism involving, among other host proteins, the virus receptor CD81. How CD81 governs HCV entry is poorly characterized, and CD81 protein interactions after virus binding remain elusive. We have developed a quantitative proteomics protocol to identify HCV-triggered CD81 interactions and found 26 dynamic binding partners. At least six of these proteins promote HCV infection, as indicated by RNAi. We further characterized serum response factor binding protein 1 (SRFBP1, which is recruited to CD81 during HCV uptake and supports HCV infection in hepatoma cells and primary human hepatocytes. SRFBP1 facilitates host cell penetration by all seven HCV genotypes, but not of vesicular stomatitis virus and human coronavirus. Thus, SRFBP1 is an HCV-specific, pan-genotypic host entry factor. These results demonstrate the use of quantitative proteomics to elucidate pathogen entry and underscore the importance of host protein-protein interactions during HCV invasion.

  12. Human Sterol Regulatory Element-Binding Protein 1a Contributes Significantly to Hepatic Lipogenic Gene Expression

    Directory of Open Access Journals (Sweden)

    Andreas Bitter

    2015-01-01

    Full Text Available Background/Aims: Sterol regulatory element-binding protein (SREBP 1, the master regulator of lipogenesis, was shown to be associated with non-alcoholic fatty liver disease, which is attributed to its major isoform SREBP1c. Based on studies in mice, the minor isoform SREBP1a is regarded as negligible for hepatic lipogenesis. This study aims to elucidate the expression and functional role of SREBP1a in human liver. Methods: mRNA expression of both isoforms was quantified in cohorts of human livers and primary human hepatocytes. Hepatocytes were treated with PF-429242 to inhibit the proteolytic activation of SREBP precursor protein. SREBP1a-specifc and pan-SREBP1 knock-down were performed by transfection of respective siRNAs. Lipogenic SREBP-target gene expression was analyzed by real-time RT-PCR. Results: In human liver, SREBP1a accounts for up to half of the total SREBP1 pool. Treatment with PF-429242 indicated SREBP-dependent auto-regulation of SREBP1a, which however was much weaker than of SREBP1c. SREBP1a-specifc knock-down also reduced significantly the expression of SREBP1c and of SREBP-target genes. Regarding most SREBP-target genes, simultaneous knock-down of both isoforms resulted in effects of only similar extent as SREBP1a-specific knock-down. Conclusion: We here showed that SREBP1a is significantly contributing to the human hepatic SREBP1 pool and has a share in human hepatic lipogenic gene expression.

  13. Golgi localization and dynamics of hyaluronan binding protein 1 (HABP1/p32/C1QBP) during the cell cycle

    Institute of Scientific and Technical Information of China (English)

    Aniruddha SENGUPTA; Bhaswati BANERJEE; Rakesh K. TYAGI; Kasturi DATTA

    2005-01-01

    Hyaluronan binding protein 1 (HABP1) is a negatively charged multifunctional mammalian protein with a unique structural fold. Despite the fact that HABP1 possesses mitochondrial localization signal, it has also been localized to other cellular compartments. Using indirect immunofluorescence, we examined the sub-cellular localization of HABP1 and its dynamics during mitosis. We wanted to determine whether it distributes in any distinctive manner after mitotic nuclear envelope disassembly or is dispersed randomly throughout the cell. Our results reveal the golgi localization of HABP1 and demonstrate its complete dispersion throughout the cell during mitosis. This distinctive distribution pattern of HABP1 during mitosis resembles its ligand hyaluronan, suggesting that in concert with each other the two molecules play critical roles in this dynamic process.

  14. Tsetse salivary gland proteins 1 and 2 are high affinity nucleic acid binding proteins with residual nuclease activity.

    Directory of Open Access Journals (Sweden)

    Guy Caljon

    Full Text Available Analysis of the tsetse fly salivary gland EST database revealed the presence of a highly enriched cluster of putative endonuclease genes, including tsal1 and tsal2. Tsal proteins are the major components of tsetse fly (G. morsitans morsitans saliva where they are present as monomers as well as high molecular weight complexes with other saliva proteins. We demonstrate that the recombinant tsetse salivary gland proteins 1&2 (Tsal1&2 display DNA/RNA non-specific, high affinity nucleic acid binding with K(D values in the low nanomolar range and a non-exclusive preference for duplex. These Tsal proteins exert only a residual nuclease activity with a preference for dsDNA in a broad pH range. Knockdown of Tsal expression by in vivo RNA interference in the tsetse fly revealed a partially impaired blood digestion phenotype as evidenced by higher gut nucleic acid, hematin and protein contents.

  15. Depletion of Paraspeckle Protein 1 Enhances Methyl Methanesulfonate-Induced Apoptosis through Mitotic Catastrophe.

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    Xiangjing Gao

    Full Text Available Previously, we have shown that paraspeckle protein 1 (PSPC1, a protein component of paraspeckles that was involved in cisplatin-induced DNA damage response (DDR, probably functions at the G1/S checkpoint. In the current study, we further examined the role of PSPC1 in another DNA-damaging agent, methyl methanesulfonate (MMS-induced DDR, in particular, focusing on MMS-induced apoptosis in HeLa cells. First, it was found that MMS treatment induced the expression of PSPC1. While MMS treatment alone can induce apoptosis, depletion of PSPC1 expression using siRNA significantly increased the level of apoptosis following MMS exposure. In contrast, overexpressing PSPC1 decreased the number of apoptotic cells. Interestingly, morphological observation revealed that many of the MMS-treated PSPC1-knockdown cells contained two or more nuclei, indicating the occurrence of mitotic catastrophe. Cell cycle analysis further showed that depletion of PSPC1 caused more cells entering the G2/M phase, a prerequisite of mitosis catastrophe. On the other hand, over-expressing PSPC1 led to more cells accumulating in the G1/S phase. Taken together, these observations suggest an important role for PSPC1 in MMS-induced DDR, and in particular, depletion of PSPC1 can enhance MMS-induced apoptosis through mitotic catastrophe.

  16. Transcriptional regulation and biological functions of selenium-binding protein 1 in colorectal cancer in vitro and in nude mouse xenografts.

    Directory of Open Access Journals (Sweden)

    Nicole M Pohl

    Full Text Available BACKGROUND: It has been shown that selenium-binding protein 1 (SBP1 is significantly downregulated in different human cancers. Its regulation and function have not yet been established. METHODOLOGY AND PRINCIPAL FINDINGS: We show that the SBP1 promoter is hypermethylated in colon cancer tissues and human colon cancer cells. Treatment with 5'-Aza-2'-deoxycytidine leads to demethylation of the SBP1 promoter and to an increase of SBP1 promoter activity, rescues SBP1 mRNA and protein expression in human colon cancer cells. Additionally, overexpression of SBP1 sensitizes colon cancer cells to H2O2-induced apoptosis, inhibits cancer cell migration in vitro and inhibits tumor growth in nude mice. CONCLUSION AND SIGNIFICANCE: These data demonstrate that SBP1 has tumor suppressor functions that are inhibited in colorectal cancer through epigenetic silencing.

  17. Follistatin-like protein 1 suppressed pro-inflammatory cytokines expression during neuroinflammation induced by lipopolysaccharide.

    Science.gov (United States)

    Cheng, Kai-Yuan; Liu, Yi; Han, Ying-Guang; Li, Jing-Kun; Jia, Jia-Lin; Chen, Bin; Yao, Zhi-Xiao; Nie, Lin; Cheng, Lei

    2017-04-01

    Follistain-like protein 1 (FSTL1), has been recently demonstrated to be involved in the embryo development of nervous system and glioblastoma. However, the role of FSTL1 in neuroinflammation remains unexplored. In this study, the expression of FSTL1 in astrocytes was verified and its role was studied in neuroinflammation induced by in vivo intracerebroventricular (ICV) injection of lipopolysaccharide (LPS) or LPS treatment to astrocytes in vitro. FSTL1 was significantly induced after ICV LPS injection or LPS treatment. FSTL1 suppressed upregulation of pro-inflammatory cytokines in astrocytes after LPS treatment. Moreover, FSTL1 downregulated expression of pro-inflammatory cytokines through suppressing MAPK/p-ERK1/2 pathway in astrocytes. Our results suggest that FSTL1 may play an anti-inflammatory role in neuroinflammation mediated by astrocytes.

  18. Loss of Selenium-Binding Protein 1 Decreases Sensitivity to Clastogens and Intracellular Selenium Content in HeLa Cells

    Science.gov (United States)

    Zhao, Changhui; Zeng, Huawei; Wu, Ryan T. Y.; Cheng, Wen-Hsing

    2016-01-01

    Selenium-binding protein 1 (SBP1) is not a selenoprotein but structurally binds selenium. Loss of SBP1 during carcinogenesis usually predicts poor prognosis. Because genome instability is a hallmark of cancer, we hypothesize that SBP1 sequesters cellular selenium and sensitizes cancer cells to DNA-damaging agents. To test this hypothesis, we knocked down SBP1 expression in HeLa cervical cancer cells by employing a short hairpin RNA (shRNA) approach. Reduced sensitivity to hydrogen peroxide, paraquat and camptothecin, reactive oxygen species content, and intracellular retention of selenium after selenomethionine treatment were observed in SBP1 shRNA HeLa cells. Results from Western analyses showed that treatment of HeLa cells with selenomethionine resulted in increased SBP1 protein expression in a dose-dependent manner. Knockdown of SBP1 rendered HeLa cells increased expression of glutathione peroxidase-1 but not glutathione peroxidase-4 protein levels and accelerated migration from a wound. Altogether, SBP1 retains supplemental selenium and sensitizes HeLa cancer cells to clastogens, suggesting a new cancer treatment strategy by sequestering selenium through SBP1. PMID:27404728

  19. MicroRNA-181b targets cAMP responsive element binding protein 1 in gastric adenocarcinomas.

    Science.gov (United States)

    Chen, Lin; Yang, Qian; Kong, Wei-Qing; Liu, Tao; Liu, Min; Li, Xin; Tang, Hua

    2012-07-01

    MicroRNAs are a class of small endogenous non-coding RNAs that function as post-transcriptional regulators. In our previous study, we found that miR-181b was significantly downregulated in human gastric adenocarcinoma tissue samples compared to the adjacent normal gastric tissues. In this study, we confirm the down-regulation of miR-181b in human gastric cancer cell lines versus the gastric epithelial cells. Overexpression of miR-181b suppressed the proliferation and colony formation rate of gastric cancer cells. miR-181b downregulated the expression of cAMP responsive element binding protein 1 (CREB1) by binding its 3' untranslated region. Overexpression of CREB1 counteracted the suppression of growth in gastric cancer cells caused by ectopic expression of miR-181b. These results indicate that miR-181b may function as a tumor suppressor in gastric adenocarcinoma cells through negative regulation of CREB1.

  20. Myc promoter-binding protein-1 (MBP-1 is a novel potential prognostic marker in invasive ductal breast carcinoma.

    Directory of Open Access Journals (Sweden)

    Mariavera Lo Presti

    Full Text Available BACKGROUND: Alpha-enolase is a glycolytic enzyme that catalyses the formation of phosphoenolpyruvate in the cell cytoplasm. α-Enolase and the predominantly nuclear Myc promoter-binding protein-1 (MBP-1 originate from a single gene through the alternative use of translational starting sites. MBP-1 binds to the P2 c-myc promoter and competes with TATA-box binding protein (TBP to suppress gene transcription. Although several studies have shown an antiproliferative effect of MBP-1 overexpression on several human cancer cells, to date detailed observations of α-enolase and MBP-1 relative expression in primary tumors versus normal tissues and their correlation with clinicopathological features have not been undertaken. METHODOLOGY AND FINDINGS: We analyzed α-enolase and MBP-1 expression in normal breast epithelium and primary invasive ductal breast carcinoma (IDC from 177 patients by Western blot and immunohistochemical analyses, using highly specific anti-α-enolase monoclonal antibodies. A significant increase in the expression of cytoplasmic α-enolase was observed in 98% of the tumors analysed, compared to normal tissues. Nuclear MBP-1 was found in almost all the normal tissues while its expression was retained in only 35% of the tumors. Statistically significant associations were observed among the nuclear expression of MBP-1 and ErbB2 status, Ki-67 expression, node status and tumor grade. Furthermore MBP-1 expression was associated with good survival of patients with IDC. CONCLUSIONS: MBP-1 functions in repressing c-myc gene expression and the results presented indicate that the loss of nuclear MBP-1 expression in a large number of IDC may be a critical step in the development and progression of breast cancer and a predictor of adverse outcome. Nuclear MBP-1 appears to be a novel and valuable histochemical marker with potential prognostic value in breast cancer.

  1. Dynamin-Related Protein 1 Translocates from the Cytosol to Mitochondria during UV-Induced Apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Zhenzhen; Wu Shengnan; Feng Jie, E-mail: wushn@scnu.edu.cn [MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631 (China)

    2011-01-01

    Mitochondria are dynamic structures that frequently divide and fuse with one another to form interconnecting network. This network disintegrates into punctiform organelles during apoptosis. However, the mechanisms involved in these processes are still not well characterized. In this study, we investigate the role of dynamin-related protein 1 (Drp1), a large GTPase that mediates outer mitochondrial membrane fission, in mitochondrial dynamics in response to UV irradiation in human lung adenocarcinoma cells (ASTC-{alpha}-1) and HeLa cells. Using time-lapse fluorescent imaging, we find that Drp1 primarily distributes in cytosol under physiological conditions. After UV treatment, Drp1 translocates from cytosol to mitochondria, indicating the enhancement of Drp1 mitochondrial accumulation. Our results suggest that Drp1 is involved in the regulation of transition from an interconnecting network to a punctiform mitochondrial phenotype during UV-induced apoptosis.

  2. Expression of ErbB3-binding protein-1 (EBP1 during primordial follicle formation: role of estradiol-17ß.

    Directory of Open Access Journals (Sweden)

    Anindit Mukherjee

    Full Text Available The formation of primordial follicles involves the interaction between the oocytes and surrounding somatic cells, which differentiate into granulosa cells. Estradiol-17ß (E promotes primordial follicle formation in vivo and in vitro; however, the underlying mechanisms are poorly understood. The expression of an ERBB3-binding protein 1 (EBP1 is downregulated in 8-day old hamster ovaries concurrent with the increase in serum estradiol levels and the formation of primordial follicles. The objectives of the present study were to determine the spatio-temporal expression and putative E regulation of EBP1 in ovarian cells during perinatal development with respect to primordial follicle formation. Hamster EBP1 nucleic acid and amino acid sequences were more than 93% and 98% similar, respectively, to those of mouse and human, and contained nucleolar localization signal, RNA-binding domain and several phosphorylation sites. EBP1 protein was present in somatic cells and oocytes from E15, and declined in oocytes by P1 and in somatic cells by P5. Thereafter, EBP1 expression increased through P7 with a transient decline on P8 primarily in interstitial cells. EBP1 mRNA levels mirrored protein expression pattern. E treatment on P1 and P4 upregulated EBP1 expression by P8 whereas E treatment on P4 downregulated it by 72 h suggesting a compensatory upregulation due to E pretreatment. Treatment with an FSH-antiserum, which suppressed primordial follicle formation, prevented the decline in EBP1 levels, and the effect was reversed by E treatment. Therefore, the results provide the first evidence that EBP1 may play an important role in mediating the effect of E in the differentiation of somatic cells into granulosa cells during primordial follicle formation.

  3. Cellular localization of Y-box binding protein 1 in brain tissue of rats, macaques, and humans

    Directory of Open Access Journals (Sweden)

    Horn Anja

    2009-03-01

    Full Text Available Abstract Background The Y-box binding protein 1 (YB-1 is considered to be one of the key regulators of transcription and translation. However, so far only limited knowledge exists regarding its cellular distribution in the adult brain. Results Analysis of YB-1 immunolabelling as well as double-labelling with the neuronal marker NeuN in rat brain tissue revealed a predominant neuronal expression in the dentate gyrus, the cornu ammonis pyramidal cell layer, layer III of the piriform cortex as well as throughout all layers of the parahippocampal cortex. In the hilus of the hippocampus single neurons expressed YB-1. The neuronal expression pattern was comparable in the hippocampus and parahippocampal cortex of adult macaques and humans. Double-labelling of YB-1 with the endothelial cell marker Glut-1, the multidrug transporter P-glycoprotein, and the astrocytic marker GFAP did not indicate a co-localization. Following status epilepticus in rats, no induction of YB-1 occurred in brain capillary endothelial cells and neurons. Conclusion In conclusion, our study demonstrates that YB-1 is predominantly expressed in neurons in the adult brain of rats, macaques and humans. Lack of a co-localization with Glut-1 and P-glycoprotein argues against a direct role of YB-1 in the regulation of blood-brain barrier P-glycoprotein.

  4. Ataxin 2-binding protein 1 is a context-specific positive regulator of Notch signaling during neurogenesis in Drosophila melanogaster.

    Science.gov (United States)

    Shukla, Jay Prakash; Deshpande, Girish; Shashidhara, L S

    2017-03-01

    The role of the Notch pathway during the lateral inhibition that underlies binary cell fate choice is extensively studied, but the context specificity that generates diverse outcomes is less well understood. In the peripheral nervous system of Drosophila melanogaster, differential Notch signaling between cells of the proneural cluster orchestrates sensory organ specification. Here we report functional analysis of Drosophila Ataxin 2-binding protein 1 (A2BP1) during this process. Its human ortholog is linked to type 2 spinocerebellar ataxia and other complex neuronal disorders. Downregulation of Drosophila A2BP1 in the proneural cluster increases adult sensory bristle number, whereas its overexpression results in loss of bristles. We show that A2BP1 regulates sensory organ specification by potentiating Notch signaling. Supporting its direct involvement, biochemical analysis shows that A2BP1 is part of the Suppressor of Hairless [Su(H)] complex in the presence and absence of Notch. However, in the absence of Notch signaling, the A2BP1 interacting fraction of Su(H) does not associate with the repressor proteins Groucho and CtBP. We propose a model explaining the requirement of A2BP1 as a positive regulator of context-specific Notch activity.

  5. Monocyte chemoattractant protein-1 contributes to morphine tolerance in rats with cancer-induced bone pain.

    Science.gov (United States)

    Liu, Lei; Gao, Xiu-Juan; Ren, Chun-Guang; Hu, Ji-Hua; Liu, Xian-Wen; Zhang, Ping; Zhang, Zong-Wang; Fu, Zhi-Jian

    2017-02-01

    Cancer-induced bone pain can severely compromise the life quality of patients, while tolerance limits the use of opioids in the treatment of cancer pain. Monocyte chemoattractant protein-1 (MCP-1) is known to contribute to neuropathic pain. However, the role of spinal MCP-1 in the development of morphine tolerance in patients with cancer-induced bone pain remains unclear. The aim of the present study was to investigate the role of spinal MCP-1 in morphine tolerance in bone cancer pain rats (MTBP rats). Bone cancer pain was induced by intramedullary injection of Walker 256 cells into the tibia of the rats, while morphine tolerance was induced by continuous intrathecal injection of morphine over a period of 9 days. In addition, anti-MCP-1 antibodies were intrathecally injected to rats in various groups in order to investigate the association of MCP-1 with mechanical and heat hyperalgesia using the paw withdrawal threshold (PWT) and thermal withdrawal latency (TWL) tests, respectively. Furthermore, MCP-1 and CCR2 expression levels were measured using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis, and CCR2 expression levels were measured using RT-qPCR. The results indicated that MCP-1 and CCR2 expression levels were significantly increased in the spinal cord of MTBP rats. Intrathecal administration of anti-MCP-1 neutralizing antibodies was observed to attenuate the mechanical and thermal allodynia in MTBP rats. Therefore, the upregulation of spinal MCP-1 and CCR2 expression levels may contribute to the development of mechanical allodynia in MTBP rats. In conclusion, MCP-1/CCR2 signaling may serve a crucial role in morphine tolerance development in rats suffering from cancer-induced bone pain.

  6. Secreted Ectodomain of Sialic Acid-Binding Ig-Like Lectin-9 and Monocyte Chemoattractant Protein-1 Synergistically Regenerate Transected Rat Peripheral Nerves by Altering Macrophage Polarity.

    Science.gov (United States)

    Kano, Fumiya; Matsubara, Kohki; Ueda, Minoru; Hibi, Hideharu; Yamamoto, Akihito

    2017-03-01

    Peripheral nerves (PNs) exhibit remarkable self-repairing reparative activity after a simple crush or cut injury. However, the neuronal transection involving a nerve gap overwhelms their repairing activity and causes persistent paralysis. Here, we show that an implantation of the serum-free conditioned medium from stem cells from human exfoliated deciduous teeth (SHED-CM) immersed in a collagen sponge into the nerve gap formed by rat facial nerves transection restored the neurological function. In contrast, SHED-CM specifically depleted of a set of anti-inflammatory M2 macrophage inducers, monocyte chemoattractant protein-1 (MCP-1) and the secreted ectodomain of sialic acid-binding Ig-like lectin-9 (sSiglec-9) lost the ability to restore neurological function in this model. Notably, the combination of MCP-1 and sSiglec-9 induced the polarization of M2 macrophages in vitro, resulting in the expression of multiple trophic factors that enhanced proliferation, migration, and differentiation of Schwann cells, blood vessel formation, and nerve fiber extension. Furthermore, the implantation of a collagen graft containing MCP-1/sSiglec-9 into the nerve gap induced anti-inflammatory M2 macrophage polarization, generated a Schwann-cell bridge instead of fibrotic scar, induced axonal regrowth, and restored nerve function. The specific elimination of M2 macrophages by Mannosylated-Clodrosome suppressed the MCP-1/sSiglec-9-mediated neurological recovery. Taken together, our data suggest that MCP-1/sSiglec-9 regenerates PNs by inducing tissue-repairing M2 macrophages and may provide therapeutic benefits for severe peripheral nerve injuries. Stem Cells 2017;35:641-653.

  7. β-Hydroxybutyrate Facilitates Fatty Acids Synthesis Mediated by Sterol Regulatory Element-Binding Protein1 in Bovine Mammary Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Min Zhang

    2015-11-01

    Full Text Available Background/Aims: In dairy cows, β-hydroxybutyrate (BHBA is utilized as precursors of de novo synthesized fatty acids in mammary gland. Ketotic cows are characterized by excessive negative energy balance (NEB, which can further increase the blood BHBA concentration. Sterol regulatory element-binding protein1 (SREBP1 and cell death-inducing DNA fragmentation factor-alpha-like effector α (Cidea play crucial roles in lipid synthesis. Therefore, we hypothesized that BHBA could stimulate SREBP1/Cidea pathway to increase milk fat synthesis in bovine mammary epithelial cells. Methods: Bovine mammary epithelial cells were treated with different concentrations of BHBA and transfected with adenovirus to silence SREBP1 expression. The effects of BHBA on the lipid synthesis in bovine mammary epithelial cells were investigated. Results: The results showed that BHBA could significantly increase the expression of SREBP1, fatty acid synthase (FAS, acetyl-CoA carboxylase α (ACC-α, Cidea and diacylglycerol transferase-1 (DGAT-1, as well as the triglycerides (TG content in bovine mammary epithelial cells. BHBA treatment also increased the transfer of mature SREBP1 to nucleus compared with control group. However, SREBP1 silencing could significantly down-regulate the overexpression of FAS, ACC-α, Cidea and DGAT-1, as well as TG content induced by BHBA. Conclusion: The present data indicate that BHBA can significantly increase TG secretion mediated by SREBP1 in bovine mammary epithelial cells.

  8. A novel method for evaluating microglial activation using ionized calcium-binding adaptor protein-1 staining: cell body to cell size ratio

    NARCIS (Netherlands)

    Hovens, Iris; Nyakas, Csaba; Schoemaker, Regina

    2014-01-01

    Aim: The aim was to validate a newly developed methodology of semi-automatic image analysis to analyze microglial morphology as marker for microglial activation in ionized calcium-binding adaptor protein-1 (IBA-1) stained brain sections. Methods: The novel method was compared to currently used analy

  9. Protein phosphatase PPM1G regulates protein translation and cell growth by dephosphorylating 4E binding protein 1 (4E-BP1).

    Science.gov (United States)

    Liu, Jianyu; Stevens, Payton D; Eshleman, Nichole E; Gao, Tianyan

    2013-08-09

    Protein translation initiation is a tightly controlled process responding to nutrient availability and mitogen stimulation. Serving as one of the most important negative regulators of protein translation, 4E binding protein 1 (4E-BP1) binds to translation initiation factor 4E and inhibits cap-dependent translation in a phosphorylation-dependent manner. Although it has been demonstrated previously that the phosphorylation of 4E-BP1 is controlled by mammalian target of rapamycin in the mammalian target of rapamycin complex 1, the mechanism underlying the dephosphorylation of 4E-BP1 remains elusive. Here, we report the identification of PPM1G as the phosphatase of 4E-BP1. A coimmunoprecipitation experiment reveals that PPM1G binds to 4E-BP1 in cells and that purified PPM1G dephosphorylates 4E-BP1 in vitro. Knockdown of PPM1G in 293E and colon cancer HCT116 cells results in an increase in the phosphorylation of 4E-BP1 at both the Thr-37/46 and Ser-65 sites. Furthermore, the time course of 4E-BP1 dephosphorylation induced by amino acid starvation or mammalian target of rapamycin inhibition is slowed down significantly in PPM1G knockdown cells. Functionally, the amount of 4E-BP1 bound to the cap-dependent translation initiation complex is decreased when the expression of PPM1G is depleted. As a result, the rate of cap-dependent translation, cell size, and protein content are increased in PPM1G knockdown cells. Taken together, our study has identified protein phosphatase PPM1G as a novel regulator of cap-dependent protein translation by negatively controlling the phosphorylation of 4E-BP1.

  10. MicroRNA-490 regulates lung cancer metastasis by targeting poly r(C)-binding protein 1.

    Science.gov (United States)

    Li, Jindong; Feng, Qingchuan; Wei, Xudong; Yu, Yongkui

    2016-11-01

    Lung cancer remains a leading cause of cancer-related mortality, with metastatic progression remaining the single largest cause of lung cancer mortality. Hence, it is imperative to determine reliable biomarkers of lung cancer prognosis. MicroRNA-490-3p has been previously reported to be a positive prognostic biomarker for hepatocellular cancer. However, its role in human lung cancer has not yet been elucidated. Here, we report that hsa-miR-490-3p expression is significantly higher in human lung cancer tissue specimens and cell line. Gain- and loss-of-function studies of hsa-miR-490-3p showed that it regulates cell proliferation and is required for induction of in vitro migration and invasion-the latter being a hallmark of epithelial to mesenchymal transition. In situ analysis revealed that hsa-miR-490-3p targets poly r(C)-binding protein 1 (PCBP1), which has been previously shown to be a negative regulator of lung cancer metastasis. Reporter assays confirmed PCBP1 as a bona fide target of miR-490-3p, and metagenomic analysis revealed an inverse relation between expression of miR-490-3p and PCBP1 in metastatic lung cancer patients. In fact, PCBP1 expression, as detected by immunohistochemistry, was undetectable in advanced stages of lung cancer patients' brain and lymph node tissues. Xenograft tail vein colonization assays proved that high expression of miR-490-3p is a prerequisite for metastatic progression of lung cancer. Our results suggest that hsa-miR-490-3p might be a potential biomarker for lung cancer prognosis. In addition, we can also conclude that the lung cancer cells have evolved refractory mechanisms to downregulate the expression of the metastatic inhibitor, PCBP1.

  11. Epididymosomes transfer epididymal sperm binding protein 1 (ELSPBP1) to dead spermatozoa during epididymal transit in bovine.

    Science.gov (United States)

    D'Amours, Olivier; Frenette, Gilles; Bordeleau, Louis-Jean; Allard, Nancy; Leclerc, Pierre; Blondin, Patrick; Sullivan, Robert

    2012-10-01

    Previously, we showed that epididymal sperm binding protein 1 (ELSPBP1) characterizes spermatozoa already dead before ejaculation in bovine. In this study, we investigated the presence of ELSPBP1 in bull genital tract as well as its acquisition by spermatozoa during epididymal transit. As assessed by real-time RT-PCR, ELSPBP1 was highly expressed in the caput and the corpus epididymis but was present in lower expression levels in the testis and the cauda epididymis. Immunohistochemistry revealed the same expression pattern. However, Western blot on tissue homogenates showed some discrepancies, as ELSPBP1 was found in a comparable concentration all along the epididymis. This difference was due to the presence of ELSPBP1 in the epididymal fluid. In both caput and cauda epididymal fluid, ELSPBP1 was associated with the epididymosomes, small membranous vesicles secreted by epithelial cells of the epididymis and implicated in the transfer of proteins to spermatozoa. As assessed by immunocytometry, ELSPBP1 was found on a subset of dead spermatozoa in caput epididymis but was found on all dead spermatozoa in cauda epididymis. To assess ELSPBP1 acquisition by spermatozoa, caput epididymal spermatozoa were incubated with cauda epididymosomes under various conditions. ELSPBP1 detection by immunocytometry assay revealed that only spermatozoa already dead before incubation were receptive to ELSPBP1 transfer by epididymosomes. This receptivity was enhanced by the presence of zinc in the incubation medium. This specificity for a sperm subpopulation suggests that an underlying mechanism is involved and that ELSPBP1 could be a tag for the recognition of dead spermatozoa during epididymal transit.

  12. The role of the mycobacterial DNA-binding protein 1 (MDP1 from Mycobacterium bovis BCG in host cell interaction

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    Kunisch Ralph

    2012-08-01

    Full Text Available Abstract Background Mycobacterium tuberculosis differs from most pathogens in its ability to multiply inside monocytes and to persist during long periods of time within granuloma in a status of latency. A class of proteins called mycobacterial histone-like proteins has been associated with regulation of replication and latency, but their precise role in the infection process has yet to be uncovered. Our study aimed at defining the impact of the histone-like protein MDP1 from M. bovis BCG (mycobacterial DNA-binding protein 1, corresponding to Rv2986c from M. tuberculosis on early steps of infection. Results Previously, a BCG (Bacillus Calmette Guérin strain had been generated by antisense-technique exhibiting reduced MDP1 expression. This strain was now used to analyse the impact of reduced amount of MDP1 on the interaction with human blood monocytes, macrophage lines and PBMC (peripheral blood mononuclear cells. MDP1 was revealed to be required for growth at acidic pH and for intracellular replication in human blood monocytes. Down-regulation of MDP1 resulted in reduced secretion of the cytokine IL-1β by infected human PBMC. In addition, a reduction of MDP1 expression had a major impact on the formation of fused multi-nucleated macrophages. In monocyte preparations from human blood as well as in human and mouse macrophage cell lines, both the percentage of multi-nucleated cells and the number of nuclei per cell were much enhanced when the monocytes were infected with BCG expressing less MDP1. Conclusion MDP1 from M. bovis BCG affects the growth at acidic pH and the intracellular replication in human monocytes. It furthermore affects cytokine secretion by host cells, and the formation of fused multi-nucleated macrophages. Our results suggest an important role of MDP1 in persistent infection.

  13. The mycobacterial DNA-binding protein 1 (MDP1 from Mycobacterium bovis BCG influences various growth characteristics

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    Maurischat Sven

    2008-06-01

    Full Text Available Abstract Background Pathogenic mycobacteria such as M. tuberculosis, M. bovis or M. leprae are characterised by their extremely slow growth rate which plays an important role in mycobacterial virulence and eradication of the bacteria. Various limiting factors influence the generation time of mycobacteria, and the mycobacterial DNA-binding protein 1 (MDP1 has also been implicated in growth regulation. Our strategy to investigate the role of MDP1 in mycobacterial growth consisted in the generation and characterisation of a M. bovis BCG derivative expressing a MDP1-antisense gene. Results The expression rate of the MDP1 protein in the recombinant M. bovis BCG containing the MDP1-antisense plasmid was reduced by about 50% compared to the reference strain M. bovis BCG containing the empty vector. In comparison to this reference strain, the recombinant M. bovis BCG grew faster in broth culture and reached higher cell masses in stationary phase. Likewise its intracellular growth in mouse and human macrophages was ameliorated. Bacterial clumping in broth culture was reduced by the antisense plasmid. The antisense plasmid increased the susceptibility of the bacteria towards Ampicillin. 2-D protein gels of bacteria maintained under oxygen-poor conditions demonstrated a reduction in the number and the intensity of many protein spots in the antisense strain compared to the reference strain. Conclusion The MDP1 protein has a major impact on various growth characteristics of M. bovis BCG. It plays an important role in virulence-related traits such as aggregate formation and intracellular multiplication. Its impact on the protein expression in a low-oxygen atmosphere indicates a role in the adaptation to the hypoxic conditions present in the granuloma.

  14. Tumor necrosis factor-α-induced protein 1 and immunity to hepatitis B virus

    Institute of Scientific and Technical Information of China (English)

    Marie C Lin; Nikki P Lee; Ning Zheng; Pai-Hao Yang; Oscar G Wong; Hsiang-Fu Kung; Chee-Kin Hui; John M Luk; George Ka-Kit Lau

    2005-01-01

    AIM: To compare the gene expression profile in a pair of HBV-infected twins.METHODS: The gene expression profile was compared in a pair of HBV-infected twins.RESULTS: The twins displayed different disease outcomes. One acquired natural immunity against HBV,whereas the other became a chronic HBV carrier. Eightyeight and forty-six genes were found to be up- or downregulated in their PBMCs, respectively. Tumor necrosis factor-alpha-induced protein 1 (TNF-αIP1) that expressed at a higher level in the HBV-immune twins was identified and four pairs of siblings with HBV immunity by RTPCR. However, upon HBV core antigen stimulation,TNF-αIP1 was downregulated in PBMCs from subjects with immunity, whereas it was slightly upregulated in HBV carriers. Bioinformatics analysis revealed a K+channel tetramerization domain in TNF-αIP1 that shares a significant homology with some human, mouse, and C elegan proteins.CONCLUSION: TNF-αIP1 may play a role in the innate immunity against HBV.

  15. Isolation, Identification and Bioinformatics Analysis of Phosphatidy Lethanolamine-binding Protein 1 (PEBP1) Associated with Liver Toxicity Induced by Copper Nanoparticles in Rats (Rattus norvegicus)%纳米铜对大鼠肝毒性相关蛋白磷脂酰乙醇胺结合蛋白1(PEBP1)的分离鉴定及生物信息学分析

    Institute of Scientific and Technical Information of China (English)

    高昭辉; 薛慧文; 荔霞; 董书伟; 申小云

    2013-01-01

    In order to screen the differentially expressed protein and explore the mechanism of hepatotoxicity induced by copper nanoparticles in rat (Rattus norvegicus), the differential proteins were separated and identified by two dimensional gel electro-phoresis (2-DE) and MALDI-TOF-TOF MS, and then verified by Real-time PCR, and analyzed by bioinformatics. Total 43 spots of differentially expressed proteins were found, of which a spot 1006 associated with hepatotoxity was identified as phosphatidy lethanolamine-binding protein 1 (PEBP1) (accession No. IPI002309), the results of Real-time PCR was the same as that of 2-DE. Bioinformatics analysis showed that PEBP1 was located in the cytoplasm, and had no signal peptide, it may belongs to non-secretory protein, and contain phosphatidy lethanolamine-binding protein family signature ^YTLVLTDPDAPSRKDPKFREWHH86; the random coils and extended chains were its main secondary structural elements. The homology analysis showed that PEBP1 had a high homology between rat and other nine species, and the phylogenetic tree of PEBP1 was constructed by Neighbor-joint method. The expression of PEBP1 protein was reduced in poisoned rats so as to liver cell mitochondrial dysfunction, which may be a pathway of copper nanoparticles to exert the hepatotoxic effects.%为筛选纳米铜对大鼠(Rattus norve gic us)肝脏毒性的差异蛋白,探讨其毒性作用机制,本研究应用双向电泳(two dimensional gel electro-phoresis,2-DE)和质谱等蛋白质组学方法,分离和鉴定肝毒性相关差异蛋白,并利用荧光定量PCR验证和生物信息学分析.结果共筛选到显著差异表达的蛋白斑点共43个,其中下调的一个差异蛋白点1006被鉴定为磷脂酰乙醇胺结合蛋白1 (phosphatidy lethanolamine-binding protein 1,PEBP1);荧光定量PCR验证与双向电泳结果一致.PEBP1蛋白的生物信息学分析表明其性质稳定,不存在信号肽,定位于细胞质,可能属于非分泌性蛋白,含磷脂酰乙

  16. Amblyomma americanum tick saliva insulin-like growth factor binding protein-related protein 1 binds insulin but not insulin-like growth factors.

    Science.gov (United States)

    Radulović, Ž M; Porter, L M; Kim, T K; Bakshi, M; Mulenga, A

    2015-10-01

    Silencing Amblyomma americanum insulin-like growth factor binding protein-related protein 1 (AamIGFBP-rP1) mRNA prevented ticks from feeding to repletion. In this study, we used recombinant (r)AamIGFBP-rP1 in a series of assays to obtain further insight into the role(s) of this protein in tick feeding regulation. Our results suggest that AamIGFBP-1 is an antigenic protein that is apparently exclusively expressed in salivary glands. We found that both males and females secrete AamIGFBP-rP1 into the host during feeding and confirmed that female ticks secrete this protein from within 24-48 h after attachment. Our data suggest that native AamIGFBP-rP1 is a functional insulin binding protein in that both yeast- and insect cell-expressed rAamIGFBP-rP1 bound insulin, but not insulin-like growth factors. When subjected to anti-blood clotting and platelet aggregation assays, rAamIGFBP-rP1 did not have any effect. Unlike human IGFBP-rP1, which is controlled by trypsinization, rAamIGFBP-rP1 is resistant to digestion, suggesting that the tick protein may not be under mammalian host control at the tick feeding site. The majority of tick-borne pathogens are transmitted 48 h after the tick has attached. Thus, the demonstrated antigenicity and secretion into the host within 24-48 h of the tick starting to feed makes AamIGFBP-rP1 an attractive target for antitick vaccine development.

  17. Insulin-like growth factor binding protein 1 and human embryonic development during 6-10 gestational weeks

    Institute of Scientific and Technical Information of China (English)

    方群; 王艳霞; 周祎

    2004-01-01

    Background Insulin-like growth factor binding protein-1 (IGFBP-1), which is a carrier of Insulin-like growth factors (IGFs) regulates the fetal development by working as an active factor controlling the combination of IGFs with their receptors. This study was designed to investigate the relationship between IGFBP-1 and human embryonic development during weeks 6 -10 of gestation.Methods A total of 44 pregnant women with singleton pregnancy were divided into two groups: one with abnormal embryo development (n = 32) and the other with normal embryo development (n = 12).Enzyme-linked immunosorbent assay (ELISA) was employed to detect IGFBP-1 levels in maternal serum and decidual tissue. The expression of IGFBP-1 mRNA in deciduas was examined by reverse transcription polymerase chain reaction (RT-PCR) technique.Results The level of IGFBP-1 protein in maternal serum was significantly higher in the abnormal group [ (125.36 ± 47.93) μg/ml] than in the normal group [(70.72 ± 21.21) μg/ml ]. Both of IGFBP-1 and IGFBP-1 mRNA in deciduas were higher in abnormal group [ (1.60 ± 1.39) μg/ml and 1.66 ± 1.64, respectively ] than in the normal group [ (0.35 ± 0.23) μg/mi and 0.40 ± 0.20,respectively]. The level of IGFBP-1 in maternal serum was positively correlated with IGFBP-1 mRNA (r=0. 90, P<0.05) and IGFBP-1 protein (r=0.92, P<0.05) in decidual tissue.Conclusions During weeks 6 -10 of gestation, abnormal embryonic development is correlated with elevated IGFBP-1. The level of IGFBP-1 in maternal serum is related to the concentrations of IGFBP1 mRNA and IGFBP-1 in decidual tissue. The IGFBP-1 level in maternal serum may be used as a predictive marker to evaluate embryonic development.

  18. Angiotensin Ⅱ stimulates phosphorylation of 4E-binding protein 1 and p70 S6 kinase in cultured vascular smooth muscle cells

    Institute of Scientific and Technical Information of China (English)

    Na LI; Ke-gui WU; Xiang-yu WANG; Liang-di XIE; Chang-sheng XU; Hua-jun WANG

    2004-01-01

    AIM: To examine the regulatory effects of angiotensin Ⅱ (Ang Ⅱ) on the phosphorylation of 4E-binding protein 1 (4E-BP1) and p70 S6 kinase in cultured vascular smooth muscle cells (VSMC), and the contribution of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (PKB) signaling pathway in this process. METHODS: VSMC obtained from rat thoracic aortas were cultured. The phosphorylation of 4E-BP1 and p70 S6 kinase was detected by immunoblotting. RESULTS: Ang Ⅱ significantly increased the phosphorylation of 4E-BP1 and p70 S6 kinase,with the peaks occurring at, respectively, 10 min and 30 min, after stimulation with Ang Ⅱ. The stimulatory effect of Ang Ⅱ on 4E-BP1 and p70 S6 kinase phosphorylation was abrogated by Ang Ⅱ type 1 receptor (AT1 receptor)antagonist losartan, and suppressed by PI3K inhibitor LY294002 in a concentration-dependent manner.CONCLUSION: Ang Ⅱ treatment of VSMC induces the phosphorylation of 4E-BP1 and p70 S6 kinase via AT1 receptor, and PI3K signaling pathway is involved in this process.

  19. X-box binding protein 1 (XBP1s is a critical determinant of Pseudomonas aeruginosa homoserine lactone-mediated apoptosis.

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    Cathleen D Valentine

    Full Text Available Pseudomonas aeruginosa infections are associated with high mortality rates and occur in diverse conditions including pneumonias, cystic fibrosis and neutropenia. Quorum sensing, mediated by small molecules including N-(3-oxo-dodecanoyl homoserine lactone (C12, regulates P. aeruginosa growth and virulence. In addition, host cell recognition of C12 initiates multiple signalling responses including cell death. To gain insight into mechanisms of C12-mediated cytotoxicity, we studied the role of endoplasmic reticulum stress in host cell responses to C12. Dramatic protection against C12-mediated cell death was observed in cells that do not produce the X-box binding protein 1 transcription factor (XBP1s. The leucine zipper and transcriptional activation motifs of XBP1s were sufficient to restore C12-induced caspase activation in XBP1s-deficient cells, although this polypeptide was not transcriptionally active. The XBP1s polypeptide also regulated caspase activation in cells stimulated with N-(3-oxo-tetradecanoyl homoserine lactone (C14, produced by Yersinia enterolitica and Burkholderia pseudomallei, and enhanced homoserine lactone-mediated caspase activation in the presence of endogenous XBP1s. In C12-tolerant cells, responses to C12 including phosphorylation of p38 MAPK and eukaryotic initiation factor 2α were conserved, suggesting that C12 cytotoxicity is not heavily dependent on these pathways. In summary, this study reveals a novel and unconventional role for XBP1s in regulating host cell cytotoxic responses to bacterial acyl homoserine lactones.

  20. Molecular decoy to the Y-box binding protein-1 suppresses the growth of breast and prostate cancer cells whilst sparing normal cell viability.

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    Jennifer H Law

    Full Text Available The Y-box binding protein-1 (YB-1 is an oncogenic transcription/translation factor that is activated by phosphorylation at S102 whereby it induces the expression of growth promoting genes such as EGFR and HER-2. We recently illustrated by an in vitro kinase assay that a novel peptide to YB-1 was highly phosphorylated by the serine/threonine p90 S6 kinases RSK-1 and RSK-2, and to a lesser degree PKCα and AKT. Herein, we sought to develop this decoy cell permeable peptide (CPP as a cancer therapeutic. This 9-mer was designed as an interference peptide that would prevent endogenous YB-1(S102 phosphorylation based on molecular docking. In cancer cells, the CPP blocked P-YB-1(S102 and down-regulated both HER-2 and EGFR transcript level and protein expression. Further, the CPP prevented YB-1 from binding to the EGFR promoter in a gel shift assay. Notably, the growth of breast (SUM149, MDA-MB-453, AU565 and prostate (PC3, LNCap cancer cells was inhibited by ∼90% with the CPP. Further, treatment with this peptide enhanced sensitivity and overcame resistance to trastuzumab in cells expressing amplified HER-2. By contrast, the CPP had no inhibitory effect on the growth of normal immortalized breast epithelial (184htert cells, primary breast epithelial cells, nor did it inhibit differentiation of hematopoietic progenitors. These data collectively suggest that the CPP is a novel approach to suppressing the growth of cancer cells while sparing normal cells and thereby establishes a proof-of-concept that blocking YB-1 activation is a new course of cancer therapeutics.

  1. A novel processing system of sterol regulatory element-binding protein-1c regulated by polyunsaturated fatty acid.

    Science.gov (United States)

    Nakakuki, Masanori; Kawano, Hiroyuki; Notsu, Tatsuto; Imada, Kazunori; Mizuguchi, Kiyoshi; Shimano, Hitoshi

    2014-05-01

    The proteolytic cascade is the key step in transactivation of sterol regulatory element-binding proteins (SREBPs), a transcriptional factor of lipid synthesis. Proteolysis of SREBP-2 is strictly regulated by sterols, but that of SREBP-1c was not strongly sterol-regulated, but inhibited by polyunsaturated fatty acids (PUFAs). In this study, the proteolytic processing of SREBP-1 and -2 was examined by transfection studies of cDNA-encoding mutants in which all the known cleavage sites were disrupted. In cultured cells, sterol-regulated SREBP-2 processing was completely eliminated by mutation of cleavage sites. In contrast, the corresponding SREBP-1c mutants as well as wild type exhibited large amounts of cleaved products in the nuclear extracts from culture cells and murine liver in vivo. The nuclear form of the mutant SREBP-1c was induced by delipidated condition and suppressed by eicosapentaenoic acid, an n-3 PUFA, but not by sterols. This novel processing mechanism was affected by neither SREBP cleavage-activating protein (SCAP) nor insulin-induced gene (Insig)-1, unlike SREBP-2, but abolished by a serine protease inhibitor. Through analysis of deletion mutant, a site-2 protease recognition sequence (DRSR) was identified to be involved in this novel processing. These findings suggest that SREBP-1c cleavage could be subjected to a novel PUFA-regulated cleavage system in addition to the sterol-regulatory SCAP/Insig system.

  2. Down-expression of tumor protein p53-induced nuclear protein 1 in human gastric cancer

    Institute of Scientific and Technical Information of China (English)

    Pei-Hong Jiang; Yoshiharu Motoo; Stéphane Garcia; Juan Lucio Iovanna; Marie-Josèphe Pébusque; Norio Sawabu

    2006-01-01

    AIM: Overexpression of tumor protein p53-induced nuclear protein 1 (TP53INP1) induces G1 cell cycle arrest and increases p53-mediated apoptosis. To clarify the clinical importance of TP53INP1, we analyzed TP53INP1and p53 expression in gastric cancer.METHODS: TP53INP1 and p53 expression were examined using immunohistochemistry in 142 cases of gastric cancer. The apoptosis of gastric cancer cells was analyzed using the TUNEL method. The relationship between the expression of TP53INP1 and clinicopathological factors was statistically analyzed.RESULTS: TP53INP1 was expressed in 98% (139/142cases) of non-cancerous gastric tissues and was downexpressed in 64% (91/142 cases) of gastric cancer lesions from the same patients. TP53INP1 expression was significantly decreased (43.9%) in poorly differentiated adenocarcinoma compared with well or moderately differentiated adenocarcinoma (81.6%).Cancers invading the submucosa or deeper showed lower positively (59.1%) compared with mucosal cancers (85.2%). Decrease or loss of TP53INP1 expression was significantly correlated with lymphatic invasion (54.3%vs 82.0% without lymphatic invasion) and node-positive patients (31.3% vs 68.3% in node-negative patients).P53 was expressed in 68 (47.9%) patients of gastric cancer, whereas it was absent in normal gastric tissues.A significant association was also observed between TP53INP1 status and the level of apoptosis in tumor cells: the apoptotic index in TP53INP1-positive tissues was significantly higher than that in TP53INP1-negative portions. Finally, when survival data were analyzed,loss of TP53INP1 expression had a significant effect in predicting a poor prognosis (P= 0.0006).CONCLUSION: TP53INP1-positive rate decreases with the progression of gastric cancer. TP53INP1 protein negativity is significantly associated with aggressive pathological phenotypes of gastric cancer. TP53INP1is related to the apoptosis of gastric cancer cells. The decreased expression of the TP53INP1 protein may

  3. Inhibitory effects of omega-3 fatty acids on early brain injury after subarachnoid hemorrhage in rats: Possible involvement of G protein-coupled receptor 120/β-arrestin2/TGF-β activated kinase-1 binding protein-1 signaling pathway.

    Science.gov (United States)

    Yin, Jia; Li, Haiying; Meng, Chengjie; Chen, Dongdong; Chen, Zhouqing; Wang, Yibin; Wang, Zhong; Chen, Gang

    2016-06-01

    Omega-3 fatty acids have been reported to improve neuron functions during aging and in patients affected by mild cognitive impairment, and mediate potent anti-inflammatory via G protein-coupled receptor 120 (GPR120) signal pathway. Neuron dysfunction and inflammatory response also contributed to the progression of subarachnoid hemorrhage (SAH)-induced early brain injury (EBI). This study was to examine the effects of omega-3 fatty acids on SAH-induced EBI. Two weeks before SAH, 30% Omega-3 fatty acids was administered by oral gavage at 1g/kg body weight once every 24h. Specific siRNA for GPR120 was exploited. Terminal deoxynucleotidyl transferase dUTP nick end labeling, fluoro-Jade B staining, and neurobehavioral scores and brain water content test showed that omega-3 fatty acids effectively suppressed SAH-induced brain cell apoptosis and neuronal degradation, behavioral impairment, and brain edema. Western blot, immunoprecipitation, and electrophoretic mobility shift assays results showed that omega-3 fatty acids effectively suppressed SAH-induced elevation of inflammatory factors, including cyclooxygenase-2, monocyte chemoattractant protein-1, and inducible nitric oxide synthase. In addition, omega-3 fatty acids could inhibit phosphorylation of transforming growth factor β activated kinase-1 (TAK1), MEK4, c-Jun N-terminal kinase, and IkappaB kinase as well as activation of nuclear factor kappa B through regulating GPR120/β-arrestin2/TAK1 binding protein-1 pathway. Furthermore, siRNA-induced GPR120 silencing blocked the protective effects of omega-3 fatty acids. Here, we show that stimulation of GPR120 with omega-3 fatty acids pretreatment causes anti-apoptosis and anti-inflammatory effects via β-arrestin2/TAK1 binding protein-1/TAK1 pathway in the brains of SAH rats. Fish omega-3 fatty acids as part of a daily diet may reduce EBI in an experimental rat model of SAH.

  4. Huntingtin-associated protein 1 (HAP1) interacts with androgen receptor (AR) and suppresses SBMA-mutant-AR-induced apoptosis.

    Science.gov (United States)

    Takeshita, Yukio; Fujinaga, Ryutaro; Zhao, Changjiu; Yanai, Akie; Shinoda, Koh

    2006-08-01

    Huntingtin-associated protein 1 (HAP1), an interactor of huntingtin, has been known as an essential component of the stigmoid body (STB) and recently reported to play a protective role against neurodegeneration in Huntington's disease (HD). In the present study, subcellular association between HAP1 and androgen receptor (AR) with a long polyglutamine tract (polyQ) derived from spinal-and-bulbar-muscular-atrophy (SBMA) was examined using HEp-2 cells cotransfected with HAP1 and/or normal ARQ25, SBMA-mutant ARQ65 or deletion-mutant AR cDNAs. The results provided the first clear evidence that HAP1 interacts with AR through its ligand-binding domain in a polyQ-length-dependent manner and forms prominent inclusions sequestering polyQ-AR, and that addition of dihydrotestosterone reduces the association strength of HAP1 with ARQ25 more dramatically than that with ARQ65. Furthermore, SBMA-mutant-ARQ65-induced apoptosis was suppressed by cotransfection with HAP1. Our findings strongly suggest that HAP1/STB is relevant to polyQ-length-dependent modification on subcellular AR functions and critically involved in pathogenesis of not only HD but also SBMA as an important intrinsic neuroprotectant determining the threshold for cellular vulnerability to apoptosis. Taking together with previous reports that HAP1/STB is selectively expressed in the brain regions spared from degenerative targets in HD and SBMA, the current study might explain the region-specific occurrence of neurodegeneration in both diseases, shedding light on common aspects of their molecular pathological mechanism and yet-to-be-uncovered diagnostic or therapeutic applications for HD and SBMA patients.

  5. Progesterone stimulates adipocyte determination and differentiation 1/sterol regulatory element-binding protein 1c gene expression. potential mechanism for the lipogenic effect of progesterone in adipose tissue.

    Science.gov (United States)

    Lacasa, D; Le Liepvre, X; Ferre, P; Dugail, I

    2001-04-13

    Fatty acid synthase (FAS), a nutritionally regulated lipogenic enzyme, is transcriptionally controlled by ADD1/SREBP1c (adipocyte determination and differentiation 1/sterol regulatory element-binding protein 1c), through insulin-mediated stimulation of ADD1/SREBP1c expression. Progesterone exerts lipogenic effects on adipocytes, and FAS is highly induced in breast tumor cell lines upon progesterone treatment. We show here that progesterone up-regulates ADD1/SREBP1c expression in the MCF7 breast cancer cell line and the primary cultured preadipocyte from rat parametrial adipose tissue. In MCF7, progesterone induced ADD1/SREBP1c and Metallothionein II (a well known progesterone-regulated gene) mRNAs, with comparable potency. In preadipocytes, progesterone increased ADD1/SREBP1c mRNA dose-dependently, but not SREBP1a or SREBP2. Run-on experiments demonstrated that progesterone action on ADD1/SREBP1c was primarily at the transcriptional level. The membrane-bound and mature nuclear forms of ADD1/SREBP1 protein accumulated in preadipocytes cultured with progesterone, and FAS induction could be abolished by adenovirus-mediated overexpression of a dominant negative form of ADD1/SREBP1 in these cells. Finally, in the presence of insulin, progesterone was unable to up-regulate ADD1/SREBP1c mRNA in preadipocytes, whereas its effect was restored after 24 h of insulin deprivation. Together these results demonstrate that ADD1/SREBP1c is controlled by progesterone, which, like insulin, acts by increasing ADD1/SREBP1c gene transcription. This provides a potential mechanism for the lipogenic actions of progesterone on adipose tissue.

  6. High-mobility group box protein 1 promotes the survival of myeloid-derived suppressor cells by inducing autophagy.

    Science.gov (United States)

    Parker, Katherine H; Horn, Lucas A; Ostrand-Rosenberg, Suzanne

    2016-09-01

    Myeloid-derived suppressor cells are immune-suppressive cells that are elevated in most individuals with cancer, where their accumulation and suppressive activity are driven by inflammation. As myeloid-derived suppressor cells inhibit anti-tumor immunity and promote tumor progression, we are determining how their viability is regulated. Previous studies have established that the damage-associated molecular pattern molecule high-mobility group box protein 1 drives myeloid-derived suppressor cell accumulation and suppressive potency and is ubiquitously present in the tumor microenvironment. As high-mobility group box protein 1 also facilitates tumor cell survival by inducing autophagy, we sought to determine if high-mobility group box protein 1 regulates myeloid-derived suppressor cell survival through induction of autophagy. Inhibition of autophagy increased the quantity of apoptotic myeloid-derived suppressor cells, demonstrating that autophagy extends the survival and increases the viability of myeloid-derived suppressor cells. Inhibition of high-mobility group box protein 1 similarly increased the level of apoptotic myeloid-derived suppressor cells and reduced myeloid-derived suppressor cell autophagy, demonstrating that in addition to inducing the accumulation of myeloid-derived suppressor cells, high-mobility group box protein 1 sustains myeloid-derived suppressor cell viability. Circulating myeloid-derived suppressor cells have a default autophagic phenotype, and tumor-infiltrating myeloid-derived suppressor cells are more autophagic, consistent with the concept that inflammatory and hypoxic conditions within the microenvironment of solid tumors contribute to tumor progression by enhancing immune-suppressive myeloid-derived suppressor cells. Overall, these results demonstrate that in addition to previously recognized protumor effects, high-mobility group box protein 1 contributes to tumor progression by increasing myeloid-derived suppressor cell viability by

  7. Differential distribution of Y-box-binding protein 1 and cold shock domain protein A in developing and adult human brain.

    Science.gov (United States)

    Bernstein, Hans-Gert; Lindquist, Jonathan A; Keilhoff, Gerburg; Dobrowolny, Henrik; Brandt, Sabine; Steiner, Johann; Bogerts, Bernhard; Mertens, Peter R

    2015-07-01

    The two cold shock domain containing proteins, Y-box-binding protein-1 and cold shock domain protein A were immunolocalized in developing and adult human brain. With the exception of a small population of hypothalamic astrocytes, brain Y-box-binding protein-1 was predominantly found in multiple neurons in the mature human CNS, which might be related to its involvement in neurotransmission and other neuron-associated functions. Cold shock domain protein A was typically observed in astrocytes, oligodendrocytes, choroid plexus epithelia and nerve fibers. However, in circumscribed brain regions as hypothalamus, habenula, and cerebellum, this protein was also expressed in neurons. In the prenatal brain, both proteins were found to be abundantly expressed in radial glial cells, neuroblasts and neurons, which might be an anatomical correlate of the proposed roles of both proteins in cell proliferation and differentiation. In addition, Y-box-binding protein-1 was identified in cultured, lipopolysaccharide-stimulated microglial cells, which underscores its putative role as a mediator in immune and inflammatory processes.

  8. Confined housing system increased abdominal and subcutaneous fat deposition and gene expressions of carbohydrate response element-binding protein and sterol regulatory element-binding protein 1 in chicken.

    Science.gov (United States)

    Li, Q; Zhao, X L; Gilbert, E R; Liu, Y P; Wang, Y; Qiu, M H; Zhu, Q

    2015-02-06

    Free-range production system is increasingly being used in poultry breeding and feed production in many countries. The objective of the current experiment was to evaluate the effects of different raising systems on fat-related traits and mRNA levels of liver lipogenesis genes in Erlang Mountainous chicken. Each of 10 birds (91 day old) from caged, indoor-floor housed, and free-range housing systems was slaughtered, and fat-related traits, live body weight (BW), subcutaneous fat thickness (SFT), abdominal fat weight (AFW), abdominal fat percentage (AFP), and intramuscular fat content were determined. The mRNA levels of liver X receptor α, carbohydrate response element-binding protein (ChREBP), sterol regulatory element-binding protein-1 (SREBP1), and fatty acid synthase were detected. The caged chicken exhibited significantly higher BW, SFT, and AFW than those of free-ranged chicken (P caged chicken, while the lowest level was found in free-ranged chicken. Association analysis indicated that there were significant (P caged chicken was probably induced by increased gene expression of ChREBP and SREBP1 in the liver.

  9. Plasmodium knowlesi Skeleton-Binding Protein 1 Localizes to the ‘Sinton and Mulligan’ Stipplings in the Cytoplasm of Monkey and Human Erythrocytes

    Science.gov (United States)

    Lucky, Amuza Byaruhanga; Sakaguchi, Miako; Katakai, Yuko; Kawai, Satoru; Yahata, Kazuhide; Templeton, Thomas J.

    2016-01-01

    The malaria parasite, Plasmodium, exports protein products to the infected erythrocyte to introduce modifications necessary for the establishment of nutrient acquisition and surface display of host interaction ligands. Erythrocyte remodeling impacts parasite virulence and disease pathology and is well documented for the human malaria parasite Plasmodium falciparum, but has been less described for other Plasmodium species. For P. falciparum, the exported protein skeleton-binding protein 1 (PfSBP1) is involved in the trafficking of erythrocyte surface ligands and localized to membranous structures within the infected erythrocyte, termed Maurer's clefts. In this study, we analyzed SBP1 orthologs across the Plasmodium genus by BLAST analysis and conserved gene synteny, which were also recently described by de Niz et al. (2016). To evaluate the localization of an SBP1 ortholog, we utilized the zoonotic malaria parasite, Plasmodium knowlesi. Immunofluorescence assay of transgenic P. knowlesi parasites expressing epitope-tagged recombinant PkSBP1 revealed a punctate staining pattern reminiscent of Maurer's clefts, following infection of either monkey or human erythrocytes. The recombinant PkSBP1-positive puncta co-localized with Giemsa-stained structures, known as ‘Sinton and Mulligan’ stipplings. Immunoelectron microscopy also showed that recombinant PkSBP1 localizes within or on the membranous structures akin to the Maurer's clefts. The recombinant PkSBP1 expressed in P. falciparum-infected erythrocytes co-localized with PfSBP1 at the Maurer's clefts, indicating an analogous trafficking pattern. A member of the P. knowlesi 2TM protein family was also expressed and localized to membranous structures in infected monkey erythrocytes. These results suggest that the trafficking machinery and induced erythrocyte cellular structures of P. knowlesi are similar following infection of both monkey and human erythrocytes, and are conserved with P. falciparum. PMID:27732628

  10. X-box binding protein 1 is essential for the anti-oxidant defense and cell survival in the retinal pigment epithelium.

    Directory of Open Access Journals (Sweden)

    Yimin Zhong

    Full Text Available Damage to the retinal pigment epithelium (RPE is an early event in the pathogenesis of age-related macular degeneration (AMD. X-box binding protein 1 (XBP1 is a key transcription factor that regulates endoplasmic reticulum (ER homeostasis and cell survival. This study aimed to delineate the role of endogenous XBP1 in the RPE. Our results show that in a rat model of light-induced retinal degeneration, XBP1 activation was suppressed in the RPE/choroid complex, accompanied by decreased anti-oxidant genes and increased oxidative stress. Knockdown of XBP1 by siRNA resulted in reduced expression of SOD1, SOD2, catalase, and glutathione synthase and sensitized RPE cells to oxidative damage. Using Cre/LoxP system, we generated a mouse line that lacks XBP1 only in RPE cells. Compared to wildtype littermates, RPE-XBP1 KO mice expressed less SOD1, SOD2, and catalase in the RPE, and had increased oxidative stress. At age 3 months and older, these mice exhibited apoptosis of RPE cells, decreased number of cone photoreceptors, shortened photoreceptor outer segment, reduced ONL thickness, and deficit in retinal function. Electron microscopy showed abnormal ultrastructure, Bruch's membrane thickening, and disrupted basal membrane infolding in XBP1-deficient RPE. These results indicate that XBP1 is an important gene involved in regulation of the anti-oxidant defense in the RPE, and that impaired activation of XBP1 may contribute to RPE dysfunction and cell death during retinal degeneration and AMD.

  11. Pertussis toxin B-oligomer suppresses IL-6 induced HIV-1 and chemokine expression in chronically infected U1 cells via inhibition of activator protein 1.

    Science.gov (United States)

    Rizzi, Chiara; Crippa, Massimo P; Jeeninga, Rienk E; Berkhout, Ben; Blasi, Francesco; Poli, Guido; Alfano, Massimo

    2006-01-15

    Pertussis toxin B-oligomer (PTX-B) inhibits HIV replication in T lymphocytes and monocyte-derived macrophages by interfering with multiple steps of the HIV life cycle. PTX-B prevents CCR5-dependent (R5) virus entry in a noncompetitive manner, and it also exerts suppressive effects on both R5- and CXCR4-dependent HIV expression at a less-characterized postentry level. We demonstrate in this study that PTX-B profoundly inhibits HIV expression in chronically infected promonocytic U1 cells stimulated with several cytokines and, particularly, the IL-6-mediated effect, a cytokine that triggers viral production in these cells independently of NF-kappaB activation. From U1 cells we have subcloned a cell line, named U1-CR1, with increased responsiveness to IL-6. In these cells, PTX-B neither down-regulated the IL-6R nor prevented IL-6 induced signaling in terms of STAT3 phosphorylation and DNA binding. In contrast, PTX-B inhibited AP-1 binding to target DNA and modified its composition with a proportional increases in FosB, Fra2, and ATF2. PTX-B inhibited IL-6-induced HIV-1 long-terminal repeat-driven transcription from A, C, E, and F viral subtypes, which contain functional AP-1 binding sites, but failed to inhibit transcription from subtypes B and D LTR devoid of these sites. In addition, PTX-B inhibited the secretion of IL-6-induced, AP-1-dependent genes, including urokinase-type plasminogen activator, CXCL8/IL-8, and CCL2/monocyte chemotactic protein-1. Thus, PTX-B suppression of IL-6 induced expression of HIV and cellular genes in chronically infected promonocytic cells is strongly correlated to inhibition of AP-1.

  12. The Anopheles gambiae odorant binding protein 1 (AgamOBP1 mediates indole recognition in the antennae of female mosquitoes.

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    Harald Biessmann

    Full Text Available Haematophagous insects are frequently carriers of parasitic diseases, including malaria. The mosquito Anopheles gambiae is the major vector of malaria in sub-Saharan Africa and is thus responsible for thousands of deaths daily. Although the role of olfaction in A. gambiae host detection has been demonstrated, little is known about the combinations of ligands and odorant binding proteins (OBPs that can produce specific odor-related responses in vivo. We identified a ligand, indole, for an A. gambiae odorant binding protein, AgamOBP1, modeled the interaction in silico and confirmed the interaction using biochemical assays. RNAi-mediated gene silencing coupled with electrophysiological analyses confirmed that AgamOBP1 binds indole in A. gambiae and that the antennal receptor cells do not respond to indole in the absence of AgamOBP1. This case represents the first documented instance of a specific A. gambiae OBP-ligand pairing combination, demonstrates the significance of OBPs in odor recognition, and can be expanded to the identification of other ligands for OBPs of Anopheles and other medically important insects.

  13. Interaction of the amyloid precursor protein-like protein 1 (APLP1) E2 domain with heparan sulfate involves two distinct binding modes

    Energy Technology Data Exchange (ETDEWEB)

    Dahms, Sven O., E-mail: sdahms@fli-leibniz.de [Leibniz Institute for Age Research (FLI), Beutenbergstrasse 11, 07745 Jena (Germany); Mayer, Magnus C. [Freie Universität Berlin, Thielallee 63, 14195 Berlin (Germany); Miltenyi Biotec GmbH, Robert-Koch-Strasse 1, 17166 Teterow (Germany); Roeser, Dirk [Leibniz Institute for Age Research (FLI), Beutenbergstrasse 11, 07745 Jena (Germany); Multhaup, Gerd [McGill University Montreal, Montreal, Quebec H3G 1Y6 (Canada); Than, Manuel E., E-mail: sdahms@fli-leibniz.de [Leibniz Institute for Age Research (FLI), Beutenbergstrasse 11, 07745 Jena (Germany)

    2015-03-01

    Two X-ray structures of APLP1 E2 with and without a heparin dodecasaccharide are presented, revealing two distinct binding modes of the protein to heparan sulfate. The data provide a mechanistic explanation of how APP-like proteins bind to heparan sulfates and how they specifically recognize nonreducing structures of heparan sulfates. Beyond the pathology of Alzheimer’s disease, the members of the amyloid precursor protein (APP) family are essential for neuronal development and cell homeostasis in mammals. APP and its paralogues APP-like protein 1 (APLP1) and APP-like protein 2 (APLP2) contain the highly conserved heparan sulfate (HS) binding domain E2, which effects various (patho)physiological functions. Here, two crystal structures of the E2 domain of APLP1 are presented in the apo form and in complex with a heparin dodecasaccharide at 2.5 Å resolution. The apo structure of APLP1 E2 revealed an unfolded and hence flexible N-terminal helix αA. The (APLP1 E2){sub 2}–(heparin){sub 2} complex structure revealed two distinct binding modes, with APLP1 E2 explicitly recognizing the heparin terminus but also interacting with a continuous heparin chain. The latter only requires a certain register of the sugar moieties that fits to a positively charged surface patch and contributes to the general heparin-binding capability of APP-family proteins. Terminal binding of APLP1 E2 to heparin specifically involves a structure of the nonreducing end that is very similar to heparanase-processed HS chains. These data reveal a conserved mechanism for the binding of APP-family proteins to HS and imply a specific regulatory role of HS modifications in the biology of APP and APP-like proteins.

  14. Activator protein 1 promotes gemcitabine-induced apoptosis in pancreatic cancer by upregulating its downstream target Bim.

    Science.gov (United States)

    Ren, Xiaoxia; Zhao, Wenjing; Du, Yongxing; Zhang, Taiping; You, Lei; Zhao, Yupei

    2016-12-01

    Gemcitabine is a commonly used chemotherapy drug in pancreatic cancer. The function of activator protein 1 (AP-1) is cell-specific, and its function depends on the expression of other complex members. In the present study, we added gemcitabine to the media of Panc-1 and SW1990 cells at clinically achieved concentrations (10 µM). Compared with constitutive c-Fos expression, c-Jun expression increased in a dose-dependent manner upon gemcitabine treatment. c-Jun overexpression increased gemcitabine-induced apoptosis through Bim activation, while cell apoptosis and Bim expression decreased following c-Jun knockdown. Furthermore, gemcitabine-induced apoptosis and Bim levels decreased when c-Jun phosphorylation was blocked by SP600125. Our findings suggest that c-Jun, which is a member of the AP-1 complex, functions in gemcitabine-induced apoptosis by regulating its downstream target Bim in pancreatic cancer cells.

  15. Monocyte chemoattractant protein-1 induces endothelial cell apoptosis in vitro through a p53-dependent mitochondrial pathway

    Institute of Scientific and Technical Information of China (English)

    Xuan Zhang; Xiping Liu; Huifeng Shang; Yan Xu; Minzhang Qian

    2011-01-01

    The cystine-cystine (CC) chemokine monocyte chemoattractant protein-1 (MCP-1) has been established playing a pathogenic role in the development of atherosclerosis due to its chemotactic ability of leading monocytes to locate to subendothelia.Recent studies have revealed more MCP-1 functions other than chemotaxis.Here we reported that various concentrations (0.1-100 ng/ml) of MCP-1 induced human umbilical vein endothelial cell (HUVEC) strain CRL-1730 apoptosis,caspase-9 activation,and a couple of mitochondrial alterations.Moreover,MCP-1 upregulated p53 expression of HUVECs and the p53-specific inhibitor pifithrin-α(PFTα) rescued the MCP-1-induced apoptosis of HUVECs.Furthermore,PKC (protein kinase C) activation or inhibition might also affect HUVECs apoptosis induced by MCP-1.These findings together demonstrate that MCP-1 exerts direct proapoptotic effects on HUVECs in vitro via a p53-dependent mitochondrial pathway.

  16. Effects of the 54G/C polymorphism of sterol regulatory element-binding protein-1c on changes of serum lipid ratios induced by high-carbohydrate/low-fat diet in healthy youth%固醇调节元件结合蛋白-1c基因54G/C多态性对高糖低脂膳食诱导的健康青年人血脂比值的影响

    Institute of Scientific and Technical Information of China (English)

    张珍; 方定志; 龚仁蓉; 杜娟; 汤慧; 黄鑫; 甘婵芬

    2010-01-01

    Objective To investigate the effects of 54G/C polymorphism of sterol regulatory elementbinding protein-1c gene (SREBP-1c)on serum lipid ratios and their response to high-carbohydrate/low-fat(HC/LF) diet in healthy youth. Methods After a regular diet for 7 days of wash-out, 56 healthy youth (22.89±1.80 yrs) were given HC/LF diet for 6 days. The regular diet contained 54% carbohydrate, 15%protein, and 31% fat of the total energy. The HC/LF diet contained 70% carbohydrate, 15% protein, and 15% fat of the total energy. The serum lipids and glucose were measured on the 1st, 8th and 14th days.The ratios of TG/HDL-C, log (TG/HDL-C), TC/HDL-C, and LDL-C/HDL-C were calculated. The 54G/C polymorphism of SREBP-1c gene was analyzed by PCR-RFLP method. Results No significant difference was found in lipid ratios and glucose at baseline and after regular diet in subjects with different genotypes in either the whole studied population or in males or females only. However, after HC/LF diet, LDL-C/HDL-C was significantly lower in females carrying the C allele than those of GG homozygotes (P< 0.05).Compared with those before HC/LF diet, TC/HDL-C and LDL-C/HDL-C were significantly decreased in all the subjects (P<0.05). When gender was taken into account, significant increase of TG/HDL-C and log(TG/HDL-C) was found only in females with GG genotype (P<0.05). All the subjects experienced significant decrease of TC/HDL-C and LDL-C/HDL-C regardless of their genders and genotypes (P<0.05). Conclusion The 54G/C polymorphism of SREBP-1c gene can influence the response of TG/HDL-C and log(TG/HDL-C) to HC/LF diet in females. The C allele may be a protective factor to prevent the increase of TG induced by HC/LF diet in females.%目的 探讨固醇调节元件结合蛋白-1c(sterol regulatory element-binding protein-1c,SREBP-1c)基因54G/C多态性对健康青年血脂比值的影响及在高糖低脂(high-carbohydrate/low-fat,HC/LF)膳食诱导的变化中的作用.方法 对56

  17. Giardia cyst wall protein 1 is a lectin that binds to curled fibrils of the GalNAc homopolymer.

    Directory of Open Access Journals (Sweden)

    Aparajita Chatterjee

    Full Text Available The infectious and diagnostic stage of Giardia lamblia (also known as G. intestinalis or G. duodenalis is the cyst. The Giardia cyst wall contains fibrils of a unique beta-1,3-linked N-acetylgalactosamine (GalNAc homopolymer and at least three cyst wall proteins (CWPs composed of Leu-rich repeats (CWP(LRR and a C-terminal conserved Cys-rich region (CWP(CRR. Our goals were to dissect the structure of the cyst wall and determine how it is disrupted during excystation. The intact Giardia cyst wall is thin (approximately 400 nm, easily fractured by sonication, and impermeable to small molecules. Curled fibrils of the GalNAc homopolymer are restricted to a narrow plane and are coated with linear arrays of oval-shaped protein complex. In contrast, cyst walls of Giardia treated with hot alkali to deproteinate fibrils of the GalNAc homopolymer are thick (approximately 1.2 microm, resistant to sonication, and permeable. The deproteinated GalNAc homopolymer, which forms a loose lattice of curled fibrils, is bound by native CWP1 and CWP2, as well as by maltose-binding protein (MBP-fusions containing the full-length CWP1 or CWP1(LRR. In contrast, neither MBP alone nor MBP fused to CWP1(CRR bind to the GalNAc homopolymer. Recombinant CWP1 binds to the GalNAc homopolymer within secretory vesicles of Giardia encysting in vitro. Fibrils of the GalNAc homopolymer are exposed during excystation or by treatment of heat-killed cysts with chymotrypsin, while deproteinated fibrils of the GalNAc homopolymer are degraded by extracts of Giardia cysts but not trophozoites. These results show the Leu-rich repeat domain of CWP1 is a lectin that binds to curled fibrils of the GalNAc homopolymer. During excystation, host and Giardia proteases appear to degrade bound CWPs, exposing fibrils of the GalNAc homopolymer that are digested by a stage-specific glycohydrolase.

  18. Giardia cyst wall protein 1 is a lectin that binds to curled fibrils of the GalNAc homopolymer.

    Science.gov (United States)

    Chatterjee, Aparajita; Carpentieri, Andrea; Ratner, Daniel M; Bullitt, Esther; Costello, Catherine E; Robbins, Phillips W; Samuelson, John

    2010-08-19

    The infectious and diagnostic stage of Giardia lamblia (also known as G. intestinalis or G. duodenalis) is the cyst. The Giardia cyst wall contains fibrils of a unique beta-1,3-linked N-acetylgalactosamine (GalNAc) homopolymer and at least three cyst wall proteins (CWPs) composed of Leu-rich repeats (CWP(LRR)) and a C-terminal conserved Cys-rich region (CWP(CRR)). Our goals were to dissect the structure of the cyst wall and determine how it is disrupted during excystation. The intact Giardia cyst wall is thin (approximately 400 nm), easily fractured by sonication, and impermeable to small molecules. Curled fibrils of the GalNAc homopolymer are restricted to a narrow plane and are coated with linear arrays of oval-shaped protein complex. In contrast, cyst walls of Giardia treated with hot alkali to deproteinate fibrils of the GalNAc homopolymer are thick (approximately 1.2 microm), resistant to sonication, and permeable. The deproteinated GalNAc homopolymer, which forms a loose lattice of curled fibrils, is bound by native CWP1 and CWP2, as well as by maltose-binding protein (MBP)-fusions containing the full-length CWP1 or CWP1(LRR). In contrast, neither MBP alone nor MBP fused to CWP1(CRR) bind to the GalNAc homopolymer. Recombinant CWP1 binds to the GalNAc homopolymer within secretory vesicles of Giardia encysting in vitro. Fibrils of the GalNAc homopolymer are exposed during excystation or by treatment of heat-killed cysts with chymotrypsin, while deproteinated fibrils of the GalNAc homopolymer are degraded by extracts of Giardia cysts but not trophozoites. These results show the Leu-rich repeat domain of CWP1 is a lectin that binds to curled fibrils of the GalNAc homopolymer. During excystation, host and Giardia proteases appear to degrade bound CWPs, exposing fibrils of the GalNAc homopolymer that are digested by a stage-specific glycohydrolase.

  19. Multiple Plasmodium falciparum erythrocyte membrane protein 1 variants per genome can bind IgM via its Fc fragment Fcμ

    DEFF Research Database (Denmark)

    Jeppesen, Anine; Ditlev, Sisse Bolm; Soroka, Vladyslav;

    2015-01-01

    The Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) adhesive proteins expressed on the surfaces of infected erythrocytes (IEs) are of key importance in the pathogenesis of P. falciparum malaria. Several structurally and functionally defined PfEMP1 types have been associated...... with severe clinical manifestations, such as cerebral malaria in children and placental malaria in pregnant women. PfEMP1 that can bind the Fc part of IgM (Fcμ) characterizes one such type, although the functional significance of this IgM binding to PfEMP1 remains unclear. In this study, we report...... the identification and functional analysis of five IgM-binding PfEMP1 proteins encoded by P. falciparum NF54. In addition to the VAR2CSA-type PFL0030c protein, already known to bind Fcμ and to mediate chondroitin sulfate A (CSA)-specific adhesion of IEs in the placenta, we found four PfEMP1 proteins not previously...

  20. Multiple Plasmodium falciparum Erythrocyte Membrane Protein 1 Variants per Genome Can Bind IgM via Its Fc Fragment Fcμ

    DEFF Research Database (Denmark)

    Jeppesen, Anine; Ditlev, Sisse Bolm; Soroka, Vladyslav;

    2015-01-01

    The Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) adhesive proteins expressed on the surfaces of infected erythrocytes (IEs) are of key importance in the pathogenesis of P. falciparum malaria. Several structurally and functionally defined PfEMP1 types have been associated...... with severe clinical manifestations, such as cerebral malaria in children and placental malaria in pregnant women. PfEMP1 that can bind the Fc part of IgM (Fcμ) characterizes one such type, although the functional significance of this IgM binding to PfEMP1 remains unclear. In this study, we report...... the identification and functional analysis of five IgM-binding PfEMP1 proteins encoded by P. falciparum NF54. In addition to the VAR2CSA-type PFL0030c protein, already known to bind Fcμ and to mediate chondroitin sulfate A (CSA)-specific adhesion of IEs in the placenta, we found four PfEMP1 proteins not previously...

  1. Piperine activates human pregnane X receptor to induce the expression of cytochrome P450 3A4 and multidrug resistance protein 1

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yue-Ming; Lin, Wenwei; Chai, Sergio C.; Wu, Jing; Ong, Su Sien [Department of Chemical Biology and Therapeutics, St. Jude Children' s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105 (United States); Schuetz, Erin G. [Department of Pharmaceutical Sciences, St. Jude Children' s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105 (United States); Chen, Taosheng, E-mail: taosheng.chen@stjude.org [Department of Chemical Biology and Therapeutics, St. Jude Children' s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105 (United States)

    2013-10-01

    Activation of the pregnane X receptor (PXR) and subsequently its target genes, including those encoding drug transporters and metabolizing enzymes, while playing substantial roles in xenobiotic detoxification, might cause undesired drug-drug interactions. Recently, an increased awareness has been given to dietary components for potential induction of diet–drug interactions through activation of PXR. Here, we studied, whether piperine (PIP), a major component extracted from the widely-used daily spice black pepper, could induce PXR-mediated expression of cytochrome P450 3A4 (CYP3A4) and multidrug resistance protein 1 (MDR1). Our results showed that PIP activated human PXR (hPXR)-mediated CYP3A4 and MDR1 expression in human hepatocytes, intestine cells, and a mouse model; PIP activated hPXR by recruiting its coactivator SRC-1 in both cellular and cell-free systems; PIP bound to the hPXR ligand binding domain in a competitive ligand binding assay in vitro. The dichotomous effects of PIP on induction of CYP3A4 and MDR1 expression observed here and inhibition of their activity reported elsewhere challenges the potential use of PIP as a bioavailability enhancer and suggests that caution should be taken in PIP consumption during drug treatment in patients, particularly those who favor daily pepper spice or rely on certain pepper remedies. - Highlights: • Piperine induces PXR-mediated CYP3A4 and MDR1 expression. • Piperine activates PXR by binding to PXR and recruiting coactivator SRC-1. • Piperine induces PXR activation in vivo. • Caution should be taken in piperine consumption during drug treatment.

  2. Tau Induces Cooperative Taxol Binding to Microtubules

    Science.gov (United States)

    Ross, Jennifer; Santangelo, Christian; Victoria, Makrides; Fygenson, Deborah

    2004-03-01

    Taxol and tau are two ligands which stabilize the microtubule (MT) lattice. Taxol is an anti-mitotic drug that binds β tubulin in the MT interior. Tau is a MT-associated protein that binds both α and β tubulin on the MT exterior. Both taxol and tau reduce MT dynamics and promote tubulin polymerization. Tau alone also acts as a buttress to bundle, stiffen, and space MTs. A structural study recently suggested that taxol and tau may interact by binding to the same site. Using fluorescence recovery after photobleaching, we find that tau induces taxol to bind MTs cooperatively depending on the tau concentration. We develop a model that correctly fits the data in the absence of tau and yields a measure of taxol cooperativity when tau is present.

  3. Ca2+-binding protein-1 facilitates and forms a postsynaptic complex with Cav1.2 (L-type) Ca2+ channels.

    Science.gov (United States)

    Zhou, Hong; Kim, Seong-Ah; Kirk, Elizabeth A; Tippens, Alyssa L; Sun, Hong; Haeseleer, Françoise; Lee, Amy

    2004-05-12

    Ca2+-binding protein-1 (CaBP1) is a Ca2+-binding protein that is closely related to calmodulin (CaM) and localized in somatodendritic regions of principal neurons throughout the brain, but how CaBP1 participates in postsynaptic Ca2+ signaling is not known. Here, we describe a novel role for CaBP1 in the regulation of Ca2+ influx through Ca(v)1.2 (L-type) Ca2+ channels. CaBP1 interacts directly with the alpha1 subunit of Ca(v)1.2 at sites that also bind CaM. CaBP1 binding to one of these sites, the IQ domain, is Ca2+ dependent and competitive with CaM binding. The physiological significance of this interaction is supported by the association of Ca(v)1.2 and CaBP1 in postsynaptic density fractions purified from rat brain. Moreover, in double-label immunofluorescence experiments, CaBP1 and Ca(v)1.2 colocalize in numerous cell bodies and dendrites of neurons, particularly in pyramidal cells in the CA3 region of the hippocampus and in the dorsal cortex. In electrophysiological recordings of cells transfected with Ca(v)1.2, CaBP1 greatly prolonged Ca2+ currents, prevented Ca2+-dependent inactivation, and caused Ca2+-dependent facilitation of currents evoked by step depolarizations and repetitive stimuli. These effects contrast with those of CaM, which promoted strong Ca2+-dependent inactivation of Ca(v)1.2 with these same voltage protocols. Our findings reveal how Ca2+-binding proteins, such as CaM and CaBP1, differentially adjust Ca2+ influx through Ca(v)1.2 channels, which may specify diverse modes of Ca2+ signaling in neurons.

  4. Involvement of dynamin-related protein 1 in free fatty acid-induced INS-1-derived cell apoptosis.

    Science.gov (United States)

    Peng, Liang; Men, Xiuli; Zhang, Wenjian; Wang, Haiyan; Xu, Shiqing; Fang, Qing; Liu, Honglin; Yang, Wenying; Lou, Jinning

    2012-01-01

    Elevated extracellular free fatty acids (FFAs) can induce pancreatic beta cell apoptosis, thereby contributing to the pathogenesis of type 2 diabetes mellitus (T2D). Mitochondrial dysfunction has been implicated in FFA-induced beta cell apoptosis. However, molecular mechanisms linking mitochondrial dysfunction and FFA-induced beta cell apoptosis are not clear. Dynamin-related protein 1 (DRP-1) is a mitochondrial fission modulator. In this study, we investigated its role in FFA-induced INS-1 beta cell apoptosis. DRP-1 protein was promptly induced in INS-1 cells and rat islets after stimulation by FFAs, and this DRP-1 upregulation was accompanied by increased INS-1 cell apoptosis. Induction of DRP-1 expression significantly promoted FFA-induced apoptosis in DRP-1 WT (DRP-1 wild type) inducible INS-1-derived cell line, but not in DRP-1K38A (a dominant negative mutant of DRP-1) inducible INS-1-derived cell line. To validate these in vitro results, we transplanted DRP-1 WT or DRP-1 K38A cells into renal capsules of streptozotocin (STZ)-treated diabetic mice to study the apoptosis in xenografts. Consistent with the in vitro results, the over-expression of DRP-1 led to aggravated INS-1-derived cell apoptosis triggered by FFAs. In contrast, dominant-negative suppression of DRP-1 function as represented by DRP-1 K38A significantly prevented FFA-induced apoptosis in xenografts. It was further demonstrated that mitochondrial membrane potential decreased, while cytochrome c release, caspase-3 activation, and generation of reactive oxygen species (ROS) were enhanced by the induction of DRP-1WT, but prevented by DRP-1 K38A in INS-1-derived cells under FFA stimulation. These results indicated that DRP-1 mediates FFA-induced INS-1-derived cell apoptosis, suggesting that suppression of DRP-1 is a potentially useful therapeutic strategy for protecting against beta cell loss that leads to type 2 diabetes.

  5. Involvement of spinal monocyte chemoattractant protein-1 (MCP-1) in cancer-induced bone pain in rats.

    Science.gov (United States)

    Hu, Ji-Hua; Zheng, Xiao-Yan; Yang, Jian-Ping; Wang, Li-Na; Ji, Fu-Hai

    2012-05-23

    In this study, we examined the involvement of chemokine monocyte chemoattractant protein-1 (MCP-1) in the spinal cord of a rat model of cancer-induced bone pain (CIBP). In this model, CIBP was established by an intramedullary injection of Walker 256 cells into the tibia of rats. We observed a significant increase in expression levels of MCP-1 and its receptor CCR2 in the spinal cord of CIBP rats. Furthermore, the intrathecal administration of an anti-MCP-1 neutralizing antibody attenuated the mechanical allodynia established in CIBP rats. Likewise, an intrathecal injection of exogenous recombinant MCP-1 induced a striking mechanical allodynia in naïve rats. These results suggest that increases in spinal MCP-1 and CCR2 expression are involved in the development of mechanical allodynia associated with bone cancer rats.

  6. Interaction between Fibrinogen and Insulin-Like Growth Factor-Binding Protein-1 in Human Plasma under Physiological Conditions.

    Science.gov (United States)

    Gligorijević, N; Nedić, O

    2016-02-01

    Fibrinogen is a plasma glycoprotein and one of the principle participants in blood coagulation. It interacts with many proteins during formation of a blood clot, including insulin-like growth factors (IGFs) and their binding proteins (IGFBP). Fibrinogen complexes were found as minor fractions in fibrinogen preparations independently of the coagulation process, and their presence influences the kinetics of polymerization. The idea of this work was to investigate whether fibrinogen in human plasma interacts with IGFBPs independently of the tissue injury or coagulation process. The results have shown that fibrinogen forms complexes with IGFBP-1 under physiological conditions. Several experimental approaches have confirmed that complexes are co-isolated with fibrinogen from plasma, they are relatively stable, and they appear as a general feature of human plasma. Several other experiments excluded the possibility that alpha-2 macroglobulin/IGFBP-1 complexes or IGFBP-1 oligomers contributed to IGFBP-1 immunoreactivity. The role of fibrinogen/IGFBP-1 complexes is still unknown. Further investigation in individuals expressing both impaired glucose control and coagulopathy could contribute to identification and understanding of their possible physiological role.

  7. Toxoplasma gondii chromodomain protein 1 binds to heterochromatin and colocalises with centromeres and telomeres at the nuclear periphery.

    Directory of Open Access Journals (Sweden)

    Mathieu Gissot

    Full Text Available BACKGROUND: Apicomplexan parasites are responsible for some of the most deadly parasitic diseases afflicting humans, including malaria and toxoplasmosis. These obligate intracellular parasites exhibit a complex life cycle and a coordinated cell cycle-dependant expression program. Their cell division is a coordinated multistep process. How this complex mechanism is organised remains poorly understood. METHODS AND FINDINGS: In this study, we provide evidence for a link between heterochromatin, cell division and the compartmentalisation of the nucleus in Toxoplasma gondii. We characterised a T. gondii chromodomain containing protein (named TgChromo1 that specifically binds to heterochromatin. Using ChIP-on-chip on a genome-wide scale, we report TgChromo1 enrichment at the peri-centromeric chromatin. In addition, we demonstrate that TgChromo1 is cell-cycle regulated and co-localised with markers of the centrocone. Through the loci-specific FISH technique for T. gondii, we confirmed that TgChromo1 occupies the same nuclear localisation as the peri-centromeric sequences. CONCLUSION: We propose that TgChromo1 may play a role in the sequestration of chromosomes at the nuclear periphery and in the process of T. gondii cell division.

  8. PolyC-binding protein 1 interacts with 5'-untranslated region of enterovirus 71 RNA in membrane-associated complex to facilitate viral replication.

    Directory of Open Access Journals (Sweden)

    Zhen Luo

    Full Text Available Enterovirus 71 (EV71 is one causative agent of hand, foot, and mouth disease (HFMD, which may lead to severe neurological disorders and mortality in children. EV71 genome is a positive single-stranded RNA containing a single open reading frame (ORF flanked by 5'-untranslated region (5'UTR and 3'UTR. The 5'UTR is fundamentally important for virus replication by interacting with cellular proteins. Here, we revealed that poly(C-binding protein 1 (PCBP1 specifically binds to the 5'UTR of EV71. Detailed studies indicated that the RNA-binding K-homologous 1 (KH1 domain of PCBP1 is responsible for its binding to the stem-loop I and IV of EV71 5'UTR. Interestingly, we revealed that PCBP1 is distributed in the nucleus and cytoplasm of uninfected cells, but mainly localized in the cytoplasm of EV71-infected cells due to interaction and co-localization with the viral RNA. Furthermore, sub-cellular distribution analysis showed that PCBP1 is located in ER-derived membrane, in where virus replication occurred in the cytoplasm of EV71-infected cells, suggesting PCBP1 is recruited in a membrane-associated replication complex. In addition, we found that the binding of PCBP1 to 5'UTR resulted in enhancing EV71 viral protein expression and virus production so as to facilitate viral replication. Thus, we revealed a novel mechanism in which PCBP1 as a positive regulator involved in regulation of EV71 replication in the host specialized membrane-associated replication complex, which provides an insight into cellular factors involved in EV71 replication.

  9. Effects of Simvastatin on NF-κB-DNA Binding Activity and Monocyte Chemoattractant Protein-1 Expression in a Rabbit Model of Atherosclerosis

    Institute of Scientific and Technical Information of China (English)

    YANG Xiaoyun; WANG Lin; ZENG Hesong; DUBEY Laxman; ZHOU Ning; PU Jun

    2006-01-01

    To observe the effects of simvastatin on nuclear factor kappaB (NF-κB)-DNA binding activity and on the expression of monocyte chemoattractant protein-1 (MCP-1) in atherosclerotic plaque in rabbits and to explore the anti-atherosclerotic properties beyond its lipid-lowering effects.Thirty-six New Zealand male rabbits were randomly divided into low-cholesterol group (LC), highcholesterol group (HC), high-cholesterol+ simvastatin group (HC+S) and then were fed for 12weeks. At the end of theexperiment, standard enzymatic assays, electrophoretic mobility shift assay (EMSA), immunohistochemical staining, and morphometry were performed to observe serum lipids, NF-κB-DNA binding activity, MCP-1 protein expression, intima thickness and plaque area of aorta respectively in all three groups. Our results showed that the serum lipids, NF-κB-DNA binding activity, expression of MCP-1 protein, intima thickness, and plaque area of aorta in the LC and HC+S groups were significantly lower than those in the HC group (P<0.05). There was no significant difference in the serum lipids between the LC and HC+S groups (P>0.05), but the NF-κB-DNA binding activity, the expression of MCP-1 protein and the intima thickness and plaque area of aorta in the HC+S group were significantly decreased as compared to the LC group (P<0.05). This study demonstrated that simvastatin could decrease atherosclerosis by inhibiting the NFκB-DNA binding activity and by reducing the expression of MCP-1 protein.

  10. Molecular dynamics simulations of the auxin-binding protein 1 in complex with indole-3-acetic acid and naphthalen-1-acetic acid.

    Science.gov (United States)

    Grandits, Melanie; Oostenbrink, Chris

    2014-10-01

    Auxin-binding protein 1 (ABP1) is suggested to be an auxin receptor which plays an important role in several processes in green plants. Maize ABP1 was simulated with the natural auxin indole-3-acetic acid (IAA) and the synthetic analog naphthalen-1-acetic acid (NAA), to elucidate the role of the KDEL sequence and the helix at the C-terminus. The KDEL sequence weakens the intermolecular interactions between the monomers but stabilizes the C-terminal helix. Conformational changes at the C-terminus occur within the KDEL sequence and are influenced by the binding of the simulated ligands. This observation helps to explain experimental findings on ABP1 interactions with antibodies that are modulated by the presence of auxin, and supports the hypothesis that ABP1 acts as an auxin receptor. Stable hydrogen bonds between the monomers are formed between Glu40 and Glu62, Arg10 and Thr97, Lys39, and Glu62 in all simulations. The amino acids Ile22, Leu25, Trp44, Pro55, Ile130, and Phe149 are located in the binding pocket and are involved in hydrophobic interactions with the ring system of the ligand. Trp151 is stably involved in a face to end interaction with the ligand. The calculated free energy of binding using the linear interaction energy approach showed a higher binding affinity for NAA as compared to IAA. Our simulations confirm the asymmetric behavior of the two monomers, the stronger interaction of NAA than IAA and offers insight into the possible mechanism of ABP1 as an auxin receptor.

  11. Factor H and factor H-related protein 1 bind to human neutrophils via complement receptor 3, mediate attachment to Candida albicans, and enhance neutrophil antimicrobial activity.

    Science.gov (United States)

    Losse, Josephine; Zipfel, Peter F; Józsi, Mihály

    2010-01-15

    The host complement system plays an important role in protection against infections. Several human-pathogenic microbes were shown to acquire host complement regulators, such as factor H (CFH), that downregulate complement activation at the microbial surface and protect the pathogens from the opsonic and lytic effects of complement. Because CFH can also bind to host cells, we addressed the role of CFH and CFH-related proteins as adhesion ligands in host-pathogen interactions. We show that the CFH family proteins CFH, CFH-like protein 1 (CFHL1), CFH-related protein (CFHR) 1, and CFHR4 long isoform bind to human neutrophil granulocytes and to the opportunistic human-pathogenic yeast Candida albicans. Two major binding sites, one within the N-terminus and one in the C-terminus of CFH, were found to mediate binding to neutrophils. Complement receptor 3 (CD11b/CD18; alpha(M)beta2 integrin) was identified as the major cellular receptor on neutrophils for CFH, CFHL1, and CFHR1, but not for CFHR4 long isoform. CFH and CFHR1 supported cell migration. Furthermore, CFH, CFHL1, and CFHR1 increased attachment of neutrophils to C. albicans. Adhesion of neutrophils to plasma-opsonized yeasts was reduced when CFH binding was inhibited by specific Abs or when using CFH-depleted plasma. Yeast-bound CFH and CFHR1 enhanced the generation of reactive oxygen species and the release of the antimicrobial protein lactoferrin by human neutrophils, and resulted in a more efficient killing of the pathogen. Thus, CFH and CFHR1, when bound on the surface of C. albicans, enhance antimicrobial activity of human neutrophils.

  12. Effects of tibolone and its metabolites on prolactin and insulin-like growth factor binding protein-1 expression in human endometrial stromal cells.

    Science.gov (United States)

    Guzel, Elif; Buchwalder, Lynn; Basar, Murat; Kayisli, Umit; Ocak, Nehir; Bozkurt, Idil; Lockwood, Charles J; Schatz, Frederick

    2015-05-01

    The effects of the postmenopausal replacement steroid tibolone and its 3α-, 3β-OH and Δ-4 tibolone metabolites were evaluated on progesterone receptor-mediated classic decidualization markers insulin-like growth factor binding protein-1 (IGFBP-1) and prolactin expression in human endometrial stromal cells (HESCs). Supernatants of conditioned medium or erxtracted RNA from experimental cell incubations of confluent HESCs were subjected to ELISAs, Western blot analysis and RT/PCR, and results were statisically assesed. Over 21 days, specific ELISAs observed linear increases in secreted IGFBP-1 and prolactin levels elicited by tibolone and its metabolites. Cultured HESCs were refractory to E2 and dexamethasone, whereas tibolone and each metabolite exceeded medroxyprogesterone acetate in significantly elevating IGFBP-1 and prolactin output. Anti-progestins eliminated IGFBP-1 and prolactin induction by tibolone and its metabolites. Immunoblotting and RT/PCR confirmed ELISA results. These observations of IGFBP-1 and prolactin expression: (a) indicate the relevance of cultured HESCs in evaluating the chronic effects of tibolone administration to women; (b) are consistent with PR-mediated endometrial atrophy and protection against endometrial bleeding despite the persistence of circulating ER-binding, but not PR-binding metabolites following tibolone administration to women.

  13. Expression of insulin-like growth factor binding protein-1 and -2 genes through the perinatal period in the rat.

    Science.gov (United States)

    Babajko, S; Hardouin, S; Segovia, B; Groyer, A; Binoux, M

    1993-06-01

    Insulin-like growth factor binding proteins (IGFBPs) are essential mediators of the bioavailability and biological effects of the IGFs. Liver expression of the rat (r) IGFBP-1 and rIGFBP-2 genes has been characterized between day 16 in utero (16 diu) and 16 days postnatally (+16 dpn). Run-on experiments showed transcriptional activity of the rIGFBP-1 and rIGFBP-2 genes at birth (B) to be 25 and 5 times that at 16 diu, respectively. After B, transcriptional activity of the rIGFBP-1 gene remained high (140% B at +6 dpn), but that of the rIGFBP-2 gene dropped to 70% B by +6 dpn. Northern blot analysis done simultaneously showed rIGFBP-1 messenger RNA (mRNA) levels to increase approximately 50-fold between 16 diu and B, whereas rIGFBP-2 mRNA increased only 5- to 10-fold. rIGFBP-1 mRNA levels decreased after birth, reaching about 20% B by +6 dpn; rIGFBP-2 mRNA, however, remained stable (about 80% B) at least up to +6 dpn. Parallel Western ligand blot and immunoblot analyses of serum rIGFBPs revealed rIGFBP-1 and rIGFBP-2 concentrations to be increased 3- and 2-fold, respectively between 20 diu and B. Maximal expression of rIGFBP-1 was at +1 dpn (220% B), and of rIGFBP-2, at B. Both rIGFBPs then decreased, reaching about 5% B at adulthood. All these data indicate that increased transcriptional activity of the rIGFBP-1 and rIGFBP-2 genes at birth would determine the increased synthesis in the liver and circulating levels of these proteins. In addition, it would seem that post-transcriptional events (reduced half-life of the rIGFBP-1 messenger after birth, translation efficiency of the rIGFBP-2 messenger) modulate transcriptional regulation.

  14. Insulin-like growth factor binding protein-1 levels are increased in patients with IgA nephropathy

    Energy Technology Data Exchange (ETDEWEB)

    Tokunaga, Koki [Department of Digestive and Life-Style Related Disease, Health Research Course, Human and Environmental Sciences, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520 (Japan); Uto, Hirofumi, E-mail: hirouto@m2.kufm.kagoshima-u.ac.jp [Department of Digestive and Life-Style Related Disease, Health Research Course, Human and Environmental Sciences, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520 (Japan); Takami, Yoichiro; Mera, Kumiko; Nishida, Chika; Yoshimine, Yozo; Fukumoto, Mayumi; Oku, Manei; Sogabe, Atsushi; Nosaki, Tsuyoshi; Moriuchi, Akihiro; Oketani, Makoto; Ido, Akio; Tsubouchi, Hirohito [Department of Digestive and Life-Style Related Disease, Health Research Course, Human and Environmental Sciences, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520 (Japan)

    2010-08-20

    Research highlights: {yields} IGFBP-1 mRNA over express in kidneys obtained from mice model of IgA nephropathy. {yields} Serum IGFBP-1 levels are high in patients with IgA nephropathy. {yields} Serum IGFBP-1 levels correlate with renal function and the severity of renal injury. -- Abstract: The mechanisms underlying the pathogenesis of immunoglobulin A (IgA) nephropathy (IgAN) are not well understood. In this study, we examined gene expression profiles in kidneys obtained from mice with high serum IgA levels (HIGA mice), which exhibit features of human IgAN. Female inbred HIGA, established from the ddY line, were used in these experiments. Serum IgA levels, renal IgA deposition, mesangial proliferation, and glomerulosclerosis were increased in 32-week-old HIGA mice in comparison to ddY animals. By microarray analysis, five genes were observed to be increased by more than 2.5-fold in 32-week-old HIGA in comparison to 16-week-old HIGA; these same five genes were decreased more than 2.5-fold in 32-week-old ddY in comparison to 16-week-old ddY mice. Of these five genes, insulin-like growth factor (IGF) binding protein (IGFBP)-1 exhibited differential expression between these mouse lines, as confirmed by quantitative RT-PCR. In addition, serum IGFBP-1 levels were significantly higher in patients with IgAN than in healthy controls. In patients with IgAN, these levels correlated with measures of renal function, such as estimated glomerular filtration rate (eGFR), but not with sex, age, serum IgA, C3 levels, or IGF-1 levels. Pathologically, serum IGFBP-1 levels were significantly associated with the severity of renal injury, as assessed by mesangial cell proliferation and interstitial fibrosis. These results suggest that increased IGFBP-1 levels are associated with the severity of renal pathology in patients with IgAN.

  15. Changes in circulating level of IGF-I and IGF-binding protein-1 from the first to second trimester as predictors of preeclampsia

    DEFF Research Database (Denmark)

    Vatten, Lars J; Nilsen, Tom I L; Juul, Anders;

    2008-01-01

    OBJECTIVE: To assess whether circulating IGF-I and IGF-binding protein-1 (IGFBP-1) in the first and second trimester are associated with subsequent risk of preterm and term preeclampsia. METHODS: Nested case-control study within a cohort of 29 948 pregnant women. Cases were women, who later...... developed preeclampsia, and controls were randomly selected women, who did not develop preeclampsia. IGF-I and IGFBP-1 were measured with ELISA in maternal blood samples that were collected in the first and second trimesters. We assessed associations of IGF-I and IGFBP-1 concentrations with later...... development of preterm (before the 37th week of gestation) and term preeclampsia. RESULTS: An increase in IGF-I from the first to second trimester was associated with higher risk of preterm preeclampsia; the odds ratio (OR) for the highest compared with lowest quartile of increase was 4.9 (95% confidence...

  16. Transient ectopic overexpression of agouti-signalling protein 1 (asip1 induces pigment anomalies in flatfish.

    Directory of Open Access Journals (Sweden)

    Raúl Guillot

    Full Text Available While flatfish in the wild exhibit a pronounced countershading of the dorso-ventral pigment pattern, malpigmentation is commonly observed in reared animals. In fish, the dorso-ventral pigment polarity is achieved because a melanization inhibition factor (MIF inhibits melanoblast differentiation and encourages iridophore proliferation in the ventrum. A previous work of our group suggested that asip1 is the uncharacterized MIF concerned. In order to further support this hypothesis, we have characterized asip1 mRNAs in both turbot and sole and used deduced peptide alignments to analyze the evolutionary history of the agouti-family of peptides. The putative asip precursors have the characteristics of a secreted protein, displaying a putative hydrophobic signal. Processing of the potential signal peptide produces mature proteins that include an N-terminal region, a basic central domain with a high proportion of lysine residues as well as a proline-rich region that immediately precedes the C-terminal poly-cysteine domain. The expression of asip1 mRNA in the ventral area was significantly higher than in the dorsal region. Similarly, the expression of asip1 within the unpigmented patches in the dorsal skin of pseudoalbino fish was higher than in the pigmented dorsal regions but similar to those levels observed in the ventral skin. In addition, the injection/electroporation of asip1 capped mRNA in both species induced long term dorsal skin paling, suggesting the inhibition of the melanogenic pathways. The data suggest that fish asip1 is involved in the dorsal-ventral pigment patterning in adult fish, where it induces the regulatory asymmetry involved in precursor differentiation into mature chromatophore. Adult dorsal pseudoalbinism seems to be the consequence of the expression of normal developmental pathways in an inaccurate position that results in unbalanced asip1 production levels. This, in turn, generates a ventral-like differentiation environment

  17. IgG antibodies to endothelial protein C receptor-binding Cysteine-rich interdomain region domains of Plasmodium falciparum erythrocyte membrane protein 1 are acquired early in life in individuals exposed to malaria

    DEFF Research Database (Denmark)

    Turner, Louise; Lavstsen, Thomas; Mmbando, Bruno P

    2015-01-01

    Severe malaria syndromes are precipitated by Plasmodium falciparum parasites binding to endothelial receptors on the vascular lining. This binding is mediated by members of the highly variant P. falciparum erythrocyte membrane protein 1 (PfEMP1) family. We have previously identified a subset of Pf...

  18. GTP is an allosteric modulator of the interaction between the guanylate-binding protein 1 and the prosurvival kinase PIM1.

    Science.gov (United States)

    Persico, Marco; Petrella, Lella; Orteca, Nausicaa; Di Dato, Antonio; Mariani, Marisa; Andreoli, Mirko; De Donato, Marta; Scambia, Giovanni; Novellino, Ettore; Ferlini, Cristiano; Fattorusso, Caterina

    2015-02-16

    GBP1 and PIM1 are known to interact with a molar ratio 1:1. GBP1:PIM1 binding initiates a signaling pathway that induces resistance to common chemotherapeutics such as paclitaxel. Since GBP1 is a large GTPase which undergoes conformational changes in a nucleotide-dependent manner, we investigated the effect of GTP/GDP binding on GBP1:PIM1 interaction by using computational and biological studies. It resulted that only GTP decreases the formation of the GBP1:PIM1 complex through an allosteric mechanism, putting the bases for the identification of new compounds potentially able to revert resistance to paclitaxel.

  19. Increased activator protein 1 activity as well as resistance to heat-induced radiosensitization, hydrogen peroxide, and cisplatin are inhibited by indomethacin in oxidative stress-resistant cells.

    Science.gov (United States)

    Bradbury, C M; Locke, J E; Wei, S J; Rene, L M; Karimpour, S; Hunt, C; Spitz, D R; Gius, D

    2001-04-15

    It has been established that tumor cells develop resistance to a variety of therapeutic agents after multiple exposures to these agents/drugs. Many of these therapeutic agents also appear to increase the activity of transcription factors, such as activator protein 1 (AP-1), believed to be involved in cellular responses to oxidative stress. Therefore, we hypothesized that cellular resistance to cancer therapeutic agents may involve the increased activity of transcription factors that govern resistance to oxidative stress, such as AP-1. To investigate this hypothesis, a previously characterized cisplatin, hyperthermia, and oxidative stress-resistant Chinese hamster fibroblast cell line, OC-14, was compared to the parental HA-1 cell line. Electrophoretic mobility shift and Western blot assays performed on extracts isolated from OC-14 cells demonstrated a 10-fold increase in constitutive AP-1 DNA-binding activity as well as increased constitutive c-Fos and c-Jun immunoreactive protein relative to HA-1 cells. Treatment of OC-14 cells with indomethacin inhibited constitutive increases in AP-1 DNA-binding activity and c-Fos/c-Jun-immunoreactive protein levels. Clonogenic survival assays demonstrated that pretreatment with indomethacin, at concentrations that inhibited AP-1 activity, significantly reduced the resistance of OC-14 cells to heat-induced radiosensitization, hydrogen peroxide, and cisplatin. These results demonstrate a relationship between increases in AP-1 DNA-binding activity and increased cellular resistance to cancer therapeutic agents and oxidative stress that is inhibited by indomethacin. These results support the hypothesis that inhibition of AP-1 activity with nonsteroidal anti-inflammatory drugs, such as indomethacin, may represent a useful adjuvant to cancer therapy.

  20. Polypyrimidine tract binding protein-1 (PTB1) is a determinant of the tissue and host tropism of a human rhinovirus/poliovirus chimera PV1(RIPO).

    Science.gov (United States)

    Jahan, Nusrat; Wimmer, Eckard; Mueller, Steffen

    2013-01-01

    The internal ribosomal entry site (IRES) of picornavirus genomes serves as the nucleation site of a highly structured ribonucleoprotein complex essential to the binding of the 40S ribosomal subunit and initiation of viral protein translation. The transition from naked RNA to a functional "IRESome" complex are poorly understood, involving the folding of secondary and tertiary RNA structure, facilitated by a tightly concerted binding of various host cell proteins that are commonly referred to as IRES trans-acting factors (ITAFs). Here we have investigated the influence of one ITAF, the polypyrimidine tract-binding protein 1 (PTB1), on the tropism of PV1(RIPO), a chimeric poliovirus in which translation of the poliovirus polyprotein is under the control of a human rhinovirus type 2 (HRV2) IRES element. We show that PV1(RIPO)'s growth defect in restrictive mouse cells is partly due to the inability of its IRES to interact with endogenous murine PTB. Over-expression of human PTB1 stimulated the HRV2 IRES-mediated translation, resulting in increased growth of PV1(RIPO) in murine cells and human neuronal SK-N-MC cells. Mutations within the PV1(RIPO) IRES, selected to grow in restrictive mouse cells, eliminated the human PTB1 supplementation requirement, by restoring the ability of the IRES to interact with endogenous murine PTB. In combination with our previous findings these results give a compelling insight into the thermodynamic behavior of IRES structures. We have uncovered three distinct thermodynamic aspects of IRES formation which may independently contribute to overcome the observed PV1(RIPO) IRES block by lowering the free energy δG of the IRESome formation, and stabilizing the correct and functional structure: 1) lowering the growth temperature, 2) modifying the complement of ITAFs in restricted cells, or 3) selection of adaptive mutations. All three mechanisms can conceivably modulate the thermodynamics of RNA folding, and thus facilitate and stabilize the

  1. Polypyrimidine tract binding protein-1 (PTB1 is a determinant of the tissue and host tropism of a human rhinovirus/poliovirus chimera PV1(RIPO.

    Directory of Open Access Journals (Sweden)

    Nusrat Jahan

    Full Text Available The internal ribosomal entry site (IRES of picornavirus genomes serves as the nucleation site of a highly structured ribonucleoprotein complex essential to the binding of the 40S ribosomal subunit and initiation of viral protein translation. The transition from naked RNA to a functional "IRESome" complex are poorly understood, involving the folding of secondary and tertiary RNA structure, facilitated by a tightly concerted binding of various host cell proteins that are commonly referred to as IRES trans-acting factors (ITAFs. Here we have investigated the influence of one ITAF, the polypyrimidine tract-binding protein 1 (PTB1, on the tropism of PV1(RIPO, a chimeric poliovirus in which translation of the poliovirus polyprotein is under the control of a human rhinovirus type 2 (HRV2 IRES element. We show that PV1(RIPO's growth defect in restrictive mouse cells is partly due to the inability of its IRES to interact with endogenous murine PTB. Over-expression of human PTB1 stimulated the HRV2 IRES-mediated translation, resulting in increased growth of PV1(RIPO in murine cells and human neuronal SK-N-MC cells. Mutations within the PV1(RIPO IRES, selected to grow in restrictive mouse cells, eliminated the human PTB1 supplementation requirement, by restoring the ability of the IRES to interact with endogenous murine PTB. In combination with our previous findings these results give a compelling insight into the thermodynamic behavior of IRES structures. We have uncovered three distinct thermodynamic aspects of IRES formation which may independently contribute to overcome the observed PV1(RIPO IRES block by lowering the free energy δG of the IRESome formation, and stabilizing the correct and functional structure: 1 lowering the growth temperature, 2 modifying the complement of ITAFs in restricted cells, or 3 selection of adaptive mutations. All three mechanisms can conceivably modulate the thermodynamics of RNA folding, and thus facilitate and stabilize

  2. Minimally modified low density lipoprotein induces monocyte chemotactic protein 1 in human endothelial cells and smooth muscle cells

    Energy Technology Data Exchange (ETDEWEB)

    Cushing, S.D.; Berliner, J.A.; Valente, A.J.; Territo, M.C.; Navab, M.; Parhami, F.; Gerrity, R.; Schwartz, C.J.; Fogelman, A.M.

    1990-07-01

    After exposure to low density lipoprotein (LDL) that had been minimally modified by oxidation (MM-LDL), human endothelial cells (EC) and smooth muscle cells (SMC) cultured separately or together produced 2- to 3-fold more monocyte chemotactic activity than did control cells or cells exposed to freshly isolated LDL. This increase in monocyte chemotactic activity was paralleled by increases in mRNA levels for a monocyte chemotactic protein 1 (MCP-1) that is constitutively produced by the human glioma U-105MG cell line. Antibody that had been prepared against cultured baboon smooth muscle cell chemotactic factor (anti-SMCF) did not inhibit monocyte migration induced by the potent bacterial chemotactic factor f-Met-Leu-Phe. However, anti-SMCF completely inhibited the monocyte chemotactic activity found in the media of U-105MG cells, EC, and SMC before and after exposure to MM-LDL. Moreover, monocyte migration into the subendothelial space of a coculture of EC and SMC that had been exposed to MM-LDL was completely inhibited by anti-SMCF. Anti-SMCF specifically immunoprecipitated 10-kDa and 12.5-kDa proteins from EC. Incorporation of (35S)methionine into the immunoprecipitated proteins paralleled the monocyte chemotactic activity found in the medium of MM-LDL stimulated EC and the levels of MCP-1 mRNA found in the EC. We conclude that SMCF is in fact MCP-1 and MCP-1 is induced by MM-LDL.

  3. Telomerase Cajal body protein 1 depletion inhibits telomerase trafficking to telomeres and induces G1 cell cycle arrest in A549 cells.

    Science.gov (United States)

    Yuan, Ping; Wang, Zhitian; Lv, Wang; Pan, Hui; Yang, Yunhai; Yuan, Xiaoshuai; Hu, Jian

    2014-09-01

    Telomerase Cajal body protein 1 (TCAB1) is a telomerase holoenzyme, which is markedly enriched in Cajal bodies (CBs) and facilitates the recruitment of telomerase to CBs in the S phase of the cell cycle. This recruitment is dependent on TCAB1 binding to a telomerase RNA component. The majority of cancer cells are able to grow indefinitely due to telomerase and its mechanism of trafficking to telomeres. In the present study, a certain level of TCAB1 expression in A549 human lung cells was identified and TCAB1 knockdown exhibited a potent antiproliferative effect on these cells, which was coupled with a decrease in the cell density and activity of the cellular enzymes. In addition, TCAB1-depletion was demonstrated to inhibit telomerase trafficking to telomeres in the A549 cells, leading to subsequent G1 cell cycle arrest without inducing apoptotic cell death. Overall, these observations indicated that TCAB1 may be essential for A549 cell proliferation and cell cycle regulation, and may be a potential candidate for the development of a therapeutic target for lung adenocarcinomas.

  4. Hepatitis C virus nonstructural protein-5A activates sterol regulatory element-binding protein-1c through transcription factor Sp1

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, Zhonghua; Qiao, Ling; Zhou, Yan [Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5E3 (Canada); Babiuk, Lorne A. [University of Alberta, Edmonton, Alberta (Canada); Liu, Qiang, E-mail: qiang.liu@usask.ca [Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5E3 (Canada)

    2010-11-19

    Research highlights: {yields} A chimeric subgenomic HCV replicon expresses HCV-3a NS5A in an HCV-1b backbone. {yields} HCV-3a NS5A increases mature SREBP-1c protein level. {yields} HCV-3a NS5A activates SREBP-1c transcription. {yields} Domain II of HCV-3a NS5A is more effective in SREBP-1c promoter activation. {yields} Transcription factor Sp1 is required for SREBP-1c activation by HCV-3a NS5A. -- Abstract: Steatosis is an important clinical manifestation of hepatitis C virus (HCV) infection. The molecular mechanisms of HCV-associated steatosis are not well understood. Sterol regulatory element-binding protein-1c (SREBP-1c) is a key transcription factor which activates the transcription of lipogenic genes. Here we showed that the nuclear, mature SREBP-1c level increases in the nucleus of replicon cells expressing HCV-3a nonstructural protein-5A (NS5A). We further showed that HCV-3a NS5A up-regulates SREBP-1c transcription. Additional analysis showed that transcriptional factor Sp1 is involved in SREBP-1c activation by HCV-3a NS5A because inhibition of Sp1 activity by mithramycin A or a dominant-negative Sp1 construct abrogated SREBP-1c promoter activation by HCV-3a NS5A. In addition, chromatin immunoprecipitation (ChIP) assay demonstrated enhanced binding of Sp1 on the SREBP-1c promoter in HCV-3a NS5A replicon cells. These results showed that HCV-3a NS5A activates SREBP-1c transcription through Sp1. Taken together, our results suggest that HCV-3a NS5A is a contributing factor for steatosis caused by HCV-3a infection.

  5. An analysis of the calcium-binding protein 1 of Fasciola gigantica with a comparison to its homologs in the phylum Platyhelminthes.

    Science.gov (United States)

    Vichasri-Grams, Suksiri; Subpipattana, Pornpimol; Sobhon, Prasert; Viyanant, Vithoon; Grams, Rudi

    2006-03-01

    A full-length cDNA encoding the Fasciola gigantica calcium-binding protein 1 (FgCaBP1) was cloned from an adult stage cDNA expression library in an immunoscreen using rabbit immune serum against the parasite's excretion/secretion antigens. The deduced amino acid sequence showed 96.3% identity to Fh22CBP of Fasciola hepatica. During development in the mammalian host FgCaBP1 RNA was detected in metacercariae, juveniles and adults and was exclusively localized to the tegumental cell bodies. Immune serum of a rabbit infected with F. gigantica detected recombinant FgCaBP1 starting from the sixth week of infection. Immune sera of mice infected with Schistosoma mansoni and Schistosoma mekongi cross-reacted with recombinant FgCaBP1 in immunoblots. Recombinant FgCaBP1 showed calcium and magnesium-binding activity by a mobility shift during non-denaturing PAGE in the presence of Ca2+ or Mg2+, respectively. A polyclonal mouse anti-rFgCaBP1 antiserum detected the native protein as a major component of the parasite's tegumental antigens in immunoblots and as a strictly tegumental antigen in tissue cross-sections of adult and juvenile parasites. Comparative sequence analysis of homologs from Fasciola and Schistosoma present in the GenBank database revealed sequence signatures specific to these trematode proteins and thereby indicates their origin from a single ancestor. FgCaBP1 contains two adjacent, N-terminal located EF-hands and a C-terminal located domain similar to dynein light chain type 1. Independent structure predictions of the two domains suggest that they will fold according to the already determined structures of the EF-hand motif and the dynein light chain type 1 proteins.

  6. GLYCINE-RICH RNA-BINDING PROTEIN1 interacts with RECEPTOR-LIKE CYTOPLASMIC PROTEIN KINASE1 and suppresses cell death and defense responses in pepper (Capsicum annuum).

    Science.gov (United States)

    Kim, Dae Sung; Kim, Nak Hyun; Hwang, Byung Kook

    2015-01-01

    Plants use a variety of innate immune regulators to trigger cell death and defense responses against pathogen attack. We identified pepper (Capsicum annuum) GLYCINE-RICH RNA-BINDING PROTEIN1 (CaGRP1) as a RECEPTOR-LIKE CYTOPLASMIC PROTEIN KINASE1 (CaPIK1)-interacting partner, based on bimolecular fluorescence complementation and coimmunoprecipitation analyses as well as gene silencing and transient expression analysis. CaGRP1 contains an N-terminal RNA recognition motif and a glycine-rich region at the C-terminus. The CaGRP1 protein had DNA- and RNA-binding activity in vitro. CaGRP1 interacted with CaPIK1 in planta. CaGRP1 and CaGRP1-CaPIK1 complexes were localized to the nucleus in plant cells. CaPIK1 phosphorylated CaGRP1 in vitro and in planta. Transient coexpression of CaGRP1 with CaPIK1 suppressed the CaPIK1-triggered cell death response, accompanied by a reduced CaPIK1-triggered reactive oxygen species (ROS) burst. The RNA recognition motif region of CaGRP1 was responsible for the nuclear localization of CaGRP1 as well as the suppression of the CaPIK1-triggered cell death response. CaGRP1 silencing in pepper conferred enhanced resistance to Xanthomonas campestris pv vesicatoria (Xcv) infection; however, CaPIK1-silenced plants were more susceptible to Xcv. CaGRP1 interacts with CaPIK1 and negatively regulates CaPIK1-triggered cell death and defense responses by suppressing ROS accumulation.

  7. Urinary monocyte chemoattractant protein-1 and vitamin D-binding protein as biomarkers for early detection of diabetic nephropathy in type 2 diabetes mellitus.

    Science.gov (United States)

    Shoukry, Amira; Bdeer, Shereen El-Arabi; El-Sokkary, Rehab H

    2015-10-01

    Diabetic nephropathy is a serious complication of both type 1 and type 2 diabetes and, unless arrested, leads to end-stage renal disease. Therefore, early prediction and detection of DN would greatly benefit the disease management and delay its progression. The aim of this study is to evaluate the levels of urinary monocyte chemoattractant protein-1 (uMCP-1) and urinary vitamin D-binding protein (uVDBP) in type 2 diabetic patients with different degrees of diabetic nephropathy (DN) and to assess the value of uMCP-1 and uVDBP in the early detection of DN. Seventy-five type 2 diabetic patients with normoalbuminuria (n = 25), microalbuminuria (n = 25), macroalbuminuria (n = 25), and 25 healthy controls were included in this study. Urinary MCP-1 and VDBP levels were evaluated by enzyme-linked immunosorbent assay. A significant elevation in the uMCP-1 and uVDBP levels was found in macroalbuminuric (p diabetic patients compared to that in normoalbuminuric diabetic patients and control subjects (p diagnosis and detection of DN revealed that the cut-off value of uMCP-1 was 110 pg/mg with 92% sensitivity and 100% specificity; whereas, the cut-off value of uVDBP was 550 ng/mg with 96% sensitivity and 84% specificity. The findings of the present study suggest that uMCP-1 and uVDBP may be considered as novel potential diagnostic biomarkers for the early detection of diabetic nephropathy.

  8. Peroxiredoxins, thioredoxin, and Y-box-binding protein-1 are involved in the pathogenesis and progression of dialysis-associated renal cell carcinoma.

    Science.gov (United States)

    Fushimi, Fumiyoshi; Taguchi, Kenichi; Izumi, Hiroto; Kohno, Kimitoshi; Kuwano, Michihiko; Ono, Mayumi; Nakashima, Yutaka; Takesue, Tetsuro; Naito, Seiji; Oda, Yoshinao

    2013-10-01

    Patients with end-stage renal disease are exposed to increased oxidative stress and impairment of antioxidant mechanisms. We focused on dialysis renal cell carcinoma (RCC), including epithelial hyperplasia in acquired cystic disease of the kidney (ACDK). We attempted to obtain insight into the carcinogenesis and tumor progression in terms of cellular defense mechanisms associated with oxidative stress by investigating the expression of antioxidant proteins by immunohistochemistry. We evaluated retrospectively 43 cases of dialysis RCC and, as a control group, 49 cases of sporadic RCC. Peroxiredoxin (Prx) 1, 3, 4, 5, and 6 expression in dialysis RCC was positively correlated with the duration of dialysis. In epithelial hyperplasia, in 17 cases of acquired cystic disease of the kidney, Prxs and thioredoxin were highly expressed. Moreover, in dialysis RCC, Prx 3, 4, and 5 immunoreactivity and nuclear expression of Y-box-binding protein-1 were higher than in sporadic RCC. In dialysis RCC, Prx 3, 4, and 5 immunoreactivity positively correlated with the Fuhrman nuclear grade. These data suggest that oxidative stress during dialysis enhances antioxidant activity, with an inhibiting effect on carcinogenesis. Once cancer has developed, antioxidant activity might have a stimulating effect on the progression of dialysis RCC.

  9. Possible novel roles of poly(rC)-binding protein 1 in SH-SY5Y neurocytes: an analysis using a dynamic Bayesian network

    Institute of Scientific and Technical Information of China (English)

    Li-Rong Huo; Jian-Tao Liang; Jun-Hua Zou; Lan-Ying Wang; Qi Li; Xiao-MinWang

    2012-01-01

    [Objective] Poly(rC)-binding protein 1 (PCBP1) belongs to the heterogeneous nuclear ribonucleoprotein family and participates in transcriptional and translational regulation.Previous work has identified transcripts targeted by both knockdown and overexpression of PCBP1 in SH-SY5Y neuroblastoma cells using a microarray or ProteomeLabTM protein fractionation 2-dimensions (PF-2D) and quadrupole time-of-flight mass spectrometer.The present study aimed to further determine whether these altered transcripts from major pathways (such as Wnt signaling,TGF-β signaling,cell cycling,and apoptosis) and two other genes,H2AFX and H2BFS (screened by PF-2D),have spatial relationships.[Methods] The genes were studied by qRT-PCR,and dynamic Bayesian network analysis was used to rebuild the coordination network of these transcripts.[Results] PCBP1 controlled the expression or activity of the seven transcripts.Moreover,PCBP1 indirectly regulated MAP2K2,FOS,FST,TP53 and WNT7B through H2AFX or regulated these genes through SAT.In contrast,TP53 and WNT7B are regulated by other genes.[Conclusion]The seven transcripts and PCBP1 are closely associated in a spatial interaction network.

  10. Polymorphism - 116C/G of the human X box binding protein 1 gene is associated with risk of type 2 diabetes in a Chinese Han population.

    Science.gov (United States)

    Liu, Shengyuan; Ma, Guoda; Yao, Songpo; Chen, Zhongwei; Wang, Changyi; Zhao, Bin; Li, Keshen

    2016-01-01

    Evidence has been obtained showing that endoplasmic reticulum (ER) stress is closely associated with the development of type 2 diabetes (T2D) and that the human X box binding protein 1 (XBP1) is an important transcription factor involved in the development of ER stress. The study aimed to analyze the potential association between polymorphism -116C/G of XBP1 and the risk of T2D. The association between XBP1 polymorphism -116C/G and T2D risk was assessed among 1058 consecutive unrelated subjects, including 523 T2D patients and 535 healthy controls, in a case control study. The -116GG genotype and -116G allele were more frequent in T2D subjects compared with control subjects by statistical analysis, showing that the -116GG homozygote polymorphism of XBP1 might lead to increased susceptibility to T2D in a Chinese Han population. T2D subjects with the -116GG genotype had higher fasting plasma glucose levels, fasting insulin levels, and HbA1c and worse HOMA-IR than the T2D subjects with -116CG and -116CC genotypes (PG polymorphism of the XBP1 promoter in the pathogenesis of T2D in a Chinese Han population, and more studies are needed to further evaluate our results.

  11. Detection of placental alpha microglobulin-1 versus insulin-like growth factor-binding protein-1 in amniotic fluid at term: a comparative study.

    Science.gov (United States)

    Pollet-Villard, Marie; Cartier, Régine; Gaucherand, Pascal; Doret, Muriel

    2011-06-01

    We compared two biochemical tests of premature rupture of membranes (PROM) in vitro: Actim PROM (Medix Biochemica, Kauniainen, Finland), which detects insulin-like growth factor binding protein-1, and AmniSure (AmniSure International LLC, Cambridge, MA), which detects placental alpha microglobulin-1. Samples of amniotic fluid were collected during caesarean section in 41 patients. A dilution series was prepared and both tests were performed twice at each dilution. Sensitivity, detection limit, response time, and reproducibility of both tests were compared. Both tests' sensitivity was 100% at dilution 1:10 and 1:20. AmniSure sensitivity was higher at dilution 1:40 and 1:80 ( P AmniSure had a lower detection limit than Actim PROM. AmniSure response times were shorter and reproducibility was higher than Actim PROM ( P AmniSure had a lower detection limit of amniotic fluid than Actim PROM, with a shorter response time, a higher sensitivity, and a better reproducibility.

  12. Non-Structural protein 1 (NS1) gene of Canine Parvovirus-2 regresses chemically induced skin tumors in Wistar rats.

    Science.gov (United States)

    Santra, Lakshman; Rajmani, R S; Kumar, G V P P S Ravi; Saxena, Shikha; Dhara, Sujoy K; Kumar, Amit; Sahoo, Aditya Prasad; Singh, Lakshya Veer; Desai, G S; Chaturvedi, Uttara; Kumar, Sudesh; Tiwari, Ashok K

    2014-10-01

    The Non-Structural protein 1 of Canine Parvovirus-2 (CPV2.NS1) plays a major role in viral cytotoxicity and pathogenicity. CPV2.NS1 has been proven to cause apoptosis in HeLa cells in vitro in our laboratory. Here we report that CPV2.NS1 has no toxic side effects on healthy cells but regresses skin tumors in Wistar rats. Histopathological examination of tumor tissue from CPV2.NS1 treated group revealed infiltration of mononuclear and polymorphonuclear cells with increased extra cellular matrix, indicating signs of regression. Tumor regression was also evidenced by significant decrease in mitotic index, AgNOR count and PCNA index, and increase in TUNEL positive apoptotic cells in CPV2.NS1 treated group. Further, CPV2.NS1 induced anti-tumor immune response through significant increase in CD8(+) and NK cell population in CPV2.NS1 treated group. These findings suggest that CPV2.NS1 can be a possible therapeutic candidate as an alternative to chemotherapy for the treatment of cancer.

  13. Silencing of Y-box binding protein-1 by RNA interference inhibits proliferation, invasion, and metastasis, and enhances sensitivity to cisplatin through NF-κB signaling pathway in human neuroblastoma SH-SY5Y cells.

    Science.gov (United States)

    Wang, Hong; Sun, Ruowen; Chi, Zuofei; Li, Shuang; Hao, Liangchun

    2017-04-05

    Y-box binding protein-1 (YB-1), a member of Y-box protein family binding DNA and RNA, has been proposed as a novel marker in multiple malignant tumors and found to be associated with tumor malignancy. Neuroblastoma is an embryonal tumor arising from neuroblast cells of the autonomic nervous system, which is the most common cancer diagnosed in infants. It has been reported that YB-1 is highly expressing in various human tumors including nasopharynx, thyroid, lung, breast, colon, ovary, and prostate cancers. This study aimed to investigate the functional role of YB-1 in neuroblastoma by silencing YB-1 using RNA interference (shRNA) in neuroblastoma SH-SY5Y cells. We found that silencing of YB-1 decreased the proliferation, migration, and invasion of SH-SY5Y cells. At molecular level, inhibition of YB-1 decreased the expression level of PCNA as well as MMP-2 in neuroblastoma SH-SY5Y cells. Also, we discovered that YB-1 silencing sensitized SH-SY5Y cells to cisplatin and promoted the apoptosis induced by cisplatin due to down-regulation of multidrug resistance (MDR) 1 protein via NF-κB signaling pathway. Therefore, we consider that targeting YB-1 is promising for neuroblastoma treatment and for overcoming its cisplatin resistance in the development of new neuroblastoma therapeutic strategies.

  14. Nucleosome Assembly Protein 1-Like 1 (Nap1l1 Regulates the Proliferation of Murine Induced Pluripotent Stem Cells

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    Yuan Yan

    2016-01-01

    Full Text Available Background/Aims: To investigate whether nucleosome assembly protein 1-like 1 (Nap1l1 regulates the proliferation of induced pluripotent stem cells (iPSC and the potential mechanisms. Methods: Nap1l1-knockdown-iPSC and Nap1l1-overexpression-iPSC were constructed by transfection of lentiviral particles. The proliferation of iPSC was detected by MTT analysis, and cell cycle was analyzed by flow cytometry. Results: Nap1l1 overexpression promoted iPSC proliferation and induced G2/M transition compared to their control iPSC while Nap1l1-knockdown-iPSC dramatically displayed the reduced proliferation and accumulated G2/M phase cells. Further analysis showed that Nap1l1 overexpression in iPSC increased the expression of cyclin B1, downregulated the expression of p21 and p27, while knockdown of Nap1l1 showed the opposite effects. In addition, overexpression of Nap1l1 promoted the phosphorylation of AKT and ERK in iPSC, while knockdown of Nap1l1 inhibited the effects. However, these effects displayed in Nap1l1-overexpression-iPSC were greatly suppressed by the inhibition of AKT or ERK signaling. Conclusions: The results indicate that Nap1l1 promotes the proliferation of iPSC attributable to G2/M transition caused by downregulation of p27 and p21, and upregulation of cyclin B1, the activation of AKT or ERK is involved in the process. The present study has revealed a novel molecular mechanism involved in the proliferation of iPSC.

  15. Dengue Virus Nonstructural Protein 1-Induced Antibodies Cross-React with Human Plasminogen and Enhance Its Activation.

    Science.gov (United States)

    Chuang, Yung-Chun; Lin, Jessica; Lin, Yee-Shin; Wang, Shuying; Yeh, Trai-Ming

    2016-02-01

    Dengue virus (DENV) infection is the most common mosquito-borne viral disease, and it can cause life-threatening dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Abnormal activation of the coagulation and fibrinolysis system is one of the hallmarks of DHF/DSS. However, the mechanism underlying hemorrhage in DHF/DSS remains elusive. In previous studies, plasminogen (Plg) cross-reactive Abs, which can recognize DENV nonstructural protein (NS) 1, have been found in dengue patients. However, it is unclear whether these Abs are indeed induced by DENV NS1. Thus, we immunized mice with recombinant NS1 from both bacteria and drosophila to determine whether NS1 can induce Plg cross-reactive Abs. The results from the NS1-immunized mouse sera indicated that NS1 immunization induced Abs that could cross-react with Plg. To study the effects of these NS1-induced Plg cross-reactive Abs on fibrinolysis, we isolated several Plg cross-reactive anti-NS1 mAbs from these mice and found that some of them could enhance Plg activation. In addition, epitope mapping with a phage-displayed random peptide library revealed that one of these mAbs (2A5) could recognize NS1 C-terminal residues 305-311, which share sequence homology with Plg residues 590-597. A synthetic peptide of NS1 residues 305-311 could inhibit the binding of both 2A5 and its Fab to Plg and its enhanced activation. Thus, our results suggest that DENV NS1 can induce Plg cross-reactive Abs through molecular mimicry, which can enhance Plg activation and may contribute to the pathogenesis of DHF/DSS.

  16. Tumor Necrosis Factor-alpha Induced Protein 3 Interacting Protein 1 Gene Polymorphisms and Pustular Psoriasis in Chinese Han Population

    Institute of Scientific and Technical Information of China (English)

    Jian-Wen Han; Yong Wang; Chulu Alateng; Hong-Bin Li; Yun-Hua Bai; Xin-Xiang Lyu; Rina Wu

    2016-01-01

    Background:Psoriasis is a common immune-mediated inflammatory dermatosis.Generalized pustular psoriasis (GPP) is the severe and rare type of psoriasis.The association between tumor necrosis factor-alpha induced protein 3 interacting protein 1 (TNIP1) gene and psoriasis was confirmed in people with multiple ethnicities.This study was to investigate the association between TNIP1 gene polymorphisms and pustular psoriasis in Chinese Han population.Methods:Seventy-three patients with GPP,67 patients with palmoplantar pustulosis (PPP),and 476 healthy controls were collected from Chinese Han population.Six single nucleotide polymorphisms (SNPs) of the TNIP1 gene,namely rs3805435,rs3792798,rs3792797,rs869976,rs17728338,and rs999011 were genotyped by using polymerase chain reaction-ligase detection reaction.Statistical analyses were performed using the PLINK 1.07 package.Allele frequencies and genotyping frequencies for six SNPs were compared by using Chi-square test,odd ratio (OR) (including 95% confidence interval) were calculated.The haplotype analysis was conducted by Haploview software.Results:The frequencies of alleles of five SNPs were significantly different between the GPP group and the control group (P≤ 7.22 × 10-3),especially in the GPP patients without psoriasis vulgaris (PsV).In the haplotype analysis,the most significantly different haplotype was H4:ACGAAC,with 13.1% frequency in the GPP group but only 3.4% in the control group (OR =4.16,P =4.459 × 10-7).However,no significant difference in the allele frequencies was found between the PPP group and control group for each of the six SNPs (P > 0.05).Conclusions:Polymorphisms in TNIP1 are associated with GPP in Chinese Han population.However,no association with PPP was found.These findings suggest that TNIP1 might be a susceptibility gene for GPP.

  17. Prognostic value of coexistence of abnormal expression of micro-RNA-200b and cyclic adenosine monophosphate-responsive element-binding protein 1 in human astrocytoma.

    Science.gov (United States)

    Zhang, Jun-qing; Yao, Qing-he; Kuang, Yong-qin; Ma, Yuan; Yang, Li-bin; Huang, Hai-dong; Cheng, Jing-ming; Yang, Tao; Liu, En-yu; Liang, Liang; Fan, Ke-xia; Zhao, Kai; Xia, Xun; Gu, Jian-wen

    2014-10-01

    Our aim was to investigate the expression of micro-RNA-200b (miR-200b) and cAMP-responsive element-binding protein 1 (CREB-1) in astrocytoma and its efficacy for predicting outcome. Both miR-200b and CREB-1 messenger RNA expression was measured in 122 astrocytomas and 30 nonneoplastic brain specimens by quantitative real-time polymerase chain reaction. Expression of miR-200b was significantly lower in astrocytoma than in nonneoplastic brain (P RNA expression was significantly elevated in the tumors (P < .001). Both miR-200b down-regulation and CREB-1 up-regulation were significantly associated with advanced pathologic grade (P = .002 and P = .006, respectively). Low miR-200b expression correlated negatively with Karnofsky performance score (P = .03), and high CREB-1 expression correlated positively with mean tumor diameter (P = .03). By Kaplan-Meier analysis, low miR-200b, high CREB-1, and coexistence of abnormal miR-200b and CREB-1 expression (low miR-200b/high CREB-1) were predictive of shorter progression-free survival and overall survival in both grade III and grade IV astrocytoma. By multivariate analysis, only low miR-200b/high CREB-1 expression was an independent prognostic factor for poor prognosis in astrocytoma of advanced grade. Both miR-200b and CREB-1 may play important cooperative roles in the progression of human astrocytoma. The efficacy of miR-200b and CREB-1 together as a predictor of prognosis in astrocytoma patients is shown for the first time.

  18. Association of mutations in the zona pellucida binding protein 1 (ZPBP1) gene with abnormal sperm head morphology in infertile men

    Science.gov (United States)

    Yatsenko, Alexander N.; O'Neil, Derek S.; Roy, Angshumoy; Arias-Mendoza, Paola A.; Chen, Ruihong; Murthy, Lata J.; Lamb, Dolores J.; Matzuk, Martin M.

    2012-01-01

    Nearly 7% of men are afflicted by male infertility worldwide, and genetic factors are suspected to play a significant role in the majority of these patients. Although sperm morphology is an important parameter measured in the semen analysis, only a few genetic causes of teratozoospermia are currently known. The objective of this study was to define the association between alterations in the genes encoding the Golgi-associated PDZ- and coiled-coil motif containing protein (GOPC), the protein interacting with C kinase 1 (PICK1) and the acrosomal protein zona pellucida binding protein 1 (ZPBP1/sp38) with abnormal sperm head morphology in infertile men. Previous reports demonstrated that mice lacking Gopc, Pick1 and Zpbp1 are infertile due to abnormal head morphology. Herein, using our validated RNA-based method, we studied spermatozoal cDNA encoding the human GOPC, PICK1 and ZPBP1 genes in 381 teratozoospermic and 240 controls patients via direct sequencing. Among these genes, we identified missense and splicing mutations in the sperm cDNA encoding ZPBP1 in 3.9% (15/381) of men with abnormal sperm head morphology. These mutations were not observed in 240 matched controls and the dbSNP database (χ2 = 9.3, P = 0.002). In contrast, statistically significant and functionally relevant mutations were not discovered in the GOPC and PICK1 genes. In our study ZPBP1 mutations are associated with abnormal sperm head morphology, defined according to strict criteria, resembling the mouse Zpbp1 null phenotype. We hypothesize that missense mutations exert a dominant-negative effect due to altered ZPBP1 protein folding and protein:protein interactions in the acrosome. PMID:21911476

  19. Differential RNA expression between schizophrenic patients and controls of the dystrobrevin binding protein 1 and neuregulin 1 genes in immortalized lymphocytes.

    Science.gov (United States)

    Chagnon, Y C; Roy, M-A; Bureau, A; Mérette, C; Maziade, M

    2008-03-01

    The dystrobrevin binding protein 1 (DTNBP1) and neuregulin 1 (NRG1) genes have been related to schizophrenia (SZ) and bipolar disorder (BP) by several whole-genome linkage and associations studies. Few expression studies in post-mortem brains have also reported a lower or a higher expression of DTNBP1 and NRG1, respectively, in SZ. Since the difficulty to access post-mortem brains, we evaluated RNA expression of DTNBP1 and NRG1 in immortalized lymphocytes of SZ patients and unrelated-family controls. An antipsychotic stimulation was also used to challenge the genetic background of the subjects and enhance differential expression. Immortalized lymphocytes of twelve SZ and twelve controls were grown individually in the presence or not of the antipsychotic olanzapine (Zyprexa; EliLilly). RNA was extracted and pooled in four groups of three SZ and four groups of three controls, and used to probe Agilent 18K microchips. Mean gene expression values were contrasted between SZ and control groups using a T-test. For DTNBP1, RNA expression was lower in SZ than in controls before (-28%; p=0.02) and after (-30%; p=0.01) olanzapine stimulation. Similarly, NRG1 GGF2 isoform showed a lower expression in SZ before (-29%; p=0.04) and after (-33%; p=0.02) olanzapine stimulation. In contrast, NRG1 GGF isoform showed no significant difference between SZ and controls (-7%; p=0.61, +3%; p=0.86, respectively), but was slightly repressed by olanzapine in controls (-8%; p=0.008) but not in SZ (+1%; p=0.91). These results are in agreement with those observed in post-mortem brain when the isoforms involved are considered.

  20. Reduced selenium-binding protein 1 in breast cancer correlates with poor survival and resistance to the anti-proliferative effects of selenium.

    Science.gov (United States)

    Zhang, Sheng; Li, Feng; Younes, Mamoun; Liu, Hao; Chen, Changyi; Yao, Qizhi

    2013-01-01

    Supplemental dietary selenium is associated with reduced incidence of many cancers. The antitumor function of selenium is thought to be mediated through selenium-binding protein 1 (SELENBP1). However, the significance of SELENBP1 expression in breast cancer is still largely unknown. A total of 95 normal and tumor tissues assay and 12 breast cancer cell lines were used in this study. We found that SELENBP1 expression in breast cancer tissues is reduced compared to normal control. Low SELENBP1 expression in ER(+) breast cancer patients was significantly associated with poor survival (pcancer. 17-β estradiol (E2) treatment of high SELENBP1-expressing ER(+) cell lines led to a down-regulation of SELENBP1, a result that did not occur in ER(-) cell lines. However, after ectopic expression of ER in an originally ER(-) cell line, down-regulation of SELENBP1 upon E2 treatment was observed. In addition, selenium treatment resulted in reduced cell proliferation in endogenous SELENBP1 high cells; however, after knocking-down SELENBP1, we observed no significant reduction in cell proliferation. Similarly, selenium has no effect on inhibition of cell proliferation in low endogenous SELENBP1 cells, but the inhibitory effect is regained following ectopic SELENBP1 expression. Furthermore, E2 treatment of an ER silenced high endogenous SELENBP1 expressing cell line showed no abolishment of cell proliferation inhibition upon selenium treatment. These data indicate that SELENBP1 expression is regulated via estrogen and that the cell proliferation inhibition effect of selenium treatment is dependent on the high level of SELENBP1 expression. Therefore, the expression level of SELENBP1 could be an important marker for predicting survival and effectiveness of selenium supplementation in breast cancer. This is the first study to reveal the importance of monitoring SELENBP1 expression as a potential biomarker in contributing to breast cancer prevention and treatment.

  1. Reduced selenium-binding protein 1 in breast cancer correlates with poor survival and resistance to the anti-proliferative effects of selenium.

    Directory of Open Access Journals (Sweden)

    Sheng Zhang

    Full Text Available Supplemental dietary selenium is associated with reduced incidence of many cancers. The antitumor function of selenium is thought to be mediated through selenium-binding protein 1 (SELENBP1. However, the significance of SELENBP1 expression in breast cancer is still largely unknown. A total of 95 normal and tumor tissues assay and 12 breast cancer cell lines were used in this study. We found that SELENBP1 expression in breast cancer tissues is reduced compared to normal control. Low SELENBP1 expression in ER(+ breast cancer patients was significantly associated with poor survival (p<0.01, and SELENBP1 levels progressively decreased with advancing clinical stages of breast cancer. 17-β estradiol (E2 treatment of high SELENBP1-expressing ER(+ cell lines led to a down-regulation of SELENBP1, a result that did not occur in ER(- cell lines. However, after ectopic expression of ER in an originally ER(- cell line, down-regulation of SELENBP1 upon E2 treatment was observed. In addition, selenium treatment resulted in reduced cell proliferation in endogenous SELENBP1 high cells; however, after knocking-down SELENBP1, we observed no significant reduction in cell proliferation. Similarly, selenium has no effect on inhibition of cell proliferation in low endogenous SELENBP1 cells, but the inhibitory effect is regained following ectopic SELENBP1 expression. Furthermore, E2 treatment of an ER silenced high endogenous SELENBP1 expressing cell line showed no abolishment of cell proliferation inhibition upon selenium treatment. These data indicate that SELENBP1 expression is regulated via estrogen and that the cell proliferation inhibition effect of selenium treatment is dependent on the high level of SELENBP1 expression. Therefore, the expression level of SELENBP1 could be an important marker for predicting survival and effectiveness of selenium supplementation in breast cancer. This is the first study to reveal the importance of monitoring SELENBP1 expression

  2. Notch2 controls prolactin and insulin-like growth factor binding protein-1 expression in decidualizing human stromal cells of early pregnancy.

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    Gerlinde R Otti

    Full Text Available Decidualization, the transformation of the human uterine mucosa into the endometrium of pregnancy, is critical for successful implantation and embryonic development. However, key regulatory factors controlling differentiation of uterine stromal cells into hormone-secreting decidual cells have not been fully elucidated. Hence, we herein investigated the role of the Notch signaling pathway in human decidual stromal cells (HDSC isolated from early pregnancy samples. Immunofluorescence of first trimester decidual tissues revealed expression of Notch2 receptor and its putative, membrane-anchored interaction partners Jagged1, Delta-like (DLL 1 and DLL4 in stromal cells whereas other Notch receptors and ligands were absent from these cells. During in vitro differentiation with estrogen/progesterone (E2P4 and/or cyclic adenosine monophosphate (cAMP HDSC constitutively expressed Notch2 and weakly downregulated Jagged1 mRNA and protein, measured by quantitative PCR (qPCR and Western blotting, respectively. However, increased levels of DLL1 and DLL4 were observed in the decidualizing cultures. Transfection of a Notch luciferase reporter and qPCR of the Notch target gene hairy and enhancer of split 1 (HES1 revealed an induction of canonical Notch activity during in vitro differentiation. In contrast, treatment of HDSC with a chemical Notch/γ-secretase inhibitor decreased cAMP/E2P4-stimulated Notch luciferase activity, HES1 transcript levels and mRNA expression of the decidual marker genes prolactin (PRL and insulin-like growth factor binding protein 1 (IGFBP1. Similarly, siRNA-mediated gene silencing or antibody-mediated blocking of Notch2 diminished HES1, PRL and IGFBP1 mRNA levels as well as secreted PRL protein. In summary, the data suggest that canonical, Notch2-dependent signaling plays a role in human decidualization.

  3. Molecular cloning and preliminary function study of iron responsive element binding protein 1 gene from cypermethrin-resistant Culex pipiens pallens

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    Tan Wenbin

    2011-11-01

    Full Text Available Abstract Background Insecticide resistance jeopardizes the control of mosquito populations and mosquito-borne disease control, which creates a major public health concern. Two-dimensional electrophoresis identified one protein segment with high sequence homology to part of Aedes aegypti iron-responsive element binding protein (IRE-BP. Method RT-PCR and RACE (rapid amplification of cDNA end were used to clone a cDNA encoding full length IRE-BP 1. Real-time quantitative RT-PCR was used to evaluate the transcriptional level changes in the Cr-IRE strain Aedes aegypti compared to the susceptible strain of Cx. pipiens pallens. The expression profile of the gene was established in the mosquito life cycle. Methyl tritiated thymidine (3H-TdR was used to observe the cypermethrin resistance changes in C6/36 cells containing the stably transfected IRE-BP 1 gene of Cx. pipiens pallens. Results The complete sequence of iron responsive element binding protein 1 (IRE-BP 1 has been cloned from the cypermethrin-resistant strain of Culex pipiens pallens (Cr-IRE strain. Quantitative RT-PCR analysis indicated that the IRE-BP 1 transcription level was 6.7 times higher in the Cr-IRE strain than in the susceptible strain of 4th instar larvae. The IRE-BP 1 expression was also found to be consistently higher throughout the life cycle of the Cr-IRE strain. A protein of predicted size 109.4 kDa has been detected by Western blotting in IRE-BP 1-transfected mosquito C6/36 cells. These IRE-BP 1-transfected cells also showed enhanced cypermethrin resistance compared to null-transfected or plasmid vector-transfected cells as determined by 3H-TdR incorporation. Conclusion IRE-BP 1 is expressed at higher levels in the Cr-IRE strain, and may confer some insecticide resistance in Cx. pipiens pallens.

  4. Synthesis, {sup 68}Ga labeling and preliminary evaluation of DOTA peptide binding vascular adhesion protein-1: a potential PET imaging agent for diagnosing osteomyelitis

    Energy Technology Data Exchange (ETDEWEB)

    Ujula, Tiina [Turku PET Center, Turku University Hospital, Turku (Finland); Salomaeki, Satu [Turku PET Center, Turku University Hospital, Turku (Finland); Department of Chemistry, University of Turku, Turku (Finland); Virsu, Pauliina [Turku PET Center, Turku University Hospital, Turku (Finland); Lankinen, Petteri; Maekinen, Tatu J. [Orthopedic Research Unit, University of Turku, Turku (Finland); Autio, Anu [Turku PET Center, Turku University Hospital, Turku (Finland); Yegutkin, Gennady G. [MediCity Research Laboratory, University of Turku, Turku (Finland); Knuuti, Juhani [Turku PET Center, Turku University Hospital, Turku (Finland); Jalkanen, Sirpa [MediCity Research Laboratory, University of Turku, Turku (Finland); National Public Health Institute, Turku (Finland); Roivainen, Anne [Turku PET Center, Turku University Hospital, Turku (Finland); Turku Center for Disease Modeling, University of Turku, Turku (Finland)], E-mail: anne.roivainen@utu.fi

    2009-08-15

    Introduction: Vascular adhesion protein-1 (VAP-1) is an infection/inflammation-inducible endothelial glycoprotein. Based on our previous studies, the most VAP-1-selective peptide (VAP-P1) was 1,4,7,10-tetraazacyclododecane-N',N'',N''',N,,,,-tetraacetic acid (DOTA)-conjugated, {sup 68}gallium ({sup 68}Ga)-labeled (named [{sup 68}Ga]DOTAVAP-P1) and evaluated preliminarily. Methods: Targeting was evaluated by using VAP-1-transfected cells. Biodistribution of [{sup 68}Ga]DOTAVAP-P1 was studied by positron emission tomography imaging of healthy rats and rats with bone inflammation caused by Staphylococcus aureus infection. Uptake of [{sup 68}Ga]DOTAVAP-P1 in osteomyelitis was compared with negative control peptide and competition with an excess of unlabeled DOTAVAP-P1. Results: [{sup 68}Ga]DOTAVAP-P1 bound more efficiently to VAP-1-transfected cells than to controls. In rats, [{sup 68}Ga]DOTAVAP-P1 cleared rapidly from blood circulation, excreted quickly in urine and showed an in vivo half-life of 26{+-}2.3 min. Imaging of osteomyelitis demonstrated modest target-to-background ratio. Studies with the negative control peptide and competitors revealed a significantly lower uptake at the infection site compared to [{sup 68}Ga]DOTAVAP-P1. Conclusions: The results represent a proof-of-concept that infection-induced VAP-1 can be targeted by [{sup 68}Ga]DOTA peptide. [{sup 68}Ga]DOTAVAP-P1 is just the first candidate peptide and an essential opening for developing VAP-1-specific imaging agents.

  5. Rice Hypersensitive Induced Reaction Protein 1 (OsHIR1 associates with plasma membrane and triggers hypersensitive cell death

    Directory of Open Access Journals (Sweden)

    Sun Sai-Ming

    2010-12-01

    Full Text Available Abstract Background In plants, HIR (Hypersensitive Induced Reaction proteins, members of the PID (Proliferation, Ion and Death superfamily, have been shown to play a part in the development of spontaneous hypersensitive response lesions in leaves, in reaction to pathogen attacks. The levels of HIR proteins were shown to correlate with localized host cell deaths and defense responses in maize and barley. However, not much was known about the HIR proteins in rice. Since rice is an important cereal crop consumed by more than 50% of the populations in Asia and Africa, it is crucial to understand the mechanisms of disease responses in this plant. We previously identified the rice HIR1 (OsHIR1 as an interacting partner of the OsLRR1 (rice Leucine-Rich Repeat protein 1. Here we show that OsHIR1 triggers hypersensitive cell death and its localization to the plasma membrane is enhanced by OsLRR1. Result Through electron microscopy studies using wild type rice plants, OsHIR1 was found to mainly localize to the plasma membrane, with a minor portion localized to the tonoplast. Moreover, the plasma membrane localization of OsHIR1 was enhanced in transgenic rice plants overexpressing its interacting protein partner, OsLRR1. Co-localization of OsHIR1 and OsLRR1 to the plasma membrane was confirmed by double-labeling electron microscopy. Pathogen inoculation studies using transgenic Arabidopsis thaliana expressing either OsHIR1 or OsLRR1 showed that both transgenic lines exhibited increased resistance toward the bacterial pathogen Pseudomonas syringae pv. tomato DC3000. However, OsHIR1 transgenic plants produced more extensive spontaneous hypersensitive response lesions and contained lower titers of the invading pathogen, when compared to OsLRR1 transgenic plants. Conclusion The OsHIR1 protein is mainly localized to the plasma membrane, and its subcellular localization in that compartment is enhanced by OsLRR1. The expression of OsHIR1 may sensitize the plant

  6. Cervical length and phosphorilated insulin like growth factor binding protein-1 as the predictors of spontaneus preterm delivery in symptomatic women

    Directory of Open Access Journals (Sweden)

    Hadži-Lega Marija

    2014-07-01

    Full Text Available Objective: To assess the combined use of cervical length and cervical phosphorylated insulin-like growth factor binding protein-1 (phIGFBP-1 in the prediction of preterm delivery in symptomatic women in next 14 days. Methods: Cervical length was prospectively measured in 58 consecutive singleton pregnancies with intact membranes and regular contractions at 24-36 weeks, and phIGFBP-1 was assessed. Demographic data was evaluated(history of previous preterm delivery, history of spontaneous abortion, parity, BMI, maternal age, Orthodox or Muslims. Results: Values of all variables were evaluated (demographic data, cervical length and values ofphIGFBP-1 alone and in combination with cervical length of ≤ 15 mm and more than 15 mm. In women with cervical length less than 15 mm/ /phIGFPB-1 was positive in 30 patients(22 of them delivered in 14 days. In women with cervical length less than 15 mm/phIGFBP-1was positive in 9 of delivered pregnant women in 14 days. In women with cervical length less than 25 mm/phIGFBP-1was positive in 26 patients (2 of them delivered in 14 days. In patients with cervical length more than 25 mm/ph IGFBP-1 was positive in 4 patients (2 of them delivered in 14 days. With logistic regression we confirmed that with OR 0.117 and CI 95% (0.046-0.295 and p < 0.01 odds for preterm birth among patients with negative phIGFBP-1 is 0.117 lower than the odds for preterm birth among patients with positive test results. With same test for p = 0.009 (p < 0.01 we confirmed with OR and CI 95% (0.06 to 0.671 that cervical length less than 25 mm is good predictor of preterm delivery with symptomatic patients. Probability for delivery in the following 14 days with patients with positive phIGFBP-1 and cervical length ≤ 15 mm is 0.88 or probability for not delivering in those patients is 0.12. In 88% patients with positive phIGFBP-1 and cervical length ≤ 15 mm will deliver in the following 14 days. Conclusions: In symptomatic women phIGFBP-1

  7. Low p53 Binding Protein 1 (53BP1) Expression Is Associated With Increased Local Recurrence in Breast Cancer Patients Treated With Breast-Conserving Surgery and Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Neboori, Hanmanth J.R. [Department of Radiation Oncology, Cancer Institute of New Jersey and University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Brunswick, NJ (United States); Haffty, Bruce G., E-mail: hafftybg@umdnj.edu [Department of Radiation Oncology, The Cancer Institute of New Jersey and University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Brunswick, NJ (United States); Wu Hao [Department of Radiation Oncology, Cancer Institute of New Jersey and University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Brunswick, NJ (United States); Yang Qifeng [Department of Breast Surgery, Qilu Hospital, Shandong University, Ji' nan (China); Aly, Amal [Division of Medical Oncology, The Cancer Institute of New Jersey and University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Brunswick, NJ (United States); Goyal, Sharad; Schiff, Devora [Department of Radiation Oncology, Cancer Institute of New Jersey and University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Brunswick, NJ (United States); Moran, Meena S. [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT (United States); Golhar, Ryan [Department of Radiation Oncology, Cancer Institute of New Jersey and University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Brunswick, NJ (United States); Chen Chunxia; Moore, Dirk [Department of Biostatistics, The Cancer Institute of New Jersey and University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Brunswick, NJ (United States); and others

    2012-08-01

    Purpose: To investigate whether the expression of p53 binding protein 1 (53BP1) has prognostic significance in a cohort of early-stage breast cancer patients treated with breast-conserving surgery and radiotherapy (BCS+RT). Methods and Materials: A tissue microarray of early-stage breast cancer treated with BCS+RT from a cohort of 514 women was assayed for 53BP1, estrogen receptor, progesterone receptor, and HER2 expression by immunohistochemistry. Through log-rank tests and univariate and multivariate models, the staining profile of each tumor was correlated with clinical endpoints, including ipsilateral breast recurrence-free survival (IBRFS), distant metastasis-free survival (DMFS), cause-specific survival (CSS), recurrence-free survival (RFS), and overall survival (OS). Results: Of the 477 (93%) evaluable tumors, 63 (13%) were scored as low. Low expression of 53BP1 was associated with worse outcomes for all endpoints studied, including 10-year IBRFS (76.8% vs. 90.5%; P=.01), OS (66.4% vs. 81.7%; P=.02), CSS (66.0% vs. 87.4%; P<.01), DMFS (55.9% vs. 87.0%; P<.01), and RFS (45.2% vs. 80.6%; P<.01). Multivariate analysis incorporating various clinico-pathologic markers and 53BP1 expression found that 53BP1 expression was again an independent predictor of all endpoints (IBRFS: P=.0254; OS: P=.0094; CSS: P=.0033; DMFS: P=.0006; RFS: P=.0002). Low 53BP1 expression was also found to correlate with triple-negative (TN) phenotype (P<.01). Furthermore, in subset analysis of all TN breast cancer, negative 53BP1 expression trended for lower IBRFS (72.3% vs. 93.9%; P=.0361) and was significant for worse DMFS (48.2% vs. 86.8%; P=.0035) and RFS (37.8% vs. 83.7%; P=.0014). Conclusion: Our data indicate that low 53BP1 expression is an independent prognostic indicator for local relapse among other endpoints in early-stage breast cancer and TN breast cancer patients treated with BCS+RT. These results should be verified in larger cohorts of patients to validate their clinical

  8. Fatty Acid Binding Protein-1 (FABP1) and the Human FABP1 T94A Variant: Roles in the Endocannabinoid System and Dyslipidemias.

    Science.gov (United States)

    Schroeder, Friedhelm; McIntosh, Avery L; Martin, Gregory G; Huang, Huan; Landrock, Danilo; Chung, Sarah; Landrock, Kerstin K; Dangott, Lawrence J; Li, Shengrong; Kaczocha, Martin; Murphy, Eric J; Atshaves, Barbara P; Kier, Ann B

    2016-06-01

    The first discovered member of the mammalian FABP family, liver fatty acid binding protein (FABP1, L-FABP), occurs at high cytosolic concentration in liver, intestine, and in the case of humans also in kidney. While the rat FABP1 is well studied, the extent these findings translate to human FABP1 is not clear-especially in view of recent studies showing that endocannabinoids and cannabinoids represent novel rat FABP1 ligands and FABP1 gene ablation impacts the hepatic endocannabinoid system, known to be involved in non-alcoholic fatty liver (NAFLD) development. Although not detectable in brain, FABP1 ablation nevertheless also impacts brain endocannabinoids. Despite overall tertiary structure similarity, human FABP1 differs significantly from rat FABP1 in secondary structure, much larger ligand binding cavity, and affinities/specificities for some ligands. Moreover, while both mouse and human FABP1 mediate ligand induction of peroxisome proliferator activated receptor-α (PPARα), they differ markedly in pattern of genes induced. This is critically important because a highly prevalent human single nucleotide polymorphism (SNP) (26-38 % minor allele frequency and 8.3 ± 1.9 % homozygous) results in a FABP1 T94A substitution that further accentuates these species differences. The human FABP1 T94A variant is associated with altered body mass index (BMI), clinical dyslipidemias (elevated plasma triglycerides and LDL cholesterol), atherothrombotic cerebral infarction, and non-alcoholic fatty liver disease (NAFLD). Resolving human FABP1 and the T94A variant's impact on the endocannabinoid and cannabinoid system is an exciting challenge due to the importance of this system in hepatic lipid accumulation as well as behavior, pain, inflammation, and satiety.

  9. Minimally modified low density lipoprotein induces monocyte chemotactic protein 1 in human endothelial cells and smooth muscle cells.

    OpenAIRE

    Cushing, S D; Berliner, J A; Valente, A. J.; Territo, M C; Navab, M; Parhami, F; Gerrity, R; Schwartz, C J; Fogelman, A M

    1990-01-01

    After exposure to low density lipoprotein (LDL) that had been minimally modified by oxidation (MM-LDL), human endothelial cells (EC) and smooth muscle cells (SMC) cultured separately or together produced 2- to 3-fold more monocyte chemotactic activity than did control cells or cells exposed to freshly isolated LDL. This increase in monocyte chemotactic activity was paralleled by increases in mRNA levels for a monocyte chemotactic protein 1 (MCP-1) that is constitutively produced by the human ...

  10. Crystal Structure and Functional Characterization of the Complement Regulator Mannose-binding Lectin (MBL)/Ficolin-associated Protein-1 (MAP-1)

    DEFF Research Database (Denmark)

    Skjoedt, M.-o.; Roversi, P.; Hummelshoj, T.;

    2012-01-01

    The human lectin complement pathway activation molecules comprise MBL, ficolin-1, -2 and -3, in complex with associated serine proteases MASP-1, -2 and -3, and the non-enzymatic sMAP. Recently, a novel plasma protein named MBL/ficolin associated protein-1 (MAP-1) was identified in humans. This pr......The human lectin complement pathway activation molecules comprise MBL, ficolin-1, -2 and -3, in complex with associated serine proteases MASP-1, -2 and -3, and the non-enzymatic sMAP. Recently, a novel plasma protein named MBL/ficolin associated protein-1 (MAP-1) was identified in humans...

  11. Prokaryotic Expression and Protein Purification of the Auxin Binding Protein 1 in Arabidopsis%拟南芥生长素结合蛋白ABP1的原核表达及蛋白纯化

    Institute of Scientific and Technical Information of China (English)

    刘智; 黄志刚; 吴尚虹; 彭琼; 于峰

    2012-01-01

    Objective: Auxin-binding protein can bind an auxins specifically, and can be used to study the mechanism of the signal transduction of auxin and bio-sensors. Methods: An auxin-binding protein gene (Auxin bing protein 1, ABP1) was obtained by RT-PCR from arabidopsis, and was cloned into the prokaryotic expression vector pGEX4T-l (pGEX4T-l-ABPl). Identified by digestion, PCR and DNA sequencing, the recombinant plasmid was transformed into the foreign bacteria BL21(DE3). The ABP1 protein was induced by IPTG and detected by SDS-PAGE. Results: The soluble fusion protein was expressed successfully with a molecular weight of 43 kDa. The protein was purified with GST affinity column. Conclusion: The prokaryotic expression and purity of GST-ABP1 protein show a way to development new auxin biosensor and also laid a foundation for the further study of auxin signal transduction and biosensor research.%目的:鉴于生长素结合蛋白(Auxin Binding Protein,ABP)能与生长素特异性结合,因而探讨研究其直接用于生长素信号转导机理和生物传感器的可能性与可行性.方法:通过RT-PCR获得拟南芥生长素结合蛋白1(Auxin bing protein 1,ABP1)的全长CDS,将其克隆到原核表达载体pGEX4T-1中,成功构建pGEX4T-1-ABP1重组表达载体.经酶切、PCR及DNA测序鉴定后,将阳性质粒转化表达受体菌BL21(DE3).加入异丙基-β-D-硫代半乳糖苷(IPTG)进行诱导后,取样进行SDS-PAGE分析.结果:成功表达出一个分子量约为43 kD的可溶性融合蛋白,并利用GST亲和柱纯化方式得到了ABP1.结论:通过原核表达并经GST柱纯化后获得ABP1,为生长素生物传感器的研制开辟新的途径.同时为进一步研究ABP1与生长素的信号转导机制和生长素在生物传感测定技术中的研究和应用奠定基础.

  12. Vascular endothelial growth factor induces multidrug resistance-associated protein 1 overexpression through phosphatidylinositol-3-kinase/protein kinase B signaling pathway and transcription factor specificity protein 1 in BGC823 cell line

    Institute of Scientific and Technical Information of China (English)

    Juan Li; Xiaojun Wu; Jinling Gong; Jing Yang; Jiayan Leng; Qiaoyun Chen; Wenlin Xu

    2013-01-01

    Multidrug resistance (MDR) is one of the most important causes of chemotherapy failure and carcinoma recurrence.But the roles of the MDR-associated protein MRP1 in MDR remain poorly understood.Vascular endothelial growth factor (VEGF),one of the most active and specific vascular growth factors,plays a significant role in proliferation,differentiation,and metastasis of cancers.To explore the effect of VEGF on the expression of MRP1,we used recombinant human VEGF to stimulate K562 and BGC-823 cell lines.Quantitative real-time polymerase chain reaction and western blot analysis showed that the expression of MRP1 at both mRNA and protein levels was increased.3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide results also showed that VEGF significantly enhanced the ICs0 of the cells treated with adriamycin.To explore the underlying regulatory mechanisms,we constructed MRP1 promoter and the luciferase reporter gene recombinant vector.The luciferase reporter gene assay showed that the activity of the MRP1 promoter was markedly increased by VEGF stimulation,while LY294002,an inhibitor of the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) signaling pathway,reduced this effect.Transcription factor specificity protein 1 (SP1) binding site mutation partially blocked the up-regulation of MRP1 promoter activity by VEGF.In summary,our results demonstrated that VEGF enhanced the expression of MRP1,and the PI3K/Akt signaling pathway and SP1 may be involved in this modulation.

  13. Functional interaction of hepatic nuclear factor-4 and peroxisome proliferator-activated receptor-gamma coactivator 1alpha in CYP7A1 regulation is inhibited by a key lipogenic activator, sterol regulatory element-binding protein-1c.

    Science.gov (United States)

    Ponugoti, Bhaskar; Fang, Sungsoon; Kemper, Jongsook Kim

    2007-11-01

    Insulin inhibits transcription of cholesterol 7alpha-hydroxylase (Cyp7a1), a key gene in bile acid synthesis, and the hepatic nuclear factor-4 (HNF-4) site in the promoter was identified as a negative insulin response sequence. Using a fasting/feeding protocol in mice and insulin treatment in HepG2 cells, we explored the inhibition mechanisms. Expression of sterol regulatory element-binding protein-1c (SREBP-1c), an insulin-induced lipogenic factor, inversely correlated with Cyp7a1 expression in mouse liver. Interaction of HNF-4 with its coactivator, peroxisome proliferator-activated receptor-gamma coactivator 1alpha (PGC-1alpha), was observed in livers of fasted mice and was reduced after feeding. Conversely, HNF-4 interaction with SREBP-1c was increased after feeding. In vitro studies suggested that SREBP-1c competed with PGC-1alpha for direct interaction with the AF2 domain of HNF-4. Reporter assays showed that SREBP-1c, but not of a SREBP-1c mutant lacking the HNF-4 interacting domain, inhibited HNF-4/PGC-1alpha transactivation of Cyp7a1. SREBP-1c also inhibited PGC-1alpha-coactivation of estrogen receptor, constitutive androstane receptor, pregnane X receptor, and farnesoid X receptor, implying inhibition of HNF-4 by SREBP-1c could extend to other nuclear receptors. In chromatin immunoprecipitation studies, HNF-4 binding to the promoter was not altered, but PGC-1alpha was dissociated, SREBP-1c and histone deacetylase-2 (HDAC2) were recruited, and acetylation of histone H3 was decreased upon feeding. Adenovirus-mediated expression of a SREBP-1c dominant-negative mutant, which blocks the interaction of SREBP-1c and HNF-4, partially but significantly reversed the inhibition of Cyp7a1 after feeding. Our data show that SREBP-1c functions as a non-DNA-binding inhibitor and mediates, in part, suppression of Cyp7a1 by blocking functional interaction of HNF-4 and PGC-1alpha. This mechanism may be relevant to known repression of many other HNF-4 target genes upon

  14. Roles of PTEN-induced putative kinase 1 and dynamin-related protein 1 in transient global ischemia-induced hippocampal neuronal injury

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shang-Der, E-mail: chensd@adm.cgmh.org.tw [Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taiwan (China); Center for Translational Research in Biomedical Sciences, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taiwan (China); Lin, Tsu-Kung [Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taiwan (China); Yang, Ding-I. [Institute of Brain Science and Brain Research Center, National Yang-Ming University, Taipei, Taiwan (China); Lee, Su-Ying [Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taiwan (China); Shaw, Fu-Zen [Department of Psychology, National Cheng Kung University, Tainan, Taiwan (China); Liou, Chia-Wei [Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taiwan (China); Chuang, Yao-Chung, E-mail: ycchuang@adm.cgmh.org.tw [Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taiwan (China); Center for Translational Research in Biomedical Sciences, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taiwan (China)

    2015-05-01

    Recent studies showed that increased mitochondrial fission is an early event of cell death during cerebral ischemia and dynamin-related protein 1 (Drp1) plays an important role in mitochondrial fission, which may be regulated by PTEN-induced putative kinase 1 (PINK1), a mitochondrial serine/threonine-protein kinase thought to protect cells from stress-induced mitochondrial dysfunction and regulate mitochondrial fission. However, the roles of PINK1 and Drp1 in hippocampal injury caused by transient global ischemia (TGI) remain unknown. We therefore tested the hypothesis that TGI may induce PINK1 causing downregulation of Drp1 phosphorylation to enhance hippocampal neuronal survival, thus functioning as an endogenous neuroprotective mechanism. We found progressively increased PINK1 expression in the hippocampal CA1 subfield1-48 h following TGI, reaching the maximal level at 4 h. Despite lack of changes in the expression level of total Drp1 and phosphor-Drp1 at Ser637, TGI induced a time-dependent increase of Drp1 phosphorlation at Ser616 that peaked after 24 h. Notably, PINK1-siRNA increased p-Drp1(Ser616) protein level in hippocampal CA1 subfield 24 h after TGI. The PINK1 siRNA also aggravated the TGI-induced oxidative DNA damage with an increased 8-hydroxy-deoxyguanosine (8-OHdG) content in hippocampal CA1 subfield. Furthermore, PINK1 siRNA also augmented TGI-induced apoptosis as evidenced by the increased numbers of TUNEL-positive staining and enhanced DNA fragmentation. These findings indicated that PINK1 is an endogenous protective mediator vital for neuronal survival under ischemic insult through regulating Drp1 phosphorylation at Ser616. - Highlights: • Transient global ischemia increases expression of PINK1 and p-Drp1 at Ser616 in hippocampal CA1 subfield. • PINK1-siRNA decreases PINK1 expression but increases p-Drp1 at Ser616 in hippocampal CA1 subfield. • PINK1-siRNA augments oxidative stress and neuronal damage in hippocampal CA1 subfield.

  15. Sterol Regulatory Element-Binding Protein-1c Regulates Inflammasome Activation in Gingival Fibroblasts Infected with High-Glucose-Treated Porphyromonas gingivalis

    Science.gov (United States)

    Kuo, Hsing-Chun; Chang, Li-Ching; Chen, Te-Chuan; Lee, Ko-Chao; Lee, Kam-Fai; Chen, Cheng-Nan; Yu, Hong-Ren

    2016-01-01

    Background: Porphyromonas gingivalis is a major bacterial species implicated in the progression of periodontal disease, which is recognized as a common complication of diabetes. The interleukin (IL)-1β, processed by the NLR family pyrin domain containing 3 (NLRP3) inflammasome, has been identified as a target for pathogenic infection of the inflammatory response. However, the effect of P. gingivalis in a high-glucose situation in the modulation of inflammasome activation in human gingival fibroblasts (HGFs) is not well-understood. Methods: P. gingivalis strain CCUG25226 was used to study the mechanisms underlying the regulation of HGF NLRP3 expression by the infection of high-glucose-treated P. gingivalis (HGPg). Results: HGF infection with HGPg increases the expression of IL-1β and NLRP3. We further demonstrated that the upregulation of sterol regulatory element-binding protein (SREBP)-1c by activation of the Akt and p70S6K pathways is critical for HGPg-induced NLRP3 expression. We showed that the inhibition of Janus kinase 2 (JAK2) blocks the Akt- and p70S6K-mediated SREBP-1c, NLRP3, and IL-1β expression. The effect of HGPg on HGF signaling and NLRP3 expression is mediated by β1 integrin. In addition, gingival tissues from diabetic patients with periodontal disease exhibited higher NLRP3 and SREBP-1c expression. Conclusions: Our findings identify the molecular pathways underlying HGPg-dependent NLRP3 inflammasome expression in HGFs, providing insight into the effect of P. gingivalis invasion in HGFs. PMID:28083517

  16. Binding-Induced Fluorescence of Serotonin Transporter Ligands

    DEFF Research Database (Denmark)

    Wilson, James; Ladefoged, Lucy Kate; Babinchak, Michael;

    2014-01-01

    The binding-induced fluorescence of 4-(4-(dimethylamino)-phenyl)-1-methylpyridinium (APP(+)) and two new serotonin transporter (SERT)-binding fluorescent analogues, 1-butyl-4-[4-(1-dimethylamino)phenyl]-pyridinium bromide (BPP(+)) and 1-methyl-4-[4-(1-piperidinyl)phenyl]-pyridinium (PPP(+)), has...

  17. cAMP response element binding protein1 is essential for activation of steroyl co-enzyme a desaturase 1 (Scd1 in mouse lung type II epithelial cells.

    Directory of Open Access Journals (Sweden)

    Nisha Antony

    Full Text Available Cyclic AMP Response Element-Binding Protein 1 (Creb1 is a transcription factor that mediates cyclic adenosine 3', 5'-monophosphate (cAMP signalling in many tissues. Creb1(-/- mice die at birth due to respiratory failure and previous genome-wide microarray analysis of E17.5 Creb1(-/- fetal mouse lung identified important Creb1-regulated gene targets during lung development. The lipogenic enzymes stearoyl-CoA desaturase 1 (Scd1 and fatty acid synthase (Fasn showed highly reduced gene expression in Creb1(-/- lungs. We therefore hypothesized that Creb1 plays a crucial role in the transcriptional regulation of genes involved in pulmonary lipid biosynthetic pathways during lung development. In this study we confirmed that Scd1 and Fasn mRNA levels were down regulated in the E17.5 Creb1(-/- mouse lung while the lipogenic-associated transcription factors SrebpF1, C/ebpα and Pparγ were increased. In vivo studies using germline (Creb1(-/- and lung epithelial-specific (Creb1(EpiΔ/Δ Creb1 knockout mice showed strongly reduced Scd1, but not Fasn gene expression and protein levels in lung epithelial cells. In vitro studies using mouse MLE-15 epithelial cells showed that forskolin-mediated activation of Creb1 increased both Scd1 gene expression and protein synthesis. Additionally, MLE15 cells transfected with a dominant-negative ACreb vector blocked forskolin-mediated stimulation of Scd1 gene expression. Lipid profiling in MLE15 cells showed that dominant-negative ACreb suppressed forskolin-induced desaturation of ether linked lipids to produce plasmalogens, as well as levels of phosphatidylethanolamine, ceramide and lysophosphatidylcholine. Taken together these results demonstrate that Creb1 is essential for the induction and maintenance of Scd1 in developing fetal mouse lung epithelial cells.

  18. Tension-induced binding of semiflexible biopolymers

    CERN Document Server

    Benetatos, Panayotis; Zippelius, Annette

    2014-01-01

    We investigate theoretically the effect of polymer tension on the collective behavior of reversibly binding cross-links. For this purpose, we employ a model of two weakly bending wormlike chains aligned in parallel by a tensile force, with a sequence of inter-chain binding sites regularly spaced along the contours. Reversible cross-links attach and detach at the sites with an affinity controlled by a chemical potential. In a mean-field approach, we calculate the free energy of the system and find the emergence of a free-energy barrier which controls the reversible (un)binding. The tension affects the conformational entropy of the chains which competes with the binding energy of the cross-links. This competition gives rise to a sudden increase in the fraction of bound sites as the tension increases. We show that this transition is related to the cross-over between weak and strong localization of a directed polymer in a pinning potential. The cross-over to the strongly bound state can be interpreted as a mechan...

  19. Photo-induced binding of sulfanilamide to cellular macromolecules

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, B.K.; Arnold, J.T.; Chignell, C.F. (National Inst. of Environmental Health Sciences, Research Triangle Park, NC (USA))

    1982-03-01

    Ultraviolet light (lambda > 295 nm) induced binding of sulfanilamide to cellular macromolecules has been examined. It was found that the drug bound irreversibly to native DNA, and complexes containing one drug molecule per 80 nucleotides were obtained after 60 min of irradiation under anaerobic conditions. Oxygen reduced this binding significantly. More drug was bound to RNA and heat denatured DNA under identical conditions. The binding of sulfanilamide to DNA was found to induce nicking of circular closed plasmid DNA and cross-linking of calf thymus DNA. Oxygen significantly decreased nicking and cross-linking of DNA. Irradiation of sulfanilamide and human serum albumin resulted in covalent binding of the drug to the protein and a concomitant increase in protein crosslinking. While oxygen decreased covalent binding, crosslinking increased under aerobic conditions. These reactions may be important in the photosensitization caused by sulfanilamide.

  20. Contribution of the first K-homology domain of poly(C)-binding protein 1 to its affinity and specificity for C-rich oligonucleotides.

    Science.gov (United States)

    Yoga, Yano M K; Traore, Daouda A K; Sidiqi, Mahjooba; Szeto, Chris; Pendini, Nicole R; Barker, Andrew; Leedman, Peter J; Wilce, Jacqueline A; Wilce, Matthew C J

    2012-06-01

    Poly-C-binding proteins are triple KH (hnRNP K homology) domain proteins with specificity for single stranded C-rich RNA and DNA. They play diverse roles in the regulation of protein expression at both transcriptional and translational levels. Here, we analyse the contributions of individual αCP1 KH domains to binding C-rich oligonucleotides using biophysical and structural methods. Using surface plasmon resonance (SPR), we demonstrate that KH1 makes the most stable interactions with both RNA and DNA, KH3 binds with intermediate affinity and KH2 only interacts detectibly with DNA. The crystal structure of KH1 bound to a 5'-CCCTCCCT-3' DNA sequence shows a 2:1 protein:DNA stoichiometry and demonstrates a molecular arrangement of KH domains bound to immediately adjacent oligonucleotide target sites. SPR experiments, with a series of poly-C-sequences reveals that cytosine is preferred at all four positions in the oligonucleotide binding cleft and that a C-tetrad binds KH1 with 10 times higher affinity than a C-triplet. The basis for this high affinity interaction is finally detailed with the structure determination of a KH1.W.C54S mutant bound to 5'-ACCCCA-3' DNA sequence. Together, these data establish the lead role of KH1 in oligonucleotide binding by αCP1 and reveal the molecular basis of its specificity for a C-rich tetrad.

  1. Cyclase-associated Protein 1 (CAP1) Promotes Cofilin-induced Actin Dynamics in Mammalian Nonmuscle CellsV⃞

    OpenAIRE

    Bertling, Enni; Hotulainen, Pirta; Mattila, Pieta K.; Matilainen, Tanja; Salminen, Marjo; Lappalainen, Pekka

    2004-01-01

    Cyclase-associated proteins (CAPs) are highly conserved actin monomer binding proteins present in all eukaryotes. However, the mechanism by which CAPs contribute to actin dynamics has been elusive. In mammals, the situation is further complicated by the presence of two CAP isoforms whose differences have not been characterized. Here, we show that CAP1 is widely expressed in mouse nonmuscle cells, whereas CAP2 is the predominant isoform in developing striated muscles. In cultured NIH3T3 and B1...

  2. Insulin-induced lipid binding to hemoglobin

    Directory of Open Access Journals (Sweden)

    VESNA NIKETIC

    2003-01-01

    Full Text Available Under hypoglycemic conditions, concomitant hyperinsulinism causes an apparent modification of hemoglobin (Hb which is manifested by its aggregation (Niketi} et al., Clin. Chim. Acta 197 (1991 47. In the present work the causes and mechanisms underlying this Hb modification were studied. Hemoglobin isolated from normal erythrocytes incubated with insulin was analyzed by applying 31P-spectrometry and lipid extraction and analysis. To study the dynamics of the plasma membrane during hyperinsulinism, a fluorescent lipid-analog was applied. In the presence of insulin, phosphatidylserine (PS, phosphatidylethanolamine (PE and cholesterol were found to bind to Hb. Lipid binding resulted in Hb aggregation, a condition that can be reproduced when phospholipids are incubated with Hb in vitro. Using a fluorescent lipid-analog, it was also shown that exposing erythrocytes to supraphysiological concentrations of insulin in vitro resulted in the internalization of lipids. The results presented in this work may have relevance to cases of diabetes mellitus and hypoglycemia.

  3. Pneumocystis carinii major surface glycoprotein induces interleukin-8 and monocyte chemoattractant protein-1 release from a human alveolar epithelial cell line

    DEFF Research Database (Denmark)

    Benfield, T L; Lundgren, Bettina; Shelhamer, J H;

    1999-01-01

    (IL-8) and monocyte chemoattractant protein-1 (MCP-1) from an alveolar epithelial cell line (A549). RESULTS: Incubation of A549 cells with MSG in concentrations from 0.4 to 10 microg mL-1 for 24 h caused dose-dependent increases in IL-8 release (3.4-fold above control, P ..., suggesting that MSG stimulates A549 cells in part through carbohydrate moieties. Dexamethasone significantly inhibited MSG-induced IL-8 release in concentrations of 10-6-10-8 mol L-1 compared with control experiments (P

  4. Smooth muscle LDL receptor-related protein-1 deletion induces aortic insufficiency and promotes vascular cardiomyopathy in mice.

    Directory of Open Access Journals (Sweden)

    Joshua E Basford

    Full Text Available Valvular disease is common in patients with Marfan syndrome and can lead to cardiomyopathy. However, some patients develop cardiomyopathy in the absence of hemodynamically significant valve dysfunction, suggesting alternative mechanisms of disease progression. Disruption of LDL receptor-related protein-1 (Lrp1 in smooth muscle cells has been shown to cause vascular pathologies similar to Marfan syndrome, with activation of smooth muscle cells, vascular dysfunction and aortic aneurysms. This study used echocardiography and blood pressure monitoring in mouse models to determine whether inactivation of Lrp1 in vascular smooth muscle leads to cardiomyopathy, and if so, whether the mechanism is a consequence of valvular disease. Hemodynamic changes during treatment with captopril were also assessed. Dilation of aortic roots was observed in young Lrp1-knockout mice and progressed as they aged, whereas no significant aortic dilation was detected in wild type littermates. Diastolic blood pressure was lower and pulse pressure higher in Lrp1-knockout mice, which was normalized by treatment with captopril. Aortic dilation was followed by development of aortic insufficiency and subsequent dilated cardiomyopathy due to valvular disease. Thus, smooth muscle cell Lrp1 deficiency results in aortic dilation and insufficiency that causes secondary cardiomyopathy that can be improved by captopril. These findings provide novel insights into mechanisms of cardiomyopathy associated with vascular activation and offer a new model of valvular cardiomyopathy.

  5. ERG induces epigenetic activation of Tudor domain-containing protein 1 (TDRD1 in ERG rearrangement-positive prostate cancer.

    Directory of Open Access Journals (Sweden)

    Lukasz A Kacprzyk

    Full Text Available BACKGROUND: Overexpression of ERG transcription factor due to genomic ERG-rearrangements defines a separate molecular subtype of prostate tumors. One of the consequences of ERG accumulation is modulation of the cell's gene expression profile. Tudor domain-containing protein 1 gene (TDRD1 was reported to be differentially expressed between TMPRSS2:ERG-negative and TMPRSS2:ERG-positive prostate cancer. The aim of our study was to provide a mechanistic explanation for the transcriptional activation of TDRD1 in ERG rearrangement-positive prostate tumors. METHODOLOGY/PRINCIPAL FINDINGS: Gene expression measurements by real-time quantitative PCR revealed a remarkable co-expression of TDRD1 and ERG (r(2 = 0.77 but not ETV1 (r(2<0.01 in human prostate cancer in vivo. DNA methylation analysis by MeDIP-Seq and bisulfite sequencing showed that TDRD1 expression is inversely correlated with DNA methylation at the TDRD1 promoter in vitro and in vivo (ρ = -0.57. Accordingly, demethylation of the TDRD1 promoter in TMPRSS2:ERG-negative prostate cancer cells by DNA methyltransferase inhibitors resulted in TDRD1 induction. By manipulation of ERG dosage through gene silencing and forced expression we show that ERG governs loss of DNA methylation at the TDRD1 promoter-associated CpG island, leading to TDRD1 overexpression. CONCLUSIONS/SIGNIFICANCE: We demonstrate that ERG is capable of disrupting a tissue-specific DNA methylation pattern at the TDRD1 promoter. As a result, TDRD1 becomes transcriptionally activated in TMPRSS2:ERG-positive prostate cancer. Given the prevalence of ERG fusions, TDRD1 overexpression is a common alteration in human prostate cancer which may be exploited for diagnostic or therapeutic procedures.

  6. Regulation and function of the CD3¿ DxxxLL motif: a binding site for adaptor protein-1 and adaptor protein-2 in vitro

    DEFF Research Database (Denmark)

    Dietrich, J; Kastrup, J; Nielsen, B L

    1997-01-01

    Several receptors are downregulated by internalization after ligand binding. Regulation of T cell receptor (TCR) expression is an important step in T cell activation, desensitization, and tolerance induction. One way T cells regulate TCR expression is by phosphorylation/dephosphorylation of the TCR...

  7. Investigating the function of Fc-specific binding of IgM to Plasmodium falciparum erythrocyte membrane protein 1 mediating erythrocyte rosetting

    DEFF Research Database (Denmark)

    Stevenson, Liz; Huda, Pie; Jeppesen, Anine;

    2015-01-01

    Acquired protection from Plasmodium falciparum malaria takes years to develop, probably reflecting the ability of the parasites to evade immunity. A recent example of this is the binding of the Fc region of IgM to VAR2CSA-type PfEMP1. This interferes with specific IgG recognition and phagocytosis...

  8. Lycopene supplementation elevates circulating insulin-like growth factor-binding protein-1 and-2 concentrations in persons at greater risk of colorectal cancer

    NARCIS (Netherlands)

    Vrieling, A.; Voskuil, D.W.; Bonfrer, J.M.; Korse, C.M.; Doorn, J.; Cats, A.; Depla, A.C.; Timmer, R.; Witteman, B.J.M.; Leeuwen, van F.E.; van't Veer, L.J.; Rookus, M.A.; Kampman, E.

    2007-01-01

    Background: Higher circulating insulin-like growth factor I (IGF-I) concentrations have been related to a greater risk of cancer. Lycopene intake is inversely associated with cancer risk, and experimental studies have shown that it may affect the IGF system, possibly through an effect on IGF-binding

  9. Lycopene supplementation elevates circulating insulin-like growth factor binding protein-1 and -2 concentrations in persons at greater risk of colorectal cancer.

    NARCIS (Netherlands)

    Vrieling, A.; Voskuil, D.W.; Bonfrer, J.M.G.; Korse, C.M.; Doorn, J. van; Cats, A.; Depla, A.C.; Timmer, R.; Witteman, B.J.M.; Leeuwen, F.E. van; Veer, L.J. van 't; Rookus, M.A.; Kampman, E.

    2007-01-01

    BACKGROUND: Higher circulating insulin-like growth factor I (IGF-I) concentrations have been related to a greater risk of cancer. Lycopene intake is inversely associated with cancer risk, and experimental studies have shown that it may affect the IGF system, possibly through an effect on IGF-binding

  10. 叉头状转录因子O1对游离脂肪酸诱导的人肝癌细胞株HepG-2胰岛素抵抗和脂质堆积作用的研究%Effect of forkhead transcription factor O1 on free fatty acid induced insulin resistance and steatosis by sterol-regulatory element binding protein-1c pathway

    Institute of Scientific and Technical Information of China (English)

    张鹏宇; 秦贵军; 李雪峰; 任高飞; 刘会苗

    2012-01-01

    Objective To study the effects and potential mechanisms of Forkhead transcription factor O1 (FoxO1) on free fatty acid (FFA) induced insulin resistance (IR) and steatosis.Methods HepG-2 cells were induced to a status of insulin resistance by being exposed to 5.0 × 10 4 mmol/L palmitic acid (PA) for 24 hours.HepG-2 cells were devided into 4 groups,the HepG-2 cell group cultured with normal medium,the palmitic acid group,the blank plasmid group,and the siFoxO1 group.PA was added to normal medium to a final concentration of 5.0 × 10 -4 mol/L.The expression levels of FoxO1 in different groups were detected by RT-PCR.The glucose consumption was detected by using glucose oxidase method.MTT method was used to detect the proliferation of HepG-2 cells.Steatosis of HepG-2 cells was observed by Oil Red O staining.The mRNA and protein expression of SREBP-1c were determined by RT-PCR and Western blot.Results Compared with control,the glucose consumption of cells cultured with FFA was significantly reduced( 1.17 ±0.56 vs 4.31 ±0.21,t =10.587,P <0.01 ).Cellular lipid accumulation,the expressions of FoxO1 mRNA ( 0.78 ± 0.10 vs 0.51 ± 0.12,t =3.629,P < 0.05 ),SREBP-1c mRNA (0.71 ±0.17 vs 0.25 ±0.08,t =6.290,P <0.05),and the protein of SREBP-1c (0.69 ±0.10 vs 0.41 ± 0.07,t =4.797,P <0.01 )was increased.After transfected by siFoxO1 plasmids using Lipofectamine 2000,the mRNA expression of FoxO1 (0.38 ± 0.06 vs 0.78 ± 0.1 0,t =7.164,P < 0.01 ),SREB9-1 c (0.45 ±0.13 vs 0.71 ±0.17,t =2.479,P <0.05) and the SREBP-1 c protein expression (0.41 ±0.06 vs 0.69 ±0.10,t =4.797,P <0.01 ) were significantly decreased after tranfected by siFoxO1 plasminds,whereas the glucose consumption obviously the glucose consumption obviously increased ( 2.26 ± 0.41 vs 1.17 ± 0.56,t=3.144,P <0.05).The cellular lipod accumulation was decrease after transfected by siFoxO1.There was no remarkable difference between the palmitic acid group,and the blank plasmid group. Conclusions

  11. Hepatitis C Virus Subtype 3a Envelope Protein 1 Binding with Human Leukocyte Antigen Class I Types of Pakistani Population: Candidate Epitopes for Synthetic Peptide Vaccine

    Directory of Open Access Journals (Sweden)

    Hamid Nawaz-Tipu

    2015-10-01

    Full Text Available The object of this cross sectional study was to determine the HCV subtype 3a envelope protein binding affinity with Human Leukocyte Antigen. Envelope 1 (E1 protein is one of the structural proteins responsible for entering the cells through the receptors. The binding affinity of E1 protein epitopes to the selected Human Leukocyte Antigen (HLA class I alleles was investigated using the computer-based tools. These prediction tools were also used to design the synthetic vaccine’s candidate epitopes and to identify the individuals/populations who are likely to be responder to those vaccines.The mean frequency of HLA I antigens in Pakistani population was calculated. Threealleles each from HLA A and B were selected. E1 protein sequence extracted from HCV 3a isolates was retrieved and twenty-four sequences of it were selected. NetMHCcons 1.0 server was used to determine the binding affinities of HLA alleles to the epitope sequences of 10 amino acids in length.A02, A03, A11, A24, A33, B08, B13, B15, B35 and B40 were the first five antigens moreprevalent in Pakistan each from HLA A and HLA B.. We did not find any binding affinity between HLA A*201, B*1501 and B*4001 and epitopes from E1 sequences in a threshold of50 nM. Totally five various epitopes derived from different isolates were characterized.The prediction of HLA-E1 epitope specific bindings and the forthcoming response can be a useful bioinformatics tool to uncover the right synthetic peptides for vaccine design purposes.

  12. Hepatitis C Virus Subtype 3a Envelope Protein 1 Binding with Human Leukocyte Antigen Class I Types of Pakistani Population: Candidate Epitopes for Synthetic Peptide Vaccine.

    Science.gov (United States)

    Nawaz-Tipu, Hamid

    2015-10-01

    The object of this cross sectional study was to determine the HCV subtype 3a envelope protein binding affinity with Human Leukocyte Antigen. Envelope 1 (E1) protein is one of the structural proteins responsible for entering the cells through the receptors. The binding affinity of E1 protein epitopes to the selected Human Leukocyte Antigen (HLA) class I alleles was investigated using the computer-based tools. These prediction tools were also used to design the synthetic vaccine's candidate epitopes and to identify the individuals/populations who are likely to be responder to those vaccines.The mean frequency of HLA I antigens in Pakistani population was calculated. Three alleles each from HLA A and B were selected. E1 protein sequence extracted from HCV 3a isolates was retrieved and twenty-four sequences of it were selected. NetMHCcons 1.0 server was used to determine the binding affinities of HLA alleles to the epitope sequences of 10 amino acids in length.A02, A03, A11, A24, A33, B08, B13, B15, B35 and B40 were the first five antigens more prevalent in Pakistan each from HLA A and HLA B.. We did not find any binding affinity between HLA A*201, B*1501 and B*4001 and epitopes from E1 sequences in a threshold of 50 nM. Totally five various epitopes derived from different isolates were characterized.The prediction of HLA-E1 epitope specific bindings and the forthcoming response can be a useful bioinformatics tool to uncover the right synthetic peptides for vaccine design purposes.

  13. Downregualtion of dynamin-related protein 1 attenuates glutamate-induced excitotoxicity via regulating mitochondrial function in a calcium dependent manner in HT22 cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chi; Yuan, Xian-rui; Li, Hao-yu; Zhao, Zi-jin; Liao, Yi-wei; Wang, Xiang-yu; Su, Jun; Sang, Shu-shan; Liu, Qing, E-mail: xiangyaliuqing@163.com

    2014-01-03

    Highlights: •Downregulation of Drp-1 attenuates glutamate-induced excitotoxicity. •Downregulation of Drp-1 inhibits glutamate-induced apoptosis. •Downregulation of Drp-1 reduces glutamate-induced mitochondrial dysfunction. •Downregulation of Drp-1 preserves intracellular calcium homeostasis. -- Abstract: Glutamate-mediated excitotoxicity is involved in many acute and chronic brain diseases. Dynamin related protein 1 (Drp-1), one of the GTPase family of proteins that regulate mitochondrial fission and fusion balance, is associated with apoptotic cell death in cancer and neurodegenerative diseases. Here we investigated the effect of downregulating Drp-1 on glutamate excitotoxicity-induced neuronal injury in HT22 cells. We found that downregulation of Drp-1 with specific small interfering RNA (siRNA) increased cell viability and inhibited lactate dehydrogenase (LDH) release after glutamate treatment. Downregulation of Drp-1 also inhibited an increase in the Bax/Bcl-2 ratio and cleavage of caspase-9 and caspase-3. Drp-1 siRNA transfection preserved the mitochondrial membrane potential (MMP), reduced cytochrome c release, enhanced ATP production, and partly prevented mitochondrial swelling. In addition, Drp-1 knockdown attenuated glutamate-induced increases of cytoplasmic and mitochondrial Ca{sup 2+}, and preserved the mitochondrial Ca{sup 2+} buffering capacity after excitotoxicity. Taken together, these results suggest that downregulation of Drp-1 protects HT22 cells against glutamate-induced excitatory damage, and this neuroprotection may be dependent at least in part on the preservation of mitochondrial function through regulating intracellular calcium homeostasis.

  14. Effects of retinoic acid and hydrogen peroxide on sterol regulatory element-binding protein-1a activation during adipogenic differentiation of 3T3-L1 cells

    OpenAIRE

    Eldaim, Mabrouk A. Abd; Okamatsu-Ogura, Yuko; Terao, Akira; Kimura, Kazuhiro

    2010-01-01

    Both retinoic acid (RA) and oxidative stress (H2O2) increased transcription and cleavage of membrane-bound sterol regulatory element-binding protein (SREBP)-1, leading to enhanced transcription of fatty acid synthase (FAS) in hepatoma cells. On the other hand, RA and H2O2 decreased and increased lipogenesis in adipocytes, respectively, although roles of SREBP-1 activation in these effects remain to be elucidated. To elucidate its involvement, we examined the activation of SREBP...

  15. E. coli Histidine Triad Nucleotide Binding Protein 1 (ecHinT) Is a Catalytic Regulator of D-Alanine Dehydrogenase (DadA) Activity In Vivo

    OpenAIRE

    Sanaa Bardaweel; Brahma Ghosh; Tsui-Fen Chou; Sadowsky, Michael J.; Wagner, Carston R.

    2011-01-01

    Histidine triad nucleotide binding proteins (Hints) are highly conserved members of the histidine triad (HIT) protein superfamily. Hints comprise the most ancient branch of this superfamily and can be found in Archaea, Bacteria, and Eukaryota. Prokaryotic genomes, including a wide diversity of both gram-negative and gram-positive bacteria, typically have one Hint gene encoded by hinT (ycfF in E. coli). Despite their ubiquity, the foundational reason for the wide-spread conservation of Hints a...

  16. Two Distantly Spaced Basic Patches in the Flexible Domain of Huntingtin-Interacting Protein 1 (HIP1 Are Essential for the Binding of Clathrin Light Chain

    Directory of Open Access Journals (Sweden)

    Joel A. Ybe

    2009-01-01

    Full Text Available The interaction between HIP family proteins (HIP1 and HIP12/1R and clathrin is fundamental to endocytosis. We used circular dichroism (CD to study the stability of an HIP1 subfragment (aa468-530 that is splayed open. CD thermal melts show HIP1 468-530 is only stable at low temperatures, but this HIP1 fragment contains a structural unit that does not melt out even at 83C∘. We then created HIP1 mutants to probe our hypothesis that a short hydrophobic path in the opened region is the binding site for clathrin light chain. We found that the binding of hub/LCb was sensitive to mutating two distantly separated basic residues (K474 and K494. The basic patches marked by K474 and K494 are conserved in HIP12/1R. The lack of conservation in sla2p (S. cerevisiae, HIP1 from D. melanogaster, and HIP1 homolog ZK370.3 from C. elegans implies the binding of HIP1 and HIP1 homologs to clathrin light chain may be different in these organisms.

  17. Cyclase-associated protein 1 (CAP1) promotes cofilin-induced actin dynamics in mammalian nonmuscle cells.

    Science.gov (United States)

    Bertling, Enni; Hotulainen, Pirta; Mattila, Pieta K; Matilainen, Tanja; Salminen, Marjo; Lappalainen, Pekka

    2004-05-01

    Cyclase-associated proteins (CAPs) are highly conserved actin monomer binding proteins present in all eukaryotes. However, the mechanism by which CAPs contribute to actin dynamics has been elusive. In mammals, the situation is further complicated by the presence of two CAP isoforms whose differences have not been characterized. Here, we show that CAP1 is widely expressed in mouse nonmuscle cells, whereas CAP2 is the predominant isoform in developing striated muscles. In cultured NIH3T3 and B16F1 cells, CAP1 is a highly abundant protein that colocalizes with cofilin-1 to dynamic regions of the cortical actin cytoskeleton. Analysis of CAP1 knockdown cells demonstrated that this protein promotes rapid actin filament depolymerization and is important for cell morphology, migration, and endocytosis. Interestingly, depletion of CAP1 leads to an accumulation of cofilin-1 into abnormal cytoplasmic aggregates and to similar cytoskeletal defects to those seen in cofilin-1 knockdown cells, demonstrating that CAP1 is required for proper subcellular localization and function of ADF/cofilin. Together, these data provide the first direct in vivo evidence that CAP promotes rapid actin dynamics in conjunction with ADF/cofilin and is required for several central cellular processes in mammals.

  18. Salvianolic Acid B Protects Normal Human Dermal Fibroblasts Against Ultraviolet B Irradiation-Induced Photoaging Through Mitogen-Activated Protein Kinase and Activator Protein-1 Pathways.

    Science.gov (United States)

    Sun, Zhengwang; Park, Sang-Yong; Hwang, Eunson; Zhang, Mengyang; Jin, Fengxie; Zhang, Baochun; Yi, Tae Hoo

    2015-01-01

    Exposure to ultraviolet (UV) light causes increased matrix metalloproteinase (MMP) activity and decreased collagen synthesis, leading to skin photoaging. Salvianolic acid B (SAB), a polyphenol, was extracted and purified from salvia miltiorrhiza. We assessed effects of SAB on UVB-induced photoaging and investigated its molecular mechanism of action in UVB-irradiated normal human dermal fibroblasts. Our results show that SAB significantly inhibited the UVB-induced expression of metalloproteinases-1 (MMP-1) and interleukin-6 (IL-6) while promoting the production of type I procollagen and transforming growth factor β1 (TGF-β1). Moreover, treatment with SAB in the range of 1-100 μg/mL significantly inhibited UVB-induced extracellular signal-regulated kinase (ERK), Jun N-terminal kinase (JNK) and p38 phosphorylation, which resulted in decreasing UVB-induced phosphorylation of c-Fos and c-Jun. These results indicate that SAB downregulates UV-induced MMP-1 expression by inhibiting Mitogen-activated protein kinase (MAPK) signaling pathways and activator protein-1 (AP-1) activation. Our results suggest a potential use for SAB in skin photoprotection.

  19. NITRIC OXIDE-ASSOCIATED PROTEIN1 (AtNOA1) is essential for salicylic acid-induced root waving in Arabidopsis thaliana.

    Science.gov (United States)

    Zhao, Xiang; Wang, Jin; Yuan, Jing; Wang, Xi-Li; Zhao, Qing-Ping; Kong, Pei-Tao; Zhang, Xiao

    2015-07-01

    Root waving responses have been attributed to both environmental and genetics factors, but the potential inducers and transducers of root waving remain elusive. Thus, the identification of novel signal elements related to root waving is an intriguing field of research. Genetic, physiological, cytological, live cell imaging, and pharmacological approaches provide strong evidence for the involvement of Arabidopsis thaliana NITRIC OXIDE-ASSOCIATED PROTEIN1 (AtNOA1) in salicylic acid (SA)-induced root waving. SA specially induced root waving, with an overall decrease in root elongation in A. thaliana, and this SA-induced response was disrupted in the Atnoa1 mutant, as well as in nonexpresser of pathogenesis-related genes 1 (npr1), which is defective in SA-mediated plant defense signal transduction, but not in npr3/4 single and double mutants. The expression assays revealed that the abundance of AtNOA1 was significantly increased by application of SA. Genetic and pharmacological analyses showed that SA-induced root waving involved an AtNOA1-dependent Ca(2+) signal transduction pathway, and PIN-FORMED2 (PIN2) -based polar auxin transport possibly plays a crucial role in this process. Our work suggests that SA signaling through NPR1 and AtNOA1 is involved in the control of root waving, which provides new insights into the mechanisms that control root growth behavior on a hard agar surface.

  20. Preventing Phosphorylation of Sterol Regulatory Element-Binding Protein 1a by MAP-Kinases Protects Mice from Fatty Liver and Visceral Obesity

    OpenAIRE

    Jorg Kotzka; Birgit Knebel; Jutta Haas; Lorena Kremer; Sylvia Jacob; Sonja Hartwig; Ulrike Nitzgen; Dirk Muller-Wieland

    2012-01-01

    The transcription factor sterol regulatory element binding protein (SREBP)-1a plays a pivotal role in lipid metabolism. Using the SREBP-1a expressing human hepatoma cell line HepG2 we have shown previously that human SREBP-1a is phosphorylated at serine 117 by ERK-mitogen-activated protein kinases (MAPK). Using a combination of cell biology and protein chemistry approach we show that SREBP-1a is also target of other MAPK-families, i.e. c-JUN N-terminal protein kinases (JNK) or p38 stress acti...

  1. Lycopene supplementation elevates circulating insulin-like growth factor-binding protein-1 and-2 concentrations in persons at greater risk of colorectal cancer

    OpenAIRE

    Vrieling, A.; Voskuil, D.W.; Bonfrer, J.M.; Korse, C M; van Doorn, J.; Cats, A; Depla, A.C.; Timmer, R; Witteman, B.J.M.; Leeuwen, van, P.J.; van 't Veer, L J; Rookus, M A; Kampman, E.

    2007-01-01

    Background: Higher circulating insulin-like growth factor I (IGF-I) concentrations have been related to a greater risk of cancer. Lycopene intake is inversely associated with cancer risk, and experimental studies have shown that it may affect the IGF system, possibly through an effect on IGF-binding proteins (IGFBPs). Objective: The objective of our study was to investigate the effect of an 8-wk supplementation with tomato-derived lycopene (30 mg/d) on serum concentrations of total IGF-I, IGF...

  2. Membrane-type 1 matrix metalloproteinase cytoplasmic tail binding protein-1 (MTCBP-1) acts as an eukaryotic aci-reductone dioxygenase (ARD) in the methionine salvage pathway.

    Science.gov (United States)

    Hirano, Wakako; Gotoh, Isamu; Uekita, Takamasa; Seiki, Motoharu

    2005-06-01

    MTCBP-1 was identified as a protein that binds the cytoplasmic tail of membrane-type 1 matrix metalloproteinase (MT1-MMP/MMP-14). Since MTCBP-1 has a putative beta-barrel structure, it is presumably a member of the recently proposed cupin superfamily that contains tremendously diverged functions of proteins in spite of their well-conserved beta-barrel structure. MTCBP-1 shows significant homology to the bacterial aci-reductone dioxygenase (ARD) in the cupin family, which is an enzyme in the methionine salvage pathway (MTA cycle). Since it is difficult to speculate the functions of cupin proteins simply based on their sequence homology, we examined whether the eukaryotic ARD homologs surely function in the methionine metabolism. Under sulfur-depleted conditions, yeast could grow when substrate of MTA cycle was provided. Disruption of the yeast ARD homolog, YMR009w gene, abolished ability of the cells to grow in this culture condition. Re-expression of either the YMR009w or MTCBP-1 gene restored the cell growth. Mutation analysis revealed that the glutamic acid residue in the beta-barrel fold and the N-terminal extension from the beta-barrel fold were found to be important for the activity to restore the growth. Thus, MTCBP-1 isolated as a binding protein for MT1-MMP was demonstrated to function as an ARD-like enzyme in the MTA cycle in yeast.

  3. Dichloroacetate induces protective autophagy in LoVo cells: involvement of cathepsin D/thioredoxin-like protein 1 and Akt-mTOR-mediated signaling.

    Science.gov (United States)

    Gong, F; Peng, X; Sang, Y; Qiu, M; Luo, C; He, Z; Zhao, X; Tong, A

    2013-11-07

    Dichloroacetate (DCA) is an inhibitor of pyruvate dehydrogenase kinase (PDK), and recently it has been shown as a promising nontoxic antineoplastic agent. In this study, we demonstrated that DCA could induce autophagy in LoVo cells, which were confirmed by the formation of autophagosomes, appearance of punctate patterns of LC3 immunoreactivity and activation of autophagy associated proteins. Moreover, autophagy inhibition by 3-methyladenine (3-MA) or Atg7 siRNA treatment can significantly enhance DCA-induced apoptosis. To determine the underlying mechanism of DCA-induced autophagy, target identification using drug affinity responsive target stability (DARTS) coupled with ESI-Q-TOF MS/MS analysis were utilized to profile differentially expressed proteins between control and DCA-treated LoVo cells. As a result, Cathepsin D (CTSD) and thioredoxin-like protein 1 (TXNL1) were identified with significant alterations compared with control. Further study indicated that DCA treatment significantly promoted abnormal reactive oxygen species (ROS) production. On the other hand, DCA-triggered autophagy could be attenuated by N-acetyl cysteine (NAC), a ROS inhibitor. Finally, we demonstrated that the Akt-mTOR signaling pathway, a major negative regulator of autophagy, was suppressed by DCA treatment. To our knowledge, it was the first study to show that DCA induced protective autophagy in LoVo cells, and the potential mechanisms were involved in ROS imbalance and Akt-mTOR signaling pathway suppression.

  4. Dickkopf‑related protein 1 induces angiogenesis by upregulating vascular endothelial growth factor in the synovial fibroblasts of patients with temporomandibular joint disorders.

    Science.gov (United States)

    Jiang, Sheng-Jun; Li, Wei; Li, Ying-Jie; Fang, Wei; Long, Xing

    2015-10-01

    Angiogenesis has an important role in the progression of temporomandibular joint disorders (TMD). The aim of the present study was to explore the association between dickkopf‑related protein 1 (DKK‑1) and angiogenesis in TMD. The expression levels of DKK‑1 and vascular endothelial growth factor (VEGF) were quantified by an ELISA assay of the synovial fluid from patients with TMD. The correlation between DKK‑1 and VEGF was analyzed by Pearson correlation test. Synovial fibroblasts were isolated from patients with TMD and were subsequently treated with recombinant human DKK‑1, anti‑DKK‑1 antibody, hypoxia inducible factor‑1α (HIF‑1α), or small interfering RNA (siRNA). The expression levels of DKK‑1, HIF‑1α, and VEGF were subsequently quantified. The present study also investigated the effects of DKK‑1 on the migration of human umbilical vein endothelial cells (HUVEC). Increased expression levels of DKK‑1 were concordant with increased expression levels of VEGF in the synovial fluid from patients with TMD. In the synovial fibroblasts, DKK‑1 increased the expression levels of VEGF, and promoted HIF‑1α nuclear localization. In addition, DKK‑1 induced HUVEC migration, and HIF‑1α siRNA inhibited DKK‑1‑induced cell migration. The results of the present study indicate that DKK‑1 is associated with angiogenesis in the synovial fluid of patients with TMD. Furthermore, HIF‑1α may be associated with DKK‑1‑induced HUVEC activation.

  5. Tyrosylprotein sulfotransferase-1 and tyrosine sulfation of chemokine receptor 4 are induced by Epstein-Barr virus encoded latent membrane protein 1 and associated with the metastatic potential of human nasopharyngeal carcinoma.

    Directory of Open Access Journals (Sweden)

    Juan Xu

    Full Text Available The latent membrane protein 1 (LMP1, which is encoded by the Epstein-Barr virus (EBV, is an important oncogenic protein that is closely related to carcinogenesis and metastasis of nasopharyngeal carcinoma (NPC, a prevalent cancer in China. We previously reported that the expression of the functional chemokine receptor CXCR4 is associated with human NPC metastasis. In this study, we show that LMP1 induces tyrosine sulfation of CXCR4 through tyrosylprotein sulfotransferase-1 (TPST-1, an enzyme that is responsible for catalysis of tyrosine sulfation in vivo, which is likely to contribute to the highly metastatic character of NPC. LMP1 could induce tyrosine sulfation of CXCR4 and its associated cell motility and invasiveness in a NPC cell culture model. In contrast, the expression of TPST-1 small interfering RNA reversed LMP1-induced tyrosine sulfation of CXCR4. LMP1 conveys signals through the epidermal growth factor receptor (EGFR pathway, and EGFR-targeted siRNA inhibited the induction of TPST-1 by LMP1. We used a ChIP assay to show that EGFR could bind to the TPST-1 promoter in vivo under the control of LMP1. A reporter gene assay indicated that the activity of the TPST-1 promoter could be suppressed by deleting the binding site between EGFR and TPST-1. Finally, in human NPC tissues, the expression of TPST-1 and LMP1 was directly correlated and clinically, the expression of TPST-1 was associated with metastasis. These results suggest the up-regulation of TPST-1 and tyrosine sulfation of CXCR4 by LMP1 might be a potential mechanism contributing to NPC metastasis.

  6. Role of NF-Kappa B Signaling in X-Box Binding Protein 1 (XBP1)-Mediated Antiestrogen Resistance in Breast Cancer

    Science.gov (United States)

    2013-10-01

    the cell death response to antiestrogen therapy. ERα knockdown, but not ICI treatment, reduced nuclear Nrf2 (a UPR-induced antioxidant signaling...Cancer Center, 09/2007-09/2009 Skp2 regulation of melanoma cell proliferation: mechanism and role in a skin -like microenvironment Post-doctoral

  7. Human pathogenic Borrelia spielmanii sp. nov. resists complement-mediated killing by direct binding of immune regulators factor H and factor H-like protein 1.

    Science.gov (United States)

    Herzberger, Pia; Siegel, Corinna; Skerka, Christine; Fingerle, Volker; Schulte-Spechtel, Ulrike; van Dam, Alje; Wilske, Bettina; Brade, Volker; Zipfel, Peter F; Wallich, Reinhard; Kraiczy, Peter

    2007-10-01

    Borrelia spielmanii sp. nov. has recently been shown to be a novel human pathogenic genospecies that causes Lyme disease in Europe. In order to elucidate the immune evasion mechanisms of B. spielmanii, we compared the abilities of isolates obtained from Lyme disease patients and tick isolate PC-Eq17 to escape from complement-mediated bacteriolysis. Using a growth inhibition assay, we show that four B. spielmanii isolates, including PC-Eq17, are serum resistant, whereas a single isolate, PMew, was more sensitive to complement-mediated lysis. All isolates activated complement in vitro, as demonstrated by covalent attachment of C3 fragments; however, deposition of the later activation products C6 and C5b-9 was restricted to the moderately serum-resistant isolate PMew and the serum-sensitive B. garinii isolate G1. Furthermore, serum adsorption experiments revealed that all B. spielmanii isolates acquired the host alternative pathway regulators factor H and factor H-like protein (FHL-1) from human serum. Both complement regulators retained their factor I-mediated C3b inactivation activities when bound to spirochetes. In addition, two distinct factor H and FHL-1 binding proteins, BsCRASP-1 and BsCRASP-2, were identified, which we estimated to be approximately 23 to 25 kDa in mass. A further factor H binding protein, BsCRASP-3, was found exclusively in the tick isolate, PC-Eq17. This is the first report describing an immune evasion mechanism utilized by B. spielmanii sp. nov., and it demonstrates the capture of human immune regulators to resist complement-mediated killing.

  8. The enhancement of astrocytic-derived monocyte chemoattractant protein-1 induced by the interaction of opiate and HIV tat in HIV-associated dementia

    Institute of Scientific and Technical Information of China (English)

    Xiao Han

    2009-01-01

    HIV-assodated dementia (HAD) is a public health problem and is particularly prevalent in drug abusers. The neuropathogenesis of human immunodeficiency virus (HIV) infection involves a complex cascade of inflammatory events, including monocyte/macrophage infiltration in the brain, glial immune activation and release of neurotoxic substances. In these events, astrocytic-derived monocyte chemoattractant protein-1 (MCP-1) plays an important role, whose release is elevated by HIV transactivator of transcription (HIV tat) and could be further elevated by opiates. This review will also consider some critical factors and events in MCP-1 enhancement induced by the interactions of opiate and HIV tat, including the mediating role of mu opioid receptor (MOR) and CCR2 as well as the possible signal transduction pathways within the cells. Finally, it will make some future perspectives on the exact pathways, new receptors and target cells, and the vulnerability to neurodegeneration with HIV and opiates.

  9. Intrathecal administration of low-dose nociceptin/orphanin FQ induces allodynia via c-Jun N-terminal kinase and monocyte chemoattractant protein-1.

    Science.gov (United States)

    Kawabata, Kenta; Nishimura, Isamu; Fujiwara, Takeshi; Terauchi, Shoko; Minami, Toshiaki; Ito, Seiji; Okuda-Ashitaka, Emiko

    2016-06-01

    Pathological chronic pain, which is frequently associated with prolonged tissue damage, inflammation, tumour invasion, and neurodegenerative diseases, gives rise to hyperalgesia and allodynia. We previously reported that intrathecal administration of nociceptin/orphanin FQ (N/OFQ), an endogenous ligand for the orphan opioid receptor-like receptor, in the femtomole range induces touch-evoked allodynia. N/OFQ has been implicated in multiple signalling pathways, such as inhibition of cAMP production and Ca(2+) channels, or activation of K(+) channels and mitogen-activated protein kinase, although the signalling pathways of N/OFQ-induced allodynia remain unclear. To address these issues, we developed an ex vivo mitogen-activated protein kinase assay by using intact slices of mouse spinal cord. N/OFQ markedly increased the phosphorylation of c-Jun N-terminal kinase (JNK) in the superficial dorsal horn of the spinal cord. The N/OFQ-stimulated JNK phosphorylation was significantly inhibited by pertussis toxin, the phospholipase C inhibitor U73122, and the inositol trisphosphate receptor antagonist Xestospongin C. Intrathecal administration of the JNK inhibitor SP600125 inhibited N/OFQ-evoked allodynia. The N/OFQ-induced increase in JNK phosphorylation was observed in astrocytes that expressed glial fibrillary acidic protein. N/OFQ also induced monocyte chemoattractant protein-1 (MCP-1) release via the JNK pathway, and N/OFQ-induced JNK phosphorylation was observed in MCP-1-immunoreactive astrocytes. Intrathecal administration of the MCP-1 receptor antagonist RS504393 inhibited N/OFQ-evoked allodynia. These results suggest that, in the spinal dorsal horn, N/OFQ induces allodynia through activation of JNK via the phospholipase C-inositol trisphosphate pathway, which is coupled to pertussis toxin-sensitive G-protein, and following the release of MCP-1 from astrocytes.

  10. Immunohistochemical investigation of voltage-gated potassium channel-interacting protein 1 in normal rat brain and Pentylenettrazole-induced seizures

    Institute of Scientific and Technical Information of China (English)

    Tao SU; Ai-Hua LUO; Wen-Dong CONG; Wei-Wen SUN; Wei-Yi DENG; Qi-Hua ZHAO; Zhuo-Hua ZHANG; Wei-Ping LIAO

    2006-01-01

    Objective To explore the possible role of voltage-gated potassium channel-interacting protein 1 (KChIP1) in the pathogenesis of epilepsy. Methods Sprague Dawley female adult rats were treated with pentylenettrazole (PTZ) to develop acute and chronic epilepsy models. The approximate coronal sections of normal and epilepsy rat brain were processed for immunohistochemistry. Double-labeling confocal microscopy was used to determine the coexistence of KChIP1 and gamma-aminobutyric acid (GABA). Results KChIP1 was expressed abundantly throughout adult rat brain.KChIP1 is highly co-localize with GABA transmitter in hippocampus and cerebral cortex. In the acute PTZ-induced convulsive rats, the number of KChIP1-postive cells was significantly increased especially in the regions of CA 1 and CA3 (P < 0.05); whereas the chronic PTZ-induced convulsive rats were found no changes. The number of GABA-labeled and co-labeled neurons in the hippocampus appeared to have no significant alteration responding to the epilepsy-genesis treatments. Conclusion KChIP1 might be involved in the PTZ-induced epileptogenesis process as a regulator to neuronal excitability through influencing the properties of potassium channels. KChIP1 is preferentially expressed in GABAergic neurons, but its changes did not couple with GABA in the epileptic models.

  11. IgE in the absence of allergen induces the expression of monocyte chemoattractant protein-1 in the rat basophilic cell-line RBL-2H3.

    Science.gov (United States)

    Ahn, Ki Bum; Jeon, Jun Ho; Kang, Seok-Seong; Chung, Dae Kyun; Yun, Cheol-Heui; Han, Seung Hyun

    2014-11-01

    Recently, basophils have been suggested to produce inflammatory mediators in response to IgE in the absence of allergens. Monocyte chemoattractant protein-1 (MCP-1) plays an important role in the initiation of inflammatory responses by recruiting various immune cells to the site of allergic inflammation. In the present study, we examined whether IgE under allergen-free conditions could stimulate basophils and lead to the production of MCP-1. Exposure of the rat basophilic cell-line RBL-2H3 to IgE without allergen resulted in a dose- and time-dependent induction of MCP-1 expression at both the mRNA and protein level. Although allergen was not necessary for IgE-induced MCP-1 expression, it was essential for degranulation as determined by β-hexosaminidase release assay. IgE enhanced phosphorylation of MAP kinases including ERK, p38 kinase, and JNK. However, IgE-induced MCP-1 expression was attenuated by inhibitors for JNK and PKC. Concomitantly, IgE induced activation of AP-1, which is an important transcription factor for MCP-1 gene expression in RBL-2H3 cells. Taken together, our results suggest that IgE alone is sufficient to stimulate basophils to increase expression of MCP-1, which in turn might contribute to the inflammatory response.

  12. Mutation and crystallization of the first KH domain of human polycytosine-binding protein 1 (PCBP1) in complex with DNA.

    Science.gov (United States)

    Yoga, Yano M K; Traore, Daouda A K; Wilce, Jacqueline A; Wilce, Matthew C J

    2011-10-01

    Polycytosine-binding proteins (PCBPs) are triple KH-domain proteins that play an important role in the regulation of translation of eukaryotic mRNA. They are also utilized by viral RNA and have been shown to interact with ssDNA. Underlying their function is the specific recognition of C-rich nucleotides by their KH domains. However, the structural basis of this recognition is only partially understood. Here, the preparation of a His-tagged KH domain is described, representing the first domain of PCBP1 that incorporates a C54S mutation as well as the addition of a C-terminal tryptophan. This construct has facilitated the preparation of highly diffracting crystals in complex with C-rich DNA (sequence ACCCCA). Crystals of the KH1-DNA complex were grown using the hanging-drop vapour-diffusion method in 0.1 M phosphate-citrate pH 4.2, 40%(v/v) PEG 300. X-ray diffraction data were collected to 1.77 Å resolution and the diffraction was consistent with space group P2(1), with unit-cell parameters a = 38.59, b = 111.88, c = 43.42 Å, α = γ = 90.0, β = 93.37°. The structure of the KH1-DNA complex will further our insight into the basis of cytosine specificity by PCBPs.

  13. Antimicrobial susceptibility and penicillin-binding protein 1 and 2 mutations in Neisseria gonorrhoeae isolated from male urethritis in Sapporo, Japan.

    Science.gov (United States)

    Takahashi, Satoshi; Kurimura, Yuichiro; Hashimoto, Jiro; Uehara, Teruhisa; Hiyama, Yoshiki; Iwasawa, Akihiko; Nishimura, Masahiro; Sunaoshi, Kenichi; Takeda, Koichi; Suzuki, Nobukazu; Tsukamoto, Taiji

    2013-02-01

    The spread of antimicrobial-resistant Neisseria gonorrhoeae worldwide is a critical issue in the control of sexually transmitted infections. The purpose of this study was to clarify recent trends in the susceptibility of N. gonorrhoeae to various antimicrobial agents and to compare these data with our previous data. Minimum inhibitory concentrations (MICs) of various antimicrobial agents were determined in N. gonorrhoeae strains clinically isolated from male gonococcal urethritis. In addition, amino acid sequencing of penicillin-binding protein (PBP) 2, encoded by the penA gene, was analyzed so that genetic analysis of mosaic PBP 2 could clarify the susceptibility of the strains to cefixime and other cephalosporins. The susceptibility rate for ceftriaxone, cefodizime, and spectinomycin, agents whose use is recommended by the guideline of the Japanese Society of Sexually Transmitted Infections (JSSTI), was 100 %. The susceptibility rates of the strains to penicillin G and ciprofloxacin were lower than those in previous reports. Mosaic PBP 2 structures were detected in 51.9 % of the strains and the MICs of the strains with the mosaic PBP 2 to cefixime were much higher than those of the strains without the mosaic PBP 2. In the clinical situation, the treatment regimen recommended by the JSSTI remains appropriate; however, the susceptibility to cephalosporins should be intensively surveyed because strains with mosaic PBP 2 were commonly detected.

  14. E. coli histidine triad nucleotide binding protein 1 (ecHinT) is a catalytic regulator of D-alanine dehydrogenase (DadA) activity in vivo.

    Science.gov (United States)

    Bardaweel, Sanaa; Ghosh, Brahma; Chou, Tsui-Fen; Sadowsky, Michael J; Wagner, Carston R

    2011-01-01

    Histidine triad nucleotide binding proteins (Hints) are highly conserved members of the histidine triad (HIT) protein superfamily. Hints comprise the most ancient branch of this superfamily and can be found in Archaea, Bacteria, and Eukaryota. Prokaryotic genomes, including a wide diversity of both gram-negative and gram-positive bacteria, typically have one Hint gene encoded by hinT (ycfF in E. coli). Despite their ubiquity, the foundational reason for the wide-spread conservation of Hints across all kingdoms of life remains a mystery. In this study, we used a combination of phenotypic screening and complementation analyses with wild-type and hinT knock-out Escherichia coli strains to show that catalytically active ecHinT is required in E. coli for growth on D-alanine as a sole carbon source. We demonstrate that the expression of catalytically active ecHinT is essential for the activity of the enzyme D-alanine dehydrogenase (DadA) (equivalent to D-amino acid oxidase in eukaryotes), a necessary component of the D-alanine catabolic pathway. Site-directed mutagenesis studies revealed that catalytically active C-terminal mutants of ecHinT are unable to activate DadA activity. In addition, we have designed and synthesized the first cell-permeable inhibitor of ecHinT and demonstrated that the wild-type E. coli treated with the inhibitor exhibited the same phenotype observed for the hinT knock-out strain. These results reveal that the catalytic activity and structure of ecHinT is essential for DadA function and therefore alanine metabolism in E. coli. Moreover, they provide the first biochemical evidence linking the catalytic activity of this ubiquitous protein to the biological function of Hints in Escherichia coli.

  15. E. coli histidine triad nucleotide binding protein 1 (ecHinT is a catalytic regulator of D-alanine dehydrogenase (DadA activity in vivo.

    Directory of Open Access Journals (Sweden)

    Sanaa Bardaweel

    Full Text Available Histidine triad nucleotide binding proteins (Hints are highly conserved members of the histidine triad (HIT protein superfamily. Hints comprise the most ancient branch of this superfamily and can be found in Archaea, Bacteria, and Eukaryota. Prokaryotic genomes, including a wide diversity of both gram-negative and gram-positive bacteria, typically have one Hint gene encoded by hinT (ycfF in E. coli. Despite their ubiquity, the foundational reason for the wide-spread conservation of Hints across all kingdoms of life remains a mystery. In this study, we used a combination of phenotypic screening and complementation analyses with wild-type and hinT knock-out Escherichia coli strains to show that catalytically active ecHinT is required in E. coli for growth on D-alanine as a sole carbon source. We demonstrate that the expression of catalytically active ecHinT is essential for the activity of the enzyme D-alanine dehydrogenase (DadA (equivalent to D-amino acid oxidase in eukaryotes, a necessary component of the D-alanine catabolic pathway. Site-directed mutagenesis studies revealed that catalytically active C-terminal mutants of ecHinT are unable to activate DadA activity. In addition, we have designed and synthesized the first cell-permeable inhibitor of ecHinT and demonstrated that the wild-type E. coli treated with the inhibitor exhibited the same phenotype observed for the hinT knock-out strain. These results reveal that the catalytic activity and structure of ecHinT is essential for DadA function and therefore alanine metabolism in E. coli. Moreover, they provide the first biochemical evidence linking the catalytic activity of this ubiquitous protein to the biological function of Hints in Escherichia coli.

  16. Preventing phosphorylation of sterol regulatory element-binding protein 1a by MAP-kinases protects mice from fatty liver and visceral obesity.

    Science.gov (United States)

    Kotzka, Jorg; Knebel, Birgit; Haas, Jutta; Kremer, Lorena; Jacob, Sylvia; Hartwig, Sonja; Nitzgen, Ulrike; Muller-Wieland, Dirk

    2012-01-01

    The transcription factor sterol regulatory element binding protein (SREBP)-1a plays a pivotal role in lipid metabolism. Using the SREBP-1a expressing human hepatoma cell line HepG2 we have shown previously that human SREBP-1a is phosphorylated at serine 117 by ERK-mitogen-activated protein kinases (MAPK). Using a combination of cell biology and protein chemistry approach we show that SREBP-1a is also target of other MAPK-families, i.e. c-JUN N-terminal protein kinases (JNK) or p38 stress activated MAP kinases. Serine 117 is also the major phosphorylation site in SREBP-1a for JNK. In contrast to that the major phosphorylation sites of p38 MAPK family are serine 63 and threonine 426. Functional analyses reveal that phosphorylation of SREBP-1a does not alter protein/DNA interaction. The identified phosphorylation sites are specific for both kinase families also in cellular context. To provide direct evidence that phosphorylation of SREBP-1a is a regulatory principle of biological and clinical relevance, we generated transgenic mice expressing mature transcriptionally active N-terminal domain of human SREBP-1a variant lacking all identified phosphorylaton sites designed as alb-SREBP-1aΔP and wild type SREBP-1a designed as alb-SREBP-1a liver specific under control of the albumin promoter and a liver specific enhancer. In contrast to alb-SREBP-1a mice the phosphorylation-deficient mice develop no enlarged fatty livers under normocaloric conditions. Phenotypical examination reveales a massive accumulation of adipose tissue in alb-SREBP-1a but not in the phosphorylation deficient alb-SREBP-1aΔP mice. Moreover, preventing phosphorylation of SREBP-1a protects mice also from dyslipidemia. In conclusion, phosphorylation of SREBP-1a by ERK, JNK and p38 MAPK-families resembles a biological principle and plays a significant role, in vivo.

  17. Preventing phosphorylation of sterol regulatory element-binding protein 1a by MAP-kinases protects mice from fatty liver and visceral obesity.

    Directory of Open Access Journals (Sweden)

    Jorg Kotzka

    Full Text Available The transcription factor sterol regulatory element binding protein (SREBP-1a plays a pivotal role in lipid metabolism. Using the SREBP-1a expressing human hepatoma cell line HepG2 we have shown previously that human SREBP-1a is phosphorylated at serine 117 by ERK-mitogen-activated protein kinases (MAPK. Using a combination of cell biology and protein chemistry approach we show that SREBP-1a is also target of other MAPK-families, i.e. c-JUN N-terminal protein kinases (JNK or p38 stress activated MAP kinases. Serine 117 is also the major phosphorylation site in SREBP-1a for JNK. In contrast to that the major phosphorylation sites of p38 MAPK family are serine 63 and threonine 426. Functional analyses reveal that phosphorylation of SREBP-1a does not alter protein/DNA interaction. The identified phosphorylation sites are specific for both kinase families also in cellular context. To provide direct evidence that phosphorylation of SREBP-1a is a regulatory principle of biological and clinical relevance, we generated transgenic mice expressing mature transcriptionally active N-terminal domain of human SREBP-1a variant lacking all identified phosphorylaton sites designed as alb-SREBP-1aΔP and wild type SREBP-1a designed as alb-SREBP-1a liver specific under control of the albumin promoter and a liver specific enhancer. In contrast to alb-SREBP-1a mice the phosphorylation-deficient mice develop no enlarged fatty livers under normocaloric conditions. Phenotypical examination reveales a massive accumulation of adipose tissue in alb-SREBP-1a but not in the phosphorylation deficient alb-SREBP-1aΔP mice. Moreover, preventing phosphorylation of SREBP-1a protects mice also from dyslipidemia. In conclusion, phosphorylation of SREBP-1a by ERK, JNK and p38 MAPK-families resembles a biological principle and plays a significant role, in vivo.

  18. Fusion of NUP98 and the SET binding protein 1 (SETBP1) gene in a paediatric acute T cell lymphoblastic leukaemia with t(11;18)(p15;q12)

    DEFF Research Database (Denmark)

    Panagopoulos, Ioannis; Kerndrup, Gitte; Carlsen, Niels

    2007-01-01

    Three NUP98 chimaeras have previously been reported in T cell acute lymphoblastic leukaemia (T-ALL): NUP98/ADD3, NUP98/CCDC28A, and NUP98/RAP1GDS1. We report a T-ALL with t(11;18)(p15;q12) resulting in a novel NUP98 fusion. Fluorescent in situ hybridisation showed NUP98 and SET binding protein 1......(SETBP1) fusion signals; other analyses showed that exon 12 of NUP98 was fused in-frame with exon 5 of SETBP1. Nested polymerase chain reaction did not amplify the reciprocal SETBP1/NUP98, suggesting that NUP98/SETBP1 transcript is pathogenetically important. SETBP1 has previously not been implicated...

  19. Glucagon-like peptide-1 suppresses advanced glycation end product-induced monocyte chemoattractant protein-1 expression in mesangial cells by reducing advanced glycation end product receptor level.

    Science.gov (United States)

    Ishibashi, Yuji; Nishino, Yuri; Matsui, Takanori; Takeuchi, Masayoshi; Yamagishi, Sho-ichi

    2011-09-01

    Advanced glycation end products (AGE) and receptor for AGE (RAGE) interaction elicits reactive oxygen species (ROS) generation and inflammatory reactions, thereby being involved in the development and progression of diabetic nephropathy. Recently, we, along with others, found that glucagon-like peptide-1 (GLP-1), one of the incretins and a gut hormone secreted from L cells in the intestine in response to food intake, could have anti-inflammatory and antithrombogenic properties in cultured endothelial cells. However, the effects of GLP-1 on renal mesangial cells are largely unknown. Therefore, to elucidate the role of GLP-1 in diabetic nephropathy, this study investigated whether and how GLP-1 blocked AGE-induced monocyte chemoattractant protein-1 expression in human cultured mesangial cells. Gene and protein expression was analyzed by quantitative real-time reverse transcription polymerase chain reactions, Western blots, and enzyme-linked immunosorbent assay. The ROS generation was measured with dihydroethidium staining. Glucagon-like peptide-1 receptor (GLP-1R) was expressed in mesangial cells. Glucagon-like peptide-1 inhibited RAGE gene expression in mesangial cells, which was blocked by small interfering RNAs raised against GLP-1R. Furthermore, GLP-1 decreased ROS generation and subsequently reduced monocyte chemoattractant protein-1 gene and protein expression in AGE-exposed mesangial cells. An analogue of cyclic adenosine monophosphate mimicked the effects of GLP-1 on mesangial cells. Our present study suggests that GLP-1 may directly act on mesangial cells via GLP-1R and that it could work as an anti-inflammatory agent against AGE by reducing RAGE expression via activation of cyclic adenosine monophosphate pathway.

  20. Differential regulation of insulin-like growth factor binding protein-1 and -2 by insulin in the baboon (Papio anubis endometrium

    Directory of Open Access Journals (Sweden)

    Fazleabas Asgerally T

    2008-01-01

    Full Text Available Abstract Background The purpose of this study was to examine the effect of insulin on expression and synthesis of IGFBP-1 and IGFBP-2 in the baboon endometrium in vitro. Methods Baboon endometrial explants collected from cycling, ovariectomized, steroid-treated, simulated-pregnant and pregnant animals were cultured for 48 h in the presence or absence of insulin, with or without estradiol, progesterone and hCG. Results Insulin clearly inhibited IGFBP-1 production and mRNA expression in a time- and dose-dependent manner, whereas IGFBP-2 synthesis was not significantly affected. The inhibitory effects of insulin on IGFBP-1 were more evident in explants of non-pregnant tissue or tissue away from the implantation site. In the absence of insulin, synthesis of IGFBP-1 was induced in explants with low levels of de novo synthesis whereas IGFBP-2 synthesis was inhibited. This effect was potentiated by steroids and hCG in the explant cultures. Conclusion Insulin differentially regulates endometrial IGFBP-1 and IGFBP-2 secretion in the baboon.

  1. High cell density and latent membrane protein 1 expression induce cleavage of the mixed lineage leukemia gene at 11q23 in nasopharyngeal carcinoma cell line

    Directory of Open Access Journals (Sweden)

    Sim Sai-Peng

    2010-09-01

    Full Text Available Abstract Background Nasopharyngeal carcinoma (NPC is commonly found in Southern China and South East Asia. Epstein-Barr virus (EBV infection is well associated with NPC and has been implicated in its pathogenesis. Moreover, various chromosome rearrangements were reported in NPC. However, the underlying mechanism of chromosome rearrangement remains unclear. Furthermore, the relationship between EBV and chromosome rearrangement with respect to the pathogenesis of NPC has not been established. We hypothesize that during virus- or stress-induced apoptosis, chromosomes are initially cleaved at the base of the chromatin loop domain structure. Upon DNA repair, cell may survive with rearranged chromosomes. Methods In this study, cells were seeded at various densities to induce apoptosis. Genomic DNA extracted was processed for Southern hybridization. In order to investigate the role of EBV, especially the latent membrane protein 1 (LMP1, LMP1 gene was overexpressed in NPC cells and chromosome breaks were analyzed by inverse polymerase chain (IPCR reaction. Results Southern analysis revealed that high cell density resulted in cleavage of the mixed lineage leukemia (MLL gene within the breakpoint cluster region (bcr. This high cell density-induced cleavage was significantly reduced by caspase inhibitor, Z-DEVD-FMK. Similarly, IPCR analysis showed that LMP1 expression enhanced cleavage of the MLL bcr. Breakpoint analysis revealed that these breaks occurred within the matrix attachment region/scaffold attachment region (MAR/SAR. Conclusions Since MLL locates at 11q23, a common deletion site in NPC, our results suggest a possibility of stress- or virus-induced apoptosis in the initiation of chromosome rearrangements at 11q23. The breakpoint analysis results also support the role of chromatin structure in defining the site of chromosome rearrangement.

  2. Receptor interacting protein 1 involved in ultraviolet B induced NIH3T3 cell apoptosis through expression of matrix metalloproteinases and reactive oxygen species production

    Institute of Scientific and Technical Information of China (English)

    YAN Yan; LI Li; XU Hao-xiang; PENG Shi-guang; QU Tao; WANG Bao-xi

    2013-01-01

    Background Receptor interacting protein 1 (RIP1),which plays a key role in apoptosis,cell survival and programmed cell necrosis,is one of the most important proteins in the RIP family.The purpose of this study was to investigate the roles of RIP1 in the apoptosis,the generation of reactive oxygen species (ROS) and the expression of matrix metalloproteinases (MMPs) induced by ultraviolet B (UVB) in fibroblasts.Methods siRNA targeting RIP1 was used to silence RIP1 expression in the NIH3T3 fibroblasts.The mRNA and protein levels of MMP-1 and MMP-3,caspase-3 and-8 activities,and ROS activities were determined by reverse transcriptasequantitative polymerase chain reaction (RT-qPCR),immunoblotting,cespase activity assay,immunofiuorescence,and flow cytometry.Results The mRNA and protein expressions of MMP-1 and MMP-3 were significantly increased in RIP1 deficient NIH3T3 cells at 24 hours after UVB treatment.At 24 hours after exposure to UVB,RIP1 deficient NIH3T3 cells presented apoptotic morphology,and the apoptosis rate was significantly increased accompanied by pronounced increase in caspase-8 and-3activities.ROS production was inhibited by UVB at 12 hours in RIP1 deficient NIH3T3 cells.Conclusion RIP1 is involved in NIH3T3 cell damage induced by UVB via participating in the apoptosis,expression of MMPs and ROS production.

  3. Up-regulation of NG2 proteoglycan and interferon-induced transmembrane proteins 1 and 3 in mouse astrocytoma: a membrane proteomics approach.

    Science.gov (United States)

    Seyfried, Nicholas T; Huysentruyt, Leanne C; Atwood, James A; Xia, Qiangwei; Seyfried, Thomas N; Orlando, Ron

    2008-05-18

    Although brain tumors are classified as if their lineage were well understood, the relationship between the molecular events that specify neural cell lineage and brain tumors remains enigmatic. Traditionally, cell surface membrane antigens have served as biomarkers that distinguish brain tumor origin and malignancy. In this study, membrane proteins were identified from a terminally differentiated mouse astrocyte (AC) and CT-2A astrocytoma (CT-2A) cell line using liquid-chromatography coupled with tandem mass spectrometry (LC-MS/MS). A total of 321 and 297 protein groups with at least one unique peptide were identified in the AC and CT-2A cells. Using a label-free quantitative MS approach, 25 plasma membrane proteins in CT-2A were found significantly up- or down-regulated compared with those in AC. Three of the up-regulated proteins, chondroitin sulfate proteoglycan-4 (Cspg4), interferon-induced transmembrane protein-2 (IFITM2) and -3 (IFITM3) were further validated by semi-quantitative RT-PCR analysis. In addition, a third member of the IFITM family, interferon-induced transmembrane protein-1 (IFITM1) was also analyzed. Expression of Cspg4, IFITM1 and IFITM3 was significantly greater in the CT-2A cells than that in the AC cells. Interestingly, Cspg4, also known as neuronal/glial 2 (NG2) proteoglycan in human, is an oligodendrocyte progenitor marker. Therefore, our data suggest that the CT-2A tumor may be derived from NG2 glia rather than from fully differentiated astrocytes. Moreover, the CT-2A cells also express a series of interferon-induced signature proteins that may be specific to this tumor. These data highlight the utility of LC-MS/MS for the identification of brain tumor membrane biomarkers.

  4. Black raspberry extracts inhibit benzo(a)pyrene diol-epoxide-induced activator protein 1 activation and VEGF transcription by targeting the phosphotidylinositol 3-kinase/Akt pathway.

    Science.gov (United States)

    Huang, Chuanshu; Li, Jingxia; Song, Lun; Zhang, Dongyun; Tong, Qiangsong; Ding, Min; Bowman, Linda; Aziz, Robeena; Stoner, Gary D

    2006-01-01

    Previous studies have shown that freeze-dried black raspberry extract fractions inhibit benzo(a)pyrene [B(a)P]-induced transformation of Syrian hamster embryo cells and benzo(a)pyrene diol-epoxide [B(a)PDE]-induced activator protein-1 (AP-1) activity in mouse epidermal Cl 41 cells. The phosphotidylinositol 3-kinase (PI-3K)/Akt pathway is critical for B(a)PDE-induced AP-1 activation in mouse epidermal Cl 41 cells. In the present study, we determined the potential involvement of PI-3K and its downstream kinases on the inhibition of AP-1 activation by black raspberry fractions, RO-FOO3, RO-FOO4, RO-ME, and RO-DM. In addition, we investigated the effects of these fractions on the expression of the AP-1 target genes, vascular endothelial growth factor (VEGF) and inducible nitric oxide synthase (iNOS). Pretreatment of Cl 41 cells with fractions RO-F003 and RO-ME reduced activation of AP-1 and the expression of VEGF, but not iNOS. In contrast, fractions RO-F004 and RO-DM had no effect on AP-1 activation or the expression of either VEGF or iNOS. Consistent with inhibition of AP-1 activation, the RO-ME fraction markedly inhibited activation of PI-3K, Akt, and p70 S6 kinase (p70(S6k)). In addition, overexpression of the dominant negative PI-3K mutant delta p85 reduced the induction of VEGF by B(a)PDE. It is likely that the inhibitory effects of fractions RO-FOO3 and RO-ME on B(a)PDE-induced AP-1 activation and VEGF expression are mediated by inhibition of the PI-3K/Akt pathway. In view of the important roles of AP-1 and VEGF in tumor development, one mechanism for the chemopreventive activity of black raspberries may be inhibition of the PI-3K/Akt/AP-1/VEGF pathway.

  5. Suppression of tumor necrosis factor receptor-associated protein 1 expression induces inhibition of cell proliferation and tumor growth in human esophageal cancer cells.

    Science.gov (United States)

    Tian, Xin; Ma, Ping; Sui, Cheng-Guang; Meng, Fan-Dong; Li, Yan; Fu, Li-Ye; Jiang, Tao; Wang, Yang; Jiang, You-Hong

    2014-06-01

    Tumor necrosis factor receptor-associated protein 1 (TRAP1) is a molecular chaperone involved in multidrug resistance and antiapoptosis in some human tumors, but its regulatory mechanisms have not been revealed in esophageal squamous cell carcinoma (ESCC). In this study, 138 specimens of ESCC were analyzed. TRAP1 was overexpressed in ESCC, particularly in poorly differentiated tumors. To further explore the molecular regulatory mechanism, we constructed specific small interfering RNA-expressing vectors targeting Trap1, and knocked down Trap1 expression in the esophageal cancer cell lines ECA109 and EC9706. Knockdown of Trap1 induced increases in reactive oxygen species and mitochondrial depolarization, which have been proposed as critical regulators of apoptosis. The cell cycle was arrested in G2/M phase, and in vitro inhibition of cell proliferation was confirmed with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide and bromodeoxyuridine assays. Furthermore, re-expression of TRAP1 in Trap1 small interfering RNA-transfected ESCC cells restored cell proliferation and cell apoptosis. Bioluminescence of subcutaneously xenografted ESCC tumor cells demonstrated significant inhibition of in vivo tumor growth by Trap1 knockdown. This study shows that TRAP1 was overexpressed in most patients with ESCC, and caused an increase in antiapoptosis potency. TRAP1 may be regarded as a target in ESCC biotherapy.

  6. The effects of a selective inhibitor of c-Fos/activator protein-1 on endotoxin-induced acute kidney injury in mice

    Directory of Open Access Journals (Sweden)

    Miyazaki Hiroyuki

    2012-11-01

    Full Text Available Abstract Background Sepsis has been identified as the most common cause of acute kidney injury (AKI in intensive care units. Lipopolysaccharide (LPS induces the production of several proinflammatory cytokines including tumor necrosis factor (TNF-alpha, a major pathogenetic factor in septic AKI. c-Fos/activator protein (AP-1 controls the expression of these cytokines by binding directly to AP-1 motifs in the cytokine promoter regions. T-5224 is a new drug developed by computer-aided drug design that selectively inhibits c-Fos/AP-1 binding to DNA. In this study, we tested whether T-5224 has a potential inhibitory effect against LPS-induced AKI, by suppressing the TNF-alpha inflammatory response and other downstream effectors. Methods To test this hypothesis, male C57BL/6 mice at 7 weeks old were divided into three groups (control, LPS and T-5224 groups. Mice in the control group received saline intraperitoneally and polyvinylpyrrolidone solution orally. Mice in the LPS group were injected intraperitoneally with a 6 mg/kg dose of LPS and were given polyvinylpyrrolidone solution immediately after LPS injection. In the T-5224 group, mice were administered T-5224 orally at a dose of 300 mg/kg immediately after LPS injection. Serum concentrations of TNF-alpha, interleukin (IL-1beta, IL-6 and IL-10 were measured by ELISA. Moreover, the expression of intercellular adhesion molecule (ICAM-1 mRNA in kidney was examined by quantitative real-time RT-PCR. Finally, we evaluated renal histological changes. Results LPS injection induced high serum levels of TNF-alpha, IL-1beta and IL-6. However, the administration of T-5224 inhibited the LPS-induced increase in these cytokine levels. The serum levels of IL-10 in the LPS group and T-5224 group were markedly elevated compared with the control group. T-5224 also inhibited LPS-induced ICAM-1 mRNA expression. Furthermore histological studies supported an anti-inflammatory role of T-5224. Conclusions In endotoxin-induced

  7. Interleukin-1β,Tumor Necrosis Factor-α and Lipopolysaccharide Induce Expression of Monocyte Chemoattractant Protein-1 in Calf Aortic Smooth Muscle Cells

    Institute of Scientific and Technical Information of China (English)

    MENG Feng; DENG Zhongduan; NI Juan

    2000-01-01

    To investigate whether interleukin-1β(IL-1β), tumor necrosis factor-α (TNF-α) and lipopolysaccharide (LPS) induce expression of monocyte chemoattractant protein-1 (MCP-1)mRNA and protein in calf aortic smooth muscle cells(SMCs), calf aortic SMCs were cultured by a substrate-attached explant method. The cultured SMCs were used between the third to the fifth passage. After the cells became confluent, the SMCs were exposed to 2 ng/ml IL- 1β, 20 ng/mlTNF-lα and 100 ng/ml LPS respectively, and the total RNA of SMCs which were incubated for 4h at 37℃ were extracted from the cells by using guanidinium isothiocyanate method. The expression of MCP-1 mRNA in SMCs was detected by using dot blotting analysis using a probe of γ-32p-end-labelled 35-mer oligonucleotide. After a 24-h incubation, the media conditioned by the cultured SMCs were collected. The MCP-1 protein content in the conditioned media was determined by using sandwich ELISA. The results were as follows: Dot blotting analysis showed that the cultured SMCs could express MCP-1 mRNA. After a 4-h exposure to IL-Iβ, TNF-α and LPS, the MCP-1 mRNA expression in SMCs was increased (3.6-fold, 2.3-fold and 1.6-fold, respectively).ELISA showed that the levels of MCP-1 protein in the conditioned media were also increased (2.9-fold, 1.7-fold and 1.1-fold, respectively ). The results suggest that calf aortic SMCs could express MCP-1 mRNA and protein. IL-1β and TNF-α can induce strong expression of MCP- 1mRNA and protein, and the former is more effective than the latter.

  8. 硒结合蛋白在膀胱癌中的表达及临床意义%Expression and clinical role of Selenium binding protein 1 in bladder tumor

    Institute of Scientific and Technical Information of China (English)

    向小龙; 陈苏; 陈洪波; 胡晓辉; 江克华; 袁巍; 朱圣亮; 兰勇

    2016-01-01

    目的 探讨硒结合蛋白-1(Selenium binding protein 1,SBP1)在不同膀胱组织中的表达情况及其临床意义.方法 运用Western blot法检测膀胱癌组织、膀胱黏膜良性病变组织及正常膀胱黏膜组织中的SBP1的表达,并分析其表达差异性.结果 SBP1在膀胱癌组织中的表达明显低于膀胱黏膜良性病变组织及正常膀胱黏膜(P<0.05),且浅表性膀胱癌组织表达阳性率高于浸润性膀胱癌,无淋巴结转移的膀胱癌组织表达阳性率高于具有淋巴结转移的膀胱癌组织.结论 SBP1在膀胱癌组织中表达下调,膀胱癌的发生、进展可能与SBP1的表达抑制有关.%Objectives To investigate the expression of Selenium binding protein 1 (SBP1) in bladder tumor and its clinical significance.Methods 30 bladder cancer tissue and 20 bladder benign lesions and 8 bladder normal tissue were collected to detect the expression of SBP1 by Western blot.Results The expression of the SBP1 in bladder cancer tissue was down-regulated compared with that in bladder benign lesions and bladder normal tissue (0.325 ± 0.065vs0.578 ± 0.073vs0.749 ± 0.052), P < 0.05, and the expression of SBP1 in the bladder neoplasms was higher than that in the invasive bladder cancer (0.548 ± 0.082vs0.361 ± 0.048), P < 0.05.Moreover, the expression of SBP1 in lymphatic metastasis of bladder cancer was lower than that in no-lymphatic metastasis (0.241 ± 0.047vs0.409 ± 0.058), P < 0.05.Conclusions SBP1 is down-regulated in bladder cancer and it is strongly related with the bladder progression, which means that it is probably play an important role in tumorigenesis.

  9. Inhibitory effect of microRNA-27b on interleukin 17 (IL-17)-induced monocyte chemoattractant protein-1 (MCP1) expression.

    Science.gov (United States)

    Huang, K D; Shen, Y; Wei, X; Zhang, F Q; Liu, Y Y; Ma, L

    2016-07-14

    We investigated the effect of microRNA-27b (miR-27b), a gene expression regulatory factor, on the expression of monocyte chemoattractant protein-1 (MCP1) stimulated by interleukin 17 (IL-17). After IL-17 had been added to H9C2 cardiomyocytes, an miR-27b mimic was transfected into the H9C2 cells. The mRNA expression levels of miR-27b and MCP1 in the H9C2 cells were detected by SYBR green I fluorescence quantitative reverse transcription polymerase chain reaction. Enzyme-linked immunosorbent assay was used to measure the expression levels of MCP1 protein in the H9C2 cells. The expression of MCP1 mRNA in the H9C2 cells began to increase 2 h after IL-17 stimulation, reached a peak at 4 h, and then decreased. The MCP1 protein level increased gradually in the 24 h following IL-17 stimulation. After transfection with the miR-27b mimic, the expression of miR-27b in the H9C2 cells significantly increased than that in the miRNA negative control group (P < 0.01). The MCP1 mRNA and protein levels in the miR-27b mimic + IL-17 group were significantly reduced than that in the miRNA negative control + IL-17 group (P < 0.01). miR-27b inhibited IL-17-induced MCP1 expression in the H9C2 cells, which demonstrates that treatment with microRNA could alleviate myocardial injury in viral myocarditis.

  10. Hyperhomocysteinemia-Induced Monocyte Chemoattractant Protein-1 Promoter DNA Methylation by Nuclear Factor-κB/DNA Methyltransferase 1 in Apolipoprotein E-Deficient Mice.

    Science.gov (United States)

    Wang, Ju; Jiang, Yideng; Yang, Anning; Sun, Weiwei; Ma, Changjian; Ma, Shengchao; Gong, Huihui; Shi, Yingkang; Wei, Jun

    2013-04-01

    Hyperhomocysteinemia is considered to be a significant risk factor in atherosclerosis and plays an important role in it. The purpose of this study was to determine the molecular mechanism of blood monocyte chemoattractant protein-1 (MCP-1) promoter DNA hypomethylation in the formation of atherosclerosis induced by hyperhomocysteinemia, and to explore the effect of nuclear factor-κB (NF-κB)/DNA methyltransferase 1 (DNMT1) in this mechanism. The atherosclerotic effect of MCP-1 in apolipoprotein E-deficient (ApoE(-/-)) and wild-type C57BL/6J mice was evaluated using atherosclerotic lesion area; serum NF-κB, MCP-1, and DNMT1 levels; and MCP-1 promoter DNA methylation expression. In vitro, the mechanism responsible for the effect of NF-κB/DNMT1 on foam cells was investigated by measuring NF-κB and DNMT1 levels to determine whether NF-κB/DNMT1 had an effect on gene expression. Compared with the control group, atherosclerotic lesions in ApoE(-/-) mice fed a high methionine diet significantly increased, as did the expression of MCP-1. In vitro study showed that pyrrolidine dithiocarbamate treatment down-regulated levels of NF-κB and raised DNMT1 concentrations, confirming the effect of NF-κB/DNMT1 in the MCP-1 promoter DNA methylation process. In conclusion, our results suggest that through NF-κB/DNMT1, MCP-1 promoter DNA hypomethylation may play a key role in formation of atherosclerosis under hyperhomocysteinemia.

  11. Advanced oxidation protein products induce monocyte chemoattractant protein-1 expression via p38 mitogen-activated protein kinase activation in rat vascular smooth muscle cells

    Institute of Scientific and Technical Information of China (English)

    PENG Kan-fu; WU Xiong-fei; ZHAO Hong-wen; SUN Yan

    2006-01-01

    Background Advanced oxidation protein products (AOPPs) are new uremic toxins reported by Witko-Sarsat in 1996, which are associated with the pathogenesis of atherosclerosis. However, the mechanisms by which AOPPs enhance atherosclerosis have not been fully understood. Monocyte chemoattractant protein-1 (MCP-1) is a chemokine which stimulates migration of monocytes and plays a critical role in the development of atherosclerosis. In this study, we investigated the effect of AOPPs on MCP-1 expression in cultured vascular smooth muscle cells (VSMCs).Methods VSMCs were cultured and then co-incubated with AOPP (200 μ mol/L, 400 μ mol/L) for different times with or without pretreatment with specific p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580. RT-PCR and Western blott were used to detect MCP-1 mRNA and protein expression at different time points after AOPP stimulation in rat smooth muscle cells. Western blot was used to detect the expression of phosphorylated p38 MAPK.Results Treatment of VSMC with AOPPs resulted in a significant increase of the expression of MCP- 1 mRNA and protein in time- and dose-dependent manner, and could activated p38 MAPK. Pretreatment of VSMCs with SB203580 resulted in a dose-dependent inhibition of AOPPs-induced MCP-1 mRNA and protein expression.Conclusions AOPPs can stimulate MCP-1 expression via p38 MAPK in VSMCs. This suggests that AOPPs might contribute to the formation of atherosclerosis through this proinflammatory effect.

  12. Induction of Wnt-inducible signaling protein-1 correlates with invasive breast cancer oncogenesis and reduced type 1 cell-mediated cytotoxic immunity: a retrospective study.

    Science.gov (United States)

    Klinke, David J

    2014-01-01

    Innate and type 1 cell-mediated cytotoxic immunity function as important extracellular control mechanisms that maintain cellular homeostasis. Interleukin-12 (IL12) is an important cytokine that links innate immunity with type 1 cell-mediated cytotoxic immunity. We recently observed in vitro that tumor-derived Wnt-inducible signaling protein-1 (WISP1) exerts paracrine action to suppress IL12 signaling. The objective of this retrospective study was three fold: 1) to determine whether a gene signature associated with type 1 cell-mediated cytotoxic immunity was correlated with overall survival, 2) to determine whether WISP1 expression is increased in invasive breast cancer, and 3) to determine whether a gene signature consistent with inhibition of IL12 signaling correlates with WISP1 expression. Clinical information and mRNA expression for genes associated with anti-tumor immunity were obtained from the invasive breast cancer arm of the Cancer Genome Atlas study. Patient cohorts were identified using hierarchical clustering. The immune signatures associated with the patient cohorts were interpreted using model-based inference of immune polarization. Reverse phase protein array, tissue microarray, and quantitative flow cytometry in breast cancer cell lines were used to validate observed differences in gene expression. We found that type 1 cell-mediated cytotoxic immunity was correlated with increased survival in patients with invasive breast cancer, especially in patients with invasive triple negative breast cancer. Oncogenic transformation in invasive breast cancer was associated with an increase in WISP1. The gene expression signature in invasive breast cancer was consistent with WISP1 as a paracrine inhibitor of type 1 cell-mediated immunity through inhibiting IL12 signaling and promoting type 2 immunity. Moreover, model-based inference helped identify appropriate immune signatures that can be used as design constraints in genetically engineering better pre

  13. HIV-1 Gag Blocks Selenite-Induced Stress Granule Assembly by Altering the mRNA Cap-Binding Complex

    Directory of Open Access Journals (Sweden)

    Alessandro Cinti

    2016-03-01

    Full Text Available Stress granules (SGs are dynamic accumulations of stalled preinitiation complexes and translational machinery that assemble under stressful conditions. Sodium selenite (Se induces the assembly of noncanonical type II SGs that differ in morphology, composition, and mechanism of assembly from canonical SGs. Se inhibits translation initiation by altering the cap-binding activity of eukaryotic translation initiation factor 4E (eIF4E-binding protein 1 (4EBP1. In this work, we show that human immunodeficiency virus type 1 (HIV-1 Gag is able to block the assembly of type II noncanonical SGs to facilitate continued Gag protein synthesis. We demonstrate that expression of Gag reduces the amount of hypophosphorylated 4EBP1 associated with the 5′ cap potentially through an interaction with its target, eIF4E. These results suggest that the assembly of SGs is an important host antiviral defense that HIV-1 has evolved for inhibition through several distinct mechanisms.

  14. Advances in Study on Scaffold/matrix Attachment Region Binding Protein 1%核基质结合区结合蛋白质1研究进展

    Institute of Scientific and Technical Information of China (English)

    罗金波; 乔炜

    2012-01-01

    Change of nuclear matrix associated protein is one of the major phenotypes of malignant tumor cells leading to alteration in chromatin folding, the change of fidelity of genome replication and gene expression. Aberrant expression of matrix attachment region (MAR) binding proteins (MARBPs) modulates the chromatin constitution and disruption of transcriptional network that leads to oncogenesis. Some of these proteins are expressed specifically in tumor tissue and could be served as promising diagnostic or prognostic markers. Scaffold/matrix attachment region binding protein 1 (SMAR1) expression is drastically down-regulated in breast cancer. This article reviewed the roles of SMAR1 in cell growth, apoptosis and tumorigenesis.%核基质相关蛋白改变是恶性肿瘤细胞的主要表现形式,可使染色质发生折叠、基因复制保真度和基因表达发生改变.核基质结合区(MAR)结合蛋白(MARBPs)表达异常可影响染色质构成、干扰转录调控程序,致肿瘤形成.某些MARBPs特异性表达于肿瘤组织,是肿瘤诊断和预后的指标.核基质结合区结合蛋白质1(SMAR1)在乳腺癌中的表达急剧下调.本文就SMAR1在细胞生长、凋亡和肿瘤形成中的作用作一综述.

  15. Research progress on selenium binding protein 1 as a novel tumor biomarker%硒结合蛋白1作为肿瘤标志物的研究进展

    Institute of Scientific and Technical Information of China (English)

    张晨静; 潘驰; 潘文胜; 陈光兰

    2013-01-01

    Selenium binding protein 1 ( SBP1) has been shown to bind selenium covalently and is expressed in a variety of tissues and cell lines. Selenium is incorporated into selenoproteins that have a wide range of pleiotropic effects, including its important function in prevention of cancer progression. Recent studies have revealed that SBP1 may not only exert tumor suppressive function, but also become a novel biomarker for predicting prognosis and guiding personalized therapeutic strategies. This paper briefly reviews the studies of SBP1 as a novel biomarker and tumor suppressor in the progression of various cancers.%硒结合蛋白1(SBP1)共价结合于硒参与多种细胞内硒的转运.然而硒是一种重要的微量元素,与肿瘤的发生有密切联系,是一种新型抗肿瘤物质.近年来随着对SBP1研究的深入,发现其不但可作为预后指导个性化治疗策略的一种新型生物标志物,而且有望成为肿瘤治疗的新靶点并提高肿瘤细胞的化疗敏感性,作为一种新型抗肿瘤治疗策略应用于临床.该文旨在探讨SBP1的抗肿瘤机制及其作为潜在肿瘤标志物的研究进展,以期指导临床肿瘤个性化治疗,提高患者的预后效果.

  16. 人硒结合蛋白1在肿瘤发生发展中的作用%Research Advancement of Human Selenium Binding Protein 1 in Tumorigenesis and Progression

    Institute of Scientific and Technical Information of China (English)

    张锦

    2010-01-01

    @@ 0 引言 肿瘤是当今世界发病率及死亡率最高的疾病[1].肿瘤发生发展是一个极为复杂的过程,流行病学资料显示,食物及其营养素从多方面影响着肿瘤的发生与发展[2-3].硒(selenium,75Se)是一种具有抗癌效应的元素[4-7],它以无机亚硒酸盐或有机硒酸盐的形式存在于植物和其他有机食物中.人类硒基蛋白质组包含35种含硒蛋白质,它们具有广泛的生理功能.现将硒结合蛋白1(selenium binding protein-1,SBPl)在肿瘤中的作用综述如下.

  17. Angiotensin II induces apoptosis of human pulmonary microvascular endothelial cells in acute aortic dissection complicated with lung injury patients through modulating the expression of monocyte chemoattractant protein-1.

    Science.gov (United States)

    Wu, Zhiyong; Dai, Feifeng; Ren, Wei; Liu, Huagang; Li, Bowen; Chang, Jinxing

    2016-01-01

    Patients with acute aortic dissection (AAD) usually showed acute lung injury (ALI). However, its pathogenesis is still not well defined. Apoptosis of pulmonary microvascular endothelial cells (PMVECs) is closely related to the alveolus-capillary barrier injury and the increased vascular permeability. In this study, we aim to investigate the human PMVECs (hPMVECs) apoptosis induced by angiotensin II (AngII) and monocyte chemoattractant protein-1 (MCP-1) and their potential interaction in the pathogenesis of AAD complicated with ALI. Fifty-eight newly diagnosed AAD, 12 matched healthy individuals were included. Pulmonary tissues of AAD complicated with lung injury were obtained from 2 cadavers to determine the levels of AngII type 1 receptor (AT1-R) and MCP-1. Serum AngII was measured using commercial ELISA kit. H&E staining and immunohistostaining were performed to determine the expression of AT1-R and MCP-1. For the in vitro experiment, hPMVECs were divided into control, AngII group, AngII+Bindarit group and Bindarit group, respectively. Flow cytometry was performed to analyze the apoptosis in each group. Reverse transcription-polymerase chain reaction was performed to determine the mRNA expression of MCP-1. Western blot analysis was performed to evaluate the expression of MCP-1 and apoptosis related protein. Apoptosis of hPMVECs was observed in the lung tissues in the cadavers with AAD complicated with ALI. Besides, the expression of AT1-R and MCP-1 was remarkably elevated. Compared with normal individuals and the non-lung injury AAD patients, the expression of serum AngII was remarkably elevated in AAD patients complicated with ALI. In vitro experiments showed AngII contributed to the apoptosis and elevation of MCP1 in hPMVECs. Besides, it involved in the down-regulation of Bcl-2 protein, and up-regulation of Bax and Caspase-3. Such phenomenon was completely reversed after administration of MCP-1 inhibitor (Bindarit). The production of MCP-1 and cellular

  18. Molecular Cloning of a cDNA Encoding for Taenia solium TATA-Box Binding Protein 1 (TsTBP1) and Study of Its Interactions with the TATA-Box of Actin 5 and Typical 2-Cys Peroxiredoxin Genes.

    Science.gov (United States)

    Rodríguez-Lima, Oscar; García-Gutierrez, Ponciano; Jiménez, Lucía; Zarain-Herzberg, Ángel; Lazzarini, Roberto; Landa, Abraham

    2015-01-01

    TATA-box binding protein (TBP) is an essential regulatory transcription factor for the TATA-box and TATA-box-less gene promoters. We report the cloning and characterization of a full-length cDNA that encodes a Taenia solium TATA-box binding protein 1 (TsTBP1). Deduced amino acid composition from its nucleotide sequence revealed that encodes a protein of 238 residues with a predicted molecular weight of 26.7 kDa, and a theoretical pI of 10.6. The NH2-terminal domain shows no conservation when compared with to pig and human TBP1s. However, it shows high conservation in size and amino acid identity with taeniids TBP1s. In contrast, the TsTBP1 COOH-terminal domain is highly conserved among organisms, and contains the amino acids involved in interactions with the TATA-box, as well as with TFIIA and TFIIB. In silico TsTBP1 modeling reveals that the COOH-terminal domain forms the classical saddle structure of the TBP family, with one α-helix at the end, not present in pig and human. Native TsTBP1 was detected in T. solium cysticerci´s nuclear extract by western blot using rabbit antibodies generated against two synthetic peptides located in the NH2 and COOH-terminal domains of TsTBP1. These antibodies, through immunofluorescence technique, identified the TBP1 in the nucleus of cells that form the bladder wall of cysticerci of Taenia crassiceps, an organism close related to T. solium. Electrophoretic mobility shift assays using nuclear extracts from T. solium cysticerci and antibodies against the NH2-terminal domain of TsTBP1 showed the interaction of native TsTBP1 with the TATA-box present in T. solium actin 5 (pAT5) and 2-Cys peroxiredoxin (Ts2-CysPrx) gene promoters; in contrast, when antibodies against the anti-COOH-terminal domain of TsTBP1 were used, they inhibited the binding of TsTBP1 to the TATA-box of the pAT5 promoter gene.

  19. Metallothionein and a peptide modeled after metallothionein, EmtinB, induce neuronal differentiation and survival through binding to receptors of the low-density lipoprotein receptor family

    DEFF Research Database (Denmark)

    Ambjørn, Malene; Asmussen, Johanne W; Lindstam, Mats;

    2007-01-01

    Accumulating evidence suggests that metallothionein (MT)-I and -II promote neuronal survival and regeneration in vivo. The present study investigated the molecular mechanisms underlying the differentiation and survival-promoting effects of MT and a peptide modeled after MT, EmtinB. Both MT...... and EmtinB directly stimulated neurite outgrowth and promoted survival in vitro using primary cultures of cerebellar granule neurons. In addition, expression and surface localization of megalin, a known MT receptor, and the related lipoprotein receptor-related protein-1 (LRP) are demonstrated in cerebellar...... granule neurons. By means of surface plasmon resonance MT and EmtinB were found to bind to both megalin and LRP. The bindings were abrogated in the presence of receptor-associated protein-1, an antagonist of the low-density lipoprotein receptor family, which also inhibited MT- and EmtinB-induced neurite...

  20. Cyr61 induces the expression of monocyte chemoattractant protein-1 via the integrin ανβ3, FAK, PI3K/Akt, and NF-κB pathways in retinal vascular endothelial cells.

    Science.gov (United States)

    You, Jian-Jang; Yang, Chang-Hao; Yang, Chung-May; Chen, Muh-Shy

    2014-01-01

    Diabetes causes a number of metabolic and physiological abnormalities in the retina. Many of the molecular and physiological abnormalities that develop during diabetic retinopathy are due to inflammation. Monocyte chemoattractant protein-1 (MCP-1) is an important factor involved in diabetic retinopathy. In a previous study, we found that cysteine-rich 61 (Cyr61), an important angiogenic factor, also plays an important role in diabetic retinopathy. In addition to the direct effects of Cyr61, we observed that Cyr61 can induce the expression of MCP-1. However, the mechanism through which this occurs is not completely understood in chorioretinal vascular endothelial cells. We therefore investigated the effects of Cyr61 on MCP-1 expression in this cell type. Cyr61 stimulated the expression of MCP-1 at the mRNA, protein, and secreted protein levels in a dose-dependent and time-dependent manner. Both total MCP-1 levels and secreted MCP-1 levels were attenuated during the response to Cyr61 stimulation by pretreatment with integrin ανβ3-blocking antibodies, a FAK inhibitor (PF573228), a PI3K inhibitor (LY294002), and an Akt inhibitor (A6730). Electrophoretic mobility shift assays revealed that the above inhibitors suppressed the activation of NF-κB. Additionally, deletion of the NF-κB-binding element in the MCP-1 gene promoter led to a decrease in expression in luciferase reporter assays. These results show that the induction of MCP-1 by Cyr61 is mediated through the activation of the integrin ανβ3, FAK, PI3K/Akt, and IKK/NF-κB pathways in chorioretinal vascular endothelial cells.

  1. Pneumocystis carinii major surface glycoprotein induces interleukin-8 and monocyte chemoattractant protein-1 release from a human alveolar epithelial cell line

    DEFF Research Database (Denmark)

    Benfield, T L; Lundgren, Bettina; Shelhamer, J H

    1999-01-01

    (IL-8) and monocyte chemoattractant protein-1 (MCP-1) from an alveolar epithelial cell line (A549). RESULTS: Incubation of A549 cells with MSG in concentrations from 0.4 to 10 microg mL-1 for 24 h caused dose-dependent increases in IL-8 release (3.4-fold above control, P

  2. The telomere binding protein TRF2 induces chromatin compaction.

    Directory of Open Access Journals (Sweden)

    Asmaa M Baker

    Full Text Available Mammalian telomeres are specialized chromatin structures that require the telomere binding protein, TRF2, for maintaining chromosome stability. In addition to its ability to modulate DNA repair activities, TRF2 also has direct effects on DNA structure and topology. Given that mammalian telomeric chromatin includes nucleosomes, we investigated the effect of this protein on chromatin structure. TRF2 bound to reconstituted telomeric nucleosomal fibers through both its basic N-terminus and its C-terminal DNA binding domain. Analytical agarose gel electrophoresis (AAGE studies showed that TRF2 promoted the folding of nucleosomal arrays into more compact structures by neutralizing negative surface charge. A construct containing the N-terminal and TRFH domains together altered the charge and radius of nucleosomal arrays similarly to full-length TRF2 suggesting that TRF2-driven changes in global chromatin structure were largely due to these regions. However, the most compact chromatin structures were induced by the isolated basic N-terminal region, as judged by both AAGE and atomic force microscopy. Although the N-terminal region condensed nucleosomal array fibers, the TRFH domain, known to alter DNA topology, was required for stimulation of a strand invasion-like reaction with nucleosomal arrays. Optimal strand invasion also required the C-terminal DNA binding domain. Furthermore, the reaction was not stimulated on linear histone-free DNA. Our data suggest that nucleosomal chromatin has the ability to facilitate this activity of TRF2 which is thought to be involved in stabilizing looped telomere structures.

  3. Expression of progesterone receptor membrane component 1, serpine mRNA binding protein 1 and nuclear progesterone receptor isoforms A and B in the bovine myometrium during the estrous cycle and early pregnancy.

    Science.gov (United States)

    Slonina, Dominika; Kowalik, Magdalena K; Kotwica, Jan

    2012-01-01

    The aim of this study was to investigate the (1) expression of progesterone membrane component 1 (PGRMC1), serpine mRNA binding protein 1 (SERBP1) and progesterone receptor (PR) mRNA and (2) protein expression levels of PGRMC1, SERBP1 and PR isoforms A and B in the bovine myometrium during the estrous cycle and early pregnancy. Uteri from cows on days 1-5, 6-10, 11-16 and 17-21 of the estrous cycle and weeks 3-5, 6-8 and 9-12 of pregnancy were used (n=5-6 per period). There were no changes (P>0.05) in PGRMC1 mRNA expression during the estrous cycle, while expression of SERBP1 and PR mRNA was the lowest (P0.05) in SERBP1 protein expression in cycling and pregnant cows, while the highest (P<0.05) PGRMC1 protein expression was found during weeks 3-5 of pregnancy. Similar protein expression profiles for PRA and PRB were found, and protein levels were highest on days 1-5 of the estrous cycle. From day 6 of the cycle, PRA and PRB protein expression decreased and were maintained at this lower level during pregnancy. In conclusion, our study assessed mRNA and protein expression levels of PGRMC1, SERBP1 and PR in the bovine myometrium during the estrous cycle and the first trimester of pregnancy. It is possible that progesterone (P4) affects myometrial function in a genomic and nongenomic manner.

  4. Superlattices assembled through shape-induced directional binding.

    Science.gov (United States)

    Lu, Fang; Yager, Kevin G; Zhang, Yugang; Xin, Huolin; Gang, Oleg

    2015-01-01

    Organization of spherical particles into lattices is typically driven by packing considerations. Although the addition of directional binding can significantly broaden structural diversity, nanoscale implementation remains challenging. Here we investigate the assembly of clusters and lattices in which anisotropic polyhedral blocks coordinate isotropic spherical nanoparticles via shape-induced directional interactions facilitated by DNA recognition. We show that these polyhedral blocks--cubes and octahedrons--when mixed with spheres, promote the assembly of clusters with architecture determined by polyhedron symmetry. Moreover, three-dimensional binary superlattices are formed when DNA shells accommodate the shape disparity between nanoparticle interfaces. The crystallographic symmetry of assembled lattices is determined by the spatial symmetry of the block's facets, while structural order depends on DNA-tuned interactions and particle size ratio. The presented lattice assembly strategy, exploiting shape for defining the global structure and DNA-mediation locally, opens novel possibilities for by-design fabrication of binary lattices.

  5. Phosphorylated 4E-binding protein 1 overexpression in human cancer%磷酸化4E-BP1与恶性肿瘤研究进展

    Institute of Scientific and Technical Information of China (English)

    常成; 谷金宇

    2011-01-01

    4E-BP1是真核细胞翻译起始因子4E(eIF4E)的特异性抑制物,近年研究显示,磷酸化形式的4E-BP1(P-4E-BP1)在多种恶性肿瘤如乳腺癌、宫颈癌、甲状腺、前列腺癌、大肠癌等中存在过表达,并且其表达与肿瘤的大小、侵袭、转移能力、预后等临床病理特征密切相关。因此,阐明P-4E-BP1的表达与肿瘤的生物学行为将有助于全面了解恶性肿瘤的发生、发展、侵袭及转移机制,同时对指导临床诊断和治疗,判断预后有重大意义。更重要的是,P-4E-BP1有可能成为治疗肿瘤的新靶点,为临床治疗肿瘤提供新思路。%4E-BP1 is the specific inhibitor of eukaryotic initiation factor 4E, recent studies have shown, phosphorylated 4E-binding protein 1(P-4E-BP1)overexpression has been observed in a variety of human cancers, including breast cancer, cervical cancer, thyroid cancer, prostate cancer, colorectal cancer, et al. Its expression level is associated with tumor size, invasion, metastasis, prognosis and other clinical and pathological features. Thus evaluate P-4E-BP1 expression level which is associated with tumor biological behavior will help us better understand the etiology, development, invasion and metastasis mechanisms of cancer.Moreover, P-4E-BP1 may become a new target for cancer treatment and provide new ideas for the clinical cancer treatment.

  6. P53与端粒重复序列结合蛋白质1的体外相互作用%The molecular interaction between P53 and telomeric repeat binding protein 1 in vitro

    Institute of Scientific and Technical Information of China (English)

    李玲; 张波; 邹万忠; 郑杰

    2004-01-01

    目的:通过分析端粒主要结合蛋白中端粒重复序列结合蛋白质1(Telomeric repeat binding protein 1,TRBP1)与P53的体外结合,探讨P53通过端粒途径调节细胞增殖、衰老和凋亡的分子机制.方法:谷胱甘肽S转移酶(glutathione S-transferase,GST)和人P53-GST融合蛋白经大肠杆菌表达、谷胱甘肽-SepharoseTM4B纯化后,和人乳腺癌细胞MCF-7细胞蛋白进行体外结合反应(pull down),Western blot检测反应物中P53和TRBP1的结合.融合蛋白中人P53包括野生型(1~393)、C端缺失体P53 N5(2~293)、N端缺失体P53 2C(95~393)、175单个氨基酸突变体P53 R175H(R→H).结果:聚丙烯酰胺凝胶电泳和考马斯亮蓝R250染色显示,纯化的GST和4种P53-GST蛋白纯度在90%以上,且分子量与预计的完全一致.TRBP1的Western blot显示,野生型P53和P53-R175H均能沉淀MCF-7中的TRBP1,且结合力相似,而单独的GST则无沉淀TRBP1的作用.与野生型P53和P53 R175H相比,P53 2C与TRBP1的结合力明显增加,P53 N5与TRBP1的结合力明显减弱.结论:P53和TRBP1可以直接体外结合,P53的C端(293~393)是与TRBP1结合的结构域.P53和TRBP1结构域依赖性的结合可能与端粒动态变化所诱导的细胞活动有关.

  7. Expression and localization of progesterone receptor membrane component 1 and 2 and serpine mRNA binding protein 1 in the bovine corpus luteum during the estrous cycle and the first trimester of pregnancy.

    Science.gov (United States)

    Kowalik, Magdalena K; Rekawiecki, Robert; Kotwica, Jan

    2014-11-01

    The aim of this study was to evaluate the mRNA and protein expression and the localization of progesterone receptor membrane component 1 (PGRMC1), PGRMC2, and the PGRMC1 partner serpine mRNA binding protein 1 (SERBP1) in the bovine CL on Days 2 to 5, 6 to 10, 11 to 16, and 17 to 20 of the estrous cycle as well as during Weeks 3 to 5, 6 to 8, and 9 to 12 of pregnancy (n = 5-6 per each period). The highest levels of PGRMC1 and PGRMC2 mRNA expression were found on Days 6 to 16 (P < 0.05) and 11 to 16, respectively, of the estrous cycle and during pregnancy (P < 0.001). The level of PGRMC1 protein was the highest (P < 0.05) on Days 11 to 16 of the estrous cycle compared with the other stages of the estrous cycle and pregnancy, whereas PGRMC2 protein expression (P < 0.001) was the highest on Days 17 to 20 and also during pregnancy. The mRNA expression of SERBP1 was increased (P < 0.05) on Days 11 to 16, whereas the level of its protein product was decreased (P < 0.05) on Days 6 to 10 of the estrous cycle and was at its lowest (P < 0.001) on Days 17 to 20. In pregnant cows, the patterns of SERBP1 mRNA and protein expression remained constant and were comparable with those observed during the estrous cycle. Progesterone receptor membrane component 1 and PGRMC2 localized to both large and small luteal cells, whereas SERBP1 was observed mainly in small luteal cells and much less frequently in large luteal cells. All proteins were also localized in the endothelial cells of blood vessels. The data obtained indicate the variable expression of PGRMC1, PGRMC2, and SERBP1 mRNA and protein in the bovine CL and suggest that progesterone may regulate CL function via its membrane receptors during both the estrous cycle and pregnancy.

  8. The enhancement of astrocytic-derived monocyte chemoattractant protein-1 induced by the interaction of opiate and HIV tat in HIV-associated dementia

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    HIV-associated dementia(HAD)is a public health problem and is particularly prevalent in drug abusers.The neuropathogenesis of human immunodeficiency virus(HIV)infection involves a complex cascade of inflammatory events,including monocyte/macrophage infiltration in the brain,glial immune activation and release of neurotoxic substances.In these events,astrocytic-derived monocyte chemoattractant protein-1(MCP-1)plays an important role,whose release is elevated by HIV transactivator of transcription(HIV tat)and...

  9. Saturated Fatty Acid Induces Insulin Resistance Partially Through Nucleotide-binding Oligomerization Domain 1 Signaling Pathway in Adipocytes

    Institute of Scientific and Technical Information of China (English)

    Yi-jun Zhou; Yin-si Tang; Yu-ling Song; Ai Li; Hui Zhou; Yan Li

    2013-01-01

    Objective To investigate the potential role of nucleotide-binding oligomerization domain 1 (NOD1), a component of the innate immune system, in mediating lipid-induced insulin resistance in adipocytes. Methods Adipocytes from Toll-like receptor 4 deficiency mice were used for stimulation experiments. The effect of oleate/palmitate mixture on nuclear factor-κB (NF-κB) activation was analyzed by reporter plasmid assay. The release of proinflammatory chemokine/cytokines production was determined by using real-time PCR. Insulin-stimulated glucose uptake was measured by 2-deoxy-D-[3H] glucose uptake assay. Chemokine/cytokine expression and glucose uptake in adipocytes transfected with small interfering RNA (siRNA) targeting NOD1 upon fatty acids treatment were analyzed. Results Oleate/palmitate mixture activated the NF-κB pathway and induced interleukin-6, tumor necrosis factor-α, and monocyte chemoattractant protein-1 mRNA expressions in adipocytes from mice deficient in Toll-like receptor 4, and these effects were blocked by siRNA targeting NOD1. Furthermore, saturated fatty acids decreased the ability of insulin-stimulated glucose uptake. Importantly, siRNA targeting NOD1 partially reversed saturated fatty acid-induced suppression of insulin-induced glucose uptake. Conclusion NOD1 might play an important role in saturated fatty acid-induced insulin resistance in adipocytes, suggesting a mechanism by which reduced NOD1 activity confers beneficial effects on insulin action.

  10. Study of Transcription Activity of X-Box Binding Protein 1 Gene in Human Different Cell Lines%人类不同类型细胞中X-盒结合蛋白1转录活性研究

    Institute of Scientific and Technical Information of China (English)

    郭风劲; 宋方洲; 张静; 李婧; 唐勇

    2007-01-01

    Human X-box binding protein 1 (XBP1), an important transcription factor, participates in many signal transduction processes. To further investigate the biological function of XBP1, sequences of XBP1 promoter and its two deletion mutants were first determined using bioinformatic analysis. The report vectors containing XBP1 promoter and its deletion mutants were then constructed, namely, p1-XBP1p, p2-XBP1p, and p3-XBP1p. Each reporter vector was separately transfected into HepG2, L02, K562,SMMC-7721, HSF, and Lipocyte Ito Cell line using FuGENE 6 transfection reagents. The activity of chloramphenicol acetyltransferase (CAT) in each group of transfected cells was detected by ELISA assay, which in turn reflects the transcription activity of the XBP1 gene promoter. The activity involving p3-XBP1p was the highest in HepG2, which was 12.4-fold of that of pCAT3-Basic. The activities of p3-XBP1p in K562 and SMMC-7721 were the second and the third highest, which were 10.9-fold and 10.0-fold of that of the pCAT3-Basic, respectively. The CAT activity in L02 was lower than that in the above-mentioned abnormal cell, and no reporter activity was detected in HSF and Ito Cell. The XBP1 transcription and expression in K562, HepG2 and SMMC-7721 were found to be higher than that in L02, HSF and Ito cells, based on the results of real-time RT-PCR and Western blot. The XBP1 transcription and expression in L02, HSF was lower, whereas that in Ito cells was totally lacking. The result was similar to that of CAT-ELISA. Therefore, the XBP1 gene promoter can drive its downstream gene expression and its activity is cell line-dependent.The core sequence of XBP1 promoter was found between -227bp and 66bp sequence. This sequence was closely associated with the transcriptional activity of XBP1 promoter.%人类X-盒结合蛋白1(X-box binding protein1,XBP1)作为一种重要的转录因子,在细胞中涉及了广泛的信号调控过程.为进一步研究XBP1的生物学功能,首先利用

  11. A calmodulin binding protein from Arabidopsis is induced by ethylene and contains a DNA-binding motif

    Science.gov (United States)

    Reddy, A. S.; Reddy, V. S.; Golovkin, M.

    2000-01-01

    Calmodulin (CaM), a key calcium sensor in all eukaryotes, regulates diverse cellular processes by interacting with other proteins. To isolate CaM binding proteins involved in ethylene signal transduction, we screened an expression library prepared from ethylene-treated Arabidopsis seedlings with 35S-labeled CaM. A cDNA clone, EICBP (Ethylene-Induced CaM Binding Protein), encoding a protein that interacts with activated CaM was isolated in this screening. The CaM binding domain in EICBP was mapped to the C-terminus of the protein. These results indicate that calcium, through CaM, could regulate the activity of EICBP. The EICBP is expressed in different tissues and its expression in seedlings is induced by ethylene. The EICBP contains, in addition to a CaM binding domain, several features that are typical of transcription factors. These include a DNA-binding domain at the N terminus, an acidic region at the C terminus, and nuclear localization signals. In database searches a partial cDNA (CG-1) encoding a DNA-binding motif from parsley and an ethylene up-regulated partial cDNA from tomato (ER66) showed significant similarity to EICBP. In addition, five hypothetical proteins in the Arabidopsis genome also showed a very high sequence similarity with EICBP, indicating that there are several EICBP-related proteins in Arabidopsis. The structural features of EICBP are conserved in all EICBP-related proteins in Arabidopsis, suggesting that they may constitute a new family of DNA binding proteins and are likely to be involved in modulating gene expression in the presence of ethylene.

  12. Laminopathy-inducing lamin A mutants can induce redistribution of lamin binding proteins into nuclear aggregates.

    Science.gov (United States)

    Hübner, S; Eam, J E; Hübner, A; Jans, D A

    2006-01-15

    Lamins, members of the family of intermediate filaments, form a supportive nucleoskeletal structure underlying the nuclear envelope and can also form intranuclear structures. Mutations within the A-type lamin gene cause a variety of degenerative diseases which are collectively referred to as laminopathies. At the molecular level, laminopathies have been shown to be linked to a discontinuous localization pattern of A-type lamins, with some laminopathies containing nuclear lamin A aggregates. Since nuclear aggregate formation could lead to the mislocalization of proteins interacting with A-type lamins, we set out to examine the effects of FLAG-lamin A N195K and R386K protein aggregate formation on the subnuclear distribution of the retinoblastoma protein (pRb) and the sterol responsive element binding protein 1a (SREBP1a) after coexpression as GFP-fusion proteins in HeLa cells. We observed strong recruitment of both proteins into nuclear aggregates. Nuclear aggregate recruitment of the NPC component nucleoporin NUP153 was also observed and found to be dependent on the N-terminus. That these effects were specific was implied by the fact that a number of other coexpressed karyophilic GFP-fusion proteins, such as the nucleoporin NUP98 and kanadaptin, did not coaggregate with FLAG-lamin A N195K or R386K. Immunofluorescence analysis further indicated that the precursor form of lamin A, pre-lamin A, could be found in intranuclear aggregates. Our results imply that redistribution into lamin A-/pre-lamin A-containing aggregates of proteins such as pRb and SREBP1a could represent a key aspect underlying the molecular pathogenesis of certain laminopathies.

  13. Caloric restriction-associated remodeling of rat white adipose tissue: effects on the growth hormone/insulin-like growth factor-1 axis, sterol regulatory element binding protein-1, and macrophage infiltration.

    Science.gov (United States)

    Chujo, Yoshikazu; Fujii, Namiki; Okita, Naoyuki; Konishi, Tomokazu; Narita, Takumi; Yamada, Atsushi; Haruyama, Yushi; Tashiro, Kosuke; Chiba, Takuya; Shimokawa, Isao; Higami, Yoshikazu

    2013-08-01

    The role of the growth hormone (GH)-insulin-like growth factor (IGF)-1 axis in the lifelong caloric restriction (CR)-associated remodeling of white adipose tissue (WAT), adipocyte size, and gene expression profiles was explored in this study. We analyzed the WAT morphology of 6-7-month-old wild-type Wistar rats fed ad libitum (WdAL) or subjected to CR (WdCR), and of heterozygous transgenic dwarf rats bearing an anti-sense GH transgene fed ad libitum (TgAL) or subjected to CR (TgCR). Although less effective in TgAL, the adipocyte size was significantly reduced in WdCR compared with WdAL. This CR effect was blunted in Tg rats. We also used high-density oligonucleotide microarrays to examine the gene expression profile of WAT of WdAL, WdCR, and TgAL rats. The gene expression profile of WdCR, but not TgAL, differed greatly from that of WdAL. The gene clusters with the largest changes induced by CR but not by Tg were genes involved in lipid biosynthesis and inflammation, particularly sterol regulatory element binding proteins (SREBPs)-regulated and macrophage-related genes, respectively. Real-time reverse-transcription polymerase chain reaction analysis confirmed that the expression of SREBP-1 and its downstream targets was upregulated, whereas the macrophage-related genes were downregulated in WdCR, but not in TgAL. In addition, CR affected the gene expression profile of Tg rats similarly to wild-type rats. Our findings suggest that CR-associated remodeling of WAT, which involves SREBP-1-mediated transcriptional activation and suppression of macrophage infiltration, is regulated in a GH-IGF-1-independent manner.

  14. An insulin-induced DNA-binding protein for the human growth hormone gene.

    OpenAIRE

    Prager, D; Gebremedhin, S; Melmed, S

    1990-01-01

    The control of gene transcription is usually mediated by transacting transcriptional factors that bind to upstream regulatory elements. As insulin regulates transcription of the growth hormone (GH) gene, we tested nuclear extracts from unstimulated and insulin-stimulated Chinese hamster ovarian (CHO) cells for binding to four human GH (hGH) gene promoter oligonucleotide fragments identified as target-binding sequences by DNAse I footprinting. Using a mobility shift assay, an insulin-induced D...

  15. Neutrophils and the calcium-binding protein MRP-14 mediate carrageenan-induced antinociception in mice

    Directory of Open Access Journals (Sweden)

    Rosana L. Pagano

    2002-01-01

    Full Text Available Background: We have previously shown that the calcium-binding protein MRP-14 secreted by neutrophils mediates the antinociceptive response in an acute inflammatory model induced by the intraperitoneal injection of glycogen in mice.

  16. Contraction-induced Interleukin-6 Gene Transcription in Skeletal Muscle Is Regulated by c-Jun Terminal Kinase/Activator Protein-1*

    Science.gov (United States)

    Whitham, Martin; Chan, M. H. Stanley; Pal, Martin; Matthews, Vance B.; Prelovsek, Oja; Lunke, Sebastian; El-Osta, Assam; Broenneke, Hella; Alber, Jens; Brüning, Jens C.; Wunderlich, F. Thomas; Lancaster, Graeme I.; Febbraio, Mark A.

    2012-01-01

    Exercise increases the expression of the prototypical myokine IL-6, but the precise mechanism by which this occurs has yet to be identified. To mimic exercise conditions, C2C12 myotubes were mechanically stimulated via electrical pulse stimulation (EPS). We compared the responses of EPS with the pharmacological Ca2+ carrier calcimycin (A23187) because contraction induces marked increases in cytosolic Ca2+ levels or the classical IκB kinase/NFκB inflammatory response elicited by H2O2. We demonstrate that, unlike H2O2-stimulated increases in IL-6 mRNA, neither calcimycin- nor EPS-induced IL-6 mRNA expression is under the transcriptional control of NFκB. Rather, we show that EPS increased the phosphorylation of JNK and the reporter activity of the downstream transcription factor AP-1. Furthermore, JNK inhibition abolished the EPS-induced increase in IL-6 mRNA and protein expression. Finally, we observed an exercise-induced increase in both JNK phosphorylation and IL-6 mRNA expression in the skeletal muscles of mice after 30 min of treadmill running. Importantly, exercise did not increase IL-6 mRNA expression in skeletal muscle-specific JNK-deficient mice. These data identify a novel contraction-mediated transcriptional regulatory pathway for IL-6 in skeletal muscle. PMID:22351769

  17. Absence of tumor suppressor tumor protein 53-induced nuclear protein 1 (TP53INP1) sensitizes mouse thymocytes and embryonic fibroblasts to redox-driven apoptosis.

    Science.gov (United States)

    N'guessan, Prudence; Pouyet, Laurent; Gosset, Gaëlle; Hamlaoui, Sonia; Seillier, Marion; Cano, Carla E; Seux, Mylène; Stocker, Pierre; Culcasi, Marcel; Iovanna, Juan L; Dusetti, Nelson J; Pietri, Sylvia; Carrier, Alice

    2011-09-15

    The p53-transcriptional target TP53INP1 is a potent stress-response protein promoting p53 activity. We previously showed that ectopic overexpression of TP53INP1 facilitates cell cycle arrest as well as cell death. Here we report a study investigating cell death in mice deficient for TP53INP1. Surprisingly, we found enhanced stress-induced apoptosis in TP53INP1-deficient cells. This observation is underpinned in different cell types in vivo (thymocytes) and in vitro (thymocytes and MEFs), following different types of injury inducing either p53-dependent or -independent cell death. Nevertheless, absence of TP53INP1 is unable to overcome impaired cell death of p53-deficient thymocytes. Stress-induced ROS production is enhanced in the absence of TP53INP1, and antioxidant NAC complementation abolishes increased sensitivity to apoptosis of TP53INP1-deficient cells. Furthermore, antioxidant defenses are defective in TP53INP1-deficient mice in correlation with ROS dysregulation. Finally, we show that autophagy is reduced in TP53INP1-deficient cells both at the basal level and upon stress. Altogether, these data show that impaired ROS regulation in TP53INP1-deficient cells is responsible for their sensitivity to induced apoptosis. In addition, they suggest that this sensitivity could rely on a defect of autophagy. Therefore, these data emphasize the role of TP53INP1 in protection against cell injury.

  18. Bilirubin binding with liver cystatin induced structural and functional changes.

    Science.gov (United States)

    Mustafa, Mir Faisal; Bano, Bilqees

    2014-05-01

    Cysteine proteinases and their inhibitors play a significant role in the proteolytic environment of the cells. Inhibitors of cysteine proteinases regulate the activity of these enzymes helping in checking the degdration activity of cathepsins. The bilirubin secreated by liver cells can bind to cystatin present in the liver resulting in its functional inactivation, which may further lead to the increase in cathepsins level causing liver cirrhosis. In case of some pathophysiological conditions excess bilirubin gets accumulated e.g. in presence of Fasciola hepatica (liver fluke) in mammals and humans, leading to liver cirrhosis and possibly jaundice or normal blockade of bile duct causing increased level of bilirubin in blood. Protease-cystatin imbalance causes disease progression. In the present study, Bilirubin (BR) and liver cystatin interaction was studied to explore the cystatin inactivation and structural alteration. The binding interaction was studied by UV-absorption, FT-IR and fluorescence spectroscopy. The quenching of protein fluorescence confirmed the binding of BR with buffalo liver cystatin (BLC). Stern-Volmer analysis of BR-BLC system indicates the presence of static component in the quenching mechanism and the number of binding sites to be close to 1. The fluorescence data proved that the fluorescence quenching of liver cystatin by BR was the result of BR-cystatin complex formation. FTIR analysis of BR-Cystatin complex revealed change in the secondary structure due to perturbation in the microenvironment further confirmed by the decreased caseinolytic activity of BLC against papain. Fluorescence measurements also revealed quenching of fluorescence and shift in peak at different time intervals and at varying pH values. Photo-illumination of BR-cystatin complex causes change in the surrounding environment of liver cystatin as indicated by red-shift. The binding constant for BR-BLC complex was found to be 9.279 × 10(4) M(-1). The cystatin binding with

  19. Investigating the function of Fc -specific binding of IgM to Plasmodium falciparum erythrocyte membrane protein 1 mediating erythrocyte rosetting

    DEFF Research Database (Denmark)

    Stevenson, Liz; Huda, Pie; Jeppesen, Anine;

    2015-01-01

    Acquired protection from Plasmodium falciparum malaria takes years to develop, probably reflecting the ability of the parasites to evade immunity. A recent example of this is the binding of the Fc region of IgM to VAR2CSA-type PfEMP1. This interferes with specific IgG recognition and phagocytosis...... of opsonized infected erythrocytes (IEs) without compromising the placental IE adhesion mediated by this PfEMP1 type. IgM also binds via Fc to several other PfEMP1 proteins, where it has been proposed to facilitate rosetting (binding of uninfected erythrocytes to a central IE). To further dissect...... the functional role of Fc -mediated IgM binding to PfEMP1, we studied the PfEMP1 protein HB3VAR06, which mediates rosetting and binds IgM. Binding of IgM to this PfEMP1 involved the Fc domains Cμ3-Cμ4 in IgM and the penultimate DBL domain (DBLζ2) at the C-terminus of HB3VAR06. However, IgM binding did...

  20. Substrate Binding Induces Domain Movements in Orotidine 5'-Monophosphate Decarboxylase

    DEFF Research Database (Denmark)

    Harris, Pernille Hanne; Poulsen, Jens-Christian Navarro; Jensen, Kaj Frank;

    2002-01-01

    ); here we present the 2.5 Å structure of the uncomplexed apo enzyme, determined from twinned crystals. A structural analysis and comparison of the two structures of the E. coli enzyme show that binding of the inhibitor is accompanied by significant domain movements of approximately 12° around a hinge...... that crosses the active site. Hence, the ODCase dimer, which contains two active sites, may be divided in three domains: a central domain that is fixed, and two lids which independently move 12° upon binding. Corresponding analyses, presented herein, of the two Saccharomyces cerevisiae ODCase structures (with...

  1. Expression and clinical significance of selenium binding protein 1 in gastric cancer%胃癌中硒结合蛋白-1的表达及其临床病理学意义

    Institute of Scientific and Technical Information of China (English)

    张锦; 董卫国; 林军

    2010-01-01

    Objective To detect the expression of selenium binding protein 1 ( SBP1 ) in gastric cancer cell line SGC7901, BGC823, normal gastric epithelial cell line GES-1, gastric cancer tissues and normal gastric tissues, explore the relationship between SBP1 and pathologic features, and discuss the feasibility of SBP1 as an diagnostic marker of gastric cancer. Methods The clinical data of 135 patients with gastric cancer who were admitted to Zhongnan Hospital of Wuhan University from 2006 to 2007 were retrospectively analyzed. The expression of SBP1 in the gastric cancer tissues and 16 cases of normal gastric tissues were detected by immunohistochemistry. The mRNA and protein expressions of SBP1 of SGC7901, BGC823 and GES-1 were determined by Western blot and RT-PCR. All data were analyzed by using chi-square test and one-way analysis of variance.Results The mRNA expressions of SBP1 in BGC823 and SGC7091 were 0. 120 ± 0. 020 and 0. 133 ± 0. 015,respectively, which were significantly lower than 0. 907 ± 0. 015 in GES-1 ( F = 2106. 462, P < 0.05 ). The protein expression of SBP1 in BGC823 and SGC7901 were 0.253 ±0.015 and 0.273 ±0.015 ,respectively, which were significantly lower than 0.877 ±0.025 in GES-1 ( F = 1026. 758, P <0.05 ). A strong positive reaction of SBP1 was observed in 3 cases of gastric cancer tissues and 16 cases of normal gastric tissues. The decrease of the protein expression of SBP1 was correlated with clinical stages of the patients ( x2 = 12. 629, P < 0.05 ), rather than the sexes, ages, tumor histological types, tumor differentiation, infiltration depths and lymph node metastasis (x2 =2. 142, 0.860, 1.838, 5.001,4.858, 1.994, P>0. 05). Conclusions The decrease of SBP1 expression could be used as a marker in diagnosing gastric cancer. Down-regulation of SBP1 expression may play an important role in the genesis and prognosis of gastric cancer.%目的 检测硒结合蛋白1(SBP1)在胃癌细胞系SGC7901、BGC823、正

  2. The Epstein-Barr virus oncogene product, latent membrane protein 1, induces the downregulation of E-cadherin gene expression via activation of DNA methyltransferases

    Institute of Scientific and Technical Information of China (English)

    Chi-NeuTsai

    2005-01-01

    The latent membrane protein (LMP1) of Epstein-Barr virus (EBV) is expressed in EBV-associated nasopharyngeal carcinoma, which isnotoriously metastatic. Although it Is established that LMP1 represses E-cadherin expression and enhances the invasive ability of carcinoma cells, the mechanism underlying this repression remains to be elucidated. In this study, we demonstrate that LMP1 induces the expression and activity of the DNA methyltransferases 1, 3a, and 3b, using real-time reverse transcription-PCR and enzyme activity assay. This results in hypermethylation of the E-cadherin promoter and down-regulation of E-cadherin gene expression, as revealed by methylation-specific PCR, real-time reverse transcription-PeR and Western blotting data. The DNA methyltransferase inhibitor, 5'-Aza-2'dC, restores E-cadherin promoter activity and protein expression in LMPl-expressing cells, which in turn blocks cell migration ability, as demonstrated by the Transwell cell migration assay. Our findings suggest that LMP1 down-regulates E-cadherin gene expression and induces cell migration activity by using cellular DNA methylation machinery.

  3. An AP1 binding site upstream of the kappa immunoglobulin intron enhancer binds inducible factors and contributes to expression.

    Science.gov (United States)

    Schanke, J T; Marcuzzi, A; Podzorski, R P; Van Ness, B

    1994-01-01

    Expression of the kappa immunoglobulin light chain gene requires developmental- and tissue-specific regulation by trans-acting factors which interact with two distinct enhancer elements. A new protein-DNA interaction has been identified upstream of the intron enhancer, within the matrix-associated region of the J-C intron. The binding activity is greatly inducible in pre-B cells by bacterial lipopolysaccharide and interleukin-1 but specific complexes are found at all stages of B cell development tested. The footprinted binding site is homologous to the consensus AP1 motif. The protein components of this complex are specifically competed by an AP1 consensus motif and were shown by supershift to include c-Jun and c-Fos, suggesting that this binding site is an AP1 motif and that the Jun and Fos families of transcription factors play a role in the regulation of the kappa light chain gene. Mutation of the AP1 motif in the context of the intron enhancer was shown to decrease enhancer-mediated activation of the promoter in both pre-B cells induced with LPS and constitutive expression in mature B cells. Images PMID:7816634

  4. Thromboxane A2 receptor-mediated release of matrix metalloproteinase-1 (MMP-1) induces expression of monocyte chemoattractant protein-1 (MCP-1) by activation of protease-activated receptor 2 (PAR2) in A549 human lung adenocarcinoma cells.

    Science.gov (United States)

    Li, Xiuling; Tai, Hsin-Hsiung

    2014-08-01

    Matrix metalloproteinases (MMPs) and monocyte chemoattractant protein-1 (MCP-1, CCL2) are known to be upregulated in many tumors. Their roles in tumor invasion and metastasis are being uncovered. How they are related to each other and involved in tumor progression remains to be determined. Earlier it was reported that I-BOP-initiated activation of thromboxane A2 receptor (TP) induced the release of MMP-1, MMP-3, and MMP-9 from lung cancer A549 cells overexpressing TPα (A549-TPα). Herein it was found that MMP-1, but not MMP-3 or MMP-9, induced the expression of MCP-1 in A549 cells. Conditioned medium (CM) from I-BOP activated, MMP-1 siRNA pretreated A549-TPα cells induced greatly attenuated expression of MCP-1 in A549 cells indicating that MMP-1 in the CM contributed significantly to the expression of MCP-1. MMP-1 was shown to activate protease-activated receptor 2 (PAR2) instead of commonly assumed PAR1 to increase the expression of MCP-1 in A549 cells. This conclusion was reached from the following findings: (1) expression of MCP-1 induced by trypsin, a PAR2 agonist, and also PAR2 agonist peptide, was inhibited by a PAR2 antagonist; (2) expression of MCP-1 induced by MMP-1 and by CM from I-BOP activated A549-TPα cells was blocked by a PAR2 antagonist but not by other PAR antagonists; (3) expression of MCP-1 induced by MMP-1 and by CM from I-BOP activated A549-TPα cells was attenuated significantly by pretreatment of cells with PAR2-siRNA. These results suggest that PAR2 is a novel MMP-1 target mediating MMP-1-induced signals in A549 lung cancer cells.

  5. Targeting osteoblastic casein kinase-2 interacting protein-1 to enhance Smad-dependent BMP signaling and reverse bone formation reduction in glucocorticoid-induced osteoporosis

    Science.gov (United States)

    Liu, Jin; Lu, Changwei; Wu, Xiaohao; Zhang, Zongkang; Li, Jie; Guo, Baosheng; Li, Defang; Liang, Chao; Dang, Lei; Pan, Xiaohua; Peng, Songlin; Lu, Aiping; Zhang, Baoting; Zhang, Ge

    2017-01-01

    The underlying mechanism of the reduced bone formation during the development of glucocorticoid-induced osteoporosis (GIO) remains unclear. Here, we found that the highly expressed CKIP-1 together with lowly expressed total and phosphorylated Smad1/5 in bone samples was accompanied by either the reduced serum bone formation markers in GIO patients or the decreased bone formation in GIO mice. In vitro studies showed that the highly expressed CKIP-1 could promote Smad1 ubiquitination to suppress the Smad-dependent BMP signaling and inhibit osteogenic differentiation and mineral deposition in MC3T3-E1 cells during glucocorticoid treatment. Further, the reduced bone formation in GIO mice could not only be prevented by osteoblasts-specific Ckip-1 ablation, but also be attenuated after osteoblasts-specific Smad1 overexpression. Moreover, osteoblasts-targeting CKIP-1 siRNA treatment also attenuated the bone formation reduction in GIO mice. These study suggest that the highly expressed CKIP-1 in osteoblasts could suppress the Smad-dependent BMP signaling and contribute to the bone formation reduction in GIO. Targeting osteoblastic CKIP-1 would be a novel bone anabolic strategy for GIO patients. PMID:28128304

  6. Serum concentrations of free and total insulin-like growth factor-I, IGF binding proteins -1 and -3 and IGFBP-3 protease activity in boys with normal or precocious puberty

    DEFF Research Database (Denmark)

    Juul, A; Flyvbjerg, Allan; Frystyk, Jan;

    1996-01-01

    Circulating IGF-I and IGF binding protein-3 (IGFBP-3) levels both increase in puberty where growth velocity is high. The amount of free IGF-I is dependent on the IGF-I level and on the concentrations of the specific IGFBPs. Furthermore, IGFBP-3 proteolysis regulates the bioavailability of IGF......-I. However, the concentration of free IGF-I and possible IGFBP-3 proteolytic activity in puberty has not previously been studied....

  7. Epstein-Barr virus encoded latent membrane protein 1 induces TRAF1 expression to promote anti-apoptosis activity via NF-κB signaling pathway in nasopharyngeal carcinoma

    Institute of Scientific and Technical Information of China (English)

    王承兴; 艾米丹; 任维; 肖绘; 李小燕; 唐发清; 顾焕华; 易薇; 翁新宪; 邓锡云; 曹亚

    2003-01-01

    Objectives To identify whether Epstein-Barr virus (EBV) encoded latent membrane protein 1 (LMP1) can induce tumor necrosis factor receptor-associated factor 1 (TRAF1) expression and promote its anti-apoptosis activity via the NF-κB signaling pathway, and assess that LMP1 suppresses apoptosis in nasopharyngeal carcinoma (NPC). Methods A stable transfected cell line HNE2-LMP1 was established by introducing LMP1 cDNA into HNE2 cells. Transactivation of TRAF1 was determined by luciferase reporter assay, while expression of TRAF1 mRNA was detected by RT-PCR and expression of TRAF1 protein and caspase 3 by Western blot analysis. Apoptosis activity was observed through fluorescence staining. Results LMP1 induced TRAF1 expression in NPC cells and caused a decrease in apoptosis. This induction could be blocked by antisense LMP1. Moreover, LMP1-mediated induction of a TRAF1 promoter-driven reporter gene was significantly impaired when the κB site κB1 or κB5 was disrupted, whereas mutation of κB3 had only a minor effect on LMP1 dependent up-regulation of the reporter gene. Conclusion LMP1 induces TRAF1 expression and promotes its anti-apoptosis activity via the NF-κB signaling pathway, which may be one of the mechanisms that LMP1 uses to suppress apoptosis in NPC cells.

  8. 组氨酸三聚体核苷结合蛋白1的结构及其肿瘤抑制功能%Structure and tumor-inhibiting function of histidine triad nucleotide-binding protein 1 (H1NT1)

    Institute of Scientific and Technical Information of China (English)

    关杨; 孙建方

    2011-01-01

    组氨酸三聚体核苷结合蛋白1是一种嘌呤核苷酸结合蛋白,以二聚体形式存在,是组氨酸三聚体超家族最古老的分支之一.研究发现,组氨酸三聚体核苷结合蛋白1是一种肿瘤抑制基因,具有肿瘤抑制的功能.组氨酸三聚体核苷结合蛋白1在体内、外可抑制多种肿瘤细胞的增殖,并可通过线粒体依赖凋亡途径诱导肿瘤细胞凋亡;组氨酸三聚体核苷结合蛋白1可与激活蛋白-1、小眼畸形转录因子等多种转录因子相互作用,调节细胞的增殖及凋亡;组氨酸三聚体核苷结合蛋白1还可作用于Wnt信号通路,抑制肿瘤细胞的生长与增殖.组氨酸三聚体核苷结合蛋白1在部分肿瘤细胞中的低表达可能与启动子区超甲基化有关.%HINT1 is a dimeric purine nucleotide-binding protein, and represents the most conserved branch of histidine triad superfamily. It has been evidenced that HINT1 is a tumor suppressor gene and possesses tumor-inhibiting activity. Moreover, HINT1 can suppress the proliferation of various tumor cells in vitro and in vivo, induce the apoptosis in tumor cells via mitochondrial-dependent apoptotic pathway, interact with such transcription factors as activator protein-1 (AP-1) and microphthalmia transcription factor (MITF),modulate the proliferation of and apoptosis in cells, act on Wnt signaling pathway, and inhibit the growth and proliferation of tumor cells. The low expression of HINT1 in some tumor cells might be related to the hypermethylation of promoter region of this gene.

  9. Species-specific and cross-reactive IgG1 antibody binding to viral capsid protein 1 (VP1 antigens of human rhinovirus species A, B and C.

    Directory of Open Access Journals (Sweden)

    Jua Iwasaki

    Full Text Available BACKGROUND: Human rhinoviruses (HRV are associated with upper and lower respiratory illnesses, including severe infections causing hospitalization in both children and adults. Although the clinical significance of HRV infections is now well established, no detailed investigation of the immune response against HRV has been performed. The purpose of this study was to assess the IgG1 antibody response to the three known HRV species, HRV-A, -B and -C in healthy subjects. METHODS: Recombinant polypeptides of viral capsid protein 1 (VP1 from two genotypes of HRV-A, -B and -C were expressed as glutathione S-transferase (GST fusion proteins and purified by affinity and then size exclusion chromatography. The presence of secondary structures similar to the natural antigens was verified by circular dichroism analysis. Total and species-specific IgG1 measurements were quantitated by immunoassays and immunoabsorption using sera from 63 healthy adults. RESULTS: Most adult sera reacted with the HRV VP1 antigens, at high titres. As expected, strong cross-reactivity between HRV genotypes of the same species was found. A high degree of cross-reactivity between different HRV species was also evident, particularly between HRV-A and HRV-C. Immunoabsorption studies revealed HRV-C specific titres were markedly and significantly lower than the HRV-A and HRV-B specific titres (P<0.0001. A truncated construct of HRV-C VP1 showed greater specificity in detecting anti-HRV-C antibodies. CONCLUSIONS: High titres of IgG1 antibody were bound by the VP1 capsid proteins of HRV-A, -B and -C, but for the majority of people, a large proportion of the antibody to HRV-C was cross-reactive, especially to HRV-A. The improved specificity found for the truncated HRV-C VP1 indicates species-specific and cross-reactive regions could be defined.

  10. Arctigenin suppresses transforming growth factor-β1-induced expression of monocyte chemoattractant protein-1 and the subsequent epithelial-mesenchymal transition through reactive oxygen species-dependent ERK/NF-κB signaling pathway in renal tubular epithelial cells.

    Science.gov (United States)

    Li, A; Wang, J; Zhu, D; Zhang, X; Pan, R; Wang, R

    2015-01-01

    Transforming growth factor-β1 (TGF-β1) induces expression of the proinflammatory and profibrotic cytokine monocyte chemoattractant protein-1 (MCP-1) in tubular epithelial cells (TECs) and thereby contributes to the tubular epithelial-mesenchymal transition (EMT), which in turn leads to the progression of tubulointerstitial inflammation into tubulointerstitial fibrosis. Exactly how TGF-β1 causes MCP-1 overexpression and subsequent EMT is not well understood. Using human tubular epithelial cultures, we found that TGF-β1 upregulated the expression of reduced nicotinamide adenine dinucleotide phosphate oxidases 2 and 4 and their regulatory subunits, inducing the production of reactive oxygen species. These reactive species activated a signaling pathway mediated by extracellular signal-regulated kinase (ERK1/2) and nuclear factor-κB (NF-κB), which upregulated expression of MCP-1. Incubating cultures with TGF-β1 was sufficient to induce hallmarks of EMT, such as downregulation of epithelial marker proteins (E-cadherin and zonula occludens-1), induction of mesenchymal marker proteins (α-smooth muscle actin, fibronectin, and vimentin), and elevated cell migration and invasion in an EMT-like manner. Overexpressing MCP-1 in cells exposed to TGF-β1 exacerbated these EMT-like changes. Pretreating cells with the antioxidant and anti-inflammatory compound arctigenin (ATG) protected them against these TGF-β1-induced EMT-like changes; the compound worked by inhibiting the ROS/ERK1/2/NF-κB pathway to decrease MCP-1 upregulation. These findings suggest ATG as a new therapeutic candidate to inhibit or even reverse tubular EMT-like changes during progression to tubulointerstitial fibrosis, and they provide the first clues to how ATG may work.

  11. Tumor Necrosis Factor Receptor-associated Protein 1 (TRAP1) Mutation and TRAP1 Inhibitor Gamitrinib-triphenylphosphonium (G-TPP) Induce a Forkhead Box O (FOXO)-dependent Cell Protective Signal from Mitochondria.

    Science.gov (United States)

    Kim, Hyunjin; Yang, Jinsung; Kim, Min Ju; Choi, Sekyu; Chung, Ju-Ryung; Kim, Jong-Min; Yoo, Young Hyun; Chung, Jongkyeong; Koh, Hyongjong

    2016-01-22

    TRAP1 (tumor necrosis factor receptor-associated protein 1), a mitochondrial Hsp90 family chaperone, has been identified as a critical regulator of cell survival and bioenergetics in tumor cells. To discover novel signaling networks regulated by TRAP1, we generated Drosophila TRAP1 mutants. The mutants successfully developed into adults and produced fertile progeny, showing that TRAP1 is dispensable in development and reproduction. Surprisingly, mutation or knockdown of TRAP1 markedly enhanced Drosophila survival under oxidative stress. Moreover, TRAP1 mutation ameliorated mitochondrial dysfunction and dopaminergic (DA) neuron loss induced by deletion of a familial Parkinson disease gene PINK1 (Pten-induced kinase 1) in Drosophila. Gamitrinib-triphenylphosphonium, a mitochondria-targeted Hsp90 inhibitor that increases cell death in HeLa and MCF7 cells, consistently inhibited cell death induced by oxidative stress and mitochondrial dysfunction induced by PINK1 mutation in mouse embryonic fibroblast cells and DA cell models such as SH-SY5Y and SN4741 cells. Additionally, gamitrinib-triphenylphosphonium also suppressed the defective locomotive activity and DA neuron loss in Drosophila PINK1 null mutants. In further genetic analyses, we showed enhanced expression of Thor, a downstream target gene of transcription factor FOXO, in TRAP1 mutants. Furthermore, deletion of FOXO almost nullified the protective roles of TRAP1 mutation against oxidative stress and PINK1 mutation. These results strongly suggest that inhibition of the mitochondrial chaperone TRAP1 generates a retrograde cell protective signal from mitochondria to the nucleus in a FOXO-dependent manner.

  12. Tumor Necrosis Factor Receptor-associated Protein 1 (TRAP1) Mutation and TRAP1 Inhibitor Gamitrinib-triphenylphosphonium (G-TPP) Induce a Forkhead Box O (FOXO)-dependent Cell Protective Signal from Mitochondria*

    Science.gov (United States)

    Kim, Hyunjin; Yang, Jinsung; Kim, Min Ju; Choi, Sekyu; Chung, Ju-Ryung; Kim, Jong-Min; Yoo, Young Hyun; Chung, Jongkyeong; Koh, Hyongjong

    2016-01-01

    TRAP1 (tumor necrosis factor receptor-associated protein 1), a mitochondrial Hsp90 family chaperone, has been identified as a critical regulator of cell survival and bioenergetics in tumor cells. To discover novel signaling networks regulated by TRAP1, we generated Drosophila TRAP1 mutants. The mutants successfully developed into adults and produced fertile progeny, showing that TRAP1 is dispensable in development and reproduction. Surprisingly, mutation or knockdown of TRAP1 markedly enhanced Drosophila survival under oxidative stress. Moreover, TRAP1 mutation ameliorated mitochondrial dysfunction and dopaminergic (DA) neuron loss induced by deletion of a familial Parkinson disease gene PINK1 (Pten-induced kinase 1) in Drosophila. Gamitrinib-triphenylphosphonium, a mitochondria-targeted Hsp90 inhibitor that increases cell death in HeLa and MCF7 cells, consistently inhibited cell death induced by oxidative stress and mitochondrial dysfunction induced by PINK1 mutation in mouse embryonic fibroblast cells and DA cell models such as SH-SY5Y and SN4741 cells. Additionally, gamitrinib-triphenylphosphonium also suppressed the defective locomotive activity and DA neuron loss in Drosophila PINK1 null mutants. In further genetic analyses, we showed enhanced expression of Thor, a downstream target gene of transcription factor FOXO, in TRAP1 mutants. Furthermore, deletion of FOXO almost nullified the protective roles of TRAP1 mutation against oxidative stress and PINK1 mutation. These results strongly suggest that inhibition of the mitochondrial chaperone TRAP1 generates a retrograde cell protective signal from mitochondria to the nucleus in a FOXO-dependent manner. PMID:26631731

  13. Involvement of Nurr-1/Nur77 in corticotropin-releasing factor/urocortin1-induced tyrosinase-related protein 1 gene transcription in human melanoma HMV-II cells.

    Science.gov (United States)

    Watanuki, Yutaka; Takayasu, Shinobu; Kageyama, Kazunori; Iwasaki, Yasumasa; Sakihara, Satoru; Terui, Ken; Nigawara, Takeshi; Suda, Toshihiro

    2013-05-06

    Recent molecular and biochemical analyses have revealed the presence of corticotropin-releasing factor (CRF) and urocortin (Ucn), together with their corresponding receptors in mammalian skin. The melanosomal enzyme tyrosinase-related protein 1 (TRP1) is involved in modulation of pigment production in response to stressors. Although CRF and Ucn are thought to have potent effects on the skin system, their possible roles and regulation have yet to be fully determined. This study aimed to explore the effects of CRF and Ucn on TRP1 gene expression using human melanoma HMV-II cells. The mRNA of CRF, Ucn1, Ucn2, and CRF receptor type 1 (CRF1 receptor) was detected in HMV-II cells. CRF and Ucn1 stimulated TRP1 gene transcription via the CRF1 receptor, and increased both Nurr-1 and Nur77 mRNA expression levels. Both CRF- and Ucn1-induced Nurr-1/Nur77 acted via a NGFI-B response element on the TRP1 promoter. The combination of Nurr-1/Nur77 and microphthalmia-associated transcription factor, a melanocyte-specific transcription factor gene induced by α-melanocyte-stimulating hormone, had additive effects on activation of TRP1 gene transcription. The findings suggest that in human melanoma HMV-II cells both CRF and Ucn1 regulate TRP1 gene expression via Nurr-1/Nur77 production, independent of pro-opiomelanocortin or α-melanocyte-stimulating hormone stimulation.

  14. Ca2+ and Mg2+ binding induce conformational stability of Calfumirin-1 from Dictyostelium discoideum

    Indian Academy of Sciences (India)

    Bairagi C Mallick; Sa-Ouk Kang; Suman Jha

    2014-05-01

    The apo-Calfumirin-1 (CAF-1) binds to Ca2+ with high affinity and also to Mg2+ with high positive cooperativity. The thermal unfolding curves of wtCAF-1 monitored at neutral pH by CD spectroscopy are reversible and show different thermal stabilities in the absence or presence of Ca2+ and Mg2+ ions. Metalfree wtCAF-1 shows greater thermal stability than EF-IV mutant protein. We observed that GdnHCl-induced unfolding of apo-wtCAF-1 monitored by CD and fluorescence spectroscopies increases co-operative folding with approximately same C values. Binding of Ca2+ and Mg2+ ions to CAF-1 dramatically altered the fluorescence and CD spectra, indicating metal ion-induced conformational changes both in the wild-type and mutant proteins. The hydrophobic probe, ANS is used to observe alteration in surface hydrophobicity of the protein in different ligation states. In apo-wtCAF-1, the exposed hydrophobic surfaces are able to bind ANS which is in contrast to the unfolded or the metal ions ligated conformations. Isothermal titration calorimetry (ITC) resultsshow two possible independent binding sites of comparable affinity for the metal ions. However, their binding to the EF-IV E helix-loop-F helix mutant apo-protein happens with different affinities. The present study demonstrates that Ca2+ or Mg2+ binding plays a possible role in the conformational stability of the protein.

  15. Platelet-collagen adhesion enhances platelet aggregation induced by binding of VWF to platelets

    Energy Technology Data Exchange (ETDEWEB)

    Laduca, F.M.; Bell, W.R.; Bettigole, R.E. (Johns Hopkins Univ. School of Medicine, Baltimore, MD (USA) State Univ. of New York, Buffalo (USA))

    1987-11-01

    Ristocetin-induced platelet aggregation (RIPA) was evaluated in the presence of platelet-collagen adhesion. RIPA of normal donor platelet-rich plasma (PRP) demonstrated a primary wave of aggregation mediated by the binding of von Willebrand factor (VWF) to platelets and a secondary aggregation wave, due to a platelet-release reaction, initiated by VWF-platelet binding and inhibitable by acetylsalicylic acid (ASA). An enhanced RIPA was observed in PRP samples to which collagen had been previously added. These subthreshold concentrations of collagen, which by themselves were insufficient to induce aggregation, caused measurable platelet-collagen adhesion. Subthreshold collagen did not cause microplatelet aggregation, platelet release of ({sup 3}H)serotonin, or alter the dose-responsive binding of {sup 125}I-labeled VWF to platelets, which occurred with increasing ristocetin concentrations. However, ASA inhibition of the platelet release reaction prevented collagen-enhanced RIPA. These results demonstrate that platelet-collagen adhesion altered the platelet-release reaction induced by the binding of VWF to platelets causing a platelet-release reaction at a level of VWF-platelet binding not normally initiating a secondary aggregation. These findings suggest that platelet-collagen adhesion enhances platelet function mediated by VWF.

  16. From Binding-Induced Dynamic Effects in SH3 Structures to Evolutionary Conserved Sectors

    OpenAIRE

    Ana Zafra Ruano; Elisa Cilia; Couceiro, José R.; Javier Ruiz Sanz; Joost Schymkowitz; Frederic Rousseau; Irene Luque; Tom Lenaerts

    2016-01-01

    Src Homology 3 domains are ubiquitous small interaction modules known to act as docking sites and regulatory elements in a wide range of proteins. Prior experimental NMR work on the SH3 domain of Src showed that ligand binding induces long-range dynamic changes consistent with an induced fit mechanism. The identification of the residues that participate in this mechanism produces a chart that allows for the exploration of the regulatory role of such domains in the activity of the encompassing...

  17. Growth factors induce monocyte binding to vascular smooth muscle cells: implications for monocyte retention in atherosclerosis.

    Science.gov (United States)

    Cai, Qiangjun; Lanting, Linda; Natarajan, Rama

    2004-09-01

    Adhesive interactions between monocytes and vascular smooth muscle cells (VSMC) may contribute to subendothelial monocyte-macrophage retention in atherosclerosis. We investigated the effects of angiotensin II (ANG II) and platelet-derived growth factor (PDGF)-BB on VSMC-monocyte interactions. Treatment of human aortic VSMC (HVSMC) with ANG II or PDGF-BB significantly increased binding to human monocytic THP-1 cells and to peripheral blood monocytes. This was inhibited by antibodies to monocyte beta(1)- and beta(2)-integrins. The binding was also attenuated by blocking VSMC arachidonic acid (AA) metabolism by inhibitors of 12/15-lipoxygenase (12/15-LO) or cyclooxygenase-2 (COX-2). Conversely, binding was enhanced by overexpression of 12/15-LO or COX-2. Direct treatment of HVSMC with AA or its metabolites also increased binding. Furthermore, VSMC derived from 12/15-LO knockout mice displayed reduced binding to mouse monocytic cells relative to genetic control mice. Using specific signal transduction inhibitors, we demonstrated the involvement of Src, phosphoinositide 3-kinase, and MAPKs in ANG II- or PDGF-BB-induced binding. Interestingly, after coculture with HVSMC, THP-1 cell surface expression of the scavenger receptor CD36 was increased. These results show for the first time that growth factors may play additional roles in atherosclerosis by increasing monocyte binding to VSMC via AA metabolism and key signaling pathways. This can lead to monocyte subendothelial retention, CD36 expression, and foam cell formation.

  18. Aging-induced changes in brain regional serotonin receptor binding: Effect of Carnosine.

    Science.gov (United States)

    Banerjee, S; Poddar, M K

    2016-04-05

    Monoamine neurotransmitter, serotonin (5-HT) has its own specific receptors in both pre- and post-synapse. In the present study the role of carnosine on aging-induced changes of [(3)H]-5-HT receptor binding in different brain regions in a rat model was studied. The results showed that during aging (18 and 24 months) the [(3)H]-5-HT receptor binding was reduced in hippocampus, hypothalamus and pons-medulla with a decrease in their both Bmax and KD but in cerebral cortex the [(3)H]-5-HT binding was increased with the increase of its only Bmax. The aging-induced changes in [(3)H]-5-HT receptor binding with carnosine (2.0 μg/kg/day, intrathecally, for 21 consecutive days) attenuated in (a) 24-month-aged rats irrespective of the brain regions with the attenuation of its Bmax except hypothalamus where both Bmax and KD were significantly attenuated, (b) hippocampus and hypothalamus of 18-month-aged rats with the attenuation of its Bmax, and restored toward the [(3)H]-5-HT receptor binding that observed in 4-month-young rats. The decrease in pons-medullary [(3)H]-5-HT binding including its Bmax of 18-month-aged rats was promoted with carnosine without any significant change in its cerebral cortex. The [(3)H]-5-HT receptor binding with the same dosages of carnosine in 4-month-young rats (a) increased in the cerebral cortex and hippocampus with the increase in their only Bmax whereas (b) decreased in hypothalamus and pons-medulla with a decrease in their both Bmax and KD. These results suggest that carnosine treatment may (a) play a preventive role in aging-induced brain region-specific changes in serotonergic activity (b) not be worthy in 4-month-young rats in relation to the brain regional serotonergic activity.

  19. Lack of upregulation of epidermal fatty acid binding protein in dithranol induced irritation.

    NARCIS (Netherlands)

    Kucharekova, M.; Vissers, W.H.P.M.; Schalkwijk, J.; Kerkhof, P.C.M. van de; Valk, P.G.M. van der

    2003-01-01

    The exact role of epidermal fatty acid binding protein (E-FABP) in skin is unknown. A restoration of the barrier function may be associated with an upregulation of E-FABP. Moreover, E-FABP is upregulated in a variety of cells in response to oxidative stress. A recent observation that dithranol induc

  20. Unfractionated heparin suppresses lipopolysaccharide-induced monocyte chemoattractant protein-1 expression in human microvascular endothelial cells by blocking Krüppel-like factor 5 and nuclear factor-κB pathway.

    Science.gov (United States)

    Li, Xu; Li, Xin; Zheng, Zhen; Liu, Yina; Ma, Xiaochun

    2014-10-01

    Unfractionated heparin (UFH) and low-molecular-weight heparins (LMWH), apart from anticoagulant activities, contain a variety of biological properties such as anti-inflammatory actions possibly affecting sepsis. Chemokines are vital for promoting the movement of circulating leukocytes to the site of infection and are involved in the pathogenesis of sepsis. The purpose of this study was to investigate the effects and potential mechanisms of UFH on lipopolysaccharide (LPS)-induced chemokine production in human pulmonary microvascular endothelial cells (HPMECs). HPMECs were pretreated with UFH (0.1 U/ml and 1 U/ml), 15 min prior to stimulation with LPS (10 μg/ml). Cells were cultured under various experimental conditions for 2 h and 6 h for analysis. UFH markedly decreased LPS-induced interleukin (IL)-8 and monocyte chemoattractant protein-1 (MCP-1) mRNA and protein expression in HPMECs. UFH also attenuated the secretion of these chemokines in culture supernatants. In addition, UFH blocked the chemotactic activities of LPS-stimulated HPMECs supernatants on monocytes migration as expected. UFH inhibited LPS-induced Krüppel-like factor 5 (KLF-5) mRNA and protein levels. Concurrently, UFH reduced nuclear factor (NF)-κB nuclear translocation. Importantly, transfection with siRNA targeting KLF-5 reduced NF-κB activation and chemokines expression. These results demonstrate that interfering with KLF-5 mediated NF-κB activation might contribute to the inhibitory effects of chemokines and monocytes migration by UFH in LPS-stimulated HPMECs.

  1. Actin filament-associated protein 1 (AFAP-1) is a key mediator in inflammatory signaling-induced rapid attenuation of intrinsic P-gp function in human brain capillary endothelial cells.

    Science.gov (United States)

    Hoshi, Yutaro; Uchida, Yasuo; Tachikawa, Masanori; Ohtsuki, Sumio; Terasaki, Tetsuya

    2017-01-23

    The purpose of this study was to identify regulatory molecule(s) involved in the inflammatory signaling-induced decrease in P-glycoprotein (P-gp) efflux function at the blood-brain barrier (BBB) that may occur in brain diseases. We confirmed that in vivo P-gp efflux activity at the BBB was decreased without any change in P-gp protein expression level in a mouse model of acute inflammation induced by 3 mg/kg lipopolysaccharide. In a human BBB model cell line (human brain capillary endothelial cells; hCMEC/D3), 1-h treatment with 10 ng/mL tumor necrosis factor-α (TNF-α; an inflammatory mediator) rapidly reduced P-gp efflux activity, but had no effect on P-gp protein expression level. To clarify the non-transcriptional mechanism that causes the decrease in intrinsic efflux activity of P-gp in acute inflammation, we applied comprehensive quantitative phosphoproteomics to compare hCMEC/D3 cells treated with TNF-α and vehicle (control). Actin filament-associated protein-1 (AFAP-1), MAPK1, and transcription factor AP-1 (AP-1) were significantly phosphorylated in TNF-α-treated cells, and were selected as candidate proteins. In validation experiments, knockdown of AFAP-1 expression blocked the reduction in P-gp efflux activity by TNF-α treatment, whereas inhibition of MAPK function or knockdown of AP-1 expression did not. Quantitative targeted absolute proteomics revealed that the reduction in P-gp activity by TNF-α did not require any change in P-gp protein expression levels in the plasma membrane. Our results demonstrate that AFAP-1 is a key mediator in the inflammatory signaling-induced, translocation-independent rapid attenuation of P-gp efflux activity in human brain capillary endothelial cells.

  2. DNA damage-inducible SUMOylation of HERC2 promotes RNF8 binding via a novel SUMO-binding Zinc finger

    DEFF Research Database (Denmark)

    Danielsen, Jannie Michaela Rendtlew; Povlsen, Lou Klitgaard; Villumsen, Bine Hare;

    2012-01-01

    Nonproteolytic ubiquitylation of chromatin surrounding deoxyribonucleic acid (DNA) double-strand breaks (DSBs) by the RNF8/RNF168/HERC2 ubiquitin ligases facilitates restoration of genome integrity by licensing chromatin to concentrate genome caretaker proteins near the lesions. In parallel......, SUMOylation of so-far elusive upstream DSB regulators is also required for execution of this ubiquitin-dependent chromatin response. We show that HERC2 and RNF168 are novel DNA damage-dependent SUMOylation targets in human cells. In response to DSBs, both HERC2 and RNF168 were specifically modified with SUMO1...... at DSB sites in a manner dependent on the SUMO E3 ligase PIAS4. SUMOylation of HERC2 was required for its DSB-induced association with RNF8 and for stabilizing the RNF8-Ubc13 complex. We also demonstrate that the ZZ Zinc finger in HERC2 defined a novel SUMO-specific binding module, which together...

  3. Special AT-rich sequence-binding protein-1 participates in the maintenance of breast cancer stem cells through regulation of the Notch signaling pathway and expression of Snail1 and Twist1.

    Science.gov (United States)

    Sun, Zhengkui; Zhang, Chao; Zou, Xuesen; Jiang, Guixiang; Xu, Zongquan; Li, Wenting; Xie, Hui

    2015-05-01

    The stem cell populations in cancerous tissues and cell lines vary widely and are often associated with aggressive cases of breast cancer. Despite research on the topic, the mechanism underlying the regulation of the breast cancer stem cell (BCSC) population within tumors remains to be fully elucidated. To investigate the function of special AT‑rich sequence‑binding protein‑1 (SATB1) in the maintenance of the BCSC population, SATB1 was overexpressed with lentivirus in MCF‑7 cells or knocked down with shRNA‑lentivirus in BT‑549 cells. The effects of SATB1 overexpression or knockdown on mammosphere formation, the size of the of BCSC population, cell invasion and tumorigenesis were investigated. Activation of the Notch signaling pathway and expression of Snail1 and Twist1 were also examined in the cells. Overexpression of SATB1 in MCF‑7 cells was observed to increase mammosphere formation, the size of the BCSC population, cell invasion and tumorigenesis, accompanied by an increase in the activation of Notch signaling and expression levels of Snail1 and Twist1. Conversely, knockdown of SATB1 in BT‑549 cells produced the opposite effects. The results indicated that expression of SATB1 may increase the size of the BCSC population via the activation of the Notch signaling pathway and by increasing expression levels of Snail1 and Twist1.

  4. Epicatechin induces NF-kappaB, activator protein-1 (AP-1) and nuclear transcription factor erythroid 2p45-related factor-2 (Nrf2) via phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) and extracellular regulated kinase (ERK) signalling in HepG2 cells.

    Science.gov (United States)

    Granado-Serrano, Ana Belén; Martín, María Angeles; Haegeman, Guy; Goya, Luis; Bravo, Laura; Ramos, Sonia

    2010-01-01

    The dietary flavonoid epicatechin has been reported to exhibit a wide range of biological activities. The objective of the present study was to investigate the time-dependent regulation by epicatechin on the activity of the main transcription factors (NF-kappaB, activator protein-1 (AP-1) and nuclear transcription factor erythroid 2p45-related factor (Nrf2)) related to antioxidant defence and survival and proliferation pathways in HepG2 cells. Treatment of cells with 10 microm-epicatechin induced the NF-kappaB pathway in a time-dependent manner characterised by increased levels of IkappaB kinase (IKK) and phosphorylated inhibitor of kappaB subunit-alpha (p-IkappaBalpha) and proteolytic degradation of IkappaB, which was consistent with an up-regulation of the NF-kappaB-binding activity. Time-dependent activation of the AP-1 pathway, in concert with enhanced c-Jun nuclear levels and induction of Nrf2 translocation and phosphorylation were also demonstrated. Additionally, epicatechin-induced NF-kappaB and Nrf2 were connected to reactive oxygen species intracellular levels and to the activation of cell survival and proliferation pathways, being phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) and extracellular regulated kinase (ERK) associated to Nrf2 modulation and ERK to NF-kappaB induction. These data suggest that the epicatechin-induced survival effect occurs by the induction of redox-sensitive transcription factors through a tight regulation of survival and proliferation pathways.

  5. Accommodation of structural rearrangements in the huntingtin-interacting protein 1 coiled-coil domain

    Energy Technology Data Exchange (ETDEWEB)

    Wilbur, Jeremy D., E-mail: jwilbur@msg.ucsf.edu [Graduate Program in Biophysics, University of California, San Francisco, California 94143 (United States); Hwang, Peter K. [Department of Biochemistry and Biophysics, University of California, San Francisco, California 94143 (United States); Brodsky, Frances M. [The G. W. Hooper Foundation, Departments of Microbiology and Immunology and of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California 94143 (United States); Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143 (United States); Fletterick, Robert J. [Department of Biochemistry and Biophysics, University of California, San Francisco, California 94143 (United States); Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143 (United States); Graduate Program in Biophysics, University of California, San Francisco, California 94143 (United States)

    2010-03-01

    Variable packing interaction related to the conformational flexibility within the huntingtin-interacting protein 1 coiled coil domain. Huntingtin-interacting protein 1 (HIP1) is an important link between the actin cytoskeleton and clathrin-mediated endocytosis machinery. HIP1 has also been implicated in the pathogenesis of Huntington’s disease. The binding of HIP1 to actin is regulated through an interaction with clathrin light chain. Clathrin light chain binds to a flexible coiled-coil domain in HIP1 and induces a compact state that is refractory to actin binding. To understand the mechanism of this conformational regulation, a high-resolution crystal structure of a stable fragment from the HIP1 coiled-coil domain was determined. The flexibility of the HIP1 coiled-coil region was evident from its variation from a previously determined structure of a similar region. A hydrogen-bond network and changes in coiled-coil monomer interaction suggest that the HIP1 coiled-coil domain is uniquely suited to allow conformational flexibility.

  6. "Wilms Tumor Protein 1" (WT1) peptide vaccination-induced complete remission in a patient with acute myeloid leukemia is accompanied by the emergence of a predominant T-cell clone both in blood and bone marrow.

    Science.gov (United States)

    Ochsenreither, Sebastian; Fusi, Alberto; Busse, Antonia; Bauer, Sandra; Scheibenbogen, Carmen; Stather, David; Thiel, Eckhard; Keilholz, Ulrich; Letsch, Anne

    2011-01-01

    Within the last few years, the first peptide vaccination trials for treatment of acute myeloid leukemia (AML) have been initiated. Athough the presence of epitope-specific T cells could be seen both in bone marrow (BM) and peripheral blood (PB), nothing is known about their clonal composition. In this study, we analyzed material from a patient with recurrent AML vaccinated with "Wilms Tumor Protein 1" (WT1) peptide, who achieved a complete remission (CR) lasting for 12 months. For identification of expanded WT1-specific T-cell clones, enrichment by tetramer and IFNγ secretion were followed by comparative quantitative reverse transcribed PCR (qRT PCR) quantification of all TCR Vβ-families. Vβ-families with increase in the enriched fraction were cloned and sequenced. A predominant clone was quantified by clonotypic qRT PCR from PB and BM. Quantity and functionality of WT1-specific cells were assessed by tetramer analyses and intracellular IFNγ staining. A specific predominant clone was identified during clinical remission. Clone-specific qRT PCR showed an increase both in PB and BM after 8 vaccinations. Six months after achieving CR, the transcript levels in BM decreased. Relapse was accompanied by secondary rise of the WT1-specific clone in PB but not in BM. In parallel, a lack of vaccine-induced WT1 specific IFNγ production was observed at that timepoint. In conclusion, we provide first data regarding evolution and compartmentalization of a peptide vaccine-induced T-cell clone in PB and BM of an AML patient. At the time of relapse, the same clone reappeared spontaneously in PB but not in BM showing impaired functionality.

  7. A novel prohibitin-binding compound induces the mitochondrial apoptotic pathway through NOXA and BIM upregulation.

    Science.gov (United States)

    Moncunill-Massaguer, Cristina; Saura-Esteller, José; Pérez-Perarnau, Alba; Palmeri, Claudia Mariela; Núñez-Vázquez, Sonia; Cosialls, Ana M; González-Gironès, Diana M; Pomares, Helena; Korwitz, Anne; Preciado, Sara; Albericio, Fernando; Lavilla, Rodolfo; Pons, Gabriel; Langer, Thomas; Iglesias-Serret, Daniel; Gil, Joan

    2015-12-08

    We previously described diaryl trifluorothiazoline compound 1a (hereafter referred to as fluorizoline) as a first-in-class small molecule that induces p53-independent apoptosis in a wide range of tumor cell lines. Fluorizoline directly binds to prohibitin 1 and 2 (PHBs), two proteins involved in the regulation of several cellular processes, including apoptosis. Here we demonstrate that fluorizoline-induced apoptosis is mediated by PHBs, as cells depleted of these proteins are highly resistant to fluorizoline treatment. In addition, BAX and BAK are necessary for fluorizoline-induced cytotoxic effects, thereby proving that apoptosis occurs through the intrinsic pathway. Expression analysis revealed that fluorizoline induced the upregulation of Noxa and Bim mRNA levels, which was not observed in PHB-depleted MEFs. Finally, Noxa(-/-)/Bim(-/-) MEFs and NOXA-downregulated HeLa cells were resistant to fluorizoline-induced apoptosis. All together, these findings show that fluorizoline requires PHBs to execute the mitochondrial apoptotic pathway.

  8. Analysis of the role of the gene coding the Amyloid-Precursor Protein Binding Protein 1 (APP-BP1) in the radio-sensitivity of epidermoid carcinomas of the upper aero-digestive tract infected by the human papillomavirus; Analyse du role du gene codant l'Amyloid-Precursor Protein Binding Protein 1 (APP-BP1) dans la radiosensibilite des carcinomes epidermoides des voies aero-digestives superieures infectees par le papillomavirus humain

    Energy Technology Data Exchange (ETDEWEB)

    Guihard, S.; Altmeyer, A.; Ramolu, L.; Macabre, C.; Abecassis, J.; Noel, G.; Jung, A.C. [Centre de lutte contre le cancer Paul-Strauss, 67 - Strasbourg (France)

    2010-10-15

    As the human papillomavirus (HPV) is at the origin of 25% of upper aero-digestive tract cancers, and as these tumours present an increased radio-sensitivity compared to other tumours, probably due to a greater transcriptional activity of p53, the authors report the study on the influence of a decrease of the expression of the APP-BP1 in these tumours which could favour a radio-induced apoptosis. By using a reverse transcriptase polymerase chain reaction (RT-PCR), they assessed the APP-BP1 expression levels as well as expression levels of transcriptions coding onco-proteins known to be over-expressed in HPV+ tumours. They compared the radio-sensitivities of HPV+ and HPV- cells, the first one appearing to be greater than the second one. Short communication

  9. Solvent fluctuations induce non-Markovian kinetics in hydrophobic pocket-ligand binding

    CERN Document Server

    Weiß, R Gregor; Dzubiella, Joachim

    2016-01-01

    We investigate the impact of water fluctuations on the key-lock association kinetics of a hydrophobic ligand (key) binding to a hydrophobic pocket (lock) by means of a minimalistic stochastic model system. It describes the collective hydration behavior of the pocket by bimodal fluctuations of a water-pocket interface that dynamically couples to the diffusive motion of the approaching ligand via the hydrophobic interaction. This leads to a set of overdamped Langevin equations in 2D-coordinate-space, that is Markovian in each dimension. Numerical simulations demonstrate locally increased friction of the ligand, decelerated binding kinetics, and local non-Markovian (memory) effects in the ligand's reaction coordinate as found previously in explicit-water molecular dynamics studies of model hydrophobic pocket-ligand binding [1,2]. Our minimalistic model elucidates the origin of effectively enhanced friction in the process that can be traced back to long-time decays in the force-autocorrelation function induced by...

  10. Treatment with Ginger Ameliorates Fructose-Induced Fatty Liver and Hypertriglyceridemia in Rats: Modulation of the Hepatic Carbohydrate Response Element-Binding Protein-Mediated Pathway

    Directory of Open Access Journals (Sweden)

    Huanqing Gao

    2012-01-01

    Full Text Available Ginger has been demonstrated to improve lipid derangements. However, its underlying triglyceride-lowering mechanisms remain unclear. Fructose overconsumption is associated with increase in hepatic de novo lipogenesis, thereby resulting in lipid derangements. Here we found that coadministration of the alcoholic extract of ginger (50 mg/kg/day, oral gavage, once daily over 5 weeks reversed liquid fructose-induced increase in plasma triglyceride and glucose concentrations and hepatic triglyceride content in rats. Plasma nonesterified fatty acid concentration was also decreased. Attenuation of the increased vacuolization and Oil Red O staining area was evident on histological examination of liver in ginger-treated rats. However, ginger treatment did not affect chow intake and body weight. Further, ginger treatment suppressed fructose-stimulated overexpression of carbohydrate response element-binding protein (ChREBP at the mRNA and protein levels in the liver. Consequently, hepatic expression of the ChREBP-targeted lipogenic genes responsible for fatty acid biosynthesis was also downregulated. In contrast, expression of neither peroxisome proliferator-activated receptor- (PPAR- alpha and its downstream genes, nor PPAR-gamma and sterol regulatory element-binding protein 1c was altered. Thus the present findings suggest that in rats, amelioration of fructose-induced fatty liver and hypertriglyceridemia by ginger treatment involves modulation of the hepatic ChREBP-mediated pathway.

  11. A possible role of LIM mineralization protein 1 in tertiary dentinogenesis of dental caries treatment.

    Science.gov (United States)

    Wang, Xiao-Ying; Zhang, Qi; Chen, Zhi

    2007-01-01

    Dental caries is a slowly progressive infectious disease with high risks. In response to dental caries stimuli, the tertiary dentin might be formed, protecting the dental pulp. Tertiary dentinogenesis contributes greatly to the treatment of carious lesions as well as the preservation and restoration of entire tooth function. A number of studies have found that application of exogenous growth factors such as transforming growth factors and bone morphogenetic proteins on unexposed pulps are able to signal tertiary dentinogenesis. Since precise mechanism of tertiary dentinogenesis is still not clear, more potential signaling factors might contribute to this process. Dentinogenesis shares many similarities with osteogenesis. The factors involved in osteogenesis and bone repair such as bone morphogenetic proteins 2, 7 and core binding factor alpha1 play important roles in dentinogenesis. LIM mineralization protein 1 is a critical positive regulator of osteoblast differentiation, bone formation and repair. It is logical to postulate that LIM mineralization protein 1 might be involved in odontoblast differentiation and dentin formation both in normal and in pathological conditions. Application of LIM mineralization protein 1 might be a promising approach for inducing tertiary dentinogenesis in dental caries treatment.

  12. Ansamitocin P3 depolymerizes microtubules and induces apoptosis by binding to tubulin at the vinblastine site.

    Science.gov (United States)

    Venghateri, Jubina B; Gupta, Tilak Kumar; Verma, Paul J; Kunwar, Ambarish; Panda, Dulal

    2013-01-01

    Maytansinoid conjugates are currently under different phases of clinical trials and have been showing promising activity for various types of cancers. In this study, we have elucidated the mechanism of action of ansamitocin P3, a structural analogue of maytansine for its anticancer activity. Ansamitocin P3 potently inhibited the proliferation of MCF-7, HeLa, EMT-6/AR1 and MDA-MB-231 cells in culture with a half-maximal inhibitory concentration of 20±3, 50±0.5, 140±17, and 150±1.1 pM, respectively. Ansamitocin P3 strongly depolymerized both interphase and mitotic microtubules and perturbed chromosome segregation at its proliferation inhibitory concentration range. Treatment of ansamitocin P3 activated spindle checkpoint surveillance proteins, Mad2 and BubR1 and blocked the cells in mitotic phase of the cell cycle. Subsequently, cells underwent apoptosis via p53 mediated apoptotic pathway. Further, ansamitocin P3 was found to bind to purified tubulin in vitro with a dissociation constant (Kd) of 1.3±0.7 µM. The binding of ansamitocin P3 induced conformational changes in tubulin. A docking analysis suggested that ansamitocin P3 may bind partially to vinblastine binding site on tubulin in two different positions. The analysis indicated that the binding of ansamitocin P3 to tubulin is stabilized by hydrogen bonds. In addition, weak interactions such as halogen-oxygen interactions may also contribute to the binding of ansamitocin P3 to tubulin. The study provided a significant insight in understanding the antiproliferative mechanism of action of ansamitocin P3.

  13. Ansamitocin P3 depolymerizes microtubules and induces apoptosis by binding to tubulin at the vinblastine site.

    Directory of Open Access Journals (Sweden)

    Jubina B Venghateri

    Full Text Available Maytansinoid conjugates are currently under different phases of clinical trials and have been showing promising activity for various types of cancers. In this study, we have elucidated the mechanism of action of ansamitocin P3, a structural analogue of maytansine for its anticancer activity. Ansamitocin P3 potently inhibited the proliferation of MCF-7, HeLa, EMT-6/AR1 and MDA-MB-231 cells in culture with a half-maximal inhibitory concentration of 20±3, 50±0.5, 140±17, and 150±1.1 pM, respectively. Ansamitocin P3 strongly depolymerized both interphase and mitotic microtubules and perturbed chromosome segregation at its proliferation inhibitory concentration range. Treatment of ansamitocin P3 activated spindle checkpoint surveillance proteins, Mad2 and BubR1 and blocked the cells in mitotic phase of the cell cycle. Subsequently, cells underwent apoptosis via p53 mediated apoptotic pathway. Further, ansamitocin P3 was found to bind to purified tubulin in vitro with a dissociation constant (Kd of 1.3±0.7 µM. The binding of ansamitocin P3 induced conformational changes in tubulin. A docking analysis suggested that ansamitocin P3 may bind partially to vinblastine binding site on tubulin in two different positions. The analysis indicated that the binding of ansamitocin P3 to tubulin is stabilized by hydrogen bonds. In addition, weak interactions such as halogen-oxygen interactions may also contribute to the binding of ansamitocin P3 to tubulin. The study provided a significant insight in understanding the antiproliferative mechanism of action of ansamitocin P3.

  14. Aptamer/target binding-induced triple helix forming for signal-on electrochemical biosensing.

    Science.gov (United States)

    Mao, Yinfei; Liu, Jinquan; He, Dinggen; He, Xiaoxiao; Wang, Kemin; Shi, Hui; Wen, Li

    2015-10-01

    Owing to its diversified structures, high affinity, and specificity for binding a wide range of non-nucleic acid targets, aptamer is a useful molecular recognition tool for the design of various biosensors. Herein, we report a new signal-on electrochemical biosensing platform which is based on an aptamer/target binding-induced strand displacement and triple-helix forming. The biosensing platform is composed of a signal transduction probe (STP) modified with a methylene blue (MB) and a sulfhydryl group, a triplex-forming oligonucleotides probe (TFO) and a target specific aptamer probe (Apt). Through hybridization with the TFO probe and the Apt probe, the self-assembled STP on Au electrode via Au-S bonding keeps its rigid structure. The MB on the STP is distal to the Au electrode surface. It is eT off state. Target binding releases the Apt probe and liberates the end of the MB tagged STP to fold back and form a triplex-helix structure with TFO (STP/TFO/STP), allowing MB to approach the Au electrode surface and generating measurable electrochemical signals (eT ON). As test for the feasibility and universality of this signal-on electrochemical biosensing platform, two aptamers which bind to adenosine triphosphate (ATP) and human α-thrombin (Tmb), respectively, are selected as models. The detection limit of ATP was 7.2 nM, whereas the detection limit of Tmb was 0.86 nM.

  15. Flap loop of GluD2 binds to Cbln1 and induces presynaptic differentiation.

    Science.gov (United States)

    Kuroyanagi, Tomoaki; Hirano, Tomoo

    2010-07-30

    Glutamate receptor delta2 (GluD2) is selectively expressed on the postsynaptic spines at parallel-fiber (PF)-Purkinje neuron (PN) synapses. GluD2 knockout mice show a reduced number of PF-PN synapses, suggesting that GluD2 is involved in synapse formation. Recent studies revealed that GluD2 induces presynaptic differentiation in a manner dependent on its N-terminal domain (NTD) through binding of Cbln1 secreted from cerebellar granule neurons. However, the underlying mechanism of the specific binding of the NTD to Cbln1 remains elusive. Here, we have identified the flap loop (Arg321-Trp339) in the NTD of GluD2 (GluD2-NTD) as a crucial region for the binding to Cbln1 and the induction of presynaptic differentiation. Both induction of presynaptic differentiation and binding of Cbln1 were abolished in the HEK cells expressing not wild-type GluD2 but GluD2 with mutations in the flap loop. Especially, single amino acid substitution of either Arg321 or Trp323 to alanine was sufficient to disable the GluD2 function. Finally, a homology model of GluD2-NTD suggested that the flap loop is located at the distal end, which appears consistent with an interaction with Cbln1 and a presynaptic varicosity.

  16. Changes of conformation and aggregation state induced by binding of lanthanide ions to insulin

    Institute of Scientific and Technical Information of China (English)

    程驿; 李荣昌; 王夔

    2002-01-01

    To clarify the mechanism of lanthanide ions (Ln3+) on the across-membrane transport of insulin and subsequent reducing blood glucose, the interactions of Ln3+ with Zn-insulin and Zn-free insulin are investigated by spectroscopic methods. The results reveal that the binding of Ln3+ to insulin can induce its structure changes from secondary to quaternary structure, depending on the Ln3+ concentration. In the lower concentration, it triggers the conformational changes of insulin monomer in the binding region with insulin receptor (B(24-30)). It would affect insulin-insulin receptor interaction. Moreover, Ln3+ binding promotes the assembly of insulin monomer from dimer to polymer. The potency of Ln3+ in inducing insulin's aggregation is stronger than that of Zn2+. Furthermore, the aggregation can be reversed partly by EDTA-treatment, indicating that it is not due to denaturation. Similar to Zn2+ effect, Ln3+ can stabilize insulin hexamer in a certain range of concentration, but is stronger than the former.

  17. DNA-Binding Kinetics Determines the Mechanism of Noise-Induced Switching in Gene Networks.

    Science.gov (United States)

    Tse, Margaret J; Chu, Brian K; Roy, Mahua; Read, Elizabeth L

    2015-10-20

    Gene regulatory networks are multistable dynamical systems in which attractor states represent cell phenotypes. Spontaneous, noise-induced transitions between these states are thought to underlie critical cellular processes, including cell developmental fate decisions, phenotypic plasticity in fluctuating environments, and carcinogenesis. As such, there is increasing interest in the development of theoretical and computational approaches that can shed light on the dynamics of these stochastic state transitions in multistable gene networks. We applied a numerical rare-event sampling algorithm to study transition paths of spontaneous noise-induced switching for a ubiquitous gene regulatory network motif, the bistable toggle switch, in which two mutually repressive genes compete for dominant expression. We find that the method can efficiently uncover detailed switching mechanisms that involve fluctuations both in occupancies of DNA regulatory sites and copy numbers of protein products. In addition, we show that the rate parameters governing binding and unbinding of regulatory proteins to DNA strongly influence the switching mechanism. In a regime of slow DNA-binding/unbinding kinetics, spontaneous switching occurs relatively frequently and is driven primarily by fluctuations in DNA-site occupancies. In contrast, in a regime of fast DNA-binding/unbinding kinetics, switching occurs rarely and is driven by fluctuations in levels of expressed protein. Our results demonstrate how spontaneous cell phenotype transitions involve collective behavior of both regulatory proteins and DNA. Computational approaches capable of simulating dynamics over many system variables are thus well suited to exploring dynamic mechanisms in gene networks.

  18. Changes of conformation and aggregation state induced by binding of lanthanide ions to insulin

    Institute of Scientific and Technical Information of China (English)

    程驿; 李荣昌; 王夔

    2002-01-01

    To clarify the mechanism of lanthanide ions (Ln3+) on the across-membrane transport of insulin and subsequent reducing blood glucose, the interactions of Ln3+with Zn-insulin and Zn-free insulin are investigated by spectroscopic methods. The results reveal that the binding of Ln3+ to insulin can induce its structure changes from secondary to quaternary structure, depending on the Ln3+ concentration. In the lower concentration, it triggers the conformational changes of insulin monomer in the binding region with insulin receptor (B(24-30)). It would affect insulin-insulin receptor interaction. Moreover, Ln3+ binding promotes the assembly of insulin monomer from dimer to polymer. The potency of Ln3+ in inducing insulin’s aggregation is stronger than that of Zn2+. Furthermore, the aggregation can be reversed partly by EDTA-treatment, indicating that it is not due to denaturation. Similar to Zn2+ effect, Ln3+ can stabilize insulin hexamer in a certain range of concentration, but is stronger than the former.

  19. Interferon-induced guanylate-binding proteins in inflammasome activation and host defense.

    Science.gov (United States)

    Kim, Bae-Hoon; Chee, Jonathan D; Bradfield, Clinton J; Park, Eui-Soon; Kumar, Pradeep; MacMicking, John D

    2016-05-01

    Traditional views of the inflammasome highlight the assembly of pre-existing core components shortly after infection or tissue damage. Emerging work, however, suggests that the inflammasome machinery is also subject to 'tunable' or inducible signals that might accelerate its autocatalytic properties and dictate where inflammasome assembly takes place in the cell. Many of these signals operate downstream of interferon receptors to elicit inflammasome regulators, including a new family of interferon-induced GTPases called 'guanylate-binding proteins' (GBPs). Here we investigate the critical roles of interferon-induced GBPs in directing inflammasome subtype-specific responses and their consequences for cell-autonomous immunity to a wide variety of microbial pathogens. We discuss emerging mechanisms of action and the potential effect of these GBPs on predisposition to sepsis and other infectious or inflammatory diseases.

  20. Identification of a novel hypocholesterolemic protein, major royal jelly protein 1, derived from royal jelly.

    Directory of Open Access Journals (Sweden)

    Yuri Kashima

    Full Text Available Royal jelly (RJ intake lowers serum cholesterol levels in animals and humans, but the active component in RJ that lowers serum cholesterol level and its molecular mechanism are unclear. In this study, we set out to identify the bile acid-binding protein contained in RJ, because dietary bile acid-binding proteins including soybean protein and its peptide are effective in ameliorating hypercholesterolemia. Using a cholic acid-conjugated column, we separated some bile acid-binding proteins from RJ and identified the major RJ protein 1 (MRJP1, MRJP2, and MRJP3 as novel bile acid-binding proteins from RJ, based on matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Purified MRJP1, which is the most abundant protein of the bile acid-binding proteins in RJ, exhibited taurocholate-binding activity in vitro. The micellar solubility of cholesterol was significantly decreased in the presence of MRJP1 compared with casein in vitro. Liver bile acids levels were significantly increased, and cholesterol 7α-hydroxylase (CYP7A1 mRNA and protein tended to increase by MRJP1 feeding compared with the control. CYP7A1 mRNA and protein levels were significantly increased by MRJP1 tryptic hydrolysate treatment compared with that of casein tryptic hydrolysate in hepatocytes. MRJP1 hypocholesterolemic effect has been investigated in rats. The cholesterol-lowering action induced by MRJP1 occurs because MRJP1 interacts with bile acids induces a significant increase in fecal bile acids excretion and a tendency to increase in fecal cholesterol excretion and also enhances the hepatic cholesterol catabolism. We have identified, for the first time, a novel hypocholesterolemic protein, MRJP1, in RJ. Interestingly, MRJP1 exhibits greater hypocholesterolemic activity than the medicine β-sitosterol in rats.

  1. Binding of lipoic acid induces conformational change and appearance of a new binding site in methylglyoxal modified serum albumin.

    Science.gov (United States)

    Suji, George; Khedkar, Santosh A; Singh, Sreelekha K; Kishore, Nand; Coutinho, Evans C; Bhor, Vikrant M; Sivakami, S

    2008-06-01

    The binding of lipoic acid (LA), to methylglyoxal (MG) modified BSA was studied using isothermal titration calorimetry in combination with enzyme kinetics and molecular modelling. The binding of LA to BSA was sequential with two sites, one with higher binding constant and another comparatively lower. In contrast the modified protein showed three sequential binding sites with a reduction in affinity at the high affinity binding site by a factor of 10. CD results show appreciable changes in conformation of the modified protein as a result of binding to LA. The inhibition of esterase like activity of BSA by LA revealed that it binds to site II in domain III of BSA. The pH dependence of esterase activity of native BSA indicated a catalytic group with a pK(a) = 7.9 +/- 0.1, assigned to Tyr411 with the conjugate base stabilised by interaction with Arg410. Upon modification by MG, this pK(a) increased to 8.13. A complex obtained by docking of LA to BSA and BSA in which Arg410 is modified to hydroimidazolone showed that the long hydrocarbon chain of lipoic acid sits in a cavity different from the one observed for unmodified BSA. The molecular electrostatic potential showed that the modification of Arg410 reduced the positive electrostatic potential around the protein-binding site. Thus it can be concluded that the modification of BSA by MG resulted in altered ligand binding characteristics due to changes in the internal geometry and electrostatic potential at the binding site.

  2. Role of the monocyte chemoattractant protein-1/C-C chemokine receptor 2 signaling pathway in transient receptor potential vanilloid type 1 ablation-induced renal injury in salt-sensitive hypertension.

    Science.gov (United States)

    Wang, Youping; Zhu, Mingjun; Xu, Hui; Cui, Lin; Liu, Weihong; Wang, Xiaoxiao; Shen, Si; Wang, Donna H

    2015-09-01

    Our recent studies indicate that the transient receptor potential vanilloid type 1 (TRPV1) channel may act as a potential regulator of monocyte/macrophage recruitment to reduce renal injury in salt-sensitive hypertension. This study tests the hypothesis that deletion of TRPV1 exaggerates salt-sensitive hypertension-induced renal injury due to enhanced inflammatory responses via monocyte chemoattractant protein-1 (MCP-1)/C-C chemokine receptor 2 (CCR2)-dependent pathways. Wild type (WT) and TRPV1-null mutant (TRPV1(-/-)) mice were subjected to uninephrectomy and deoxycorticosterone acetate (DOCA)-salt treatment for four weeks with or without the selective CCR2 antagonist, RS504393. DOCA-salt treatment increased systolic blood pressure (SBP) to the same degree in both strains, but increased urinary excretion of albumin and 8-isoprostane and decreased creatinine clearance with greater magnitude in TRPV1(-/-) mice compared to WT mice. DOCA-salt treatment also caused renal glomerulosclerosis, tubulointerstitial injury, collagen deposition, monocyte/macrophage infiltration, proinflammatory cytokine and chemokine production, and NF-κB activation in greater degree in TRPV1(-/-) mice compared to WT mice. Blockade of the CCR2 with RS504393 (4 mg/kg/day) had no effect on SBP in DOCA-salt-treated WT or TRPV1(-/-) mice compared to their respective controls. However, treatment with RS504393 ameliorated renal dysfunction and morphological damage, and prevented the increase in monocyte/macrophage infiltration, cytokine/chemokine production, and NF-κB activity in both DOCA-salt hypertensive strains with a greater effect in DOCA-salt-treated TRPV1(-/-) mice compared to DOCA-salt-treated WT mice. No differences in CCR2 protein expression in kidney were found between DOCA-salt-treated WT and TRPV1(-/-) mice with or without RS504393 treatment. Our studies for the first time indicate that deletion of TRPV1 aggravated renal injury in salt-sensitive hypertension via enhancing MCP-1

  3. Extracellular Y-box binding protein-1 promotes proliferation and metastasis of HepG2 cells through Notch3 receptor%胞外Y-盒结合蛋白1通过Notch3受体促进肝癌细胞HepG2的增殖与转移

    Institute of Scientific and Technical Information of China (English)

    史静; 李朴; 邹麟; 陈瀑; 张莉萍

    2016-01-01

    Objective To clarifywhether HepG2 cells actively secrete Y-box binding protein-1 (YB-1) under stress conditions,and to investigate the pathological significance and mechanism of action of extracellular YB-1.Methods HepG2 cells were stimulated and treated by gradient concentrations of lipopolysaccharide (LPS) and adtiamycin,the supematant of the culture solution was collected by centrifugation,and the established chemiluminescence immunoassay (CLIA) was used for real-time quantitative determination of YB-1 level in the supernatant.The co-immunoprecipitation assay was used to detect whether extracellular YB-1 specifically bound to Notch3 receptor,and Western blot was used to measure the expression of Notch-NICD.The gradient concentrations of recombinant YB-1 were co-cultured with HepG2 cells,and MTT and migration assays were used to analyze the proliferation and invasion/metastasis of HepG2 cells.One-way analysis of variance was used for comparison of data between multiple groups.Results The results of CLIA confirmed that the level of extracellular YB-1 in the supematant was significantly higher than that in the control group (F =10.54,P < 0.001),and the secretory expression of YB-1 reached its peak after 4 hours of stimulation (LPS:8 ng/ml;adriamycin:10 ng/ml).The results of co-immunoprecipitation assay and Western blot showed that extracellular YB-1 specifically bound to Notch3 receptor and upregulated the expression of the Notch3 receptor.MTT and migration assays showed that extracellular YB-1 significantly promoted the proliferation and invasion/metastasis of HepG2 cells (F =9.405,P < 0.001).Conclusion Under the stress conditions induced by chemotherapeutics,HepG2 cells can actively secrete YB-1 via non-classical pathways.Extracellular YB-1 can specifically bind to Notch3 receptor and further up-regulate its expression,and then promote the proliferation and invasion/metastasis of HepG2 cells.This study lays a foundation for further clarifying the pathogenesis

  4. A cDNA encoding a cold-induced glycine-rich RNA binding protein from Prunus avium expressed in embryonic axes.

    Science.gov (United States)

    Stephen, John R; Dent, Katherine C; Finch-Savage, William E

    2003-11-27

    A cDNA clone encoding a presumed full-length glycine-rich ribonucleic acid (RNA) binding protein was isolated from a lambda-ZAP Express cDNA library generated from primarily nondormant Prunus avium (wild cherry) embryonic axes. The cDNA, designated Pa-RRM-GRP1 (Prunus avium RNA recognition motif glycine-rich protein 1), contains a single N-terminal RNA recognition motif (RRM) and single C-terminal glycine-rich domain. The glycine-rich domain is unusually long at 91 amino acids, 58 of which are glycines. The 534-base pair (bp) open reading frame (ORF) of this clone encodes a 178-amino-acid polypeptide with a predicted molecular weight of 17.33 kDa and pI of 7.84. Comparative sequence alignment of Pa-RRM-GRP1 reveals extensive homology to known and presumed glycine-rich RNA binding proteins from angiosperms and gymnosperms. Genomic Southern blot analysis suggests that this gene exists as a single copy in P. avium. Expression of this gene in P. avium embryonic axes during low-temperature dormancy-breaking treatments was studied and found to be induced by cold (3 degrees C) using real-time PCR of total cDNA supported by Northern blot analysis of total RNA. Expression dropped during prolonged storage at 3 degrees C and was reduced to control levels by interruption of cold treatment by warming to 20 degrees C.

  5. Flap loop of GluD2 binds to Cbln1 and induces presynaptic differentiation

    OpenAIRE

    Kuroyanagi, Tomoaki; Hirano, Tomoo

    2010-01-01

    Glutamate receptor delta2 (GluD2) is selectively expressed on the postsynaptic spines at parallel-fiber (PF)-Purkinje neuron (PN) synapses. GluD2 knockout mice show a reduced number of PF-PN synapses, suggesting that GluD2 is involved in synapse formation. Recent studies revealed that GluD2 induces presynaptic differentiation in a manner dependent on its N-terminal domain (NTD) through binding of Cbln1 secreted from cerebellar granule neurons. However, the underlying mechanism of the specific...

  6. Fusion proteins of HIV-1 envelope glycoprotein gp120 with CD4-induced antibodies showed enhanced binding to CD4 and CD4 binding site antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Weizao, E-mail: chenw3@mail.nih.gov [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); Feng, Yang [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); Wang, Yanping [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); The Basic Research Program, Science Applications International Corporation-Frederick, Inc., National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); Zhu, Zhongyu; Dimitrov, Dimiter S. [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States)

    2012-09-07

    Highlights: Black-Right-Pointing-Pointer Some recombinant HIV-1 gp120s do not preserve their conformations on gp140s. Black-Right-Pointing-Pointer We hypothesize that CD4i antibodies could induce conformational changes in gp120. Black-Right-Pointing-Pointer CD4i antibodies enhance binding of CD4 and CD4bs antibodies to gp120. Black-Right-Pointing-Pointer CD4i antibody-gp120 fusion proteins could have potential as vaccine immunogens. -- Abstract: Development of successful AIDS vaccine immunogens continues to be a major challenge. One of the mechanisms by which HIV-1 evades antibody-mediated neutralizing responses is the remarkable conformational flexibility of its envelope glycoprotein (Env) gp120. Some recombinant gp120s do not preserve their conformations on gp140s and functional viral spikes, and exhibit decreased recognition by CD4 and neutralizing antibodies. CD4 binding induces conformational changes in gp120 leading to exposure of the coreceptor-binding site (CoRbs). In this study, we test our hypothesis that CD4-induced (CD4i) antibodies, which target the CoRbs, could also induce conformational changes in gp120 leading to better exposed conserved neutralizing antibody epitopes including the CD4-binding site (CD4bs). We found that a mixture of CD4i antibodies with gp120 only weakly enhanced CD4 binding. However, such interactions in single-chain fusion proteins resulted in gp120 conformations which bound to CD4 and CD4bs antibodies better than the original or mutagenically stabilized gp120s. Moreover, the two molecules in the fusion proteins synergized with each other in neutralizing HIV-1. Therefore, fusion proteins of gp120 with CD4i antibodies could have potential as components of HIV-1 vaccines and inhibitors of HIV-1 entry, and could be used as reagents to explore the conformational flexibility of gp120 and mechanisms of entry and immune evasion.

  7. A substrate-induced biotin binding pocket in the carboxyltransferase domain of pyruvate carboxylase.

    Science.gov (United States)

    Lietzan, Adam D; St Maurice, Martin

    2013-07-05

    Biotin-dependent enzymes catalyze carboxyl transfer reactions by efficiently coordinating multiple reactions between spatially distinct active sites. Pyruvate carboxylase (PC), a multifunctional biotin-dependent enzyme, catalyzes the bicarbonate- and MgATP-dependent carboxylation of pyruvate to oxaloacetate, an important anaplerotic reaction in mammalian tissues. To complete the overall reaction, the tethered biotin prosthetic group must first gain access to the biotin carboxylase domain and become carboxylated and then translocate to the carboxyltransferase domain, where the carboxyl group is transferred from biotin to pyruvate. Here, we report structural and kinetic evidence for the formation of a substrate-induced biotin binding pocket in the carboxyltransferase domain of PC from Rhizobium etli. Structures of the carboxyltransferase domain reveal that R. etli PC occupies a symmetrical conformation in the absence of the biotin carboxylase domain and that the carboxyltransferase domain active site is conformationally rearranged upon pyruvate binding. This conformational change is stabilized by the interaction of the conserved residues Asp(590) and Tyr(628) and results in the formation of the biotin binding pocket. Site-directed mutations at these residues reduce the rate of biotin-dependent reactions but have no effect on the rate of biotin-independent oxaloacetate decarboxylation. Given the conservation with carboxyltransferase domains in oxaloacetate decarboxylase and transcarboxylase, the structure-based mechanism described for PC may be applicable to the larger family of biotin-dependent enzymes.

  8. Protection against chemotherapy-induced alopecia: targeting ATP-binding cassette transporters in the hair follicle?

    Science.gov (United States)

    Haslam, Iain S; Pitre, Aaron; Schuetz, John D; Paus, Ralf

    2013-11-01

    Currently, efficacious treatments for chemotherapy-induced alopecia (hair loss) are lacking, and incidences of permanent hair loss following high-dose chemotherapy are on the increase. In this article, we describe mechanisms by which the pharmacological defense status of the hair follicle might be enhanced, thereby reducing the accumulation of cytotoxic cancer drugs and preventing or reducing hair loss and damage. We believe this could be achieved via the selective increase in ATP-binding cassette (ABC) transporter expression within the hair follicle epithelium, following application of topical agonists for regulatory nuclear receptors. Clinical application would require the development of hair follicle-targeted formulations, potentially utilizing nanoparticle technology. This novel approach has the potential to yield entirely new therapeutic options for the treatment and management of chemotherapy-induced alopecia, providing significant psychological and physical benefit to cancer patients.

  9. Mannose binding lectin is required for alphavirus-induced arthritis/myositis.

    Directory of Open Access Journals (Sweden)

    Bronwyn M Gunn

    Full Text Available Mosquito-borne alphaviruses such as chikungunya virus and Ross River virus (RRV are emerging pathogens capable of causing large-scale epidemics of virus-induced arthritis and myositis. The pathology of RRV-induced disease in both humans and mice is associated with induction of the host inflammatory response within the muscle and joints, and prior studies have demonstrated that the host complement system contributes to development of disease. In this study, we have used a mouse model of RRV-induced disease to identify and characterize which complement activation pathways mediate disease progression after infection, and we have identified the mannose binding lectin (MBL pathway, but not the classical or alternative complement activation pathways, as essential for development of RRV-induced disease. MBL deposition was enhanced in RRV infected muscle tissue from wild type mice and RRV infected MBL deficient mice exhibited reduced disease, tissue damage, and complement deposition compared to wild-type mice. In contrast, mice deficient for key components of the classical or alternative complement activation pathways still developed severe RRV-induced disease. Further characterization of MBL deficient mice demonstrated that similar to C3(-/- mice, viral replication and inflammatory cell recruitment were equivalent to wild type animals, suggesting that RRV-mediated induction of complement dependent immune pathology is largely MBL dependent. Consistent with these findings, human patients diagnosed with RRV disease had elevated serum MBL levels compared to healthy controls, and MBL levels in the serum and synovial fluid correlated with severity of disease. These findings demonstrate a role for MBL in promoting RRV-induced disease in both mice and humans and suggest that the MBL pathway of complement activation may be an effective target for therapeutic intervention for humans suffering from RRV-induced arthritis and myositis.

  10. Inducible nucleosome depletion at OREBP-binding-sites by hypertonic stress.

    Directory of Open Access Journals (Sweden)

    Edith H Y Tong

    Full Text Available BACKGROUND: Osmotic Response Element-Binding Protein (OREBP, also known as TonEBP or NFAT5, is a unique transcription factor. It is hitherto the only known mammalian transcription factor that regulates hypertonic stress-induced gene transcription. In addition, unlike other monomeric members of the NFAT family, OREBP exists as a homodimer and it is the only transcription factor known to bind naked DNA targets by complete encirclement in vitro. Nevertheless, how OREBP interacts with target DNA, also known as ORE/TonE, and how it elicits gene transcription in vivo, remains unknown. METHODOLOGY: Using hypertonic induction of the aldose reductase (AR gene activation as a model, we showed that OREs contained dynamic nucleosomes. Hypertonic stress induced a rapid and reversible loss of nucleosome(s around the OREs. The loss of nucleosome(s was found to be initiated by an OREBP-independent mechanism, but was significantly potentiated in the presence of OREBP. Furthermore, hypertonic induction of AR gene was associated with an OREBP-dependent hyperacetylation of histones that spanned the 5' upstream sequences and at least some exons of the gene. Nevertheless, nucleosome loss was not regulated by the acetylation status of histone. SIGNIFICANCE: Our findings offer novel insights into the mechanism of OREBP-dependent transcriptional regulation and provide a basis for understanding how histone eviction and transcription factor recruitment are coupled.

  11. Binding induced conformational changes of proteins correlate with their intrinsic fluctuations: a case study of antibodies

    Directory of Open Access Journals (Sweden)

    Keskin Ozlem

    2007-05-01

    Full Text Available Abstract Background How antibodies recognize and bind to antigens can not be totally explained by rigid shape and electrostatic complimentarity models. Alternatively, pre-existing equilibrium hypothesis states that the native state of an antibody is not defined by a single rigid conformation but instead with an ensemble of similar conformations that co-exist at equilibrium. Antigens bind to one of the preferred conformations making this conformation more abundant shifting the equilibrium. Results Here, two antibodies, a germline antibody of 36–65 Fab and a monoclonal antibody, SPE7 are studied in detail to elucidate the mechanism of antibody-antigen recognition and to understand how a single antibody recognizes different antigens. An elastic network model, Anisotropic Network Model (ANM is used in the calculations. Pre-existing equilibrium is not restricted to apply to antibodies. Intrinsic fluctuations of eight proteins, from different classes of proteins, such as enzymes, binding and transport proteins are investigated to test the suitability of the method. The intrinsic fluctuations are compared with the experimentally observed ligand induced conformational changes of these proteins. The results show that the intrinsic fluctuations obtained by theoretical methods correlate with structural changes observed when a ligand is bound to the protein. The decomposition of the total fluctuations serves to identify the different individual modes of motion, ranging from the most cooperative ones involving the overall structure, to the most localized ones. Conclusion Results suggest that the pre-equilibrium concept holds for antibodies and the promiscuity of antibodies can also be explained this hypothesis: a limited number of conformational states driven by intrinsic motions of an antibody might be adequate to bind to different antigens.

  12. Tumor Necrosis Factor Receptor-associated Protein 1 (TRAP1) Mutation and TRAP1 Inhibitor Gamitrinib-triphenylphosphonium (G-TPP) Induce a Forkhead Box O (FOXO)-dependent Cell Protective Signal from Mitochondria*

    OpenAIRE

    Kim, Hyunjin; Yang, Jinsung; Kim, Min Ju; Choi, Sekyu; Chung, Ju-Ryung; Kim, Jong-Min; Yoo, Young Hyun; Chung, Jongkyeong; Koh, Hyongjong

    2015-01-01

    TRAP1 (tumor necrosis factor receptor-associated protein 1), a mitochondrial Hsp90 family chaperone, has been identified as a critical regulator of cell survival and bioenergetics in tumor cells. To discover novel signaling networks regulated by TRAP1, we generated Drosophila TRAP1 mutants. The mutants successfully developed into adults and produced fertile progeny, showing that TRAP1 is dispensable in development and reproduction. Surprisingly, mutation or knockdown of TRAP1 markedly enhance...

  13. The Experiment Study of Kaiyuqingre's Prescription on the Expression of Sterol Regulatory Element Binding Protein-1c and Fatty Acid Synthase in Peritoneal Adipose Tissue of Spontaneous Type 2 Diabetes Mellitus Rats(OLETF rats)%开郁清热方干预自发2型糖尿病大鼠腹腔脂肪组织SREBP-1c、FAS表达的实验研究

    Institute of Scientific and Technical Information of China (English)

    朴春丽; 仝小林; 韩笑

    2011-01-01

    目的:研究开郁清热方对自发2型糖尿病大鼠(OLETF大鼠)腹腔脂肪组织SIREBP-1c、FAS蛋白及mRNA表达的影响.方法:将成模OLETF大鼠随机分为模型组、二甲双胍组、开郁清热方组,以LETO大鼠为空白对照组.采用免第疫组化、RT-PCR法检测腹腔脂肪组织SREBP-1c、FAS蛋白及mRNA的表达.结果:开郁清热方组的脂肪组织SBEBP-1c、FAS蛋白及mPNA表达水平较模型组明显减低(P<0.01,P<0.05).结论:开郁清热方具有降低自发2型糖尿病大鼠脂肪组织SREBP-lc、FAS蛋白及mRNA表达的作用.%Objective: To observe the effect of Kaiyuqingre's Prescription on the protein and mRNA expression of sterol regulatory element binding protein - 1c and fatty acid synthase in peritoneal adipose tissue of spontaneous Type 2 Diabetes Mellitus rats(OLEFF rats). Methods :A control study was carried out between the OLETF rats and LETO rats,and all OLETF rats were divided into three groups randomly:Model group,Metformin group and Kaiyuqingre′s Prescription group. Immunohistochemical method and real-time flourescent quantitative polymerase chain reaction(PCR)technology were used to detect the expression of sterol regulatory element binding protein - 1c and fatty acid synthaso in adipose tissue from the protein and gene levels in each group. Results: The sterol regulatory dement binding protein - 1c and fatty acid synthase protein and mRNA expression in rats 'adipose tissue:Contrast to Modal group,the Kaiyuqingre′s Prescription group is significantly lower. Conclusion :Kaiyuqingre's Prescription has a role of reducing the expression of protein and mRNA of sterol regulatory dement binding protein - 1c and fatty acid synthase in adipose tissue of spontaneous Type 2 Diabetes Mellitus rats.

  14. Decipher the mechanisms of protein conformational changes induced by nucleotide binding through free-energy landscape analysis: ATP binding to Hsp70.

    Directory of Open Access Journals (Sweden)

    Adrien Nicolaï

    Full Text Available ATP regulates the function of many proteins in the cell by transducing its binding and hydrolysis energies into protein conformational changes by mechanisms which are challenging to identify at the atomic scale. Based on molecular dynamics (MD simulations, a method is proposed to analyze the structural changes induced by ATP binding to a protein by computing the effective free-energy landscape (FEL of a subset of its coordinates along its amino-acid sequence. The method is applied to characterize the mechanism by which the binding of ATP to the nucleotide-binding domain (NBD of Hsp70 propagates a signal to its substrate-binding domain (SBD. Unbiased MD simulations were performed for Hsp70-DnaK chaperone in nucleotide-free, ADP-bound and ATP-bound states. The simulations revealed that the SBD does not interact with the NBD for DnaK in its nucleotide-free and ADP-bound states whereas the docking of the SBD was found in the ATP-bound state. The docked state induced by ATP binding found in MD is an intermediate state between the initial nucleotide-free and final ATP-bound states of Hsp70. The analysis of the FEL projected along the amino-acid sequence permitted to identify a subset of 27 protein internal coordinates corresponding to a network of 91 key residues involved in the conformational change induced by ATP binding. Among the 91 residues, 26 are identified for the first time, whereas the others were shown relevant for the allosteric communication of Hsp70 s in several experiments and bioinformatics analysis. The FEL analysis revealed also the origin of the ATP-induced structural modifications of the SBD recently measured by Electron Paramagnetic Resonance. The pathway between the nucleotide-free and the intermediate state of DnaK was extracted by applying principal component analysis to the subset of internal coordinates describing the transition. The methodology proposed is general and could be applied to analyze allosteric communication in

  15. Cold-inducible RNA-binding protein is an important mediator of alcohol-induced brain inflammation.

    Directory of Open Access Journals (Sweden)

    Salil R Rajayer

    Full Text Available Binge drinking has been associated with cerebral dysfunction. Ethanol induced microglial activation initiates an inflammatory process that causes upregulation of proinflammatory cytokines which in turn creates neuronal inflammation and damage. However, the molecular mechanism is not fully understood. We postulate that cold-inducible RNA-binding protein (CIRP, a novel proinflammatory molecule, can contribute to alcohol-induced neuroinflammation. To test this theory male wild-type (WT mice were exposed to alcohol at concentrations consistent to binge drinking and blood and brain tissues were collected. At 5 h after alcohol, a significant increase of 53% in the brain of CIRP mRNA was observed and its expression remained elevated at 10 h and 15 h. Brain CIRP protein levels were increased by 184% at 10 h and remained high at 15 h. We then exposed male WT and CIRP knockout (CIRP(-/- mice to alcohol, and blood and brain tissues were collected at 15 h post-alcohol infusion. Serum levels of tissue injury markers (AST, ALT and LDH were significantly elevated in alcohol-exposed WT mice while they were less increased in the CIRP(-/- mice. Brain TNF-α mRNA and protein expressions along with IL-1β protein levels were significantly increased in WT mice, which was not seen in the CIRP(-/- mice. In cultured BV2 cells (mouse microglia, ethanol at 100 mM showed an increase of CIRP mRNA by 274% and 408% at 24 h and 48 h respectively. Corresponding increases in TNF-α and IL-1β were also observed. CIRP protein levels were markedly increased in the medium, suggesting that CIRP was secreted by the BV2 cells. From this we conclude that alcohol exposure activates microglia to produce and secrete CIRP and possibly induce pro-inflammatory response and thereby causing neuroinflammation. CIRP could be a novel mediator of alcohol-induced brain inflammation.

  16. Sulfated polymannuroguluronate inhibits Tat-induced SLK cell adhesion via a novel binding site, a KKR spatial triad

    Institute of Scientific and Technical Information of China (English)

    Yan-lin WU; Jing AI; Jing-ming ZHAO; Bing XIONG; Xiao-jie XIN; Mei-yu GENG; Xian-liang XIN; Han-dong JIANG

    2011-01-01

    Aim: Sulfated polymannuroguluronate (SPMG), a candidate anti-AIDS drug, inhibited HIV replication and interfered with HIV entry into host T lymphocytes. SPMG has high binding affinity for the transactivating factor of the HIV-1 virus (Tat) via its basic domain. However, deletion or substitution of the basic domain affected, but did not completely eliminated Tat-SPMG interactions. Here, we sought to identify other SPMG binding sites in addition to the basic domain.Methods: The potential SPMG binding sites were determined using molecular simulation and a surface plasmon resonance (SPR) based competitive inhibition assay. The effect of SPMG on Tat induced adhesion was evaluated using a cell adhesion assay. Results: The KKR domain, a novel high-affinity heparin binding site, was identified, which consisted of a triad of Lys12, Lys41, and Arg78. The KKR domain, spatially enclosed SPMG binding site on Tat, functions as another binding domain for SPMG. Further func- tional evaluation demonstrated that SPMG inhibits Tat-mediated SLK cell adhesion by directly binding to the KKR region.Conclusion: The KKR domain is a novel high-affinity binding domain for SPMG. Our findings provide important new insights into the molecular mechanisms of SPMG and a potential therapeutic intervention for Tat-induced cell adhesion.

  17. Cigarette smoke-induced reduction in binding of the salivary translocator protein is not mediated by free radicals.

    Science.gov (United States)

    Nagler, R; Savulescu, D; Gavish, M

    2016-02-01

    Oral cancer is the most common malignancy of the head and neck and its main inducer is exposure to cigarette smoke (CS) in the presence of saliva. It is commonly accepted that CS contributes to the pathogenesis of oral cancer via reactive free radicals and volatile aldehydes. The 18 kDa translocator protein (TSPO) is an intracellular receptor involved in proliferation and apoptosis, and has been linked to various types of cancer. The presence of TSPO in human saliva has been linked to oral cancer, and its binding affinity to its ligand is reduced following exposure to CS. In the present study we wished to further investigate the mechanism behind the CS-induced reduction of TSPO binding by exploring the possible mediatory role of reactive oxygen species (ROS) and volatile aldehydes in this process. We first analyzed TSPO binding in control saliva and in saliva exposed to CS in the presence and absence of various antioxidants. These experiments found that TSPO binding ability was not reversed by any of the antioxidants added, suggesting that CS exerts its effect on TSPO via mechanisms that do not involve volatile aldehydes and free radicals tested. Next, we analyzed TSPO binding in saliva following addition of exogenous ROS in the form of H2O2. These experiments found that TSPO binding was enhanced due to the treatment, once again showing that the CS-induced TSPO binding reduction is not mediated by this common form of ROS. However, the previously reported CS-induced reduction in salivary TSPO binding together with the role of TSPO in cells and its link to cancer strongly suggest that TSPO has a critical role in the pathogenesis of CS-induced oral cancer. The importance of further elucidating the mechanisms behind it should be emphasized.

  18. Oxidative stress effect on progesterone-induced blocking factor (PIBF) binding to PIBF-receptor in lymphocytes.

    Science.gov (United States)

    de la Haba, Carlos; Palacio, José R; Palkovics, Tamas; Szekeres-Barthó, Júlia; Morros, Antoni; Martínez, Paz

    2014-01-01

    Receptor-ligand binding is an essential interaction for biological function. Oxidative stress can modify receptors and/or membrane lipid dynamics, thus altering cell physiological functions. The aim of this study is to analyze how oxidative stress may alter receptor-ligand binding and lipid domain distribution in the case of progesterone-induced blocking factor/progesterone-induced blocking factor-receptor. For membrane fluidity regionalization analysis of MEC-1 lymphocytes, two-photon microscopy was used in individual living cells. Lymphocytes were also double stained with AlexaFluor647/progesterone-induced blocking factor and Laurdan to evaluate -induced blocking factor/progesterone-induced blocking factor-receptor distribution in the different membrane domains, under oxidative stress. A new procedure has been developed which quantitatively analyzes the regionalization of a membrane receptor among the lipid domains of different fluidity in the plasma membrane. We have been able to establish a new tool which detects and evaluates lipid raft clustering from two-photon microscopy images of individual living cells. We show that binding of progesterone-induced blocking factor to progesterone-induced blocking factor-receptor causes a rigidification of plasma membrane which is related to an increase of lipid raft clustering. However, this clustering is inhibited under oxidative stress conditions. In conclusion, oxidative stress decreases membrane fluidity, impairs receptor-ligand binding and reduces lipid raft clustering.

  19. Monocyte transmigration induced by modification of low density lipoprotein in cocultures of human aortic wall cells is due to induction of monocyte chemotactic protein 1 synthesis and is abolished by high density lipoprotein.

    OpenAIRE

    Navab, M; Imes, S S; Hama, S Y; Hough, G P; Ross, L.A.; Bork, R W; Valente, A. J.; Berliner, J A; Drinkwater, D C; Laks, H

    1991-01-01

    Incubation of cocultures of human aortic endothelial (HAEC) and smooth muscle cells (HASMC) with LDL in the presence of 5-10% human serum resulted in a 7.2-fold induction of mRNA for monocyte chemotactic protein 1 (MCP-1), a 2.5-fold increase in the levels of MCP-1 protein in the coculture supernatants, and a 7.1-fold increase in the transmigration of monocytes into the subendothelial space of the cocultures. Monocyte migration was inhibited by 91% by antibody to MCP-1. Media collected from t...

  20. Kaempferol-human serum albumin interaction: Characterization of the induced chirality upon binding by experimental circular dichroism and TDDFT calculations

    Science.gov (United States)

    Matei, Iulia; Ionescu, Sorana; Hillebrand, Mihaela

    2012-10-01

    The experimental induced circular dichroism (ICD) and absorption spectra of the achiral flavonoid kaempferol upon binding to human serum albumin (HSA) were correlated to electronic CD and UV-vis spectra theoretically predicted by time-dependent density functional theory (TDDFT). The neutral and four anionic species of kaempferol in various conformations were considered in the calculations. The appearance of the experimental ICD signal was rationalized in terms of kaempferol binding to HSA in a distorted, chiral, rigid conformation. The comparison between the experimental and simulated spectra allowed for the identification of the kaempferol species that binds to HSA, namely the anion generated by deprotonation of the hydroxyl group in position 7. This approach constitutes a convenient method for evidencing the binding species and for determining its conformation in the binding pocket of the protein. Its main advantage over the UV-vis absorption method lays in the fact that only the bound ligand species gives an ICD signal.

  1. Combined albumin and bicarbonate induces head-to-head sperm agglutination which physically prevents equine sperm-oviduct binding.

    Science.gov (United States)

    Leemans, Bart; Gadella, Bart M; Stout, Tom A E; Sostaric, Edita; De Schauwer, Catharina; Nelis, Hilde; Hoogewijs, Maarten; Van Soom, Ann

    2016-04-01

    In many species, sperm binding to oviduct epithelium is believed to be an essential step in generating a highly fertile capacitated sperm population primed for fertilization. In several mammalian species, this interaction is based on carbohydrate-lectin recognition. D-galactose has previously been characterized as a key molecule that facilitates sperm-oviduct binding in the horse. We used oviduct explant and oviduct apical plasma membrane (APM) assays to investigate the effects of various carbohydrates; glycosaminoglycans; lectins; S-S reductants; and the capacitating factors albumin, Ca(2+) and HCO3(-) on sperm-oviduct binding in the horse. Carbohydrate-specific lectin staining indicated that N-acetylgalactosamine, N-acetylneuraminic acid (sialic acid) and D-mannose or D-glucose were the most abundant carbohydrates on equine oviduct epithelia, whereas D-galactose moieties were not detected. However, in a competitive binding assay, sperm-oviduct binding density was not influenced by any tested carbohydrates, glycosaminoglycans, lectins or D-penicillamine, nor did the glycosaminoglycans induce sperm tail-associated protein tyrosine phosphorylation. Furthermore, N-glycosidase F (PNGase) pretreatment of oviduct explants and APM did not alter sperm-oviduct binding density. By contrast, a combination of the sperm-capacitating factors albumin and HCO3(-) severely reduced (>10-fold) equine sperm-oviduct binding density by inducing rapid head-to-head agglutination, both of which events were independent of Ca(2+) and an elevated pH (7.9). Conversely, neither albumin and HCO3(-) nor any other capacitating factor could induce release of oviduct-bound sperm. In conclusion, a combination of albumin and HCO3(-) markedly induced sperm head-to-head agglutination which physically prevented stallion sperm to bind to oviduct epithelium.

  2. Identification of Functional Regulatory Residues of the β-Lactam Inducible Penicillin Binding Protein in Methicillin-Resistant Staphylococcus aureus

    OpenAIRE

    Mbah, Andreas N.; Isokpehi, Raphael D

    2013-01-01

    Resistance to methicillin by Staphylococcus aureus is a persistent clinical problem worldwide. A mechanism for resistance has been proposed in which methicillin resistant Staphylococcus aureus (MRSA) isolates acquired a new protein called β -lactam inducible penicillin binding protein (PBP-2′). The PBP-2′ functions by substituting other penicillin binding proteins which have been inhibited by β -lactam antibiotics. Presently, there is no structural and regulatory information on PBP-2′ protein...

  3. Myo1c binding to submembrane actin mediates insulin-induced tethering of GLUT4 vesicles.

    Science.gov (United States)

    Boguslavsky, Shlomit; Chiu, Tim; Foley, Kevin P; Osorio-Fuentealba, Cesar; Antonescu, Costin N; Bayer, K Ulrich; Bilan, Philip J; Klip, Amira

    2012-10-01

    GLUT4-containing vesicles cycle between the plasma membrane and intracellular compartments. Insulin promotes GLUT4 exocytosis by regulating GLUT4 vesicle arrival at the cell periphery and its subsequent tethering, docking, and fusion with the plasma membrane. The molecular machinery involved in GLUT4 vesicle tethering is unknown. We show here that Myo1c, an actin-based motor protein that associates with membranes and actin filaments, is required for insulin-induced vesicle tethering in muscle cells. Myo1c was found to associate with both mobile and tethered GLUT4 vesicles and to be required for vesicle capture in the total internal reflection fluorescence (TIRF) zone beneath the plasma membrane. Myo1c knockdown or overexpression of an actin binding-deficient Myo1c mutant abolished insulin-induced vesicle immobilization, increased GLUT4 vesicle velocity in the TIRF zone, and prevented their externalization. Conversely, Myo1c overexpression immobilized GLUT4 vesicles in the TIRF zone and promoted insulin-induced GLUT4 exposure to the extracellular milieu. Myo1c also contributed to insulin-dependent actin filament remodeling. Thus we propose that interaction of vesicular Myo1c with cortical actin filaments is required for insulin-mediated tethering of GLUT4 vesicles and for efficient GLUT4 surface delivery in muscle cells.

  4. Ribosome binding induces repositioning of the signal recognition particle receptor on the translocon

    Science.gov (United States)

    Kuhn, Patrick; Draycheva, Albena; Vogt, Andreas; Petriman, Narcis-Adrian; Sturm, Lukas; Drepper, Friedel; Warscheid, Bettina; Wintermeyer, Wolfgang

    2015-01-01

    Cotranslational protein targeting delivers proteins to the bacterial cytoplasmic membrane or to the eukaryotic endoplasmic reticulum membrane. The signal recognition particle (SRP) binds to signal sequences emerging from the ribosomal tunnel and targets the ribosome-nascent-chain complex (RNC) to the SRP receptor, termed FtsY in bacteria. FtsY interacts with the fifth cytosolic loop of SecY in the SecYEG translocon, but the functional role of the interaction is unclear. By using photo-cross-linking and fluorescence resonance energy transfer measurements, we show that FtsY–SecY complex formation is guanosine triphosphate independent but requires a phospholipid environment. Binding of an SRP–RNC complex exposing a hydrophobic transmembrane segment induces a rearrangement of the SecY–FtsY complex, which allows the subsequent contact between SecY and ribosomal protein uL23. These results suggest that direct RNC transfer to the translocon is guided by the interaction between SRP and translocon-bound FtsY in a quaternary targeting complex. PMID:26459600

  5. Acidic pH-Induced Conformations and LAMP1 Binding of the Lassa Virus Glycoprotein Spike.

    Directory of Open Access Journals (Sweden)

    Sai Li

    2016-02-01

    Full Text Available Lassa virus is an enveloped, bi-segmented RNA virus and the most prevalent and fatal of all Old World arenaviruses. Virus entry into the host cell is mediated by a tripartite surface spike complex, which is composed of two viral glycoprotein subunits, GP1 and GP2, and the stable signal peptide. Of these, GP1 binds to cellular receptors and GP2 catalyzes fusion between the viral envelope and the host cell membrane during endocytosis. The molecular structure of the spike and conformational rearrangements induced by low pH, prior to fusion, remain poorly understood. Here, we analyzed the three-dimensional ultrastructure of Lassa virus using electron cryotomography. Sub-tomogram averaging yielded a structure of the glycoprotein spike at 14-Å resolution. The spikes are trimeric, cover the virion envelope, and connect to the underlying matrix. Structural changes to the spike, following acidification, support a viral entry mechanism dependent on binding to the lysosome-resident receptor LAMP1 and further dissociation of the membrane-distal GP1 subunits.

  6. Acidic pH-Induced Conformations and LAMP1 Binding of the Lassa Virus Glycoprotein Spike.

    Science.gov (United States)

    Li, Sai; Sun, Zhaoyang; Pryce, Rhys; Parsy, Marie-Laure; Fehling, Sarah K; Schlie, Katrin; Siebert, C Alistair; Garten, Wolfgang; Bowden, Thomas A; Strecker, Thomas; Huiskonen, Juha T

    2016-02-01

    Lassa virus is an enveloped, bi-segmented RNA virus and the most prevalent and fatal of all Old World arenaviruses. Virus entry into the host cell is mediated by a tripartite surface spike complex, which is composed of two viral glycoprotein subunits, GP1 and GP2, and the stable signal peptide. Of these, GP1 binds to cellular receptors and GP2 catalyzes fusion between the viral envelope and the host cell membrane during endocytosis. The molecular structure of the spike and conformational rearrangements induced by low pH, prior to fusion, remain poorly understood. Here, we analyzed the three-dimensional ultrastructure of Lassa virus using electron cryotomography. Sub-tomogram averaging yielded a structure of the glycoprotein spike at 14-Å resolution. The spikes are trimeric, cover the virion envelope, and connect to the underlying matrix. Structural changes to the spike, following acidification, support a viral entry mechanism dependent on binding to the lysosome-resident receptor LAMP1 and further dissociation of the membrane-distal GP1 subunits.

  7. A programmable DNA origami nanospring that reveals force-induced adjacent binding of myosin VI heads.

    Science.gov (United States)

    Iwaki, M; Wickham, S F; Ikezaki, K; Yanagida, T; Shih, W M

    2016-12-12

    Mechanosensitive biological nanomachines such as motor proteins and ion channels regulate diverse cellular behaviour. Combined optical trapping with single-molecule fluorescence imaging provides a powerful methodology to clearly characterize the mechanoresponse, structural dynamics and stability of such nanomachines. However, this system requires complicated experimental geometry, preparation and optics, and is limited by low data-acquisition efficiency. Here we develop a programmable DNA origami nanospring that overcomes these issues. We apply our nanospring to human myosin VI, a mechanosensory motor protein, and demonstrate nanometre-precision single-molecule fluorescence imaging of the individual motor domains (heads) under force. We observe force-induced transitions of myosin VI heads from non-adjacent to adjacent binding, which correspond to adapted roles for low-load and high-load transport, respectively. Our technique extends single-molecule studies under force and clarifies the effect of force on biological processes.

  8. Ligand-induced conformational changes: Improved predictions of ligand binding conformations and affinities

    DEFF Research Database (Denmark)

    Frimurer, T.M.; Peters, Günther H.J.; Iversen, L.F.

    2003-01-01

    A computational docking strategy using multiple conformations of the target protein is discussed and evaluated. A series of low molecular weight, competitive, nonpeptide protein tyrosine phosphatase inhibitors are considered for which the x-ray crystallographic structures in complex with protein...... tyrosine phosphatase 1 B (PTP1B) are known. To obtain a quantitative measure of the impact of conformational changes induced by the inhibitors, these were docked to the active site region of various structures of PTP1B using the docking program FlexX. Firstly, the inhibitors were docked to a PTP1B crystal...... predicted binding energy and a correct docking mode. Thirdly, to improve the predictability of the docking procedure in the general case, where only a single target protein structure is known, we evaluate an approach which takes possible protein side-chain conformational changes into account. Here, side...

  9. A programmable DNA origami nanospring that reveals force-induced adjacent binding of myosin VI heads

    Science.gov (United States)

    Iwaki, M.; Wickham, S. F.; Ikezaki, K.; Yanagida, T.; Shih, W. M.

    2016-01-01

    Mechanosensitive biological nanomachines such as motor proteins and ion channels regulate diverse cellular behaviour. Combined optical trapping with single-molecule fluorescence imaging provides a powerful methodology to clearly characterize the mechanoresponse, structural dynamics and stability of such nanomachines. However, this system requires complicated experimental geometry, preparation and optics, and is limited by low data-acquisition efficiency. Here we develop a programmable DNA origami nanospring that overcomes these issues. We apply our nanospring to human myosin VI, a mechanosensory motor protein, and demonstrate nanometre-precision single-molecule fluorescence imaging of the individual motor domains (heads) under force. We observe force-induced transitions of myosin VI heads from non-adjacent to adjacent binding, which correspond to adapted roles for low-load and high-load transport, respectively. Our technique extends single-molecule studies under force and clarifies the effect of force on biological processes. PMID:27941751

  10. A novel PRD I and TG binding activity involved in virus-induced transcription of IFN-A genes.

    Science.gov (United States)

    Génin, P; Bragança, J; Darracq, N; Doly, J; Civas, A

    1995-01-01

    Comparative analysis of the inducible elements of the mouse interferon A4 and A11 gene promoters (IE-A4 and IE-A11) by transient transfection experiments, DNase 1 footprinting and electrophoretic mobility shift assays resulted in identification of a virus-induced binding activity suggested to be involved in NDV-induced activation of transcription of these genes. The virus-induced factor, termed VIF, is activated early by contact of virions with cells. It specifically recognizes the PRD I-like domain shared by both inducible elements, as well as the TG-like domain of IE-A4. This factor, distinct from the IRF-1, IRF-2 and the alpha F1 binding proteins and presenting a different affinity pattern from that of the TG protein, is proposed as a candidate for IFN-type I gene regulation. Images PMID:8559665

  11. Sialoadhesin expressed on IFN-induced monocytes binds HIV-1 and enhances infectivity.

    Directory of Open Access Journals (Sweden)

    Hans Rempel

    Full Text Available BACKGROUND: HIV-1 infection dysregulates the immune system and alters gene expression in circulating monocytes. Differential gene expression analysis of CD14(+ monocytes from subjects infected with HIV-1 revealed increased expression of sialoadhesin (Sn, CD169, Siglec 1, a cell adhesion molecule first described in a subset of macrophages activated in chronic inflammatory diseases. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed sialoadhesin expression on CD14(+ monocytes by flow cytometry and found significantly higher expression in subjects with elevated viral loads compared to subjects with undetectable viral loads. In cultured CD14(+ monocytes isolated from healthy individuals, sialoadhesin expression was induced by interferon-alpha and interferon-gamma but not tumor necrosis factor-alpha. Using a stringent binding assay, sialoadhesin-expressing monocytes adsorbed HIV-1 through interaction with the sialic acid residues on the viral envelope glycoprotein gp120. Furthermore, monocytes expressing sialoadhesin facilitated HIV-1 trans infection of permissive cells, which occurred in the absence of monocyte self-infection. CONCLUSIONS/SIGNIFICANCE: Increased sialoadhesin expression on CD14(+ monocytes occurred in response to HIV-1 infection with maximum expression associated with high viral load. We show that interferons induce sialoadhesin in primary CD14(+ monocytes, which is consistent with an antiviral response during viremia. Our findings suggest that circulating sialoadhesin-expressing monocytes are capable of binding HIV-1 and effectively delivering virus to target cells thereby enhancing the distribution of HIV-1. Sialoadhesin could disseminate HIV-1 to viral reservoirs during monocyte immunosurveillance or migration to sites of inflammation and then facilitate HIV-1 infection of permissive cells.

  12. Cold-inducible RNA-binding protein inhibits neuron apoptosis through the suppression of mitochondrial apoptosis.

    Science.gov (United States)

    Zhang, Hai-Tao; Xue, Jing-Hui; Zhang, Zhi-Wen; Kong, Hai-Bo; Liu, Ai-Jun; Li, Shou-Chun; Xu, Dong-Gang

    2015-10-01

    Cold-inducible RNA-binding protein (CIRP) is induced by mild hypothermia in several mammals, but the precise mechanism by which CIRP mediates hypothermia-induced neuroprotection remains unknown. We aimed to investigate the molecular mechanisms by which CIRP protects the nervous system during mild hypothermia. Rat cortical neurons were isolated and cultured in vitro under mild hypothermia (32°C). Apoptosis was measured by annexin V and propidium iodide staining, visualized by flow cytometry. Neuron ultrastructure was visualized by transmission electron microscopy. CIRP overexpression and knockdown were achieved via infection with pL/IRES/GFP-CIRP and pL/shRNA/F-CIRP-A lentivirus. RT(2) Profiler PCR Array Pathway Analysis and western blotting were used to evaluate the effects of CIRP overexpresion/knockdown on the neurons׳ transcriptome. Neuron late apoptosis was significantly reduced at day 7 of culture by 12h hypothermia, but neuron ultrastructure remained relatively intact. RT(2) Profiler PCR Array Pathway Analysis of 84 apoptosis pathway-associated factors revealed that mild hypothermia and CIRP overexpression induce similar gene expression profiles, specifically alterations of genes implicated in the mitochondrial apoptosis pathway. Mild hypothermia-treated neurons up-regulated 12 and down-regulated 38 apoptosis pathway-associated genes. CIRP-overexpressing neurons up-regulated 15 and down-regulated 46 genes. CIRP-knocked-down hypothermia-treated cells up-regulated 9 and down-regulated 40 genes. Similar results were obtained at the protein level. In conclusion, CIRP may inhibit neuron apoptosis through the suppression of the mitochondria apoptosis pathway during mild hypothermia.

  13. Convergent Signaling Pathways Controlled by LRP1 (Receptor-related Protein 1) Cytoplasmic and Extracellular Domains Limit Cellular Cholesterol Accumulation.

    Science.gov (United States)

    El Asmar, Zeina; Terrand, Jérome; Jenty, Marion; Host, Lionel; Mlih, Mohamed; Zerr, Aurélie; Justiniano, Hélène; Matz, Rachel L; Boudier, Christian; Scholler, Estelle; Garnier, Jean-Marie; Bertaccini, Diego; Thiersé, Danièle; Schaeffer, Christine; Van Dorsselaer, Alain; Herz, Joachim; Bruban, Véronique; Boucher, Philippe

    2016-03-04

    The low density lipoprotein receptor-related protein 1 (LRP1) is a ubiquitously expressed cell surface receptor that protects from intracellular cholesterol accumulation. However, the underlying mechanisms are unknown. Here we show that the extracellular (α) chain of LRP1 mediates TGFβ-induced enhancement of Wnt5a, which limits intracellular cholesterol accumulation by inhibiting cholesterol biosynthesis and by promoting cholesterol export. Moreover, we demonstrate that the cytoplasmic (β) chain of LRP1 suffices to limit cholesterol accumulation in LRP1(-/-) cells. Through binding of Erk2 to the second of its carboxyl-terminal NPXY motifs, LRP1 β-chain positively regulates the expression of ATP binding cassette transporter A1 (ABCA1) and of neutral cholesterol ester hydrolase (NCEH1). These results highlight the unexpected functions of LRP1 and the canonical Wnt5a pathway and new therapeutic potential in cholesterol-associated disorders including cardiovascular diseases.

  14. Deficiency of CCAAT/enhancer binding protein family DNA binding prevents malignant conversion of adenoma to carcinoma in NNK-induced lung carcinogenesis in the mouse

    Directory of Open Access Journals (Sweden)

    Kimura Shioko

    2012-12-01

    Full Text Available Abstract Background The CCAAT/enhancer binding proteins (C/EBPs play important roles in carcinogenesis of many tumors including the lung. Since multiple C/EBPs are expressed in lung, the combinatorial expression of these C/EBPs on lung carcinogenesis is not known. Methods A transgenic mouse line expressing a dominant negative A-C/EBP under the promoter of lung epithelial Clara cell secretory protein (CCSP gene in doxycycline dependent fashion was subjected to 4-(methylnitrosamino-1-(3-pyridyl-1-butanone (NNK-induced lung carcinogenesis bioassay in the presence and absence of doxycycline, and the effect of abolition of DNA binding activities of C/EBPs on lung carcinogenesis was examined. Results A-C/EBP expression was found not to interfere with tumor development; however, it suppressed the malignant conversion of adenoma to carcinoma during NNK-induced lung carcinogenesis. The results suggested that Ki67 may be used as a marker for lung carcinomas in mouse. Conclusions The DNA binding of C/EBP family members can be used as a potential molecular target for lung cancer therapy.

  15. Parietal disruption alters audiovisual binding in the sound-induced flash illusion.

    Science.gov (United States)

    Kamke, Marc R; Vieth, Harrison E; Cottrell, David; Mattingley, Jason B

    2012-09-01

    Selective attention and multisensory integration are fundamental to perception, but little is known about whether, or under what circumstances, these processes interact to shape conscious awareness. Here, we used transcranial magnetic stimulation (TMS) to investigate the causal role of attention-related brain networks in multisensory integration between visual and auditory stimuli in the sound-induced flash illusion. The flash illusion is a widely studied multisensory phenomenon in which a single flash of light is falsely perceived as multiple flashes in the presence of irrelevant sounds. We investigated the hypothesis that extrastriate regions involved in selective attention, specifically within the right parietal cortex, exert an influence on the multisensory integrative processes that cause the flash illusion. We found that disruption of the right angular gyrus, but not of the adjacent supramarginal gyrus or of a sensory control site, enhanced participants' veridical perception of the multisensory events, thereby reducing their susceptibility to the illusion. Our findings suggest that the same parietal networks that normally act to enhance perception of attended events also play a role in the binding of auditory and visual stimuli in the sound-induced flash illusion.

  16. A novel L-fucose-binding lectin from Fenneropenaeus indicus induced cytotoxicity in breast cancer cells.

    Science.gov (United States)

    Chatterjee, Biji; Ghosh, Krishna; Yadav, Nitin; Kanade, Santosh R

    2017-01-01

    Lectins are omnipresent in almost all life forms, being the proteins which specifically bind to carbohydrate moieties on the cell surface; they have been explored for their anti-tumour activities. In this study, we purified a fucose specific-lectin (IFL) from Fenneropenaeus indicus haemolymph using fucose-affinity column and characterized for its haemagglutination activity, carbohydrate specificity, dependency on cations and cytotoxicity against cancer cells. The lectin showed non-specificity against human erythrocytes. It was a Ca(2+)-dependent lectin which remained stable over wide pH and temperature ranges. The lectin showed effective dose dependent cytotoxicity against different human cancer cell lines and induced apoptosis in MCF-7 cells as evidenced by DNA ladder assay and PARP cleavage in a dose dependent manner. Moreover, an increased p21 level corresponding to cyclin D downregulation in response to IFL treatment was observed which might work as probable factors to inhibit cell growth and induce apoptosis of MCF-7 cells. Therefore, we report a novel lectin from the prawn haemolymph with high specificity for L-fucose and antiproliferative towards human cancer cells. However, further establishment of the modus operandi of this lectin is required to enable its biotechnological applications.

  17. The role of interstitial binding in radiation induced segregation in W-Re alloys

    Science.gov (United States)

    Gharaee, Leili; Marian, Jaime; Erhart, Paul

    2016-07-01

    Due to their high strength and advantageous high-temperature properties, tungsten-based alloys are being considered as plasma-facing candidate materials in fusion devices. Under neutron irradiation, rhenium, which is produced by nuclear transmutation, has been found to precipitate in elongated precipitates forming thermodynamic intermetallic phases at concentrations well below the solubility limit. Recent measurements have shown that Re precipitation can lead to substantial hardening, which may have a detrimental effect on the fracture toughness of W alloys. This puzzle of sub-solubility precipitation points to the role played by irradiation induced defects, specifically mixed solute-W interstitials. Here, using first-principles calculations based on density functional theory, we study the energetics of mixed interstitial defects in W-Re, W-V, and W-Ti alloys, as well as the heat of mixing for each substitutional solute. We find that mixed interstitials in all systems are strongly attracted to each other with binding energies of -2.4 to -3.2 eV and form interstitial pairs that are aligned along parallel first-neighbor strings. Low barriers for defect translation and rotation enable defect agglomeration and alignment even at moderate temperatures. We propose that these elongated agglomerates of mixed-interstitials may act as precursors for the formation of needle-shaped intermetallic precipitates. This interstitial-based mechanism is not limited to radiation induced segregation and precipitation in W-Re alloys but is also applicable to other body-centered cubic alloys.

  18. A new generation of proto-oncogenes: cold-inducible RNA binding proteins.

    Science.gov (United States)

    Lleonart, M E

    2010-01-01

    This review focuses on the roles of two major cold-inducible RNA binding proteins known in human cells: CIRP and RBM3. Both proteins were discovered when they were shown to be induced after exposure to a moderate cold-shock and other cellular stresses such as UV radiation and hypoxia. Initially, it was suggested that these proteins have a suppressive rather stimulatory effect on proliferation; however, proliferative and/or proto-oncogenic functions have recently been assigned to CIRP and RBM3. In a high throughput genetic screen, we recently identified CIRP as an immortalized gene in murine primary cells. On the other hand, the role of RBM3 in transformation has already been demonstrated. Interestingly, both CIRP and RBM3 have been found to be up-regulated in human tumors. This article highlights the roles of CIRP and RBM3 in tumorigenesis, and proposes a model by which CIRP might contribute to senescence bypass by counteracting the deleterious effects of oxidative damage.

  19. RNA-binding protein HuD reduces triglyceride production in pancreatic β cells by enhancing the expression of insulin-induced gene 1.

    Science.gov (United States)

    Kim, Chongtae; Lee, Heejin; Kang, Hoin; Shin, Jung Jae; Tak, Hyosun; Kim, Wook; Gorospe, Myriam; Lee, Eun Kyung

    2016-04-01

    Although triglyceride (TG) accumulation in the pancreas leads to β-cell dysfunction and raises the chance to develop metabolic disorders such as type 2 diabetes (T2DM), the molecular mechanisms whereby intracellular TG levels are regulated in pancreatic β cells have not been fully elucidated. Here, we present evidence that the RNA-binding protein HuD regulates TG production in pancreatic β cells. Mouse insulinoma βTC6 cells stably expressing a small hairpin RNA targeting HuD (shHuD) (βTC6-shHuD) contained higher TG levels compared to control cells. Moreover, downregulation of HuD resulted in a decrease in insulin-induced gene 1 (INSIG1) levels but not in the levels of sterol regulatory element-binding protein 1c (SREBP1c), a key transcription factor for lipid production. We identified Insig1 mRNA as a direct target of HuD by using ribonucleoprotein immunoprecipitation (RIP) and biotin pulldown analyses. By associating with the 3'-untranslated region (3'UTR) of Insig1 mRNA, HuD promoted INSIG1 translation; accordingly, HuD downregulation reduced while ectopic HuD expression increased INSIG1 levels. We further observed that HuD downregulation facilitated the nuclear localization of SREBP1c, thereby increasing the transcriptional activity of SREBP1c and the expression of target genes involved in lipogenesis; likewise, we observed lower INSIG1 levels in the pancreatic islets of HuD-null mice. Taken together, our results indicate that HuD functions as a novel repressor of lipid synthesis in pancreatic β cells.

  20. Reduction of GABA/sub B/ receptor binding induced by climbing fiber degeneration in the rat cerebellum

    Energy Technology Data Exchange (ETDEWEB)

    Kato, K.; Fukuda, H.

    1985-07-22

    When the rat cerebellar climbing fibers degenerated, as induced by lesioning the inferior olive with 3-acetylpyridine (3-AP), GABA/sub B/ receptor binding determined with /sup 3/H-(+/-)baclofen was reduced in the cerebellum but not in the cerebral cortex of rats. Computer analysis of saturation data revealed two components of the binding sites, and indicated that decrease of the binding in the cerebellum was due to reduction in receptor density, mainly of the high-affinity sites, the B/sub max/ of which was reduced to one-third that in the control animals. In vitro treatment with 3-AP, of the membranes prepared from either the cerebellum or the cerebral cortex, induced no alteration in the binding sites, thereby indicating that the alteration of GABA/sub B/ sites induced by in vivo treatment with 3-AP is not due to a direct action of 3-AP on the receptor. GABA/sub A/ and benzodiazepine receptor binding labelled with /sup 3/H-muscimol and /sup 3/H-diazepam, respectively, in both of brain regions was not affected by destruction of the inferior olive. These results provide evidence that some of the GABA/sub B/ sites but neither GABA/sub A/ nor benzodiazepine receptors in the cerebellum are located at the climbing fiber terminals. 28 references, 4 figures, 2 tables.

  1. Subtle bilirubin-induced neurodevelopmental dysfunction (BIND) in the term and late preterm infant : Does it exist?

    NARCIS (Netherlands)

    Lunsing, Roelineke J.

    2014-01-01

    Subtle bilirubin-induced neurological dysfunction (BIND) is defined as disturbances in sensory and sensorimotor integration, central auditory processing, coordination, and muscle tone in the absence of the classical findings of kernicterus. This review is restricted to the (sensori)motor signs of BI

  2. Azadirachtin interacts with the tumor necrosis factor (TNF) binding domain of its receptors and inhibits TNF-induced biological responses.

    Science.gov (United States)

    Thoh, Maikho; Kumar, Pankaj; Nagarajaram, Hampathalu A; Manna, Sunil K

    2010-02-19

    The role of azadirachtin, an active component of a medicinal plant Neem (Azadirachta indica), on TNF-induced cell signaling in human cell lines was investigated. Azadirachtin blocks TNF-induced activation of nuclear factor kappaB (NF-kappaB) and also expression of NF-kappaB-dependent genes such as adhesion molecules and cyclooxygenase 2. Azadirachtin inhibits the inhibitory subunit of NF-kappaB (IkappaB alpha) phosphorylation and thereby its degradation and RelA (p65) nuclear translocation. It blocks IkappaB alpha kinase (IKK) activity ex vivo, but not in vitro. Surprisingly, azadirachtin blocks NF-kappaB DNA binding activity in transfected cells with TNF receptor-associated factor (TRAF)2, TNF receptor-associated death domain (TRADD), IKK, or p65, but not with TNFR, suggesting its effect is at the TNFR level. Azadirachtin blocks binding of TNF, but not IL-1, IL-4, IL-8, or TNF-related apoptosis-inducing ligand (TRAIL) with its respective receptors. Anti-TNFR antibody or TNF protects azadirachtin-mediated down-regulation of TNFRs. Further, in silico data suggest that azadirachtin strongly binds in the TNF binding site of TNFR. Overall, our data suggest that azadirachtin modulates cell surface TNFRs thereby decreasing TNF-induced biological responses. Thus, azadirachtin exerts an anti-inflammatory response by a novel pathway, which may be beneficial for anti-inflammatory therapy.

  3. X盒结合蛋白1反应产物在局灶性脑缺血后内源性神经干细胞增殖过程中的作用%Effect of X box-binding protein 1 on the proliferation of endogenous neural stem cells after focal cerebral ischemia

    Institute of Scientific and Technical Information of China (English)

    邢雪松; 吕威力

    2011-01-01

    背景:细胞核转录因子X盒结合蛋白1在中枢神经系统发育中表达,对神经元的增殖都有很重要的作用.目的:检测细胞核转录因子X盒结合蛋白1在大鼠脑缺血再灌注海马组织神经干细胞中的表达及碱性成纤维细胞生长因子的干预作用.方法:采用大脑中动脉栓塞制作大鼠脑缺血再灌注模型.大鼠随机分为对照组、缺血再灌注组、碱性成纤维细胞生长因子组,免疫组织化学法检测海马神经干细胞BrdU、X盒结合蛋白1的表达及碱性成纤维细胞生长因子的干预作用.结果与结论:脑缺血再灌注第3天缺血海马神经元BrdU阳性细胞明显增多,第7天达高峰.X盒结合蛋白1反应产物第3天较对照组增多,随缺血再灌注时间的延长逐渐增多,第7天达高峰,以后表达逐渐减少.说明碱性成纤维细胞生长因子促进神经干细胞的增殖及缺血脑组织X盒结合蛋白1的表达,其促进神经干细胞增殖作用可能由X盒结合蛋白1信号介导.%BACKGROUND: Nuclear transcription factor X box-binding protein 1 (Xbp1) is expressed during the development of the cental nervous system, and plays an important role in neurons cell proliferation.OBJECTIVE: To investigate the expression of nuclear transcription factor Xbp1 in neural stem cells of cerebral ischemia/reperfusion hippocampal tissue and the inhibition effects of basic fibroblast growth factor (bFGF). METHODS: A novel model of cerebral ischemia/reperfusion was established with the method of middle cerebral artery occlusionin rats. The rate were divided into control group, ischemia/reperfusion group and bFGF group. The expression of BrdU and Xbp1 and the inhibition effect of bFGF in hippocampal neural stem cells were detected with immunohstochemical method. RESULTS AND CONCLUSION: After 3 days. BrdU positive cells in the hippocampus were obviously increased. To the 7hday. BrdU positive cells were more than those at any time. At 3 days. Xbp1

  4. Assessment of altered binding specificity of bacteriophage for ciprofloxacin-induced antibiotic-resistant Salmonella Typhimurium.

    Science.gov (United States)

    Kim, Jeongjin; Jo, Ara; Ding, Tian; Lee, Hyeon-Yong; Ahn, Juhee

    2016-08-01

    This study describes a new effort toward understanding the interaction mechanisms between antibiotic-resistant Salmonella Typhimurium and phages. The antibiotic susceptibility, β-lactamase activity, bacterial motility, gene expression, and lytic activity were evaluated in ciprofloxacin-induced antibiotic-sensitive Salmonella Typhimurium (ASST(CIP)) and ciprofloxacin-induced antibiotic-resistant S. Typhimurium (ARST(CIP)), which were compared to the wild-type strains (ASST(WT) and ARST(WT)). The MIC values of ampicillin, norfloxacin, chloramphenicol, and tetracycline were significantly increased to > 512, 16, 16, and 256 μg/ml, respectively, in the ARST(CIP). The lowest and highest extracellular lactamase activities were observed in ASST(WT) (6.85 μmol/min/ml) and ARST(CIP) (48.83 μmol/min/ml), respectively. The acrA, lpfE, and hilA genes were significantly upregulated by more than tenfold in both ASST(CIP) and ARST(CIP). The induction of multiple antibiotic resistance resulted from the increased efflux pump activity (AcrAB-TolC). The highest phage adsorption rates were more than 95 % for ASST(WT), ASST(CIP), and ARST(WT), while the lowest adsorption rate was 52 % for ARST(CIP) at 15 min of infection. The least lytic activity of phage was 20 % against the ARST(CIP), followed by ASST(CIP) (30 %). The adsorption rate of phage against ARST(CIP) was 52 % at 15 min of infection, which resulted in the decrease in lytic activity (12 %). Understanding the interaction of phage and bacteria is essential for the practical application of phage to control and detect antibiotic-resistant bacteria. The results provide useful information for understanding the binding specificity of phages for multiple antibiotic-resistant pathogens.

  5. Hypoxia-inducible factor-1 (HIF-1) is involved in the regulation of hypoxia-stimulated expression of monocyte chemoattractant protein-1 (MCP-1/CCL2) and MCP-5 (Ccl12) in astrocytes

    OpenAIRE

    Mojsilovic-Petrovic Jelena; Callaghan Debbie; Cui Hong; Dean Clare; Stanimirovic Danica B; Zhang Wandong

    2007-01-01

    Abstract Background Neuroinflammation has been implicated in various brain pathologies characterized by hypoxia and ischemia. Astroglia play an important role in the initiation and propagation of hypoxia/ischemia-induced inflammation by secreting inflammatory chemokines that attract neutrophils and monocytes into the brain. However, triggers of chemokine up-regulation by hypoxia/ischemia in these cells are poorly understood. Hypoxia-inducible factor-1 (HIF-1) is a dimeric transcriptional fact...

  6. Hepatitis C virus induces epidermal growth factor receptor activation via CD81 binding for viral internalization and entry.

    Science.gov (United States)

    Diao, Jingyu; Pantua, Homer; Ngu, Hai; Komuves, Laszlo; Diehl, Lauri; Schaefer, Gabriele; Kapadia, Sharookh B

    2012-10-01

    While epidermal growth factor receptor (EGFR) has been shown to be important in the entry process for multiple viruses, including hepatitis C virus (HCV), the molecular mechanisms by which EGFR facilitates HCV entry are not well understood. Using the infectious cell culture HCV model (HCVcc), we demonstrate that the binding of HCVcc particles to human hepatocyte cells induces EGFR activation that is dependent on interactions between HCV and CD81 but not claudin 1. EGFR activation can also be induced by antibody mediated cross-linking of CD81. In addition, EGFR ligands that enhance the kinetics of HCV entry induce EGFR internalization and colocalization with CD81. While EGFR kinase inhibitors inhibit HCV infection primarily by preventing EGFR endocytosis, antibodies that block EGFR ligand binding or inhibitors of EGFR downstream signaling have no effect on HCV entry. These data demonstrate that EGFR internalization is critical for HCV entry and identify a hitherto-unknown association between CD81 and EGFR.

  7. An induced pocket for the binding of potent fusion inhibitor CL-385319 with H5N1 influenza virus hemagglutinin.

    Directory of Open Access Journals (Sweden)

    Runming Li

    Full Text Available The influenza glycoprotein hemagglutinin (HA plays crucial roles in the early stage of virus infection, including receptor binding and membrane fusion. Therefore, HA is a potential target for developing anti-influenza drugs. Recently, we characterized a novel inhibitor of highly pathogenic H5N1 influenza virus, CL-385319, which specifically inhibits HA-mediated viral entry. Studies presented here identified the critical binding residues for CL-385319, which clustered in the stem region of the HA trimer by site-directed mutagenesis. Extensive computational simulations, including molecular docking, molecular dynamics simulations, molecular mechanics generalized Born surface area (MM_GBSA calculations, charge density and Laplacian calculations, have been carried out to uncover the detailed molecular mechanism that underlies the binding of CL-385319 to H5N1 influenza virus HA. It was found that the recognition and binding of CL-385319 to HA proceeds by a process of "induced fit" whereby the binding pocket is formed during their interaction. Occupation of this pocket by CL-385319 stabilizes the neutral pH structure of hemagglutinin, thus inhibiting the conformational rearrangements required for membrane fusion. This "induced fit" pocket may be a target for structure-based design of more potent influenza fusion inhibitors.

  8. Uveitis in horses induced by interphotoreceptor retinoid-binding protein is similar to the spontaneous disease.

    Science.gov (United States)

    Deeg, Cornelia A; Thurau, Stephan R; Gerhards, Hartmut; Ehrenhofer, Marion; Wildner, Gerhild; Kaspers, Bernd

    2002-09-01

    Equine recurrent uveitis (ERU) is an inflammatory eye disease with high similarity to uveitis in man. It is the only spontaneous animal model for uveitis and the most frequent eye disease in horses affecting up to 10% of the population. To further investigate the pathophysiology of ERU we now report the establishment of an inducible uveitis model in horses. An ERU-like disease was elicited in seven out of seven horses by injection of interphotoreceptor retinoid-binding protein (IRBP) in complete Freund's adjuvant. Control horses did not develop uveitis. The disease model is characterized by a highly reproducible disease course and recurrent episodes with an identical time course elicited in all horses by repeated IRBP injections. The histology revealed the formation of lymphoid follicle-like structures in the eyes and an intraocular infiltration dominated by CD3(+) lymphocytes, morphological patterns typical for the spontaneous disease. Antigen-specific T cell proliferation of PBL was monitored prior to clinical uveitis and during disease episodes. An initial T cell response to IRBP-derived peptides was followed by epitope spreading to S-antigen-derived peptides in response to subsequent immunizations. Thus, horse experimental uveitis represents a valuable disease model for comparative studies with the spontaneous disease and the investigation of immunomodulatory therapeutic approaches after onset of the disease.

  9. Pulse EPR-enabled interpretation of scarce pseudocontact shifts induced by lanthanide binding tags

    Energy Technology Data Exchange (ETDEWEB)

    Abdelkader, Elwy H.; Yao, Xuejun [Australian National University, Research School of Chemistry (Australia); Feintuch, Akiva [Weizmann Institute of Science, Department of Chemical Physics (Israel); Adams, Luke A.; Aurelio, Luigi; Graham, Bim [Monash University, Monash Institute of Pharmaceutical Sciences (Australia); Goldfarb, Daniella [Weizmann Institute of Science, Department of Chemical Physics (Israel); Otting, Gottfried, E-mail: gottfried.otting@anu.edu.au [Australian National University, Research School of Chemistry (Australia)

    2016-01-15

    Pseudocontact shifts (PCS) induced by tags loaded with paramagnetic lanthanide ions provide powerful long-range structure information, provided the location of the metal ion relative to the target protein is known. Usually, the metal position is determined by fitting the magnetic susceptibility anisotropy (Δχ) tensor to the 3D structure of the protein in an 8-parameter fit, which requires a large set of PCSs to be reliable. In an alternative approach, we used multiple Gd{sup 3+}-Gd{sup 3+} distances measured by double electron–electron resonance (DEER) experiments to define the metal position, allowing Δχ-tensor determinations from more robust 5-parameter fits that can be performed with a relatively sparse set of PCSs. Using this approach with the 32 kDa E. coli aspartate/glutamate binding protein (DEBP), we demonstrate a structural transition between substrate-bound and substrate-free DEBP, supported by PCSs generated by C3-Tm{sup 3+} and C3-Tb{sup 3+} tags attached to a genetically encoded p-azidophenylalanine residue. The significance of small PCSs was magnified by considering the difference between the chemical shifts measured with Tb{sup 3+} and Tm{sup 3+} rather than involving a diamagnetic reference. The integrative sparse data approach developed in this work makes poorly soluble proteins of limited stability amenable to structural studies in solution, without having to rely on cysteine mutations for tag attachment.

  10. Human immunodeficiency virus type 1 efficiently binds to human fetal astrocytes and induces neuroinflammatory responses independent of infection

    Directory of Open Access Journals (Sweden)

    Potash Mary

    2007-05-01

    Full Text Available Abstract Background HIV-1 infects human astrocytes in vitro and in vivo but the frequency of infected cells is low and its biological significance is unknown. In studies in vitro, recombinant gp120 alone can induce profound effects on astrocyte biology, suggesting that HIV-1 interaction with astrocytes and its functional consequences extend beyond the limited levels of infection in these cells. Here we determined the relative efficiencies of HIV-1 binding and infection in human fetal astrocytes (HFA, mainly at the single cell level, using HIV-1 tagged with green fluorescence protein (GFP-Vpr fusion proteins, termed HIV-GFP, to detect virus binding and HIV-1 expressing Rev and NefGFP fusion proteins to detect productive infection. Results Essentially all HFA in a population bound HIV-GFP specifically and independently of CCR5 and CXCR4. The dynamics of this binding at 37°C resembled binding of an HIV fusion mutant to CD4-positive cells, indicating that most of HIV-GFP arrested infection of HFA at the stage of virus-cell fusion. Despite extensive binding, only about 1% of HFA were detectably infected by HIV-RevGFP or HIV-NefGFP, but this proportion increased to the majority of HFA when the viruses were pseudotyped with vesicular stomatitis virus envelope glycoprotein G, confirming that HFA impose a restriction upon HIV-1 entry. Exposure of HFA to HIV-1 through its native proteins rapidly induced synthesis of interleukin-6 and interleukin-8 with increased mRNA detected within 3 h and increased protein detected within 18 h of exposure. Conclusion Our results indicate that HIV-1 binding to human astrocytes, although extensive, is not generally followed by virus entry and replication. Astrocytes respond to HIV-1 binding by rapidly increased cytokine production suggesting a role of this virus-brain cell interaction in HIV-1 neuropathogenesis.

  11. Identification of Functional Regulatory Residues of the β-Lactam Inducible Penicillin Binding Protein in Methicillin-Resistant Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Andreas N. Mbah

    2013-01-01

    Full Text Available Resistance to methicillin by Staphylococcus aureus is a persistent clinical problem worldwide. A mechanism for resistance has been proposed in which methicillin resistant Staphylococcus aureus (MRSA isolates acquired a new protein called β-lactam inducible penicillin binding protein (PBP-2′. The PBP-2′ functions by substituting other penicillin binding proteins which have been inhibited by β-lactam antibiotics. Presently, there is no structural and regulatory information on PBP-2′ protein. We conducted a complete structural and functional regulatory analysis of PBP-2′ protein. Our analysis revealed that the PBP-2′ is very stable with more hydrophilic amino acids expressing antigenic sites. PBP-2′ has three striking regulatory points constituted by first penicillin binding site at Ser25, second penicillin binding site at Ser405, and finally a single metallic ligand binding site at Glu657 which binds to Zn2+ ions. This report highlights structural features of PBP-2′ that can serve as targets for developing new chemotherapeutic agents and conducting site direct mutagenesis experiments.

  12. Identification of Functional Regulatory Residues of the β -Lactam Inducible Penicillin Binding Protein in Methicillin-Resistant Staphylococcus aureus.

    Science.gov (United States)

    Mbah, Andreas N; Isokpehi, Raphael D

    2013-01-01

    Resistance to methicillin by Staphylococcus aureus is a persistent clinical problem worldwide. A mechanism for resistance has been proposed in which methicillin resistant Staphylococcus aureus (MRSA) isolates acquired a new protein called β -lactam inducible penicillin binding protein (PBP-2'). The PBP-2' functions by substituting other penicillin binding proteins which have been inhibited by β -lactam antibiotics. Presently, there is no structural and regulatory information on PBP-2' protein. We conducted a complete structural and functional regulatory analysis of PBP-2' protein. Our analysis revealed that the PBP-2' is very stable with more hydrophilic amino acids expressing antigenic sites. PBP-2' has three striking regulatory points constituted by first penicillin binding site at Ser25, second penicillin binding site at Ser405, and finally a single metallic ligand binding site at Glu657 which binds to Zn(2+) ions. This report highlights structural features of PBP-2' that can serve as targets for developing new chemotherapeutic agents and conducting site direct mutagenesis experiments.

  13. Subchronic treatment with antiepileptic drugs modifies pentylenetetrazol-induced seizures in mice: Its correlation with benzodiazepine receptor binding

    Directory of Open Access Journals (Sweden)

    Luisa Rocha

    2008-06-01

    Full Text Available Luisa RochaPharmacobiology Department, Center for Research and Advanced Studies, Calz, Tenorios, MéxicoAbstract: Experiments using male CD1 mice were carried out to investigate the effects of subchronic (daily administration for 8 days pretreatments with drugs enhancing GABAergic transmission (diazepam, 10 mg/kg, ip; gabapentin, 100 mg/kg, po; or vigabatrin, 500 mg/kg, po on pentylenetetrazol (PTZ-induced seizures, 24 h after the last injection. Subchronic administration of diazepam reduced latencies to clonus, tonic extension and death induced by PTZ. Subchronic vigabatrin produced enhanced latency to the first clonus but faster occurrence of tonic extension and death induced by PTZ. Subchronic gabapentin did not modify PTZ-induced seizures. Autoradiography experiments revealed reduced benzodiazepine receptor binding in several brain areas after subchronic treatment with diazepam or gabapentin, whereas subchronic vigabatrin did not induce significant receptor changes. The present results indicate differential effects induced by the subchronic administration of diazepam, vigabatrin, and gabapentin on the susceptibility to PTZ-induced seizures, benzodiazepine receptor binding, or both.Keywords: diazepam, gabapentin, vigabatrin, pentylenetetrazol, benzodiazepine receptors

  14. On involvement of transcription factors nuclear factor kappa-light-chain-enhancer of activated B cells, activator protein-1 and signal transducer and activator of transcription-3 in photodynamic therapy-induced death of crayfish neurons and satellite glial cells

    Science.gov (United States)

    Berezhnaya, Elena; Neginskaya, Marya; Kovaleva, Vera; Sharifulina, Svetlana; Ischenko, Irina; Komandirov, Maxim; Rudkovskii, Mikhail; Uzdensky, Anatoly B.

    2015-07-01

    Photodynamic therapy (PDT) is currently used in the treatment of brain tumors. However, not only malignant cells but also neighboring normal neurons and glial cells are damaged during PDT. In order to study the potential role of transcription factors-nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), activator protein (AP-1), and signal transducer and activator of transcription-3 (STAT-3)-in photodynamic injury of normal neurons and glia, we photosensitized the isolated crayfish mechanoreceptor consisting of a single sensory neuron enveloped by glial cells. Application of different inhibitors and activators showed that transcription factors NF-κB (inhibitors caffeic acid phenethyl ester and parthenolide, activator betulinic acid), AP-1 (inhibitor SR11302), and STAT-3 (inhibitors stattic and cucurbitacine) influenced PDT-induced death and survival of neurons and glial cells in different ways. These experiments indicated involvement of NF-κB in PDT-induced necrosis of neurons and apoptosis of glial cells. However, in glial cells, it played the antinecrotic role. AP-1 was not involved in PDT-induced necrosis of neurons and glia, but mediated glial apoptosis. STAT-3 was involved in PDT-induced apoptosis of glial cells and necrosis of neurons and glia. Therefore, signaling pathways that regulate cell death and survival in neurons and glial cells are different. Using various inhibitors or activators of transcription factors, one can differently influence the sensitivity and resistance of neurons and glial cells to PDT.

  15. Humic acid in drinking well water induces inflammation through reactive oxygen species generation and activation of nuclear factor-κB/activator protein-1 signaling pathways: A possible role in atherosclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Hseu, You-Cheng [Department of Cosmeceutics, China Medical University, Taichung 40402, Taiwan (China); Department of Molecular and Cellular Oncology, University of Texas, MD Anderson Cancer Center, TX 77030 (United States); Senthil Kumar, K.J. [Department of Cosmeceutics, China Medical University, Taichung 40402, Taiwan (China); Chen, Chih-Sheng; Cho, Hsin-Ju; Lin, Shu-Wei; Shen, Pei-Chun [Institute of Nutrition, China Medical University, Taichung 40402, Taiwan (China); Lin, Cheng-Wen [Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung 40402, Taiwan (China); Lu, Fung-Jou [Institute of Medicine, Chun Shan Medical University, Taichung 40201, Taiwan (China); Yang, Hsin-Ling, E-mail: hlyang@mail.cmu.edu.tw [Institute of Nutrition, China Medical University, Taichung 40402, Taiwan (China); Department of Molecular and Cellular Oncology, University of Texas, MD Anderson Cancer Center, TX 77030 (United States)

    2014-01-15

    Humic acid (HA) has been implicated as one of the etiological factors in the peripheral vasculopathy of blackfoot disease (BFD) in Taiwan. However, the underlying pathophysiological mechanisms of BFD are not well defined. In this study, we used an in vitro and in vivo model, in which HA (25–200 μg/mL) activated macrophages to produce pro-inflammatory molecules by activating their transcriptional factors. HA exposure induced NO and PGE{sub 2} production followed by induction of iNOS and COX-2 through NF-κB/AP-1 transactivation in macrophages. In addition, the production of TNF-α and IL-1β was significantly increased by HA. Moreover, HA-induced iNOS and COX-2 expression were down-regulated by the NF-κB and AP-1 inhibitors pyrrolidine dithiocarbamate (PDTC) and Tanshinone, respectively. Furthermore, generations of ROS and nitrotyrosine, as well as activation of the AKT and MAPKs signaling cascades were observed after HA exposure. Specifically, HA-induced NF-κB activation was mediated by ROS and AKT, and that HA-induced AP-1 activation was mediated by JNK and ERK. Notably, HA-mediated AKT, JNK, and ERK activation was ROS-independent. The inflammatory potential of HA was correlated with increased expression of HO-1 and Nrf2. Furthermore, an in vivo study confirms that mice exposed to HA, the serum levels of TNF-α and IL-1β was significantly increased in a dose-dependent manner. This report marks the first confirmation that environmental exposure of HA induces inflammation in macrophages, which may be one of the main causes of early atherogenesis in blackfoot disease. - Highlights: • Humic acid (HA) induce pro-inflammatory cytokines and mediators in macrophages. • HA-induced inflammation is mediated by ROS and NF-κB/AP-1 signaling pathways. • The inflammatory potential of HA correlated with activation of Nrf2/HO-1 genes. • HA exposure to mice increased pro-inflammatory cytokines production in vivo. • HA may be one of the main causes of early

  16. Autoantigenic targets of B-cell receptors derived from chronic lymphocytic leukemias bind to and induce proliferation of leukemic cells.

    Science.gov (United States)

    Zwick, Carsten; Fadle, Natalie; Regitz, Evi; Kemele, Maria; Stilgenbauer, Stephan; Bühler, Andreas; Pfreundschuh, Michael; Preuss, Klaus-Dieter

    2013-06-06

    Antigenic targets of the B-cell receptor (BCR) derived from malignant cells in chronic lymphocytic leukemia (CLL) might play a role in the pathogenesis of this neoplasm. We screened human tissue-derived protein macroarrays with antigen-binding fragments derived from 47 consecutive cases of CLL. An autoantigenic target was identified for 12/47 (25.5%) of the cases, with 3 autoantigens being the target of the BCRs from 2 patients each. Recombinantly expressed autoantigens bound specifically to the CLL cells from which the BCR used for the identification of the respective autoantigen was derived. Moreover, binding of the autoantigen to the respective leukemic cells induced a specific activation and proliferation of these cells. In conclusion, autoantigens are frequent targets of CLL-BCRs. Their specific binding to and induction of proliferation in the respective leukemic cells provide the most convincing evidence to date for the long-time hypothesized role of autoantigens in the pathogenesis of CLL.

  17. Essential dynamics of the cellular retinol-binding protein - Evidence for ligand-induced conformational changes

    NARCIS (Netherlands)

    van Aalten, D.M.F.; Findlay, J.B.C.; Amadei, A; Berendsen, H.J.C.

    1995-01-01

    The cellular retinol-binding protein (CRBP) is an intracellular retinol carrier protein belonging to a family of hydrophobic ligand-binding proteins, It transports retinol to specific locations in the cell where, for instance, it is esterified for storage, Recently solved crystallographic structures

  18. Trapping conformational states along ligand-binding dynamics of peptide deformylase: the impact of induced fit on enzyme catalysis.

    Directory of Open Access Journals (Sweden)

    Sonia Fieulaine

    2011-05-01

    Full Text Available For several decades, molecular recognition has been considered one of the most fundamental processes in biochemistry. For enzymes, substrate binding is often coupled to conformational changes that alter the local environment of the active site to align the reactive groups for efficient catalysis and to reach the transition state. Adaptive substrate recognition is a well-known concept; however, it has been poorly characterized at a structural level because of its dynamic nature. Here, we provide a detailed mechanism for an induced-fit process at atomic resolution. We take advantage of a slow, tight binding inhibitor-enzyme system, actinonin-peptide deformylase. Crystal structures of the initial open state and final closed state were solved, as well as those of several intermediate mimics captured during the process. Ligand-induced reshaping of a hydrophobic pocket drives closure of the active site, which is finally "zipped up" by additional binding interactions. Together with biochemical analyses, these data allow a coherent reconstruction of the sequence of events leading from the encounter complex to the key-lock binding state of the enzyme. A "movie" that reconstructs this entire process can be further extrapolated to catalysis.

  19. Fluorescence analysis of the lipid binding-induced conformational change of apolipoprotein E4.

    Science.gov (United States)

    Mizuguchi, Chiharu; Hata, Mami; Dhanasekaran, Padmaja; Nickel, Margaret; Phillips, Michael C; Lund-Katz, Sissel; Saito, Hiroyuki

    2012-07-17

    Apolipoprotein (apo) E is thought to undergo conformational changes in the N-terminal helix bundle domain upon lipid binding, modulating its receptor binding activity. In this study, site-specific fluorescence labeling of the N-terminal (S94) and C-terminal (W264 or S290) helices in apoE4 by pyrene maleimide or acrylodan was employed to probe the conformational organization and lipid binding behavior of the N- and C-terminal domains. Guanidine denaturation experiments monitored by acrylodan fluorescence demonstrated the less organized, more solvent-exposed structure of the C-terminal helices compared to the N-terminal helix bundle. Pyrene excimer fluorescence together with gel filtration chromatography indicated that there are extensive intermolecular helix-helix contacts through the C-terminal helices of apoE4. Comparison of increases in pyrene fluorescence upon binding of pyrene-labeled apoE4 to egg phosphatidylcholine small unilamellar vesicles suggests a two-step lipid-binding process; apoE4 initially binds to a lipid surface through the C-terminal helices followed by the slower conformational reorganization of the N-terminal helix bundle domain. Consistent with this, fluorescence resonance energy transfer measurements from Trp residues to acrylodan attached at position 94 demonstrated that upon binding to the lipid surface, opening of the N-terminal helix bundle occurs at the same rate as the increase in pyrene fluorescence of the N-terminal domain. Such a two-step mechanism of lipid binding of apoE4 is likely to apply to mostly phospholipid-covered lipoproteins such as VLDL. However, monitoring pyrene fluorescence upon binding to HDL(3) suggests that not only apoE-lipid interactions but also protein-protein interactions are important for apoE4 binding to HDL(3).

  20. Anion-induced increases in the affinity of colcemid binding to tubulin.

    Science.gov (United States)

    Ray, K; Bhattacharyya, B; Biswas, B B

    1984-08-01

    Colcemid binds tubulin rapidly and reversibly in contrast to colchicine which binds tubulin relatively slowly and essentially irreversibly. At 37 degrees C the association rate constant for colcemid binding is 1.88 X 10(6) M-1 h-1, about 10 times higher than that for colchicine; this is reflected in the activation energies for binding which are 51.4 kJ/mol for colcemid and 84.8 kJ/mol for colchicine. Scatchard analysis indicates two binding sites on tubulin having different affinities for colcemid. The high-affinity site (Ka = 0.7 X 10(5) M-1 at 37 degrees C) is sensitive to temperature and binds both colchicine and colcemid and hence they are mutually competitive inhibitors. The low-affinity site (Kb = 1.2 X 10(4) M-1) is rather insensitive to temperature and binds only colcemid. Like colchicine, 0.6 mol of colcemid are bound/mol of tubulin dimer (at the high-affinity site) and the reaction is entropy driven (163 J K-1 mol-1). Similar to colchicine, colcemid binding to tubulin is stimulated by certain anions (viz. sulfate and tartrate) but by a different mechanism. Colcemid binding affinity at the lower-affinity site of tubulin is increased in the presence of ammonium sulfate. Interestingly, the lower-affinity site on tubulin for colcemid, even when converted to higher affinity in presence of ammonium sulfate, is not recognized by colchicine. We conclude that tubulin possesses two binding sites, one of which specifically recognized the groups present on the B-ring of colchicine molecule and is effected by the ammonium sulfate, whereas the higher-affinity site, which could accommodate both colchicine and colcemid, possibly recognized the A and C ring of colchicine.

  1. Hepatitis C Virus Induces Epidermal Growth Factor Receptor Activation via CD81 Binding for Viral Internalization and Entry

    OpenAIRE

    Diao, Jingyu; Pantua, Homer; Ngu, Hai; Komuves, Laszlo; Diehl, Lauri; Schaefer, Gabriele; Kapadia, Sharookh B.

    2012-01-01

    While epidermal growth factor receptor (EGFR) has been shown to be important in the entry process for multiple viruses, including hepatitis C virus (HCV), the molecular mechanisms by which EGFR facilitates HCV entry are not well understood. Using the infectious cell culture HCV model (HCVcc), we demonstrate that the binding of HCVcc particles to human hepatocyte cells induces EGFR activation that is dependent on interactions between HCV and CD81 but not claudin 1. EGFR activation can also be ...

  2. Transcriptional regulation, stabilization, and subcellular redistribution of multidrug resistance-associated protein 1 (MRP1) by glycogen synthase kinase 3αβ: novel insights on modes of cadmium-induced cell death stimulated by MRP1.

    Science.gov (United States)

    Kim, Hak-Ryul; Lee, Kang-Yo; Lee, Kang-Yoo; Ahn, Sang-Gun; Lee, Byung-Hoon; Jung, Ki-Tae; Yoon, Jung-Hoon; Yoon, Hyo-Eun; Oh, Seon-Hee

    2015-08-01

    Cadmium (Cd) resistance is associated with the suppression of autophagy in H460 lung cancer cells, which is regulated by phospho(p)serine-glycogen synthase kinase (GSK) 3αβ. However, the involvement of multidrug resistance (MDR) in this signaling pathway and its underlying mechanisms remain to be elucidated. In this study, we used Cd-resistant cells (RH460), developed from H460 lung cancer cells, to demonstrate that the induction of MDR-associated protein (MRP1) in response to Cd is enhanced in H460 cells compared to RH460. Treating RH460 cells with Cd induced large cytoplasmic vacuoles, which was inhibited by the autophagy inhibitor 3-methyladenine. MRP1 was detected in the nuclear-rich membrane fractions and redistributed from the perinuclear to the cytoplasmic compartment following exposure to Cd. Cd-induced MRP1, p-Ser/p-Tyr GSK3αβ, and LC3-II were all suppressed by the GSK3 inhibitor SB216763, but increased by lithium. Furthermore, MRP1 was upregulated by the Ser/Thr phosphatase inhibitor okadaic acid and downregulated by the tyrosine phosphatase inhibitor vanadate, suggesting that MRP1 protein was stabilized by p-Ser GSK3αβ. In addition, co-immunoprecipitation and co-localization analyzes revealed a physical interaction between MRP1 and p-Ser GSK3αβ. Genetic knockdown of GSK3β decreased Cd-induced MRP1 mRNA and protein levels, whereas its overexpression upregulated MRP1 protein expression. MRP1 also co-localized with lysosomal membrane protein-2, which may cause lysosomal membrane permeabilization and the subsequent release of cathepsins into the cytosol. In mice chronically injected with Cd, MRP1 localized to the perinuclear region of bronchial and alveolar epithelial cells. Collectively, these data suggest that Cd toxicity is regulated by the transcriptional regulation, stabilization, and subcellular redistribution of MRP1 via the posttranslational modification of GSK3αβ. Therefore, the serine phosphorylation of GSK3αβ plays a critical role in

  3. Saturation of retinol-binding protein correlates closely to the severity of alcohol-induced liver disease

    DEFF Research Database (Denmark)

    Wagnerberger, S.; Schäfer, C.; Bode, C.;

    2006-01-01

    Impaired metabolism of retinol has been shown to occur in alcohol-induced liver disease (ALD). The purpose of the present study was to investigate the saturation of retinol-binding protein (RBP) in 6 patients with different stages of ALD. Hospitalized alcohol consumers (n=118) with different stages......: 43.5+/-6.2%; ALD3: 29.0+/-5.1%). The present study indicates that plasma concentrations of retinol and RBP per se do not correlate to severity of ALD, but rather that the retinol/RBP ratio links to the severity of alcohol-induced liver damage. From these results, a reduced availability of retinol...

  4. Insulin-like growth factor-binding protein-5 (IGFBP-5) inhibits TNF-{alpha}-induced NF-{kappa}B activity by binding to TNFR1

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Jae Ryoung; Huh, Jae Ho; Lee, Yoonna; Lee, Sang Il [Molecular Therapy Research Center, Sungkyunkwan University, Seoul 135-710 (Korea, Republic of); Rho, Seung Bae [Research Institute, National Cancer Center, Goyang-si, Gyeonggi-do 411-769 (Korea, Republic of); Lee, Je-Ho, E-mail: jeholee@gmail.com [Molecular Therapy Research Center, Sungkyunkwan University, Seoul 135-710 (Korea, Republic of); Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2011-02-25

    Research highlights: {yields} Binding assays demonstrated that secreted- and cellular-IGFBP-5 interacted with TNFR1. {yields} The interaction between IGFBP-5 and TNFR1 was inhibited by TNF-{alpha} and was blocked TNF-{alpha}-activated NF-{kappa}B activity. {yields} IGFBP-5 interacted with TNFR1 through its N- and L-domains but the binding of L-domain to TNFR1 was blocked by TNF-{alpha}. {yields} Competition between the L-domain of IGFBP-5 and TNF-{alpha} blocked TNF-{alpha}-induced NF-{kappa}B activity. {yields} This study suggests that the L-domain of IGFBP-5 is a novel TNFR1 ligand that functions as a competitive TNF-{alpha} inhibitor. -- Abstract: IGFBP-5 is known to be involved in various cell phenomena such as proliferation, differentiation, and apoptosis. However, the exact mechanisms by which IGFBP-5 exerts its functions are unclear. In this study, we demonstrate for the first time that IGFBP-5 is a TNFR1-interacting protein. We found that ectopic expression of IGFBP-5 induced TNFR1 gene expression, and that IGFBP-5 interacted with TNFR1 in both an in vivo and an in vitro system. Secreted IGFBP-5 interacted with GST-TNFR1 and this interaction was blocked by TNF-{alpha}, demonstrating that IGFBP-5 might be a TNFR1 ligand. Furthermore, conditioned media containing secreted IGFBP-5 inhibited PMA-induced NF-{kappa}B activity and IL-6 expression in U-937 cells. Coimmunoprecipitation assays of TNFR1 and IGFBP-5 wild-type and truncation mutants revealed that IGFBP-5 interacts with TNFR1 through its N- and L-domains. However, only the interaction between the L-domain of IGFBP-5 and TNFR1 was blocked by TNF-{alpha} in a dose-dependent manner, suggesting that the L-domain of IGFBP-5 can function as a TNFR1 ligand. Competition between the L-domain of IGFBP-5 and TNF-{alpha} resulted in inhibition of TNF-{alpha}-induced NF-{kappa}{Beta} activity. Taken together, our results suggest that the L-domain of IGFBP-5 is a novel TNFR1 ligand that functions as a competitive TNF

  5. Mangiferin binding to serum albumin is non-saturable and induces conformational changes at high concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, P.G.; Barbosa, A.F. [Biochemistry Laboratory, Institute of Exact Sciences, Federal University of Alfenas, Unifal-MG, R. Gabriel Monteiro da Silva, 700, 37130-000 Alfenas, MG (Brazil); Saraiva, L.A. [Phytochemistry and Medicinal Chemistry Laboratory, Institute of Exact Sciences, Unifal-MG (Brazil); Camps, I. [Physics Laboratory, Institute of Exact Sciences, Unifal-MG (Brazil); Silveira, N.J.F. da [Bioinformatics Laboratory, Institute of Exact Sciences, Unifal-MG (Brazil); Veloso, M.P. [Phytochemistry and Medicinal Chemistry Laboratory, Institute of Exact Sciences, Unifal-MG (Brazil); Santos, M.H., E-mail: poliany.santos@gmail.com [Phytochemistry and Medicinal Chemistry Laboratory, Institute of Exact Sciences, Unifal-MG (Brazil); Schneedorf, J.M., E-mail: zemasfs@gmail.com [Biochemistry Laboratory, Institute of Exact Sciences, Federal University of Alfenas, Unifal-MG, R. Gabriel Monteiro da Silva, 700, 37130-000 Alfenas, MG (Brazil)

    2012-11-15

    The binding interaction between mangiferin (MGF), which a natural xanthone isolated from mangoes, and bovine serum albumin (BSA) was studied with absorbance and fluorescence spectroscopy, cyclic voltammetry and molecular modeling. The data were analyzed to assess the binding mechanism, effect of pH and ionic strength, conformational changes in the protein and electrical charge transfer involved. The MGF-BSA complex exhibited positive cooperativity with a 1:1 stoichiometry (K{sub d}=0.38 mmol L{sup -1}) for the first binding site and a non-saturable binding at high ligand concentrations. Furthermore, the data also suggest an increase in drug bioavailability in the acidic region and relatively low ionic strength values, which are close to physiological levels. The data suggest a specific electrostatic interaction together with hydrophobic effects and H-bonding displayed in MGF binding to the BSA IIA subdomain. Synchronous fluorescence spectra indicate that there are conformational changes in the polypeptide backbone upon ligand binding. Cyclic voltammetry indicates that there is an irreversible charge transfer between MGF and BSA that is modulated by diffusion on the electrode surface, where two electrons are transferred. These results can help the knowledge of the pharmacokinetic activities of natural or chemical xanthone-based drugs. - Highlights: Black-Right-Pointing-Pointer The MGF-BSA complex exhibited positive cooperativity beyond 1:1 stoichiometry. Black-Right-Pointing-Pointer The interaction of MGF with BSA is non-saturable at higher ligand concentration. Black-Right-Pointing-Pointer The binding was accomplished by H-bonding, hydrophobic and electrostatic forces. Black-Right-Pointing-Pointer The apparent binding constant for MGF-BSA was 0.38 mmol L{sup -1}. Black-Right-Pointing-Pointer MGF binds electrostatically to BSA, different from a hydrophobic interaction to HSA.

  6. A platinum complex that binds non-covalently to DNA and induces cell death via a different mechanism than cisplatin.

    Science.gov (United States)

    Suntharalingam, Kogularamanan; Mendoza, Oscar; Duarte, Alexandra A; Mann, David J; Vilar, Ramon

    2013-05-01

    Cisplatin and some of its derivatives have been shown to be very successful anticancer agents. Their main mode of action has been proposed to be via covalent binding to DNA. However, one of the limitations of these drugs is their poor activity against some tumours due to intrinsic or acquired resistance. Therefore, there is interest in developing complexes with different binding modes and mode of action. Herein we present a novel platinum(ii)-terpyridine complex (1) which interacts non-covalently with DNA and induces cell death via a different mechanism than cisplatin. The interaction of this complex with DNA was studied by UV/Vis spectroscopic titrations, fluorescent indicator displacement (FID) assays and circular dichroism (CD) titrations. In addition, computational docking studies were carried out with the aim of establishing the complex's binding mode. These experimental and computational studies showed the complex to have an affinity constant for DNA of ∼10(4) M(-1), a theoretical free energy of binding of -10.83 kcal mol(-1) and selectivity for the minor groove of DNA. Long-term studies indicated that 1 did not covalently bind (or nick) DNA. The cancer cell antiproliferative properties of this platinum(ii) complex were probed in vitro against human and murine cell lines. Encouragingly the platinum(ii) complex displayed selective toxicity for the cancerous (U2OS and SH-SY5Y) and proliferating NIH 3T3 cell lines. Further cell based studies were carried out to establish the mode of action. Cellular uptake studies demonstrated that the complex is able to penetrate the cell membrane and localize to the nucleus, implying that genomic DNA could be a cellular target. Detailed immunoblotting studies in combination with DNA-flow cytometry showed that the platinum(ii) complex induced cell death in a manner consistent with necrosis.

  7. The serotonin transporter: Examination of the changes in transporter affinity induced by ligand binding

    Energy Technology Data Exchange (ETDEWEB)

    Humphreys, C.J.

    1989-01-01

    The plasmalemmal serotonin transporter uses transmembrane gradients of Na{sup +}, Cl{sup {minus}} and K{sup +} to accumulate serotonin within blood platelets. Transport is competitively inhibited by the antidepressant imipramine. Like serotonin transport, imipramine binding requires Na{sup +}. Unlike serotonin, however, imipramine does not appear to be transported. To gain insight into the mechanism of serotonin transport the author have analyzed the influences of Na{sup +} and Cl{sup {minus}}, the two ions cotransported with serotonin, on both serotonin transport and the interaction of imipramine and other antidepressant drugs with the plasmalemmal serotonin transporter of human platelets. Additionally, the author have synthesized, purified and characterized the binding of 2-iodoimipramine to the serotonin transporter. Finally, the author have conducted a preliminary study of the inhibition of serotonin transport and imipramine binding produced by dicyclohexylcarbodiimide. My results reveal many instances of positive heterotropic cooperativity in ligand binding to the serotonin transporter. Na{sup +} binding enhances the transporters affinity for imipramine and several other antidepressant drugs, and also increases the affinity for Cl{sup {minus}}. Cl{sup {minus}} enhances the transporters affinity for imipramine, as well as for Na{sup +}. At concentrations in the range of its K{sub M} for transport serotonin is a competitive inhibitor of imipramine binding. At much higher concentrations, however, serotonin also inhibits imipramines dissociation rate constant. This latter effect which is Na{sup +}-independent and species specific, is apparently produced by serotonin binding at a second, low affinity site on, or near, the transporter complex. Iodoimipramine competitively inhibit both ({sup 3}H)imipramine binding and ({sup 3}H)serotonin transport.

  8. Zinc-induced oligomerization of zinc α2 glycoprotein reveals multiple fatty acid-binding sites.

    Science.gov (United States)

    Zahid, Henna; Miah, Layeque; Lau, Andy M; Brochard, Lea; Hati, Debolina; Bui, Tam T T; Drake, Alex F; Gor, Jayesh; Perkins, Stephen J; McDermott, Lindsay C

    2016-01-01

    Zinc α2 glycoprotein (ZAG) is an adipokine with a class I MHC protein fold and is associated with obesity and diabetes. Although its intrinsic ligand remains unknown, ZAG binds the dansylated C11 fatty acid 11-(dansylamino)undecanoic acid (DAUDA) in the groove between the α1 and α2 domains. The surface of ZAG has approximately 15 weak zinc-binding sites deemed responsible for precipitation from human plasma. In the present study the functional significance of these metal sites was investigated. Analytical ultracentrifugation (AUC) and CD showed that zinc, but not other divalent metals, causes ZAG to oligomerize in solution. Thus ZAG dimers and trimers were observed in the presence of 1 and 2 mM zinc. Molecular modelling of X-ray scattering curves and sedimentation coefficients indicated a progressive stacking of ZAG monomers, suggesting that the ZAG groove may be occluded in these. Using fluorescence-detected sedimentation velocity, these ZAG-zinc oligomers were again observed in the presence of the fluorescent boron dipyrromethene fatty acid C16-BODIPY (4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-hexadecanoic acid). Fluorescence spectroscopy confirmed that ZAG binds C16-BODIPY. ZAG binding to C16-BODIPY, but not to DAUDA, was reduced by increased zinc concentrations. We conclude that the lipid-binding groove in ZAG contains at least two distinct fatty acid-binding sites for DAUDA and C16-BODIPY, similar to the multiple lipid binding seen in the structurally related immune protein CD1c. In addition, because high concentrations of zinc occur in the pancreas, the perturbation of these multiple lipid-binding sites by zinc may be significant in Type 2 diabetes where dysregulation of ZAG and zinc homoeostasis occurs.

  9. Expression of monocyte chemoattractant protein-1 in the pancreas of mice

    Institute of Scientific and Technical Information of China (English)

    LI Dong; ZHU Su-wen; LIU Dong-juan; LIU Guo-liang; SHAN Zhong-yan

    2005-01-01

    Background Type 1 diabetes has been recognized as an organ specific autoimmune disease owing to the immune destruction of pancreatic islet β cells in genetically susceptible individuals.In both human and rodent models of type 1 diabetes, such as nonobese diabetic (NOD) mice, biobreeding rats, the disease has a distinct stage characterized by immune cells infiltrating in the pancreas (insulitis).The major populations of infiltrating cells are macrophages and T lymphocytes.Therefore, immune cell infiltration of pancreatic islets may be a crucial step in the pathogenesis of type 1 diabetes.Monocyte chemoattractant protein-1 can specifically attract monocytes in vivo.Interferon induced protein-10 has chemoattractant effects on the activated lymphocytes.In this study, we analysed the expression of monocyte chemoattractant protein-1 in the pancreas of mice and interferon inducible protein-10 mRNA in the pancreas of NOD mice, and discussed their possible role in the pathogenesis of type 1 diabetes.Methods The immunohistochemical method and immunoelectronmicroscopy were used to evaluate the expression of monocyte chemoattractant protein-1 in the pancreas of NOD mice and BALB/c mice.RT-PCR was used to evaluate the expression of monocyte chemoattractant protein-1 and interferon inducible protein mRNA in NOD mice.Results Monocyte chemoattractant protein-1 was positive in the pancreas of NOD mice, whereas negative in the pancreas of BALB/C mice.RT-PCR showed that monocyte chemoattractant protein-1 and interferon inducible protein-10 mRNA could be found in the pancreas of NOD mice.Immunoelectronmicroscopy demonstrated that monocyte chemoattractant protein-1 was produced by β cells and stored in the cytoplasm of the cells.Conclusions Pancreatic islet β cells produce monocyte chemoattractantprotein-1 in NOD mice.Monocyte chemoattractant protein-1 may play an important part in the pathogenesis of type 1 diabetes by attracting monocytes/macrophages to infiltrate pancreatic

  10. Kinetics of carbon monoxide binding to phenobarbital-induced cytochrome P-450 from rat liver microsomes: a simple bimolecular process.

    Science.gov (United States)

    Oertle, M; Richter, C; Winterhalter, K H; Di Iorio, E E

    1985-01-01

    The kinetics of carbon monoxide binding to phenobarbital-induced cytochrome P-450 (P-450PB) and to its enzymatically inactive form P-420PB have been investigated by both stopped-flow and flash-photolysis spectrophotometry. When the simultaneous presence of both forms of the enzyme is taken into account, the binding of CO to these two proteins can be described in terms of two bimolecular processes with rate constants of 4.5 X 10(6) M-1.S-1 and 4.7 X 10(5) M-1.S-1 for P-450PB and 1.7 X 10(7) M-1.S-1 and 1.5 X 10(6) M-1.S-1 for P-420PB. From kinetic studies of the binding of CO to P-450PB under different experimental conditions, investigations of the homogeneity of our P-450PB preparations, and comparative kinetic investigations of P-450s from different sources, we conclude that CO binding to reduced P-450PB is a simple bimolecular process and that the observed biphasic traces are due to heterogeneity of the proteins. This conclusion is in contrast with previous reports of complex reaction mechanisms for the binding of CO to P-450PB. Optical spectroscopy studies indicate the existence of an equilibrium between P-450PB and P-420PB, at least for the reduced carbonyl derivatives of the enzymes. The interconversion is strongly influenced by the aggregation state of the protein. Large differences between the CO binding properties of P-450PB and those of P-420PB are found. These are discussed in terms of possible effects of the proximal ligation state of the iron on heme reactivity. PMID:3860832

  11. Histone Deacetylase Inhibitors Activate Tristetraprolin Expression through Induction of Early Growth Response Protein 1 (EGR1 in Colorectal Cancer Cells

    Directory of Open Access Journals (Sweden)

    Cyril Sobolewski

    2015-08-01

    Full Text Available The RNA-binding protein tristetraprolin (TTP promotes rapid decay of mRNAs bearing 3' UTR AU-rich elements (ARE. In many cancer types, loss of TTP expression is observed allowing for stabilization of ARE-mRNAs and their pathologic overexpression. Here we demonstrate that histone deacetylase (HDAC inhibitors (Trichostatin A, SAHA and sodium butyrate promote TTP expression in colorectal cancer cells (HCA-7, HCT-116, Moser and SW480 cells and cervix carcinoma cells (HeLa. We found that HDAC inhibitors-induced TTP expression, promote the decay of COX-2 mRNA, and inhibit cancer cell proliferation. HDAC inhibitors were found to promote TTP transcription through activation of the transcription factor Early Growth Response protein 1 (EGR1. Altogether, our findings indicate that loss of TTP in tumors occurs through silencing of EGR1 and suggests a therapeutic approach to rescue TTP expression in colorectal cancer.

  12. Cannabinoid receptor-interacting protein 1a modulates CB1 receptor signaling and regulation.

    Science.gov (United States)

    Smith, Tricia H; Blume, Lawrence C; Straiker, Alex; Cox, Jordan O; David, Bethany G; McVoy, Julie R Secor; Sayers, Katherine W; Poklis, Justin L; Abdullah, Rehab A; Egertová, Michaela; Chen, Ching-Kang; Mackie, Ken; Elphick, Maurice R; Howlett, Allyn C; Selley, Dana E

    2015-04-01

    Cannabinoid CB1 receptors (CB1Rs) mediate the presynaptic effects of endocannabinoids in the central nervous system (CNS) and most behavioral effects of exogenous cannabinoids. Cannabinoid receptor-interacting protein 1a (CRIP1a) binds to the CB1R C-terminus and can attenuate constitutive CB1R-mediated inhibition of Ca(2+) channel activity. We now demonstrate cellular colocalization of CRIP1a at neuronal elements in the CNS and show that CRIP1a inhibits both constitutive and agonist-stimulated CB1R-mediated guanine nucleotide-binding regulatory protein (G-protein) activity. Stable overexpression of CRIP1a in human embryonic kidney (HEK)-293 cells stably expressing CB1Rs (CB1-HEK), or in N18TG2 cells endogenously expressing CB1Rs, decreased CB1R-mediated G-protein activation (measured by agonist-stimulated [(35)S]GTPγS (guanylyl-5'-[O-thio]-triphosphate) binding) in both cell lines and attenuated inverse agonism by rimonabant in CB1-HEK cells. Conversely, small-interfering RNA-mediated knockdown of CRIP1a in N18TG2 cells enhanced CB1R-mediated G-protein activation. These effects were not attributable to differences in CB1R expression or endocannabinoid tone because CB1R levels did not differ between cell lines varying in CRIP1a expression, and endocannabinoid levels were undetectable (CB1-HEK) or unchanged (N18TG2) by CRIP1a overexpression. In CB1-HEK cells, 4-hour pretreatment with cannabinoid agonists downregulated CB1Rs and desensitized agonist-stimulated [(35)S]GTPγS binding. CRIP1a overexpression attenuated CB1R downregulation without altering CB1R desensitization. Finally, in cultured autaptic hippocampal neurons, CRIP1a overexpression attenuated both depolarization-induced suppression of excitation and inhibition of excitatory synaptic activity induced by exogenous application of cannabinoid but not by adenosine A1 agonists. These results confirm that CRIP1a inhibits constitutive CB1R activity and demonstrate that CRIP1a can also inhibit agonist

  13. MicroRNA-96 promotes the proliferation of colorectal cancer cells and targets tumor protein p53 inducible nuclear protein 1, forkhead box protein O1 (FOXO1) and FOXO3a.

    Science.gov (United States)

    Gao, Feng; Wang, Wenhui

    2015-02-01

    MicroRNAs (miRNAs) are a conserved class of small, endogenous, non protein-coding RNA molecules that are capable of regulating gene expression at post-transcriptional levels and are involved in diverse cellular processes, including cancer pathogenesis. It has previously been reported that miRNA-96 (miR-96) is overexpressed in human colorectal cancer (CRC). However, the underlying mechanism of miR-96 regulation in CRC remains to be elucidated. In the present study, miR-96 was confirmed to be upregulated in CRC tissues by reverse transcription quantitative polymerase chain reaction. MTT assay, colony formation assay and cell cycle analysis revealed that miR-96 overexpression led to increased tumor cell viability, colony formation ability and cell cycle progression. By contrast, inhibition of miR-96 resulted in the suppression of cell proliferation. It was also demonstrated that miR-96 reduced the messenger RNA and protein expression levels of tumor protein p53 inducible nuclear protein 1 (TP53INP1), forkhead box protein O1 (FOXO1) and FOXO3a, which are closely associated with cell proliferation. A luciferase reporter assay indicated that miR-96 inhibited luciferase intensity controlled by the 3'UTRs of TP53INP1, FOXO1 and FOXO3a. In conclusion, the results of the present study demonstrated that miR-96 contributed to CRC cell growth and that TP53INP1, FOXO1 and FOXO3a were direct targets of miR-96, suggesting that miR-96 may have the potential to be used in the development of miRNA‑based therapies for CRC patients.

  14. Histatin 5 binds to Porphyromonas gingivalis hemagglutinin B (HagB) and alters HagB-induced chemokine responses

    Science.gov (United States)

    Borgwardt, Derek S.; Martin, Aaron D.; van Hemert, Jonathan R.; Yang, Jianyi; Fischer, Carol L.; Recker, Erica N.; Nair, Prashant R.; Vidva, Robinson; Chandrashekaraiah, Shwetha; Progulske-Fox, Ann; Drake, David; Cavanaugh, Joseph E.; Vali, Shireen; Zhang, Yang; Brogden, Kim A.

    2014-01-01

    Histatins are human salivary gland peptides with anti-microbial and anti-inflammatory activities. In this study, we hypothesized that histatin 5 binds to Porphyromonas gingivalis hemagglutinin B (HagB) and attenuates HagB-induced chemokine responses in human myeloid dendritic cells. Histatin 5 bound to immobilized HagB in a surface plasmon resonance (SPR) spectroscopy-based biosensor system. SPR spectroscopy kinetic and equilibrium analyses, protein microarray studies, and I-TASSER structural modeling studies all demonstrated two histatin 5 binding sites on HagB. One site had a stronger affinity with a KD1 of 1.9 μM and one site had a weaker affinity with a KD2 of 60.0 μM. Binding has biological implications and predictive modeling studies and exposure of dendritic cells both demonstrated that 20.0 μM histatin 5 attenuated (p < 0.05) 0.02 μM HagB-induced CCL3/MIP-1α, CCL4/MIP-1β, and TNFα responses. Thus histatin 5 is capable of attenuating chemokine responses, which may help control oral inflammation.

  15. Repeated administration of D-amphetamine induces loss of [I-123]FP-CIT binding to striatal dopamine transporters in rat brain: a validation study

    NARCIS (Netherlands)

    J. Booij; K. de Bruin; W.B. Gunning

    2006-01-01

    In recent years, several PET and SPECT studies have shown loss of striatal dopamine transporter (DAT) binding in arnphetamine (AMPH) users. However, the use of DAT SPECT tracers to detect AMPH-induced changes in DAT binding has not been validated. We therefore examined if repeated administration of

  16. Y 盒结合蛋白1在 SK-BR-3乳腺癌细胞增殖中的作用%Roles of Y box-binding protein 1 in SK-BR-3 breast cancer proliferation

    Institute of Scientific and Technical Information of China (English)

    史建红; 吕心瑞; 王冰; 林丹丹; 王亚婻; 步玉辉; 马振峰

    2014-01-01

    Objective To explore the roles of Y box-binding protein 1 (YB-1) in breast cancer cell proliferation.Methods Twenty cases of surgical removal of breast cancer tissue ( diagnosed with invasive ductal carcinoma , stage Ⅱ, by postoperative paraffin pathology ) and normal breast tissues adjacent to carcinoma were collected during June 2013 to August 2013.Quantitative real-time PCR ( qRT-PCR ) was performed to detect the YB1 mRNA levels.Cultured mammary epithelial cells (HBL-100) and breast cancer cells (MCF7, MDA-MB-231 &SK-BR-3 cells) were harvested and qRT-PCR was performed to detect the YB1 mRNA levels.SK-BR-3 cells were stimulated with various concentrations of PDGF-BB and YB1 expression levels were detected by qRT-PCR.Down-regulation or over-expression of YB1 by si-YB1 or Ad-GFP-YB1 was detected in SK-BR-3 cells.And MTS cell proliferation assay kit was used to detect cell proliferation.Results YB1 mRNA levels were significantly higher in breast cancer tissues and MDA-MB-231 and SK-BR-3 breast cancer cell lines than that in adjacent normal breast tissues and HBL -100 mammary epithelial cells respectively ( P<0.05 ).YB1 expression levels increased in PDGF-BB stimulated SK-BR-3 cells in a dose-dependent manner.Conclusion A down-regulation of endogenous YB 1 decreases and an over-expression of exogenous YB 1 promotes the proliferation activity in SK-BR-3 cells.%目的:探讨Y盒结合蛋白1(YB1)在乳腺癌细胞增殖中的作用。方法收集河北大学附属医院2013年6-8月的乳腺浸润性导管癌及癌旁正常乳腺组织标本,实时定量PCR( qRT-PCR)分析YB1基因的mRNA水平;培养乳腺上皮细胞HBL-100和乳腺癌细胞MCF-7、MDA-MB-231和SK-BR-3,qRT-PCR 观察 YB1的表达水平, MTS 法分析细胞增殖活力;血小板源性生长因子 BB ( PDGF-BB)刺激SK-BR-3细胞,观察YB1的表达水平;应用特异性小干扰RNA敲低内源性YB1或应用GFP-YB1腺病毒载体过表达外源性GFP-YB1,MTS

  17. 胰岛素样生长因子结合蛋白-1诊断胎膜早破的临床价值%Clinical Value of Insulin-Like Growth Factor Binding Protein-1 in Diagnosis of Premature Rupture of Membranes

    Institute of Scientific and Technical Information of China (English)

    孙素梅; 李守忠

    2016-01-01

    Objective To evaluate the clinical value of insulin-like growth factor binding pro-tein-1(IGFBP-1)in the diagnosis of premature rupture of membranes(PROM).Methods The vaginal secretion smear microscopy,pH test paper method and IGFBP-1 detection were performed in 276 PROM patients(PROM group)and 284 pregnant women without PROM(control group). Results were analyzed statistically.Results The positive rates achieved by IGFBP-1 detection, pH test paper method and vaginal secretion smear microscopy in PROM group were significantly higher than those in control group(all P < 0.01).The IGFBP-1 detection had a sensitivity of 97.1%(268/276),a specificity of 98.2%(279/284)and an accuracy of 95.3%,with a false posi-tive rate of 1.8%(5/284)and a false negative rate of 2.9%(8/276);The pH test paper method had a sensitivity of 80.8% (223/276 ),a specificity of 89.8% (255/284)and an accuracy of 70.6%,with a false positive rate of 10.2%(29/284)and a false negative rate of 19.2%(53/276);The vaginal secretion smear microscopy had a sensitivity of 63.0% (174/276),a specificity of 95.1%(270/284)and an accuracy of 58.1%,with a false positive rate of 4.9%(14/284)and a false negative rate of 37.0%(102/276).Compared with pH test paper method or vaginal secretion smear microscopy,IGFBP-1 detection resulted in an increase in sensitivity,specificity and accuracy and a decrease in false positive rate and false negative rate(all P <0.05).Conclusion IGFBP-1 detection is more accurate and sensitive than pH test paper method and vaginal secretion smear microscopy for diagnosing PROM,especially for diagnosing minor rupture of membranes.There-fore,GFBP-1 detection has clinical and practical value in the diagnosis of PROM.%目的:探讨胰岛素样生长因子结合蛋白-1诊断胎膜早破的临床价值。方法采用阴道分泌物涂片镜检、pH 试纸法、胰岛素样生长因子结合蛋白-1检测法检测276例胎膜早破患者(胎膜早破组)和284例行孕期体检的孕妇(

  18. Direct observation of binding stress-induced crystalline orientation change in piezoelectric plate sensors

    Science.gov (United States)

    Wu, Wei; Shih, Wei-Heng; Shih, Wan Y.

    2016-03-01

    We have examined the mechanism of the detection resonance frequency shift, Δf/f, of a 1370 μm long and 537 μm wide [Pb(Mg1/3Nb2/3)O3]0.65[PbTiO3]0.35 (PMN-PT) piezoelectric plate sensor (PEPS) made of a 8-μm thick PMN-PT freestanding film. The Δf/f of the PEPS was monitored in a three-step binding model detections of (1) binding of maleimide-activated biotin to the sulfhydryl on the PEPS surface followed by (2) binding of streptavidin to the bound biotin and (3) subsequent binding of biotinylated probe deoxyribonucleic acid to the bound streptavidin. We used a PMN-PT surrogate made of the same 8-μm thick PMN-PT freestanding film that the PEPS was made of but was about 1 cm in length and width to carry out crystalline orientation study using X-ray diffraction (XRD) scan around the (002)/(200) peaks after each of the binding steps. The result of the XRD studies indicated that each binding step caused the crystalline orientation of the PMN-PT thin layer to switch from the vertical (002) orientation to the horizontal (200) orientation, and most of the PEPS detection Δf/f was due to the change in the lateral Young's modulus of the PMN-PT thin layer as a result of the crystalline orientation change.

  19. Binding by TRBP-dsRBD2 Does Not Induce Bending of Double-Stranded RNA.

    Science.gov (United States)

    Acevedo, Roderico; Evans, Declan; Penrod, Katheryn A; Showalter, Scott A

    2016-06-21

    Protein-nucleic acid interactions are central to a variety of biological processes, many of which involve large-scale conformational changes that lead to bending of the nucleic acid helix. Here, we focus on the nonsequence-specific protein TRBP, whose double-stranded RNA-binding domains (dsRBDs) interact with the A-form geometry of double-stranded RNA (dsRNA). Crystal structures of dsRBD-dsRNA interactions suggest that the dsRNA helix must bend in such a way that its major groove expands to conform to the dsRBD's binding surface. We show through isothermal titration calorimetry experiments that dsRBD2 of TRBP binds dsRNA with a temperature-independent observed binding affinity (KD ∼500 nM). Furthermore, a near-zero observed heat capacity change (ΔCp = 70 ± 40 cal·mol(-1)·K(-1)) suggests that large-scale conformational changes do not occur upon binding. This result is bolstered by molecular-dynamics simulations in which dsRBD-dsRNA interactions generate only modest bending of the RNA along its helical axis. Overall, these results suggest that this particular dsRBD-dsRNA interaction produces little to no change in the A-form geometry of dsRNA in solution. These results further support our previous hypothesis, based on extensive gel-shift assays, that TRBP preferentially binds to sites of nearly ideal A-form structure while being excluded from sites of local deformation in the RNA helical structure. The implications of this mechanism for efficient micro-RNA processing will be discussed.

  20. Osteopontin binding to lipopolysaccharide lowers tumor necrosis factor-α and prevents early alcohol-induced liver injury in mice

    DEFF Research Database (Denmark)

    Ge, Xiadong; Leung, Tung-Ming; Arriazu, Elena;

    2014-01-01

    Although osteopontin (OPN) is induced in alcoholic patients, its role in the pathophysiology of alcoholic liver disease (ALD) remains unclear. Increased translocation of lipopolysaccharide (LPS) from the gut is key for the onset of ALD because it promotes macrophage infiltration and activation...... by decreased liver-to-body weight ratio, hepatic triglycerides, the steatosis score, oil red-O staining, and lipid peroxidation. There was also less inflammation and liver injury as demonstrated by lower alanine aminotransferase (ALT) activity, hepatocyte ballooning degeneration, LPS levels, the inflammation...... score, and the number of macrophages and TNFα+ cells. To establish if OPN could limit LPS availability and its noxious effects in the liver, binding studies were performed. OPN showed binding affinity for LPS which prevented macrophage activation, reactive oxygen, and nitrogen species generation...

  1. Interleukin 1-induced down-regulation of antibody binding to CD4 molecules on human lymphocytes

    DEFF Research Database (Denmark)

    Tvede, N; Christensen, L D; Ødum, Niels;

    1988-01-01

    Interleukin 1 (IL-1) is involved in the early activation of T lymphocytes. The CD4 antigen, described as a phenotypic marker of helper T cells, is also important in early T-cell activation by its ability to bind to MHC class II molecules on antigen-presenting cells, and to transmit positive (and......+ cells. Under optimal growth conditions, the initial reduction in antibody binding to CD4 was followed by an apparent re-expression of the CD4 antigen even in the presence of high concentrations of IL-1. This re-expression did not occur if the cells were cultured at 4 degrees C, or after treatment...

  2. Zinc-induced oligomerization of zinc α2 glycoprotein reveals multiple fatty acid-binding sites

    OpenAIRE

    Zahid, Henna; Miah, Layeque; Lau, Andy; Brochard, Lea; Hati, Debolina; Bui, T. T.; Drake, A. F.; Gor, Jayesh; Perkins, Stephen J.; McDermott, Lindsay C.

    2016-01-01

    Zinc α2 glycoprotein (ZAG) is an adipokine with a class I MHC protein fold and is associated with obesity and diabetes. Although its intrinsic ligand remains unknown, ZAG binds the dansylated C11 fatty acid 11-(dansylamino)undecanoic acid (DAUDA) in the groove between the α1 and α2 domains. The surface of ZAG has approximately 15 weak zinc-binding sites deemed responsible for precipitation from human plasma. In the present study the functional significance of these metal sites was investigate...

  3. Molecular cloning of a novel Ca2+-binding protein that is induced by NaCl stress.

    Science.gov (United States)

    Jang, H J; Pih, K T; Kang, S G; Lim, J H; Jin, J B; Piao, H L; Hwang, I

    1998-07-01

    Plant responses to high salt stress have been studied for several decades. However, the molecular mechanisms underlying these responses still elude us. In order to understand better the molecular mechanism related to NaCl stress in plants, we initiated the cloning of a large number of NaCl-induced genes in Arabidopsis. Here, we report the cloning of a cDNA encoding a novel Ca2+-binding protein, named AtCP1, which shares sequence similarities with calmodulins. AtCP1 exhibits, in particular, a high degree of amino acid sequence homology to the Ca2+-binding loops of the EF hands of calmodulin. However, unlike calmodulin, AtCP1 appears to have only three Ca2+-binding loops. We examined Ca2+ binding of the protein by a Ca2+-dependent electrophoretic mobility shift assay. A recombinant AtCP1 protein that was expressed in Escherichia coli did show a Ca2+-dependent electrophoretic mobility shift. To gain insight into the expression of the AtCP1 gene, northern blot analysis was carried out. The AtCP1 gene had a tissue-specific expression pattern: high levels of expression in flower and root tissues and nearly undetectable levels in leaves and siliques. Also, the expression of the AtCP1 gene was induced by NaCl treatment but not by ABA treatment. Finally, subcellular localization experiments using an AtCP1:smGFP fusion gene in soybean suspension culture cells and tobacco leaf protoplasts indicate that AtCP1 is most likely a cytosolic protein.

  4. Fibronectin inhibits cytokine production induced by CpG DNA in macrophages without direct binding to DNA.

    Science.gov (United States)

    Yoshida, Hiroyuki; Nishikawa, Makiya; Yasuda, Sachiyo; Toyota, Hiroyasu; Kiyota, Tsuyoshi; Takahashi, Yuki; Takakura, Yoshinobu

    2012-10-01

    Fibronectin (FN) is known to have four DNA-binding domains although their physiological significance is unknown. Primary murine peritoneal macrophages have been shown to exhibit markedly lower responsiveness to CpG motif-replete plasmid DNA (pDNA), Toll-like receptor-9 (TLR9) ligand, compared with murine macrophage-like cell lines. The present study was conducted to examine whether FN having DNA-binding domains is involved in this phenomenon. The expression of FN was significantly higher in primary macrophages than in a macrophage-like cell line, RAW264.7, suggesting that abundant FN might suppress the responsiveness in the primary macrophages. However, electrophoretic analysis revealed that FN did not bind to pDNA in the presence of a physiological concentration of divalent cations. Surprisingly, marked tumor necrosis factor - (TNF-)α production from murine macrophages upon CpG DNA stimulation was significantly reduced by exogenously added FN in a concentration-dependent manner but not by BSA, laminin or collagen. FN did not affect apparent pDNA uptake by the cells. Moreover, FN reduced TNF-α production induced by polyI:C (TLR3 ligand), and imiquimod (TLR7 ligand), but not by LPS (TLR4 ligand), or a non-CpG pDNA/cationic liposome complex. The confocal microscopic study showed that pDNA was co-localized with FN in the same intracellular compartment in RAW264.7, suggesting that FN inhibits cytokine signal transduction in the endosomal/lysosomal compartment. Taken together, the results of the present study has revealed, for the first time, a novel effect of FN whereby the glycoprotein modulates cytokine signal transduction via CpG-DNA/TLR9 interaction in macrophages without direct binding to DNA through its putative DNA-binding domains.

  5. Unusually strong binding to the DNA minor groove by a highly twisted benzimidazole diphenylether: induced fit and bound water.

    Science.gov (United States)

    Tanious, Farial A; Laine, William; Peixoto, Paul; Bailly, Christian; Goodwin, Kristie D; Lewis, Mark A; Long, Eric C; Georgiadis, Millie M; Tidwell, Richard R; Wilson, W David

    2007-06-12

    RT29 is a dicationic diamidine derivative that does not obey the classical "rules" for shape and functional group placement that are expected to result in strong binding and specific recognition of the DNA minor groove. The compound contains a benzimidazole diphenyl ether core that is flanked by the amidine cations. The diphenyl ether is highly twisted and gives the entire compound too much curvature to fit well to the shape of the minor groove. DNase I footprinting, fluorescence intercalator displacement studies, and circular dichroism spectra, however, indicate that the compound is an AT specific minor groove binding agent. Even more surprisingly, quantitative biosensor-surface plasmon resonance and isothermal titration calorimetric results indicate that the compound binds with exceptional strength to certain AT sequences in DNA with a large negative enthalpy of binding. Crystallographic results for the DNA complex of RT29 compared to calculated results for the free compound show that the compound undergoes significant conformational changes to enhance its minor groove interactions. In addition, a water molecule is incorporated directly into the complex to complete the compound-DNA interface, and it forms an essential link between the compound and base pair edges at the floor of the minor groove. The calculated DeltaCp value for complex formation is substantially less than the experimentally observed value, which supports the idea of water being an intrinsic part of the complex with a major contribution to the DeltaCp value. Both the induced fit conformational changes of the compound and the bound water are essential for strong binding to DNA by RT29.

  6. Interactions of chromatin context, binding site sequence content, and sequence evolution in stress-induced p53 occupancy and transactivation.

    Directory of Open Access Journals (Sweden)

    Dan Su

    2015-01-01

    Full Text Available Cellular stresses activate the tumor suppressor p53 protein leading to selective binding to DNA response elements (REs and gene transactivation from a large pool of potential p53 REs (p53REs. To elucidate how p53RE sequences and local chromatin context interact to affect p53 binding and gene transactivation, we mapped genome-wide binding localizations of p53 and H3K4me3 in untreated and doxorubicin (DXR-treated human lymphoblastoid cells. We examined the relationships among p53 occupancy, gene expression, H3K4me3, chromatin accessibility (DNase 1 hypersensitivity, DHS, ENCODE chromatin states, p53RE sequence, and evolutionary conservation. We observed that the inducible expression of p53-regulated genes was associated with the steady-state chromatin status of the cell. Most highly inducible p53-regulated genes were suppressed at baseline and marked by repressive histone modifications or displayed CTCF binding. Comparison of p53RE sequences residing in different chromatin contexts demonstrated that weaker p53REs resided in open promoters, while stronger p53REs were located within enhancers and repressed chromatin. p53 occupancy was strongly correlated with similarity of the target DNA sequences to the p53RE consensus, but surprisingly, inversely correlated with pre-existing nucleosome accessibility (DHS and evolutionary conservation at the p53RE. Occupancy by p53 of REs that overlapped transposable element (TE repeats was significantly higher (p<10-7 and correlated with stronger p53RE sequences (p<10-110 relative to nonTE-associated p53REs, particularly for MLT1H, LTR10B, and Mer61 TEs. However, binding at these elements was generally not associated with transactivation of adjacent genes. Occupied p53REs located in L2-like TEs were unique in displaying highly negative PhyloP scores (predicted fast-evolving and being associated with altered H3K4me3 and DHS levels. These results underscore the systematic interaction between chromatin status and p53

  7. Exploiting anthracene photodimerization within peptides: light induced sequence-selective DNA binding.

    Science.gov (United States)

    Bullen, Gemma A; Tucker, James H R; Peacock, Anna F A

    2015-05-11

    The unprecedented use of anthracene photodimerization within a protein or peptide system is explored through its incorporation into a DNA-binding peptide, derived from the GCN4 transcription factor. This study demonstrates an effective and dynamic interplay between a photoreaction and a peptide-DNA assembly, with each process able to exert control over the other.

  8. Effects of mannose-binding lectin polymorphisms on irinotecan-induced febrile neutropenia

    NARCIS (Netherlands)

    J.M. van der Bol (Jessica); M.J.A. de Jonge (Maja); R.H.N. van Schaik (Ron); A. Sparreboom (Alex); M.A. van Fessem (Marianne); F.E. Geijn (Fleur); P.L.A. van Daele (Paul); J. Verweij (Jaap); S. Sleijfer (Stefan); A.H.J. Mathijssen (Ron)

    2010-01-01

    textabstractObjective. Mannose-binding lectin (MBL) is important in the innate immune response. MBL2 gene polymorphisms affect MBL expression, and genotypes yielding low MBL levels have been associated with an elevated risk for infections in hematological cancer patients undergoing chemotherapy. How

  9. Induced binding of proteins by ammonium sulfate in affinity and ion-exchange column chromatography.

    Science.gov (United States)

    Arakawa, Tsutomu; Tsumoto, Kouhei; Ejima, Daisuke; Kita, Yoshiko; Yonezawa, Yasushi; Tokunaga, Masao

    2007-04-10

    In general, proteins bind to affinity or ion-exchange columns at low salt concentrations, and the bound proteins are eluted by raising the salt concentration, changing the solvent pH, or adding competing ligands. Blue-Sepharose is often used to remove bovine serum albumin (BSA) from samples, but when we applied BSA to Blue-Sepharose in 20 mM phosphate, pH 7.0, 50%-60% of the protein flowed through the column; however, complete binding of BSA was achieved by the addition of 2 M ammonium sulfate (AS) to the column equilibration buffer and the sample. The bound protein was eluted by decreasing the AS concentration or by adding 1 M NaCl or arginine. AS at high concentrations resulted in binding of BSA even to an ion-exchange column, Q-Sepharose, at pH 7.0. Thus, although moderate salt concentrations elute proteins from Blue-Sepharose or ion-exchange columns, proteins can be bound to these columns under extreme salting-out conditions. Similar enhanced binding of proteins by AS was observed with an ATP-affinity column.

  10. Insulin-induced glycosylphosphatidylinositol (GPI binding to red cell membrane proteins

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    NENAD TOMASEVIC

    2002-12-01

    Full Text Available In this work GPI binding to membrane proteins from erythrocytes of insulinoma patients for whom prolonged hyperinsulinism and hypoglycemia were characteristic, as well as from normal erythrocytes incubated with supraphysiological concentrations of insulin were analyzed. In the RBCs from insulinoma patients, covalent GPI binding to red cell membrane proteins in the spectrin/ankyrin region, band 4.1 and two proteins of molecular mass of 115 and 110 kD was demonstrated. In erythrocytes incubated with insulin label was associated with band 4.1 and two proteins of molecular mass of 115 and 110 kD. Extraction studies showed that the 100-kD proteins are unrelated to band 3 since they were found in Triton-prepared cytoskeleton. To our knowledge this is the first demonstration of such a modification of red cell skeletal proteins, and the first demonstration of post-translation GPI binding to red cell skeletal proteins in response to insulin. A mechanism proposed for GPI binding to red cell skeletal proteins as well as the relevance of these results for physiological disorders that are characterized by hyperinsulinism are briefly discussed.

  11. Glucose-induced binding of the polypyrimidine tract-binding protein (PTB) to the 3'-untranslated region of the insulin mRNA (ins-PRS) is inhibited by rapamycin.

    Science.gov (United States)

    Tillmar, Linda; Welsh, Nils

    2004-05-01

    Despite considerable knowledge on the regulation of insulin gene transcription, little is known about the post-transcriptional control mechanisms of this gene. We have recently reported glucose- and hypoxia-regulated binding of the polypyrimidine tract-binding protein (PTB) to the pyrimidine-rich sequence of the 3'-untranslated insulin mRNA (ins-PRS), an event which may control insulin mRNA stability. The present aim was to probe for the signaling pathways that control this binding activity. Rat islets were exposed to pharmacological inhibitors against several molecules, previously shown to be involved in glucose signaling. The inhibitors used were; LY 294002 (PI3 kinase), Rp-cAMP triatylamine (the cAMP-dependent protein kinase PKA), bisindolylmaleimide I hydrochloride (PKC), PD 098059 (ERK1/ERK2), SB 203580 (p38/SAPK2a), rapamycin (mTOR) and okadaic acid (PP1/2A). PTB-binding activity to the ins-PRS was then analyzed by elecrophoretic mobility shift assay (EMSA). The glucose-induced PTB-binding was only inhibited by the mTOR inhibitor rapamycin. Rapamycin also reduced glucose-induced insulin mRNA expression. Thus, our results suggest an involvement of mTOR in glucose-induced PTB/ins-PRS binding and insulin mRNA stability.

  12. Anion-induced increases in the rate of colchicine binding to tubulin.

    Science.gov (United States)

    Bhattacharyya, B; Wolff, J

    1976-06-01

    The rate of binding of colchicine to tubulin to tubulin is enhanced by certain anions. Among the inorganic anions tested, only sulfate was effective. The organic anions include mostly dicarboxylic acids, among which tartrate was the most effective. This effect occurs onlt at low concentrations of colchicine (less than 0.6 X 10(-5) M). The rate increase dor sulfate and L-(+)-tartrate is ca. 2.5-fold at 1.0 mM and plateaus at a limiting value of ca. 4-fold at 100mM. The overall dissociation rate of the colchicine from the complex, which includes both the true rate of dissociation and the rate of irreversible denaturation of tubulin, is not influenced by 1.0 mM tartrate. The affinity constants for colchicine determined from the rate constants are 8.7 X 10(6) and 2.1 X 10(7) M-1 in the absence and the presence of 1.0 mM L-(+)-tartrate. The limiting value is 3.2 X 10(7) M-1. The affinity constant calculated from steady-state measurements is 3.2 X 10(6) M-1 with or without anions. The binding of other ligands like podophyllotoxin, vinblastine, and 1 -anilino-8-naphthalenesulfonate to tubulin is not affected by tartrate. No major conformational changes resulting from anion treatment could be detected by circular dichroism or intrinsic fluorescence. However, the ability of tubulin to polymerize is inhibited by L-(+)-tartrate at concentrations that increase the rate of colchicine binding. We conclude that anions must have a local effect at or near the binding site which enhances the binding rate of colchicine and which may be related to inhibition of polymerization.

  13. Structural studies of human glioma pathogenesis-related protein 1

    Energy Technology Data Exchange (ETDEWEB)

    Asojo, Oluwatoyin A., E-mail: oasojo@unmc.edu [College of Medicine, Nebraska Medical Center, Omaha, NE 68198-6495 (United States); Koski, Raymond A.; Bonafé, Nathalie [L2 Diagnostics LLC, 300 George Street, New Haven, CT 06511 (United States); College of Medicine, Nebraska Medical Center, Omaha, NE 68198-6495 (United States)

    2011-10-01

    Structural analysis of a truncated soluble domain of human glioma pathogenesis-related protein 1, a membrane protein implicated in the proliferation of aggressive brain cancer, is presented. Human glioma pathogenesis-related protein 1 (GLIPR1) is a membrane protein that is highly upregulated in brain cancers but is barely detectable in normal brain tissue. GLIPR1 is composed of a signal peptide that directs its secretion, a conserved cysteine-rich CAP (cysteine-rich secretory proteins, antigen 5 and pathogenesis-related 1 proteins) domain and a transmembrane domain. GLIPR1 is currently being investigated as a candidate for prostate cancer gene therapy and for glioblastoma targeted therapy. Crystal structures of a truncated soluble domain of the human GLIPR1 protein (sGLIPR1) solved by molecular replacement using a truncated polyalanine search model of the CAP domain of stecrisp, a snake-venom cysteine-rich secretory protein (CRISP), are presented. The correct molecular-replacement solution could only be obtained by removing all loops from the search model. The native structure was refined to 1.85 Å resolution and that of a Zn{sup 2+} complex was refined to 2.2 Å resolution. The latter structure revealed that the putative binding cavity coordinates Zn{sup 2+} similarly to snake-venom CRISPs, which are involved in Zn{sup 2+}-dependent mechanisms of inflammatory modulation. Both sGLIPR1 structures have extensive flexible loop/turn regions and unique charge distributions that were not observed in any of the previously reported CAP protein structures. A model is also proposed for the structure of full-length membrane-bound GLIPR1.

  14. The epigenetic regulator CXXC finger protein 1 is essential for murine hematopoiesis.

    Directory of Open Access Journals (Sweden)

    Kristin T Chun

    Full Text Available CXXC finger protein 1 (Cfp1, encoded by the Cxxc1 gene, binds to DNA sequences containing an unmethylated CpG dinucleotide and is an epigenetic regulator of both cytosine and histone methylation. Cxxc1-null mouse embryos fail to gastrulate, and Cxxc1-null embryonic stem cells are viable but cannot differentiate, suggesting that Cfp1 is required for chromatin remodeling associated with stem cell differentiation and embryogenesis. Mice homozygous for a conditional Cxxc1 deletion allele and carrying the inducible Mx1-Cre transgene were generated to assess Cfp1 function in adult animals. Induction of Cre expression in adult animals led to Cfp1 depletion in hematopoietic cells, a failure of hematopoiesis with a nearly complete loss of lineage-committed progenitors and mature cells, elevated levels of apoptosis, and death within two weeks. A similar pathology resulted following transplantation of conditional Cxxc1 bone marrow cells into wild type recipients, demonstrating this phenotype is intrinsic to Cfp1 function within bone marrow cells. Remarkably, the Lin- Sca-1+ c-Kit+ population of cells in the bone marrow, which is enriched for hematopoietic stem cells and multi-potential progenitor cells, persists and expands in the absence of Cfp1 during this time frame. Thus, Cfp1 is necessary for hematopoietic stem and multi-potential progenitor cell function and for the developmental potential of differentiating hematopoietic cells.

  15. Activator protein 1 (Fos/Jun) functions in inflammatory bone and skin disease.

    Science.gov (United States)

    Zenz, Rainer; Eferl, Robert; Scheinecker, Clemens; Redlich, Kurt; Smolen, Josef; Schonthaler, Helia B; Kenner, Lukas; Tschachler, Erwin; Wagner, Erwin F

    2008-01-01

    Activator protein 1 (AP-1) (Fos/Jun) is a transcriptional regulator composed of members of the Fos and Jun families of DNA binding proteins. The functions of AP-1 were initially studied in mouse development as well as in the whole organism through conventional transgenic approaches, but also by gene targeting using knockout strategies. The importance of AP-1 proteins in disease pathways including the inflammatory response became fully apparent through conditional mutagenesis in mice, in particular when employing gene inactivation in a tissue-specific and inducible fashion. Besides the well-documented roles of Fos and Jun proteins in oncogenesis, where these genes can function both as tumor promoters or tumor suppressors, AP-1 proteins are being recognized as regulators of bone and immune cells, a research area termed osteoimmunology. In the present article, we review recent data regarding the functions of AP-1 as a regulator of cytokine expression and an important modulator in inflammatory diseases such as rheumatoid arthritis, psoriasis and psoriatic arthritis. These new data provide a better molecular understanding of disease pathways and should pave the road for the discovery of new targets for therapeutic applications.

  16. Porphyrin-induced photodynamic cross-linking of hepatic heme-binding proteins.

    Science.gov (United States)

    Vincent, S H; Holeman, B; Cully, B C; Muller-Eberhard, U

    1986-01-27

    Three types of hepatic proteins, a heme-binding Z protein, a mixture of the glutathione S-transferases and a cytochrome P450 isozyme, were shown to be susceptible to photodynamic cross-linking and loss in antigenicity by naturally occurring porphyrins. At 50 microM, uroporphyrin caused the most and protoporphyrin the least photodecomposition. Hemopexin, a specific serum heme carrier, was photodecomposed but no cross-linking was detected. Heme and scavengers of singlet oxygen partially prevented protein photodecomposition.

  17. Estrogen Receptor Alpha Binding to ERE is Required for Full Tlr7- and Tlr9-Induced Inflammation.

    Science.gov (United States)

    Cunningham, Melissa A; Wirth, Jena R; Naga, Osama; Eudaly, Jackie; Gilkeson, Gary S

    2014-01-20

    We previously found that a maximum innate inflammatory response induced by stimulation of Toll-like receptors (TLRs) 3, 7 and 9 requires ERα, but does not require estrogen in multiple cell types from both control and lupus-prone mice. Given the estrogen-independence, we hypothesized that ERα mediates TLR signaling by tethering to, and enhancing, the activity of downstream transcription factors such as NFκB, rather than acting classically by binding EREs on target genes. To investigate the mechanism of ERα impact on TLR signaling, we utilized mice with a knock-in ERα mutant that is unable to bind ERE. After stimulation with TLR ligands, both ex vivo spleen cells and bone marrow-derived dendritic cells (BM-DCs) isolated from mutant ERα ("KIKO") mice produced significantly less IL-6 compared with cells from wild-type (WT) littermates. These results suggest that ERα modulation of TLR signaling does indeed require ERE binding for its effect on the innate immune response.

  18. Vanadyl ions binding to GroEL (HSP60) and inducing its depolymerization

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Several vanadium compounds have been known for the hypoglycemic and anticancer effects. However, the mechanisms of the pharmacological and toxicological effects were not clear. In this work, we investigated the potential targets of vanadium in mitochondria. Vanadyl ions were found to bind to mitochondria from rat liver with a stoichiometry of 244±58 nmol/mg protein and an apparent dissocia- tion constant (Kd) of (2.0±0.8)×10-16 mol/L. Using size exclusion chromatography, a vanadium-binding protein was isolated and identified to be the 60-kDa heat shock protein (HSP60) by mass spectrometry analysis and immunoassays. Additionally, binding of vanadyl ions was found to result in depolymerization of homo-oligomeric HSP60 (GroEL). HSP60 is an indispensable molecular chaperone and involved in many kinds of pathogenesis of inflammatory and autoimmune diseases, e.g. type 1 diabetes. Our results suggested that HSP60 could be a novel important target involved in the biological and/or toxicological effects of vanadium compounds.

  19. Brain beta-adrenergic receptor binding in rats with obesity induced by a beef tallow diet.

    Science.gov (United States)

    Matsuo, T; Suzuki, M

    1997-01-01

    We have previously reported that compared with safflower oil diet, feeding a beef tallow diet leads to a greater accumulation of body fat by reducing sympathetic activities. The present study examined the effects of dietary fats consisting of different fatty acids on alpha1- and beta-adrenergic receptor binding in the hypothalamus and cerebral cortex. Male Sprague-Dawley rats were meal-fed isoenergetic diets based on safflower oil (rich in n-6 polyunsaturated fatty acids) or beef tallow (rich in saturated fatty acids) for 8 weeks. Binding affinities of the beta-adrenergic receptor in the hypothalamus and cortex were significantly lower in the beef tallow diet group, but those of the alpha1-receptor did not differ between the two groups. The polyunsaturated to saturated fatty acid (P/S) ratio and fluidities of plasma membranes in the hypothalamus and cortex were lower in the beef tallow diet group than in the safflower oil diet group. These results suggest that the beef tallow diet decreases membrane fluidity by altering the fatty acid composition of plasma membranes in the hypothalamus and cerebral cortex of rat. Consequently, beta-adrenergic receptor binding affinities in the brain were lower in rats fed the beef tallow diet than in rats fed the safflower oil diet. We recognized that there is possible link between the membrane fluidity and the changes in affinity of beta-adrenoceptors in rat brain.

  20. Functional and structural changes of human erythrocyte catalase induced by cimetidine: proposed model of binding.

    Science.gov (United States)

    Yazdi, Fatemeh; Minai-Tehrani, Dariush; Jahngirvand, Mahboubeh; Almasirad, Ali; Mousavi, Zahra; Masoud, Masoudeh; Mollasalehi, Hamidreza

    2015-06-01

    In erythrocyte, catalase plays an important role to protect cells from hydrogen peroxide toxicity. Hydrogen peroxide is a byproduct compound which is produced during metabolic pathway of cells. Cimetidine, a histamine H2 receptor antagonist, is used for gastrointestinal tract diseases and prevents the extra release of gastric acid. In this study, the effect of cimetidine on the activity of human erythrocyte catalase was investigated. Erythrocytes were broken by hypotonic solution. The supernatant was used for catalase assay and kinetics study. Lineweaver-Burk plot was performed to determine the type of inhibition. The kinetics data revealed that cimetidine inhibited the catalase activity by mixed inhibition. The IC50 (1.54 μM) and Ki (0.45 μM) values of cimetidine determined that the drug was bound to the enzyme with high affinity. Circular dichroism and fluorescence measurement showed that the binding of cimetidine to the enzyme affected the content of secondary structure of the enzyme as well as its conformational changes. Docking studies were carried out to detect the site in which the drug was bound to the enzyme. Molecular modeling and energy calculation of the binding showed that the cyanoguanidine group of the drug connected to Asp59 via two hydrogen bonds, while the imidazole group of the drug interacted with Phe64 in the enzyme by a hydrophobic interaction. In conclusion, cimetidine could bind to human erythrocyte catalase, and its interaction caused functional and conformational changes in the enzyme.

  1. Mechanistic basis of Nek7 activation through Nek9 binding and induced dimerization

    Science.gov (United States)

    Haq, Tamanna; Richards, Mark W.; Burgess, Selena G.; Gallego, Pablo; Yeoh, Sharon; O'Regan, Laura; Reverter, David; Roig, Joan; Fry, Andrew M.; Bayliss, Richard

    2015-11-01

    Mitotic spindle assembly requires the regulated activities of protein kinases such as Nek7 and Nek9. Nek7 is autoinhibited by the protrusion of Tyr97 into the active site and activated by the Nek9 non-catalytic C-terminal domain (CTD). CTD binding apparently releases autoinhibition because mutation of Tyr97 to phenylalanine increases Nek7 activity independently of Nek9. Here we find that self-association of the Nek9-CTD is needed for Nek7 activation. We map the minimal Nek7 binding region of Nek9 to residues 810-828. A crystal structure of Nek7Y97F bound to Nek9810-828 reveals a binding site on the C-lobe of the Nek7 kinase domain. Nek7Y97F crystallizes as a back-to-back dimer between kinase domain N-lobes, in which the specific contacts within the interface are coupled to the conformation of residue 97. Hence, we propose that the Nek9-CTD activates Nek7 through promoting back-to-back dimerization that releases the autoinhibitory tyrosine residue, a mechanism conserved in unrelated kinase families.

  2. HIV gp120 binds to mannose receptor on vaginal epithelial cells and induces production of matrix metalloproteinases.

    Directory of Open Access Journals (Sweden)

    Sashaina E Fanibunda

    Full Text Available BACKGROUND: During sexual transmission of HIV in women, the virus breaches the multi-layered CD4 negative stratified squamous epithelial barrier of the vagina, to infect the sub-epithelial CD4 positive immune cells. However the mechanisms by which HIV gains entry into the sub-epithelial zone is hitherto unknown. We have previously reported human mannose receptor (hMR as a CD4 independent receptor playing a role in HIV transmission on human spermatozoa. The current study was undertaken to investigate the expression of hMR in vaginal epithelial cells, its HIV gp120 binding potential, affinity constants and the induction of matrix metalloproteinases (MMPs downstream of HIV gp120 binding to hMR. PRINCIPAL FINDINGS: Human vaginal epithelial cells and the immortalized vaginal epithelial cell line Vk2/E6E7 were used in this study. hMR mRNA and protein were expressed in vaginal epithelial cells and cell line, with a molecular weight of 155 kDa. HIV gp120 bound to vaginal proteins with high affinity, (Kd = 1.2±0.2 nM for vaginal cells, 1.4±0.2 nM for cell line and the hMR antagonist mannan dose dependently inhibited this binding. Both HIV gp120 binding and hMR exhibited identical patterns of localization in the epithelial cells by immunofluorescence. HIV gp120 bound to immunopurified hMR and affinity constants were 2.9±0.4 nM and 3.2±0.6 nM for vaginal cells and Vk2/E6E7 cell line respectively. HIV gp120 induced an increase in MMP-9 mRNA expression and activity by zymography, which could be inhibited by an anti-hMR antibody. CONCLUSION: hMR expressed by vaginal epithelial cells has high affinity for HIV gp120 and this binding induces production of MMPs. We propose that the induction of MMPs in response to HIV gp120 may lead to degradation of tight junction proteins and the extracellular matrix proteins in the vaginal epithelium and basement membrane, leading to weakening of the epithelial barrier; thereby facilitating transport of HIV across the

  3. A Galactose-Binding Lectin Isolated from Aplysia kurodai (Sea Hare Eggs Inhibits Streptolysin-Induced Hemolysis

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    Imtiaj Hasan

    2014-09-01

    Full Text Available A specific galactose-binding lectin was shown to inhibit the hemolytic effect of streptolysin O (SLO, an exotoxin produced by Streptococcus pyogenes. Commercially available lectins that recognize N-acetyllactosamine (ECA, T-antigen (PNA, and Tn-antigen (ABA agglutinated rabbit erythrocytes, but had no effect on SLO-induced hemolysis. In contrast, SLO-induced hemolysis was inhibited by AKL, a lectin purified from sea hare (Aplysia kurodai eggs that recognizes α-galactoside oligosaccharides. This inhibitory effect was blocked by the co-presence of d-galactose, which binds to AKL. A possible explanation for these findings is that cholesterol-enriched microdomains containing glycosphingolipids in the erythrocyte membrane become occupied by tightly stacked lectin molecules, blocking the interaction between cholesterol and SLO that would otherwise result in penetration of the membrane. Growth of S. pyogenes was inhibited by lectins from a marine invertebrate (AKL and a mushroom (ABA, but was promoted by a plant lectin (ECA. Both these inhibitory and promoting effects were blocked by co-presence of galactose in the culture medium. Our findings demonstrate the importance of glycans and lectins in regulating mechanisms of toxicity, creation of pores in the target cell membrane, and bacterial growth.

  4. Phosphorylation of Ser8 promotes zinc-induced dimerization of the amyloid-β metal-binding domain.

    Science.gov (United States)

    Kulikova, Alexandra A; Tsvetkov, Philipp O; Indeykina, Maria I; Popov, Igor A; Zhokhov, Sergey S; Golovin, Andrey V; Polshakov, Vladimir I; Kozin, Sergey A; Nudler, Evgeny; Makarov, Alexander A

    2014-10-01

    Zinc-induced aggregation of the amyloid-β peptide (Aβ) is a hallmark molecular feature of Alzheimer's disease (AD). Recently it was shown that phosphorylation of Aβ at Ser8 promotes the formation of toxic aggregates. In this work, we have studied the impact of Ser8 phosphorylation on the mode of zinc interaction with the Aβ metal-binding domain 1-16 using isothermal titration calorimetry, electrospray ionization mass spectrometry and NMR spectroscopy. We have discovered a novel zinc binding site ((6)HDpS(8)) in the phosphorylated peptide, in which the zinc ion is coordinated by the imidazole ring of His6, the phosphate group attached to Ser8 and a backbone carbonyl group of His6 or Asp7. Interaction of the zinc ion with this site involves His6, thereby withdrawing it from the interaction pattern observed in the non-modified peptide. This event was found to stimulate dimerization of peptide chains through the (11)EVHH(14) site, where the zinc ion is coordinated by the two pairs of Glu11 and His14 in the two peptide subunits. The proposed molecular mechanism of zinc-induced dimerization could contribute to the understanding of initiation of pathological Aβ aggregation, and the (11)EVHH(14) tetrapeptide can be considered as a promising drug target for the prevention of amyloidogenesis.

  5. Xanthohumol Improves Diet-induced Obesity and Fatty Liver by Suppressing Sterol Regulatory Element-binding Protein (SREBP) Activation.

    Science.gov (United States)

    Miyata, Shingo; Inoue, Jun; Shimizu, Makoto; Sato, Ryuichiro

    2015-08-14

    Sterol regulatory element-binding proteins (SREBPs) are key transcription factors that stimulate the expression of genes involved in fatty acid and cholesterol biosynthesis. Here, we demonstrate that a prenylated flavonoid in hops, xanthohumol (XN), is a novel SREBP inactivator that reduces the de novo synthesis of fatty acid and cholesterol. XN independently suppressed the maturation of SREBPs of insulin-induced genes in a manner different from sterols. Our results suggest that XN impairs the endoplasmic reticulum-to-Golgi translocation of the SREBP cleavage-activating protein (SCAP)-SREBP complex by binding to Sec23/24 and blocking SCAP/SREBP incorporation into common coated protein II vesicles. Furthermore, in diet-induced obese mice, dietary XN suppressed SREBP-1 target gene expression in the liver accompanied by a reduction of the mature form of hepatic SREBP-1, and it inhibited the development of obesity and hepatic steatosis. Altogether, our data suggest that XN attenuates the function of SREBP-1 by repressing its maturation and that it has the potential of becoming a nutraceutical food or pharmacological agent for improving metabolic syndrome.

  6. Xanthohumol Improves Diet-induced Obesity and Fatty Liver by Suppressing Sterol Regulatory Element-binding Protein (SREBP) Activation*

    Science.gov (United States)

    Miyata, Shingo; Inoue, Jun; Shimizu, Makoto; Sato, Ryuichiro

    2015-01-01

    Sterol regulatory element-binding proteins (SREBPs) are key transcription factors that stimulate the expression of genes involved in fatty acid and cholesterol biosynthesis. Here, we demonstrate that a prenylated flavonoid in hops, xanthohumol (XN), is a novel SREBP inactivator that reduces the de novo synthesis of fatty acid and cholesterol. XN independently suppressed the maturation of SREBPs of insulin-induced genes in a manner different from sterols. Our results suggest that XN impairs the endoplasmic reticulum-to-Golgi translocation of the SREBP cleavage-activating protein (SCAP)-SREBP complex by binding to Sec23/24 and blocking SCAP/SREBP incorporation into common coated protein II vesicles. Furthermore, in diet-induced obese mice, dietary XN suppressed SREBP-1 target gene expression in the liver accompanied by a reduction of the mature form of hepatic SREBP-1, and it inhibited the development of obesity and hepatic steatosis. Altogether, our data suggest that XN attenuates the function of SREBP-1 by repressing its maturation and that it has the potential of becoming a nutraceutical food or pharmacological agent for improving metabolic syndrome. PMID:26140926

  7. Piperine Induces Hepatic Low-Density Lipoprotein Receptor Expression through Proteolytic Activation of Sterol Regulatory Element-Binding Proteins.

    Directory of Open Access Journals (Sweden)

    Ayasa Ochiai

    Full Text Available Elevated plasma low-density lipoprotein (LDL cholesterol is considered as a risk factor for atherosclerosis. Because the hepatic LDL receptor (LDLR uptakes plasma lipoproteins and lowers plasma LDL cholesterol, the activation of LDLR is a promising drug target for atherosclerosis. In the present study, we identified the naturally occurring alkaloid piperine, as an inducer of LDLR gene expression by screening the effectors of human LDLR promoter. The treatment of HepG2 cells with piperine increased LDLR expression at mRNA and protein levels and stimulated LDL uptake. Subsequent luciferase reporter gene assays revealed that the mutation of sterol regulatory element-binding protein (SREBP-binding element abolished the piperine-mediated induction of LDLR promoter activity. Further, piperine treatments increased mRNA levels of several SREBP targets and mature forms of SREBPs. However, the piperine-mediated induction of the mature forms of SREBPs was not observed in SRD-15 cells, which lack insulin-induced gene-1 (Insig-1 and Insig-2. Finally, the knockdown of SREBPs completely abolished the piperine-meditated induction of LDLR gene expression in HepG2 cells, indicating that piperine stimulates the proteolytic activation of SREBP and subsequent induction of LDLR expression and activity.

  8. Piperine Induces Hepatic Low-Density Lipoprotein Receptor Expression through Proteolytic Activation of Sterol Regulatory Element-Binding Proteins.

    Science.gov (United States)

    Ochiai, Ayasa; Miyata, Shingo; Shimizu, Makoto; Inoue, Jun; Sato, Ryuichiro

    2015-01-01

    Elevated plasma low-density lipoprotein (LDL) cholesterol is considered as a risk factor for atherosclerosis. Because the hepatic LDL receptor (LDLR) uptakes plasma lipoproteins and lowers plasma LDL cholesterol, the activation of LDLR is a promising drug target for atherosclerosis. In the present study, we identified the naturally occurring alkaloid piperine, as an inducer of LDLR gene expression by screening the effectors of human LDLR promoter. The treatment of HepG2 cells with piperine increased LDLR expression at mRNA and protein levels and stimulated LDL uptake. Subsequent luciferase reporter gene assays revealed that the mutation of sterol regulatory element-binding protein (SREBP)-binding element abolished the piperine-mediated induction of LDLR promoter activity. Further, piperine treatments increased mRNA levels of several SREBP targets and mature forms of SREBPs. However, the piperine-mediated induction of the mature forms of SREBPs was not observed in SRD-15 cells, which lack insulin-induced gene-1 (Insig-1) and Insig-2. Finally, the knockdown of SREBPs completely abolished the piperine-meditated induction of LDLR gene expression in HepG2 cells, indicating that piperine stimulates the proteolytic activation of SREBP and subsequent induction of LDLR expression and activity.

  9. Relationship between L-DOPA-induced reduction in motor and exploratory activity and degree of DAT binding in the rat

    Directory of Open Access Journals (Sweden)

    Susanne eNikolaus

    2014-12-01

    Full Text Available Purpose: The present study assessed the influence of L-DOPA administration on neostriatal dopamine (DA transporter (DAT binding in relation to motor and exploratory behaviors in the rat.Methods: Rats received injections of 5 mg/kg L-DOPA, 10 mg/kg L-DOPA or vehicle. Motor and exploratory behaviors were assessed for 30 min in an open field prior to administration of [123I]FP-CIT. DAT binding was measured with small animal SPECT 2 h after radioligand administration for 60 min. Results: Both L-DOPA doses significantly reduced DAT binding and led to significantly less head-shoulder motility and more sitting relative to vehicle. Moreover, 10 mg/kg L-DOPA induced less distance travelled and ambulation than 5 mg/kg L-DOPA. Analysis of time-behavior curves showed that L-DOPA-treated animals relative to vehicle exhibited (1 a faster rate of increase in duration of sitting, (2 a slower rate of increase in duration of head-shoulder motility, and (3 a slower rate of decrease in frequency of head-shoulder motility. Conclusions: The reductions of striatal DAT binding after L-DOPA challenges reflected elevated concentrations of synaptic DA. L-DOPA-treated animals showed less head-shoulder motility and more sitting than vehicle-treated animals, indicating an association between less behavioral activity and increased availability of striatal DA. The faster increase of sitting duration to a higher final level and the slower increase of head-shoulder motility to a lower final level relative to controls may be interpreted in terms on behavioral habituation to a novel environment.

  10. Role of CC chemokines (macrophage inflammatory protein-1 beta, monocyte chemoattractant protein-1, RANTES) in acute lung injury in rats

    DEFF Research Database (Denmark)

    Bless, N M; Huber-Lang, M; Guo, R F

    2000-01-01

    were cloned, the proteins were expressed, and neutralizing Abs were developed. mRNA and protein expression for MIP-1 beta and MCP-1 were up-regulated during the inflammatory response, while mRNA and protein expression for RANTES were constitutive and unchanged during the inflammatory response...... that in chemokine-dependent inflammatory responses in lung CC chemokines do not necessarily demonstrate redundant function.......The role of the CC chemokines, macrophage inflammatory protein-1 beta (MIP-1 beta), monocyte chemotactic peptide-1 (MCP-1), and RANTES, in acute lung inflammatory injury induced by intrapulmonary deposition of IgG immune complexes injury in rats was determined. Rat MIP-1 beta, MCP-1, and RANTES...

  11. Angiotensin II induces kidney inflammatory injury and fibrosis through binding to myeloid differentiation protein-2 (MD2)

    Science.gov (United States)

    Xu, Zheng; Li, Weixin; Han, Jibo; Zou, Chunpeng; Huang, Weijian; Yu, Weihui; Shan, Xiaoou; Lum, Hazel; Li, Xiaokun; Liang, Guang

    2017-01-01

    Growing evidence indicates that angiotensin II (Ang II), a potent biologically active product of RAS, is a key regulator of renal inflammation and fibrosis. In this study, we tested the hypothesis that Ang II induces renal inflammatory injury and fibrosis through interaction with myeloid differentiation protein-2 (MD2), the accessory protein of toll-like receptor 4 (TLR4) of the immune system. Results indicated that in MD2−/− mice, the Ang II-induced renal fibrosis, inflammation and kidney dysfunction were significantly reduced compared to control Ang II-infused wild-type mice. Similarly, in the presence of small molecule MD2 specific inhibitor L6H21 or siRNA-MD2, the Ang II-induced increases of pro-fibrotic and pro-inflammatory molecules were prevented in tubular NRK-52E cells. MD2 blockade also inhibited activation of NF-κB and ERK. Moreover, MD2 blockade prevented the Ang II-stimulated formation of the MD2/TLR4/MyD88 signaling complex, as well as the increased surface binding of Ang II in NRK-52E cells. In addition, Ang II directly bound recombinant MD2 protein, rather than TLR4 protein. We conclude that MD2 is a significant contributor in the Ang II-induced kidney inflammatory injury in chronic renal diseases. Furthermore, MD2 inhibition could be a new and important therapeutic strategy for preventing progression of chronic renal diseases.

  12. Midkine, heparin-binding growth factor, blocks kainic acid-induced seizure and neuronal cell death in mouse hippocampus

    Directory of Open Access Journals (Sweden)

    Lim In J

    2010-03-01

    Full Text Available Abstract Background Midkine (MK, a member of the heparin-binding growth factor family, which includes MK and pleiotrophin, is known to possess neurotrophic and neuroprotective properties in the central nervous system. Previous studies have shown that MK is an effective neuroprotective agent in reducing retinal degeneration caused by excessive light and decreasing hippocampal neuronal death in ischemic gerbil brain. The present study was undertaken to investigate whether MK acts as an anticonvulsant in kainic acid (KA-induced seizure in mouse and blocks KA-mediated neuronal cell death in hippocampus. Results Increased expression of MK was found in hippocampus of mouse following seizures induced by intracerebroventricular injection of KA, and MK expression was found in glial fibrillary acidic protein (GFAP-positive astrocytes. Concurrent injection of MK and KA attenuated KA-induced seizure activity and cell death of hippocampal neurons including pyramidal cells and glutamic acid decarboxylase 67 (GAD67-positive GABAergic interneurons in the CA3 and hilar area. Conclusion The results of the present study indicate that MK functions as an anticonvulsant and neuroprotective agent in hippocampus during KA-induced seizures.

  13. Mannan-binding lectin and healing of a radiation-induced chronic ulcer--a case report on mannan-binding lectin replacement therapy

    DEFF Research Database (Denmark)

    Maaløe, Nanna; Bonde, C; Laursen, I;

    2011-01-01

    Mannan-binding lectin is an important component of innate immunity, and insufficiency is associated with several clinical disorders. Recently, experimental replacement therapy with plasma-derived mannan-binding lectin has become an option. The current article presents the case of a patient with a...

  14. In silico analysis of molecular mechanisms of Galanthus nivalis agglutinin-related lectin-induced cancer cell death from carbohydrate-binding motif evolution hypothesis.

    Science.gov (United States)

    Yu, Qi-Jia; Li, Zi-Yue; Yao, Shun; Ming, Miao; Wang, Shu-Ya; Liu, Bo; Bao, Jin-Ku

    2011-10-01

    Galanthus nivalis agglutinin-related lectins, a superfamily of strictly mannose-binding-specific lectins widespread amongst monotyledonous plants, have drawn a rising attention for their remarkable anti-proliferative and apoptosis-inducing activities toward various types of cancer cells; however, the precise molecular mechanisms by which they induce tumor cell apoptosis are still only rudimentarily understood. Herein, we found that the three conserved motifs "QXDXNXVXY," the mannose-specific binding sites, could mutate at one or more amino acid sites, which might be a driving force for the sequential evolution and thus ultimately leading to the complete disappearance of the three conserved motifs. In addition, we found that the motif evolution could result in the diversification of sugar-binding types that G. nivalis agglutinin-related lectins could bind from specific mannose receptors to more types of sugar-containing receptors in cancer cells. Subsequently, we indicated that some sugar-containing receptors such as TNFR1, EGFR, Hsp90, and Hsp70 could block downstream anti-apoptotic or survival signaling pathways, which, in turn, resulted in tumor cell apoptosis. Taken together, our hypothesis that carbohydrate-binding motif evolution may impact the G. nivalis agglutinin-related lectin-induced survival or anti-apoptotic pathways would provide a new perspective for further elucidating the intricate relationships between the carbohydrate-binding specificities and complex molecular mechanisms by which G. nivalis agglutinin-related lectins induce cancer cell death.

  15. Sub-inhibitory tigecycline concentrations induce extracellular matrix binding protein Embp dependent Staphylococcus epidermidis biofilm formation and immune evasion.

    Science.gov (United States)

    Weiser, Julian; Henke, Hanae A; Hector, Nina; Both, Anna; Christner, Martin; Büttner, Henning; Kaplan, Jeffery B; Rohde, Holger

    2016-09-01

    Biofilm-associated Staphylococcus epidermidis implant infections are notoriously reluctant to antibiotic treatment. Here we studied the effect of sub-inhibitory concentrations of penicillin, oxacillin, vancomycin, daptomycin, linezolid and tigecycline on S. epidermidis 1585 biofilm formation, expression of extracellular matrix binding protein (Embp) and potential implications for S. epidermidis - macrophage interactions. Penicillin, vancomycin, daptomycin, and linezolid had no biofilm augmenting effect at any of the concentrations tested. In contrast, at sub-inhibitory concentrations tigecycline and oxacillin exhibited significant biofilm inducing activity. In S. epidermidis 1585, SarA is a negative regulator of giant 1 MDa Embp, and down regulation of sarA induces Embp-dependent assembly of a multi-layered biofilm architecture. Dot blot immune assays, confocal laser scanning microscopy, and qPCR showed that under biofilm inducing conditions, tigecycline augmented embp expression compared to the control grown without antibiotics. Conversely, expression of regulator sarA was suppressed, suggesting that tigecycline exerts its effects on embp expression through SarA. Tigecycline failed to induce biofilm formation in embp transposon mutant 1585-M135, proving that under these conditions Embp up-regulation is necessary for biofilm accumulation. As a functional consequence, tigecycline induced biofilm formation significantly impaired the up-take of S. epidermidis by mouse macrophage-like cell line J774A.1. Our data provide novel evidence for the molecular basis of antibiotic induced biofilm formation, a phenotype associated with inherently increased antimicrobial tolerance. While this could explain failure of antimicrobial therapies, persistence of S. epidermidis infections in the presence of sub-inhibitory antimicrobials is additionally propelled by biofilm-related impairment of macrophage-mediated pathogen eradication.

  16. Substrate binding of gelatinase B induces its enzymatic activity in the presence of intact propeptide.

    Science.gov (United States)

    Bannikov, Gregory A; Karelina, Tatiana V; Collier, Ivan E; Marmer, Barry L; Goldberg, Gregory I

    2002-05-03

    Expression of gelatinase B (matrix metalloprotease 9) in human placenta is developmentally regulated, presumably to fulfill a proteolytic function. Here we demonstrate that gelatinolytic activity in situ, in tissue sections of term placenta, is co-localized with gelatinase B. Judging by molecular mass, however, all the enzyme extracted from this tissue was found in a proform. To address this apparent incongruity, we examined the activity of gelatinase B bound to either gelatin- or type IV collagen-coated surfaces. Surprisingly, we found that upon binding, the purified proenzyme acquired activity against both the fluorogenic peptide (7-methoxycoumarin-4-yl)-acetic acid (MCA)-Pro-Leu-Gly-Leu-3-(2,4-dinitrophenyl)-l-2,3-diaminopropionyl-Ala-Arg-NH(2) and gelatin substrates, whereas its propeptide remained intact. These results suggest that although activation of all known matrix metalloproteases in vitro is accomplished by proteolytic processing of the propeptide, other mechanisms, such as binding to a ligand or to a substrate, may lead to a disengagement of the propeptide from the active center of the enzyme, causing its activation.

  17. IL-8-induced L-selectin shedding regulates its binding kinetics to PSGL-1

    Institute of Scientific and Technical Information of China (English)

    JIA XiaoLing; CHEN Juan; LONG Mian

    2009-01-01

    L-selectin plays a crucial role in inflammation cascade by initiating the tethering and rolling of leukocytes on endothelium wall.While many L-selectin molecules are rapidly shed from the cell surface upon activation,the remaining membrane-anchored L-selectin may still play an important role in regulating leukocyte rolling and adhesion with different binding kinetics.Here we developed an in vitro model to activate Jurkat cells via interlukin-8 (IL-8) and quantified the two-dimensional (2D) binding kinetics,using a micropipette aspiration assay,of membrane-anchored L-selectin to P-selectin glycoprotein ligand 1 (PSGL-1) ligand coupled onto human red blood cells (RBCs).The data indicated that L-selectin shedding reduced the amount of membrane-anchored L-selecUn and lowered both its reverse and forward rates.These results suggested that the rolling dynamics of activated leukocytes was determined by two opposite impacts:reducing the surface presentation would enhance the rolling but lowering the kinetic rates would decrease the rolling.This finding provides a new insight into understanding how L-selectin shedding regulates leukocyte rolling and adhesion.

  18. Heat-induced alterations in cashew allergen solubility and IgE binding

    Directory of Open Access Journals (Sweden)

    Christopher P. Mattison

    2016-01-01

    Full Text Available Cashew nuts are an increasingly common cause of food allergy. We compare the soluble protein profile of cashew nuts following heating. SDS-PAGE indicate that heating can alter the solubility of cashew nut proteins. The 11S legumin, Ana o 2, dominates the soluble protein content in ready to eat and mildly heated cashew nuts. However, we found that in dark-roasted cashew nuts, the soluble protein profile shifts and the 2S albumin Ana o 3 composes up to 40% of the soluble protein. Analysis of trypsin-treated extracts by LC/MS/MS indicate changes in the relative number and intensity of peptides. The relative cumulative intensity of the 5 most commonly observed Ana o 1 and 2 peptides are altered by heating, while those of the 5 most commonly observed Ana o 3 peptides remaine relatively constant. ELISA experiments indicate that there is a decrease in rabbit IgG and human serum IgE binding to soluble cashew proteins following heating. Our findings indicate that heating can alter the solubility of cashew allergens, resulting in altered IgE binding. Our results support the use of both Ana o 2 and Ana o 3 as potential cashew allergen diagnostic targets.

  19. (-)-Rhazinilam and the diphenylpyridazinone NSC 613241: Two compounds inducing the formation of morphologically similar tubulin spirals but binding apparently to two distinct sites on tubulin.

    Science.gov (United States)

    Bai, Ruoli; Hamel, Ernest

    2016-08-15

    The most potent microtubule assembly inhibitor of newer diphenylpyridazinone derivatives examined was NSC 613241. Because NSC 613241 and (-)-rhazinilam also induce the formation of similar 2-filament spirals, these aberrant reactions were compared. Spiral formation with both compounds was enhanced by GTP and inhibited by GDP and by 15 other inhibitors of microtubule assembly. Similarly, microtubule assembly induced by paclitaxel or laulimalide is enhanced by GTP and inhibited by GDP and assembly inhibitors, but neither [(3)H]NSC 613241 nor [(3)H](-)-rhazinilam bound to microtubules or inhibited the binding of [(3)H]paclitaxel or [(3)H]peloruside A to microtubules. Differences in the pitch of aberrant polymers were found: NSC 613241-induced and (-)-rhazinilam-induced spirals had average repeats of 85 and 79-80 nm, respectively. We found no binding of [(3)H]NSC 613241 or [(3)H](-)-rhazinilam to αβ-tubulin dimer, but both compounds were incorporated into the polymers they induced in substoichiometric reactions, with as little as 0.1-0.2 mol compound/mol of tubulin, and no cross-inhibition by NSC 613241 or (-)-rhazinilam into spirals occurred. Under reaction conditions where neither compound induced spiral formation, both compounds together synergistically induced substantial spiral formation. We conclude that (-)-rhazinilam and NSC 613241 bind to different sites on tubulin that differ from binding sites for other antitubulin agents.

  20. Curcumin inhibits srebp-2 expression in activated hepatic stellate cells in vitro by reducing the activity of specificity protein-1.

    Science.gov (United States)

    Kang, Qiaohua; Chen, Anping

    2009-12-01

    Elevated levels of cholesterol/low-density lipoprotein (LDL) are a risk factor for the development of nonalcoholic steatohepatitis and its associated hepatic fibrosis. However, underlying mechanisms remain elusive. We previously reported that curcumin induced gene expression of peroxisome proliferator-activated receptor (PPAR)-gamma and stimulated its activity, leading to the inhibition of the activation of hepatic stellate cells (HSCs), the major effector cells during hepatic fibrogenesis. We recently showed that curcumin suppressed gene expression of LDL receptor in activated HSCs in vitro by repressing gene expression of the transcription factor sterol regulatory element binding protein-2 (SREBP-2), leading to the reduction in the level of intracellular cholesterol in HSCs and to the attenuation of the stimulatory effects of LDL on HSCs activation. The current study aimed at exploring molecular mechanisms by which curcumin inhibits srebp-2 expression in HSCs. Promoter deletion assays, mutagenesis assays, and EMSAs localize a specificity protein-1 (SP-1) binding GC-box in the srebp-2 promoter, which is responsible for enhancing the promoter activity and responding to curcumin in HSCs. Curcumin suppresses gene expression of SP-1 and reduces its trans-activation activity, which are mediated by the activation of PPARgamma. The inhibitory effect of curcumin on SP-1 binding to the GC-box is confirmed by chromatin immuno-precipitation. In summary, our results demonstrate that curcumin inhibits srebp-2 expression in cultured HSCs by activating PPARgamma and reducing the SP-1 activity, leading to the repression of ldlr expression. These results provide novel insights into molecular mechanisms by which curcumin inhibits LDL-induced HSC activation.

  1. Hind Limb Unloading Model Alters Nuclear Factor kappa B and Activator Protein-1 Signaling in Mouse Brain

    Science.gov (United States)

    Ramesh, Govindarajan; Vani, Vani; Renard, Renard; Vera, Vera; Wilosn, Wilosn; Ramesh, Govindarajan

    Microgravity induces inflammatory response and also modulates immune functions, which may increase oxidative stress. Exposure to the microgravity environment induces adverse neurological effects. However, there is little research exploring the etiology of neurological effects of exposure to this environment. To explore this area we evaluated changes in Nuclear Factor kappa B, Activator Protein 1, MAPP kinase and N terminal c-Jun kinase in mouse brain exposed to a simulated microgravity environment using the hindlimb unloading model. BALB/c male mice were randomly assigned to hindlimb unloading group (n=12) and control group (n=12) to simulate a microgravity environment, for 7 days. Changes observed in NF-κB, AP- 1 DNA binding, MAPKK and N terminal c-Jun kinase were measured using electrophoretic mobility shift assay (EMSA) and western blot analysis and compared to unexposed brain regions. Hindlimb unloading exposed mice showed significant increases in generated NF-κB, AP-1, MAPKK and Kinase in all regions of the brain exposed to hindlimb unloading as compared to the control brain regions. Results suggest that exposure to simulated microgravity can induce expression of certain transcription factors and protein kinases. This work was supported by funding from NASA NCC 9-165. 504b030414000600080000002100828abc13fa0000001c020000130000005b436f6e74656e745f54797065735d2e78

  2. The calcium binding protein ALG-2 binds and stabilizes Scotin, a p53-inducible gene product localized at the endoplasmic reticulum membrane

    DEFF Research Database (Denmark)

    Draeby, Ingrid; Woods, Yvonne L; la Cour, Jonas Marstrand;

    2007-01-01

    ALG-2 (apoptosis linked gene 2 product) is a calcium binding protein for which no clear cellular function has been established. In this study we identified Scotin as a novel ALG-2 target protein containing 6 PXY and 4 PYP repeats, earlier identified in the ALG-2 binding regions of AIP1/ALIX and T...... cells. Overexpression of ALG-2 led to accumulation of Scotin in MCF7 and H1299 cells. In vitro and in vivo binding of ALG-2 to Scotin was demonstrated to be strictly calcium dependent indicating a role of this interaction in calcium signaling pathways....

  3. Dietary flavonoids bind to mono-ubiquitinated annexin A1 in nuclei, and inhibit chemical induced mutagenesis

    Energy Technology Data Exchange (ETDEWEB)

    Hirata, Fusao, E-mail: fhirata@wayne.edu; Harada, Takasuke; Corcoran, George B.; Hirata, Aiko

    2014-01-15

    Highlight: • Nuclear mono-ubiquitinated annexin A1 is involved in DNA damage induced mutagenesis. • Dietary flavonoids bind to and inhibit purified mono-ubiquitinated annexin A1 helicase. • Dietary flavonoids show anti-mutagenic action. • Annexin A1 may serve as a putative target of cancer chemoprevention by flavonoids. - Abstract: In order to investigate the mechanisms of anti-mutagenic action by dietary flavonoids, we investigated if they inhibit mutation of the thymidine kinase (tk) gene in L5178Ytk(±) lymphoma cells. Silibinin, quercetin and genistein suppressed mutation of the tk gene induced in L5178Ytk(±) lymphoma cells by methyl methanesulfonate (MMS) and As{sup 3+}. Flavone and flavonol were less effective. To establish that mutation of the tk gene in L5178Ytk(±) lymphoma cells by MMS and As{sup 3+} is mediated through mono-ubiquitinated annexin A1, L5178Ytk(±) lymphoma cells were treated with annexin A1 anti-sense oligonucleotide. The treatment reduced mRNA as well as protein levels of annexin A1, and suppressed mutation of the tk gene. Nuclear extracts from L5178Ytk(±) lymphoma cells catalyzed translesion DNA synthesis with an oligonucleotide template containing 8-oxo-guanosine in an annexin A1 dependent manner. This translesion DNA synthesis was inhibited by the anti-mutagenic flavonoids, silibinin, quercetin and genistein, in a concentration dependent manner, but only slightly by flavone and flavonol. Because these observations implicate involvement of annexin A1 in mutagenesis, we examined if flavonoids suppress nuclear annexin A1 helicase activity. Silibinin, quercetin and genistein inhibited ssDNA binding, DNA chain annealing and DNA unwinding activities of purified nuclear mono-ubiquitinated annexin A1. Flavone and flavonol were ineffective. The apparent direct binding of anti-mutagenic flavonoids to the annexin A1 molecule was supported by fluorescence quenching. Taken together, these findings illustrate that nuclear annexin A1 may be

  4. Maturation of shark single-domain (IgNAR) antibodies: evidence for induced-fit binding.

    Science.gov (United States)

    Stanfield, Robyn L; Dooley, Helen; Verdino, Petra; Flajnik, Martin F; Wilson, Ian A

    2007-03-23

    Sharks express an unusual heavy-chain isotype called IgNAR, whose variable regions bind antigen as independent soluble domains. To further probe affinity maturation of the IgNAR response, we structurally characterized the germline and somatically matured versions of a type II variable (V) region, both in the presence and absence of its antigen, hen egg-white lysozyme. Despite a disulfide bond linking complementarity determining regions (CDRs) 1 and 3, both germline and somatically matured V regions displayed significant structural changes in these CDRs upon complex formation with antigen. Somatic mutations in the IgNAR V region serve to increase the number of contacts with antigen, as reflected by a tenfold increase in affinity, and one of these mutations appears to stabilize the CDR3 region. In addition, a residue in the HV4 loop plays an important role in antibody-antigen interaction, consistent with the high rate of somatic mutations in this non-CDR loop.

  5. Maturation of Shark Single-Domain (IgNAR) Antibodies: Evidence for Induced-Fit Binding

    Energy Technology Data Exchange (ETDEWEB)

    Stanfield, R.L.; Dooley, H.; Verdino, P.; Flajnik, M.F.; Wilson, I.A.; /Scripps Res. Inst. /Maryland U.

    2007-07-13

    Sharks express an unusual heavy-chain isotype called IgNAR, whose variable regions bind antigen as independent soluble domains. To further probe affinity maturation of the IgNAR response, we structurally characterized the germline and somatically matured versions of a type II variable (V) region, both in the presence and absence of its antigen, hen egg-white lysozyme. Despite a disulfide bond linking complementarity determining regions (CDRs) 1 and 3, both germline and somatically matured V regions displayed significant structural changes in these CDRs upon complex formation with antigen. Somatic mutations in the IgNAR V region serve to increase the number of contacts with antigen, as reflected by a tenfold increase in affinity, and one of these mutations appears to stabilize the CDR3 region. In addition, a residue in the HV4 loop plays an important role in antibody-antigen interaction, consistent with the high rate of somatic mutations in this non-CDR loop.

  6. Induced fit on heme binding to the Pseudomonas aeruginosa cytoplasmic protein (PhuS) drives interaction with heme oxygenase (HemO)

    OpenAIRE

    2012-01-01

    Iron, an essential nutrient with limited bioavailability, requires specialized cellular mechanisms for uptake. Although iron uptake into the cytoplasm in the form of heme has been well characterized in many bacteria, the subsequent trafficking is poorly understood. The cytoplasmic heme-binding proteins belong to a structurally related family thought to have evolved as “induced fit” ligand-binding macromolecules. One member, Pseudomonas aeruginosa cytoplasmic protein (PhuS), has previously bee...

  7. Dengue virus specific dual HLA binding T cell epitopes induce CD8+ T cell responses in seropositive individuals.

    Science.gov (United States)

    Comber, Joseph D; Karabudak, Aykan; Huang, Xiaofang; Piazza, Paolo A; Marques, Ernesto T A; Philip, Ramila

    2014-01-01

    Dengue virus infects an estimated 300 million people each year and even more are at risk of becoming infected as the virus continues to spread into new areas. Despite the increase in viral prevalence, no anti-viral medications or vaccines are approved for treating or preventing infection. CD8+ T cell responses play a major role in viral clearance. Therefore, effective vaccines that induce a broad, multi-functional T cell response with substantial cross-reactivity between all virus serotypes can have major impacts on reducing infection rates and infection related complications. Here, we took an immunoproteomic approach to identify novel MHC class I restricted T cell epitopes presented by dengue virus infected cells, representing the natural and authentic targets of the T cell response. Using this approach we identified 4 novel MHC-I restricted epitopes: 2 with the binding motif for HLA-A24 molecules and 2 with both HLA-A2 and HLA-A24 binding motifs. These peptides were able to activate CD8+ T cell responses in both healthy, seronegative individuals and in seropositive individuals who have previously been infected with dengue virus. Importantly, the dual binding epitopes activated pre-existing T cell precursors in PBMCs obtained from both HLA-A2+ and HLA-A24+ seropositive individuals. Together, the data indicate that these epitopes are immunologically relevant T cell activating peptides presented on infected cells during a natural infection and therefore may serve as candidate antigens for the development of effective multi-serotype specific dengue virus vaccines.

  8. Induced alignment and measurement of dipolar couplings of an SH2 domain through direct binding with filamentous phage

    Energy Technology Data Exchange (ETDEWEB)

    Dahlke Ojennus, Deanna; Mitton-Fry, Rachel M.; Wuttke, Deborah S. [University of Colorado, Department of Chemistry and Biochemistry (United States)

    1999-06-15

    Large residual {sup 15}N-{sup 1}H dipolar couplings have been measured in a Src homology II domain aligned at Pf1 bacteriophage concentrations an order of magnitude lower than used for induction of a similar degree of alignment of nucleic acids and highly acidic proteins. An increase in {sup 1} H and {sup 15}N protein linewidths and a decrease in T{sub 2} and T{sub 1}{rho} relaxation time constants implicates a binding interaction between the protein and phage as the mechanism of alignment. However, the associated increased linewidth does not preclude the accurate measurement of large dipolar couplings in the aligned protein. A good correlation is observed between measured dipolar couplings and predicted values based on the high resolution NMR structure of the SH2 domain. The observation of binding-induced protein alignment promises to broaden the scope of alignment techniques by extending their applicability to proteins that are able to interact weakly with the alignment medium.

  9. The binding of NCAM to FGFR1 induces a specific cellular response mediated by receptor trafficking

    DEFF Research Database (Denmark)

    Francavilla, Chiara; Cattaneo, Paola; Berezin, Vladimir

    2009-01-01

    different from that elicited by FGF-2. In contrast to FGF-induced degradation of endocytic FGFR1, NCAM promotes the stabilization of the receptor, which is recycled to the cell surface in a Rab11- and Src-dependent manner. In turn, FGFR1 recycling is required for NCAM-induced sustained activation of various...... effectors. Furthermore, NCAM, but not FGF-2, promotes cell migration, and this response depends on FGFR1 recycling and sustained Src activation. Our results implicate NCAM as a nonconventional ligand for FGFR1 that exerts a peculiar control on the intracellular trafficking of the receptor, resulting...... in a specific cellular response. Besides introducing a further level of complexity in the regulation of FGFR1 function, our findings highlight the link of FGFR recycling with sustained signaling and cell migration and the critical role of these events in dictating the cellular response evoked by receptor...

  10. Neuroprotective effects of cold-inducible RNA-binding protein during mild hypothermia on traumatic brain injur y

    Institute of Scientific and Technical Information of China (English)

    Guan Wang; Jian-ning Zhang; Jia-kui Guo; Ying Cai; Hong-sheng Sun; Kun Dong; Cheng-gang Wu

    2016-01-01

    Cold-inducible RNA-binding protein (CIRP), a key regulatory protein, could be facilitated by mild hypothermia in the brain, heart and liver. This study observed the effects of mild hypothermia at 31 ± 0.5°C on traumatic brain injury in rats. Results demonstrated that mild hypothermia suppressed apoptosis in the cortex, hippocampus and hypothalamus, facilitated CIRP mRNA and protein expression in these regions, especially in the hypothalamus. The anti-apoptotic effect of mild hypothermia disappeared after CIRP silencing. There was no correlation between mitogen-activated extracellular signal-regulated kinase activation and CIRP silencing. CIRP silencing inhibited extracellular signal-regulated kinase-1/2 activation. These indicate that CIRP inhibits apoptosis by affecting extracellular signal-regulated kinase-1/2 activation, and exerts a neuroprotective effect during mild hypothermia for traumatic brain injury.

  11. Polyhydroxyfullerene binds cadmium ions and alleviates metal-induced oxidative stress in Saccharomyces cerevisiae.

    Science.gov (United States)

    Pradhan, Arunava; Pinheiro, José Paulo; Seena, Sahadevan; Pascoal, Cláudia; Cássio, Fernanda

    2014-09-01

    The water-soluble polyhydroxyfullerene (PHF) is a functionalized carbon nanomaterial with several industrial and commercial applications. There have been controversial reports on the toxicity and/or antioxidant properties of fullerenes and their derivatives. Conversely, metals have been recognized as toxic mainly due to their ability to induce oxidative stress in living organisms. We investigated the interactive effects of PHF and cadmium ions (Cd) on the model yeast Saccharomyces cerevisiae by exposing cells to Cd (≤5 mg liter(-1)) in the absence or presence of PHF (≤500 mg liter(-1)) at different pHs (5.8 to 6.8). In the absence of Cd, PHF stimulated yeast growth up to 10.4%. Cd inhibited growth up to 79.7%, induced intracellular accumulation of reactive oxygen species (ROS), and promoted plasma membrane disruption in a dose- and pH-dependent manner. The negative effects of Cd on growth were attenuated by the presence of PHF, and maximum growth recovery (53.8%) was obtained at the highest PHF concentration and pH. The coexposure to Cd and PHF decreased ROS accumulation up to 36.7% and membrane disruption up to 30.7% in a dose- and pH-dependent manner. Two mechanisms helped to explain the role of PHF in alleviating Cd toxicity to yeasts: PHF decreased Cd-induced oxidative stress and bound significant amounts of Cd in the extracellular medium, reducing its bioavailability to the cells.

  12. Internal field induced exciton binding energy and the optical transition in a strained Mg based II–VI quantum well

    Energy Technology Data Exchange (ETDEWEB)

    Elangovan, P. [Department of Physics, Maamallan Institute of Technology, Chennai 602105 (India); John Peter, A., E-mail: a.john.peter@gmail.com [Department of Physics, Government Arts College, Melur 625 106. Madurai (India); Kyoo Yoo, Chang [Center for Environmental Studies/Green Energy Center, Deptartment of Environmental Science and Engineering, College of Engineering, Kyung Hee University, Seocheon-dong 1, Giheung-gu, Yongin-Si, Gyeonggi-Do, 446-701 (Korea, Republic of)

    2013-11-15

    Binding energy of an exciton in a wurtzite ZnO/Zn{sub 1−x}Mg{sub x}O strained quantum well is investigated theoretically in which the strong built-in electric field due to the spontaneous and piezoelectric polarizations is included. Numerical calculations are performed using variational procedure within the single band effective mass approximation by varying the Mg composition in the barrier. The exciton oscillator strength and the exciton lifetime for radiative recombination as functions of well width and Mg content have been computed. The internal field induced interband emission energy of strained ZnO/Zn{sub 1−x}Mg{sub x}O well is investigated with the various structural parameters. The total optical absorption coefficients and the changes of refractive index as a function of normalized photon energy in the presence of built-in internal field are analyzed. The result shows that the strong built-in electric field has influence on the oscillator strength and the recombination life time of the exciton. The optical absorption coefficients and the refractive index changes strongly depend on Mg composition. The occurred blue shift of the resonant peak due to the incorporation of Mg ions will give the information about the variation of two energy levels in the quantum well. -- Highlights: • Binding energy of an exciton in a wurtzite ZnO/Zn{sub 1−x}Mg{sub x}O strained quantum well is investigated. • The built-in internal fields due to the spontaneous and piezoelectric polarizations are included. • The oscillator strength and the exciton lifetime for radiative recombination are computed. • The internal field induced transition energy of strained ZnO/Zn{sub 1−x}Mg{sub x}O well is investigated. • The results show that the nonlinear optical properties strongly depend on Mg composition.

  13. Repeated administration of D-amphetamine induces loss of [{sup 123}I]FP-CIT binding to striatal dopamine transporters in rat brain: a validation study

    Energy Technology Data Exchange (ETDEWEB)

    Booij, Jan [Department of Nuclear Medicine, Academic Medical Center, 1105 AZ Amsterdam (Netherlands)]. E-mail: j.booij@amc.uva.nl; Bruin, Kora de [Department of Nuclear Medicine, Academic Medical Center, 1105 AZ Amsterdam (Netherlands); Gunning, W. Boudewijn [Department of Neurology, Epilepsy Centre Kempenhaeghe, 5590 AB Heeze (Netherlands)

    2006-04-15

    In recent years, several PET and SPECT studies have shown loss of striatal dopamine transporter (DAT) binding in amphetamine (AMPH) users. However, the use of DAT SPECT tracers to detect AMPH-induced changes in DAT binding has not been validated. We therefore examined if repeated administration of D-AMPH or methamphetamine (METH) may induce loss of binding to striatal DATs in rats by using an experimental biodistribution study design and a SPECT tracer for the DAT ([{sup 123}I]FP-CIT). Methods: Groups of male rats (n=10 per group) were treated with D-AMPH (10 mg/kg body weight), METH (10 mg/kg body weight), or saline, twice a day for 5 consecutive days. Five days later, [{sup 123}I]FP-CIT was injected intravenously, and 2 h later, the rats were sacrificed and radioactivity was assayed. Results: In D-AMPH but not METH-treated rats, striatal [{sup 123}I]FP-CIT uptake was significantly lower (approximately 17%) than in the control group. Conclusion: These data show that [{sup 123}I]FP-CIT can be used to detect AMPH-induced changes in DAT binding and may validate the use of DAT radiotracers to study AMPH-induced changes in striatal DAT binding in vivo.

  14. Inhibition of mouse acrosome reaction and sperm-zona pellucida binding by anti-human sperm membrane protein 1 antibody%抗人精子膜蛋白抗体1对小鼠精子顶体反应和精子-透明带结合的抑制作用

    Institute of Scientific and Technical Information of China (English)

    G.Y.Cheng; J.L.Shi; M.Wang; Y.Q.Hu; C.M.Liu; Y.F.Wang; C.Xu

    2007-01-01

    Aim:To investigate the possible functions of human sperm membrane protein (hSMP-1) in the process of fertilization.Methods: A 576-bp cDNA fragment of HSD-1 gene coding for the extracellular domain of hSMP-1 was cloned and expressed. The localization of this protein on human and mouse sperm was determined by indirect immunofluorescent staining by using anti-recombinant hSMP-1 (anti-rhSMP-1) antibodies. Sperm acrosome reaction and spermzona pellucida (ZP) binding assay were carried out in 10-week-old BALB/c mice. Results: Recombinant hSMP-1 was successfully cloned and expressed. The expression of the native protein was limited on the acrosome of human and mouse sperm. Treatment of anti-rhSMP-1 antibodies significantly decreased the average number of sperms bound to each egg. Meanwhile, the percentage of acrosome reaction was decreased in comparison to pre-immune control after treatment with anti-rhSMP-1 (P < 0.05). Conclusion: The results suggest that anti-rhSMP-1 antibody inhibited mouse acrosome reaction and sperm-ZP binding.

  15. Calreticulin Binds to Fas Ligand and Inhibits Neuronal Cell Apoptosis Induced by Ischemia-Reperfusion Injury

    Directory of Open Access Journals (Sweden)

    Beilei Chen

    2015-01-01

    Full Text Available Background. Calreticulin (CRT can bind to Fas ligand (FasL and inhibit Fas/FasL-mediated apoptosis of Jurkat T cells. However, its effect on neuronal cell apoptosis has not been investigated. Purpose. We aimed to evaluate the neuroprotective effect of CRT following ischemia-reperfusion injury (IRI. Methods. Mice underwent middle cerebral artery occlusion (MCAO and SH-SY5Y cells subjected to oxygen glucose deprivation (OGD were used as models for IRI. The CRT protein level was detected by Western blotting, and mRNA expression of CRT, caspase-3, and caspase-8 was measured by real-time PCR. Immunofluorescence was used to assess the localization of CRT and FasL. The interaction of CRT with FasL was verified by coimmunoprecipitation. SH-SY5Y cell viability was determined by MTT assay, and cell apoptosis was assessed by flow cytometry. The measurement of caspase-8 and caspase-3 activity was carried out using caspase activity assay kits. Results. After IRI, CRT was upregulated on the neuron surface and bound to FasL, leading to increased viability of OGD-exposed SH-SY5Y cells and decreased activity of caspase-8 and caspase-3. Conclusions. This study for the first time revealed that increased CRT inhibited Fas/FasL-mediated neuronal cell apoptosis during the early stage of ischemic stroke, suggesting it to be a potential protector activated soon after IRI.

  16. The new platinum-based anticancer agent LA-12 induces retinol binding protein 4 in vivo

    Directory of Open Access Journals (Sweden)

    Bouchal Pavel

    2011-10-01

    Full Text Available Abstract Background The initial pharmacokinetic study of a new anticancer agent (OC-6-43-bis(acetato(1-adamantylamineamminedichloroplatinum (IV (LA-12 was complemented by proteomic screening of rat plasma. The objective of the study was to identify new LA-12 target proteins that serve as markers of LA-12 treatment, response and therapy monitoring. Methods Proteomic profiles were measured by surface-enhanced laser desorption-ionization time-of-flight mass spectrometry (SELDI-TOF MS in 72 samples of rat plasma randomized according to LA-12 dose and time from administration. Correlation of 92 peak clusters with platinum concentration was evaluated using Spearman correlation analysis. Results We identified Retinol-binding protein 4 (RBP4 whose level correlated with LA-12 level in treated rats. Similar results were observed in randomly selected patients involved in Phase I clinical trials. Conclusions RBP4 induction is in agreement with known RBP4 regulation by amantadine and cisplatin. Since retinol metabolism is disrupted in many cancers and inversely associates with malignancy, these data identify a potential novel mechanism for the action of LA-12 and other similar anti-cancer drugs.

  17. Rational Optimization of Conformational Effects Induced By Hydrocarbon Staples in Peptides and their Binding Interfaces

    Science.gov (United States)

    Lama, Dilraj; Quah, Soo T.; Verma, Chandra S.; Lakshminarayanan, Rajamani; Beuerman, Roger W.; Lane, David P.; Brown, Christopher J.

    2013-12-01

    eIF4E is frequently over-expressed in different cancers and causes increased translation of oncogenic proteins via deregulated cap-dependent translation. Inhibitors of the eIF4E:eIF4G interactions represent an approach that would normalize cap-dependent translation. Stapled peptides represent an emerging class of therapeutics that can target protein: protein interactions. We present here molecular dynamics simulations for a set of rationally designed stapled peptides in solution and in complex with eIF4E, supported with biophysical and crystallographic data. Clustering of the simulated structures revealed the favoured conformational states of the stapled peptides in their bound or free forms in solution. Identifying these populations has allowed us to design peptides with improved affinities by introducing mutations into the peptide sequence to alter their conformational distributions. These studies emphasise the effects that engineered mutations have on the conformations of free and bound peptides, and illustrate that both states must be considered in efforts to attain high affinity binding.

  18. Isolation of the phagocytosis-inducing IgG-binding antigen on senescent somatic cells

    Science.gov (United States)

    Kay, Marguerite M. B.

    1981-02-01

    To remove senescent red blood cells (RBCs) from the circulation, macrophages must distinguish them from mature RBCs. That is achieved by a specific recognition system1,2. An antigen that develops on the surface of a senescing RBC is recognized and bound by the Fab region1 of an IgG autoantibody in the serum2. Subsequently the Fc region of the autoantibody is recognized and bound by a macrophage3, which proceeds to phagocytose the RBC. The antigenic molecule can be extracted from senescent but not young RBCs with Triton X-100 (ref. 4), although 10-30% as much antigen can be extracted from middle-aged as from senescent RBCs4. I have now used IgG autoantibodies eluted from senescent RBCs to isolate and purify the IgG-binding antigen on senescent RBCs, andto detect the antigen on other somatic cells. The antigen is a ~=62,000-Mr protein which is present on stored platelets, lymphocytes and neutrophils, and on cultured human adult liver and embryonic kidney cells, as well as senescent RBCs.

  19. Electrostatically induced recruitment of membrane peptides into clusters requires ligand binding at both interfaces.

    Directory of Open Access Journals (Sweden)

    Yuri N Antonenko

    Full Text Available Protein recruitment to specific membrane locations may be governed or facilitated by electrostatic attraction, which originates from a multivalent ligand. Here we explored the energetics of a model system in which this simple electrostatic recruitment mechanism failed. That is, basic poly-L-lysine binding to one leaflet of a planar lipid bilayer did not recruit the triply-charged peptide (O-Pyromellitylgramicidin. Clustering was only observed in cases where PLL was bound to both channel ends. Clustering was indicated (i by the decreased diffusional PLL mobility D(PLL and (ii by an increased lifetime τ(PLL of the clustered channels. In contrast, if PLL was bound to only one leaflet, neither D(PLL nor τ(P changed. Simple calculations suggest that electrostatic repulsion of the unbound ends prevented neighboring OPg dimers from approaching each other. We believe that a similar mechanism may also operate in cell signaling and that it may e.g. contribute to the controversial results obtained for the ligand driven dimerization of G protein-coupled receptors.

  20. Arsenite binding-induced zinc loss from PARP-1 is equivalent to zinc deficiency in reducing PARP-1 activity, leading to inhibition of DNA repair

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xi; Zhou, Xixi [Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States); Du, Libo [Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Liu, Wenlan [Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States); Liu, Yang [Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Hudson, Laurie G. [Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States); Liu, Ke Jian, E-mail: kliu@salud.unm.edu [Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States)

    2014-01-15

    Inhibition of DNA repair is a recognized mechanism for arsenic enhancement of ultraviolet radiation-induced DNA damage and carcinogenesis. Poly(ADP-ribose) polymerase-1 (PARP-1), a zinc finger DNA repair protein, has been identified as a sensitive molecular target for arsenic. The zinc finger domains of PARP-1 protein function as a critical structure in DNA recognition and binding. Since cellular poly(ADP-ribosyl)ation capacity has been positively correlated with zinc status in cells, we hypothesize that arsenite binding-induced zinc loss from PARP-1 is equivalent to zinc deficiency in reducing PARP-1 activity, leading to inhibition of DNA repair. To test this hypothesis, we compared the effects of arsenite exposure with zinc deficiency, created by using the membrane-permeable zinc chelator TPEN, on 8-OHdG formation, PARP-1 activity and zinc binding to PARP-1 in HaCat cells. Our results show that arsenite exposure and zinc deficiency had similar effects on PARP-1 protein, whereas supplemental zinc reversed these effects. To investigate the molecular mechanism of zinc loss induced by arsenite, ICP-AES, near UV spectroscopy, fluorescence, and circular dichroism spectroscopy were utilized to examine arsenite binding and occupation of a peptide representing the first zinc finger of PARP-1. We found that arsenite binding as well as zinc loss altered the conformation of zinc finger structure which functionally leads to PARP-1 inhibition. These findings suggest that arsenite binding to PARP-1 protein created similar adverse biological effects as zinc deficiency, which establishes the molecular mechanism for zinc supplementation as a potentially effective treatment to reverse the detrimental outcomes of arsenic exposure. - Highlights: • Arsenite binding is equivalent to zinc deficiency in reducing PARP-1 function. • Zinc reverses arsenic inhibition of PARP-1 activity and enhancement of DNA damage. • Arsenite binding and zinc loss alter the conformation of zinc finger

  1. Overexpression of the cholesterol-binding protein MLN64 induces liver damage in the mouse

    Institute of Scientific and Technical Information of China (English)

    Juan Enrique Tichauer; Juan Francisco Miquel; Attilio Rigotti; Silvana Zanlungo; Mar(i)a Gabriela Morales; Ludwig Amigo; Leopoldo Galdames; Andrés Kléin; Verónica Quifio(n)es; Carla Ferrada; Alejandra Alvarez R; Marie-Christine Rio

    2007-01-01

    AIM: To examine the in vivo phenotype associated with hepatic metastatic lymph node 64 (MLN64) over-expression.METHODS: Recombinant-adenovirus-mediated MLN64 gene transfer was used to overexpress MLN64 in the livers of C57BL/6 mice. We measured the effects of MLN64 overexpression on hepatic cholesterol content, bile flow, biliary lipid secretion and apoptosis markers. For in vitro studies cultured CHO cells with transient MLN64 overexpression were utilized and apoptosis by TUNEL assay was measured.RESULTS: Livers from Ad.MLN64-infected mice exhibited early onset of liver damage and apoptosis. This response correlated with increases in liver cholesterol content and biliary bile acid concentration, and impaired bile flow. We investigated whether liver MLN64 expression could be modulated in a murine model of hepatic injury. We found increased hepatic MLN64 mRNA and protein levels in mice with chenodeoxycholic acid-induced liver damage. In addition, cultured CHO cells with transient MLN64 overexpression showed increased apoptosis.CONCLUSION: In summary, hepatic MLN64 over-expression induced damage and apoptosis in murine livers and altered cholesterol metabolism. Further studies are required to elucidate the relevance of these findings under physiologic and disease conditions.

  2. Sequential, ordered acquisition of antibodies to Plasmodium falciparum erythrocyte membrane protein 1 domains

    DEFF Research Database (Denmark)

    Cham, Gerald K K; Turner, Louise; Lusingu, John;

    2009-01-01

    The binding of erythrocytes infected with mature blood stage parasites to the vascular bed is key to the pathogenesis of malignant malaria. The binding is mediated by members of Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family. PfEMP1s can be divided into groups, and it has pr....... The identification of PfEMP1 domains expressed by parasites causing disease in infants and young children is important for development of vaccines protecting against severe malaria....

  3. Measuring cohesion between macromolecular filaments, one pair at a time: Depletion-induced microtubule binding

    CERN Document Server

    Hilitski, Feodor; Cajamarca, Luis; Hagan, Michael F; Grason, Gregory M; Dogic, Zvonimir

    2014-01-01

    In presence of non-adsorbing polymers, colloidal particles experience a ubiquitous attractive interactions induced by the depletion mechanism. We measure the depletion interaction between a pair of microtubule filaments by a method that combines optical trapping, single molecule imaging and umbrella sampling. By quantifying the dependence of filament cohesion on both polymer concentration and solution ionic strength, we demonstrate that the minimal model of depletion based, on the Asakura-Oosawa theory, fails to describe the experimental data. By measuring the cohesion strength in two- and three- filament bundles we verify pairwise additivity of the depletion interaction for the specific experimental conditions. The described experimental technique can be used to measure pairwise interactions between various biological or synthetic filaments, thus complementing information extracted from bulk osmotic stress experiments.

  4. Lentivirus-induced knockdown of low density lipoprotein receptor-related protein 1 aggravates cartilage damage in a rat model of osteoarthritis%慢病毒介导shRNA关节腔注射可加重骨关节炎的软骨破坏

    Institute of Scientific and Technical Information of China (English)

    杨二平; 彭飞; 梁杰; 杜远立

    2016-01-01

    BACKGROUND:Emerging evidence demonstrates that low density lipoprotein receptor-related protein 1 (LRP1)isinvolved in lipid metabolism and regulation of inflammatory reaction. OBJECTIVE:To explore the effectof lentivirus-induced knockdown of low density lipoprotein receptor-related protein 1 on cartilage damage and matrix metaloproteinase 13 in a rat model of osteoarthritis, so as to assess the role of low density lipoprotein receptor-related protein 1 in the pathogenesis of osteoarthritis. METHODS:Sixty-fourSprague-Dawleyratswere included andramdomlydivided into four groups (n=16 for each): negative control group, no surgery; sham-surgery group, onlythearticular cavity of the knee was exposed; osteoarthritisplus shLRP1 group, rat osteoarthritis models were established by cutting anterior cruciate ligament and removing the medial meniscus partly folowed by an intra-articular injection of lentivirus-mediated siRNA at 2 days after surgery, once a week for 2 consecutive weeks; osteoarthritis group,an intra-articular injection of the negative control lentivirus was performed after surgery. Rats inthe four groups started running on theself-made electric treadmil from 5 days after modeling, 30 minutes per day,totaly 500 meters. Cartilage damage and matrix metaloproteinase 13 expression in cartilage tissues were determined at 2, 4, 6 weeks after surgery. RESULTS AND CONCLUSION:Gross and pathological observations showed that lentivirus-induced knockdown of lowdensity lipoprotein receptor-related protein 1 aggravatedcartilage damage intherat model of osteoarthritis. At 6 weeks after surgery, Mankin’s scoreand matrix metaloproteinase 13 expression inthecartilage tissues in osteoarthritis plus shLRP1 groupweresignificantly increased compared with other three groups (P  目的:观察慢病毒介导的低密度脂蛋白受体相关蛋白1-shRNA对大鼠骨关节炎模型软骨破坏的影响,以及对软骨组织中基质金属蛋白酶13表达的作用,初步判

  5. Two types of antibodies are induced by vaccination with A/California/2009 pdm virus: binding near the sialic acid-binding pocket and neutralizing both H1N1 and H5N1 viruses.

    Directory of Open Access Journals (Sweden)

    Nobuko Ohshima

    Full Text Available Many people have a history of catching the flu several times during childhood but no additional flu in adulthood, even without vaccination. We analyzed the total repertoire of antibodies (Abs against influenza A group 1 viruses induced in such a flu-resistant person after vaccination with 2009 H1N1 pandemic influenza virus. They were classified into two types, with no exceptions. The first type, the products of B cells newly induced through vaccination, binds near the sialic acid-binding pocket. The second type, the products of long-lived memory B cells established before vaccination, utilizes the 1-69 VH gene, binds to the stem of HA, and neutralizes both H1N1 and H5N1 viruses with few exceptions. These observations indicate that the sialic acid-binding pocket and its surrounding region are immunogenically very potent and majority of the B cells whose growth is newly induced by vaccination produce Abs that recognize these regions. However, they play a role in protection against influenza virus infection for a short period since variant viruses that have acquired resistance to these Abs become dominant. On the other hand, although the stem of HA is immunogenically not potent, the second type of B cells eventually becomes dominant. Thus, a selection system should function in forming the repertoire of long-lived memory B cells and the stability of the epitope would greatly affect the fate of the memory cells. Acquisition of the ability to produce Abs that bind to the stable epitope could be a major factor of flu resistance.

  6. Adenylyl cyclase-associated protein 1 is a receptor for human resistin and mediates inflammatory actions of human monocytes.

    Science.gov (United States)

    Lee, Sahmin; Lee, Hyun-Chae; Kwon, Yoo-Wook; Lee, Sang Eun; Cho, Youngjin; Kim, Joonoh; Lee, Soobeom; Kim, Ju-Young; Lee, Jaewon; Yang, Han-Mo; Mook-Jung, Inhee; Nam, Ky-Youb; Chung, Junho; Lazar, Mitchell A; Kim, Hyo-Soo

    2014-03-04

    Human resistin is a cytokine that induces low-grade inflammation by stimulating monocytes. Resistin-mediated chronic inflammation can lead to obesity, atherosclerosis, and other cardiometabolic diseases. Nevertheless, the receptor for human resistin has not been clarified. Here, we identified adenylyl cyclase-associated protein 1 (CAP1) as a functional receptor for human resistin and clarified its intracellular signaling pathway to modulate inflammatory action of monocytes. We found that human resistin directly binds to CAP1 in monocytes and upregulates cyclic AMP (cAMP) concentration, protein kinase A (PKA) activity, and NF-κB-related transcription of inflammatory cytokines. Overexpression of CAP1 in monocytes enhanced the resistin-induced increased activity of the cAMP-dependent signaling. Moreover, CAP1-overexpressed monocytes aggravated adipose tissue inflammation in transgenic mice that express human resistin from their monocytes. In contrast, suppression of CAP1 expression abrogated the resistin-mediated inflammatory activity both in vitro and in vivo. Therefore, CAP1 is the bona fide receptor for resistin leading to inflammation in humans.

  7. Thymoquinone, an active constituent of Nigella sativa seeds, binds with bilirubin and protects mice from hyperbilirubinemia and cyclophosphamide-induced hepatotoxicity.

    Science.gov (United States)

    Laskar, Amaj A; Khan, Masood A; Rahmani, Arshad H; Fatima, Sana; Younus, Hina

    2016-08-01

    Some reports indicate that thymoquinone (TQ), the main constituent of Nigella sativa seeds, is hepatoprotective. The aim of this study was to determine whether TQ is able to bind directly to bilirubin, and whether TQ or liposomal formulation of TQ (Lip-TQ) can reduce cyclophosphamide (CYP)-induced liver toxicity, serum bilirubin level in mice. The binding of TQ with bilirubin was studied by UV-VIS, fluorescence and Near-UV CD spectroscopy. Inhibition of binding of bilirubin to erythrocytes by TQ was also examined. To increase the in vivo efficacy, Lip-TQ was prepared and used against CYP-induced toxicity. The protective role of TQ or Lip-TQ against CYP-induced toxicity was assessed by determining the liver function parameters, the levels of superoxide dismutase (SOD) and catalase (CAT), and histological studies. It was found that TQ binds to bilirubin and significantly inhibits the binding of bilirubin to erythrocytes. Lip-TQ (10 mg/kg) significantly reduced the levels of aspartate transaminase (AST) from 254 ± 48 to 66 ± 18 IU/L (P bilirubin from 2.8 ± 0.50 to 1.24 ± 0.30 mg/dl (P bilirubin in systemic circulation in disease conditions that lead to hyperbilirubinemia and liver toxicity and hence may be used as a supplement in the treatment of liver ailments.

  8. Alkane-induced expression, substrate binding profile, and immunolocalization of a cytochrome P450 encoded on the nifD excision element of Anabaena 7120

    Directory of Open Access Journals (Sweden)

    Fjetland Conrad R

    2005-03-01

    Full Text Available Abstract Background Alkanes have been hypothesized to act as universal inducers of bacterial cytochrome P450 gene expression. We tested this hypothesis on an unusual P450 gene (cyp110 found on a conserved 11 kilobase episomal DNA element of unknown function found in filamentous cyanobacteria. We also monitored the binding of potential substrates to the P450 protein and explored the distribution of P450 protein in vegetative cells and nitrogen-fixing heterocysts using immuno-electron microscopy. Results Hexadecane treatments resulted in a two-fold increase in mRNA, and a four-fold increase in P450 protein levels relative to control cultures. Hexane, octane and dodecane were toxic and induced substantial changes in membrane morphology. Long-chain saturated and unsaturated fatty acids were shown to bind the CYP110 protein using a spectroscopic spin-shift assay, but alkanes did not bind. CYP110 protein was detected in vegetative cells but not in differentiated heterocysts where nitrogen fixation occurs. Conclusion Hexadecane treatment was an effective inducer of CYP110 expression in cyanobacteria. Based on substrate binding profiles and amino acid sequence similarities it is hypothesized that CYP110 is a fatty acid ω-hydroxylase in photosynthetic cells. CYP110 was found associated with membrane fractions unlike other soluble microbial P450 proteins, and in this regard CYP110 more closely resembles eukarytotic P450s. Substrate stablization is an unlikely mechanism for alkane induction because alkanes did not bind to purified CYP110 protein.

  9. Cyclic mismatch binding ligand CMBL4 binds to the 5'-T-3'/5'-GG-3' site by inducing the flipping out of thymine base.

    Science.gov (United States)

    Mukherjee, Sanjukta; Dohno, Chikara; Asano, Kaori; Nakatani, Kazuhiko

    2016-09-01

    A newly designed cyclic bis-naphthyridine carbamate dimer CMBL4: with a limited conformational flexibility was synthesized and characterized. Absorption spectra revealed that two naphthyridines in CMBL4: were stacked on each other in aqueous solutions. The most efficient binding of CMBL4: to DNA was observed for the sequence 5'-T-3'/5'-GG-3' (T/GG) with the formation of a 1:1 complex, which is one of possible structural elements involved in the higher order structures of (TGG)n repeat DNA triggering the genome microdeletion. Surface plasmon resonance assay also showed the binding of CMBL4: with TGG repeat DNA. Potassium permanganate oxidation studies of CMBL4: -bound duplex containing the T/GG site showed that the CMBL4: -binding accelerated the oxidation of thymine at that site, which suggests the flipping out of the thymine base from a π-stack. Preferential binding was observed for CMBL4: compared with its acyclic variants, which suggests the marked significance of the macrocyclic structure for the recognition of the T/GG site.

  10. Structure of dual function iron regulatory protein 1 complexed with ferritin IRE-RNA

    Energy Technology Data Exchange (ETDEWEB)

    Walden, William E.; Selezneva, Anna I.; Dupuy, Jérôme; Volbeda, Anne; Fontecilla-Camps, Juan C.; Theil, Elizabeth C.; Volz1, Karl (IBS); (CHORI); (UIC)

    2011-07-27

    Iron regulatory protein 1 (IRP1) binds iron-responsive elements (IREs) in messenger RNAs (mRNAs), to repress translation or degradation, or binds an iron-sulfur cluster, to become a cytosolic aconitase enzyme. The 2.8 angstrom resolution crystal structure of the IRP1:ferritin H IRE complex shows an open protein conformation compared with that of cytosolic aconitase. The extended, L-shaped IRP1 molecule embraces the IRE stem-loop through interactions at two sites separated by {approx}30 angstroms, each involving about a dozen protein:RNA bonds. Extensive conformational changes related to binding the IRE or an iron-sulfur cluster explain the alternate functions of IRP1 as an mRNA regulator or enzyme.

  11. PURIFIED IGG F C-BINDING PROTEINS FROM M22 GROUP A STREPTOCOCCUS ARE ABLE TO INDUCE EXPERIMENTAL GLOMERULONEPHRITIS

    Directory of Open Access Journals (Sweden)

    L. A. Burova

    2012-01-01

    Full Text Available Abstract. Pathogenesis of acute post-streptococcal glomerulonephritis (APSGN, a major complication of group A streptococcal (GAS throat or skin disease, remains unclear. Over years, various theories were based on distinct streptococcal extracellular factors, as well as immunological mimicry of streptococci for renal tissue antigens was considered. Previously we reported that a lot of clinical GAS isolates with proven nephritogenic ability show a non-immune binding of monomeric or aggregated IgG. Moreover, using a rabbit model of APSGN, we obtained evidence for important causative role of streptococcal IgG Fc-binding proteins (IgG FcBPs belonging to the M family surface proteins. I.e., rabbits injected by whole IgG FcBP-positive streptococci showed induction of renal glomerular changes, with deposition of IgG and complement C3, resembling the picture recorded in human APSGN. These typical renal changes were always preceded by development of circulating anti-IgG antibodies. Present study was performed in the same rabbit model. Both purified IgG FcBPs isolated from type M22 GAS were found to elicit glomerular degenerative damage of renal glomeruli comparable to those caused by whole bacteria, as well as induce anti-IgG antibodies, deposition of IgG and C3 complement and production of proinflammatory cytokines (IL-1β, TNFα, IL-6 by glomerular mesangial and endothelial cells. By contrast, rabbits injected with proteins A or G, IgG FcBPs of S. aureus and group G streptococci, respectively, exhibited only low levels of circulating anti-IgG and reversible glomerular changes. In these settings, we have not observed any features of membranousproliferative glomerulonephritis (GN resembling morphological traits of acute post-streptococcal GN in humans. These data correlated with results obtained after injection of intact Staphylococcus aureus (Cowan 1 strain or group G streptococci (G148 strain. Both microbial types are known to harbor IgG Fc-binding

  12. The UV-damaged DNA binding protein mediates efficient targeting of the nucleotide excision repair complex to UV-induced photo lesions

    NARCIS (Netherlands)

    Moser, J; Volker, M; Kool, H; Alekseev, S; Vrieling, H; Yasui, A; van Zeeland, AA; Mullenders, LHF

    2005-01-01

    Previous studies point to the XPC-hHR23B complex as the principal initiator of global genome nucleotide excision repair (NER) pathway, responsible for the repair of UV-induced cyclobutane pyrimidine dimers (CPD) and 6-4 photoproducts (6-4PP) in human cells. However, the UV-damaged DNA binding protei

  13. Application of Near-Infrared and Fourier Transform Infrared Spectroscopy in the Characterization of Ligand-Induced Conformation Changes in Folate Binding Protein Purified from Bovine Milk

    DEFF Research Database (Denmark)

    Bruun, Susanne Wrang; Holm, Jan; Hansen, Steen Ingemann;

    2006-01-01

    Fourier transform infrared (FT-IR) and near-infrared (NIR) spectroscopy have been applied to detect structural alterations in folate binding protein (FBP) induced by ligation in different buffer types. The amide I region pointed to a beta-sheet to alpha-helix transition upon ligation in acetate...

  14. Identification of the human zinc transcriptional regulatory element (ZTRE): a palindromic protein-binding DNA sequence responsible for zinc-induced transcriptional repression

    NARCIS (Netherlands)

    Coneyworth, L.J.; Jackson, K.A.; Tyson, J.; Bosomworth, H.J.; Hagen, E.A.E. van der; Hann, G.M.; Ogo, O.A.; Swann, D.C.; Mathers, J.C.; Valentine, R.A.; Ford, D.

    2012-01-01

    Many genes with crucial roles in zinc homeostasis in mammals respond to fluctuating zinc supply through unknown mechanisms, and uncovering these mechanisms is essential to understanding the process at cellular and systemic levels. We detected zinc-dependent binding of a zinc-induced protein to a spe

  15. Protection against dengue virus infection in mice by administration of antibodies against modified nonstructural protein 1.

    Directory of Open Access Journals (Sweden)

    Shu-Wen Wan

    Full Text Available BACKGROUND: Infection with dengue virus (DENV may cause life-threatening disease with thrombocytopenia and vascular leakage which are related to dysfunction of platelets and endothelial cells. We previously showed that antibodies (Abs against DENV nonstructural protein 1 (NS1 cross-react with human platelets and endothelial cells, leading to functional disturbances. Based on sequence homology analysis, the C-terminal region of DENV NS1 protein contains cross-reactive epitopes. For safety in vaccine development, the cross-reactive epitopes of DENV NS1 protein should be deleted or modified. METHODOLOGY/PRINCIPAL FINDINGS: We tested the protective effects of Abs against full-length DENV NS1, NS1 lacking the C-terminal amino acids (a.a. 271-352 (designated ΔC NS1, and chimeric DJ NS1 consisting of N-terminal DENV NS1 (a.a. 1-270 and C-terminal Japanese encephalitis virus NS1 (a.a. 271-352. The anti-ΔC NS1 and anti-DJ NS1 Abs showed a lower binding activity to endothelial cells and platelets than that of anti-DENV NS1 Abs. Passive immunization with anti-ΔC NS1 and anti-DJ NS1 Abs reduced DENV-induced prolonged mouse tail bleeding time. Treatment with anti-DENV NS1, anti-ΔC NS1 and anti-DJ NS1 Abs reduced local skin hemorrhage, controlled the viral load of DENV infection in vivo, synergized with complement to inhibit viral replication in vitro, as well as abolished DENV-induced macrophage infiltration to the site of skin inoculation. Moreover, active immunization with modified NS1 protein, but not with unmodified DENV NS1 protein, reduced DENV-induced prolonged bleeding time, local skin hemorrhage, and viral load. CONCLUSIONS/SIGNIFICANCE: These results support the idea that modified NS1 proteins may represent an improved strategy for safe and effective vaccine development against DENV infection.

  16. Palmitate induces monocyte chemoattractant protein-1 expression in human aortic vascular smooth muscle cells via toll like receptor 4 signaling pathway%果蝇样受体4介导游离脂肪酸调节人血管平滑肌细胞单核细胞趋化蛋白-1的表达

    Institute of Scientific and Technical Information of China (English)

    高啸波; 权金星; 杨海静; 陈卫; 李伟华; 李永红; 刘静

    2013-01-01

    +parthenolide组、软脂酸+白屈菜红碱组、软脂酸+ wortmannin组和软脂酸+myriocin组MCP-1 mRNA表达分别为1.00±0.02、10.80±1.23、3.49±0.28、10.84±0.24、11.24±0.27和10.62±0.36(F=1313.07,P<0.05);MCP-1蛋白表达分别为(132±8)、(218±12)、(152±4)、(213±12)、(225±7)和(226±9)ng/L(F=106.83,P<0.05).成功地构建并获得TLR4 shRNA腺病毒pGSadeno-TLR4,采用pGSadeno-TLR4感染HA-VSMC阻断TLR.信号后,软脂酸+pGSadeno-TLR4组的NF-κBp65结合活性、MCP-1 mRNA和蛋白表达均显著低于软脂酸组[分别为0.48±0.12比1.24±0.16、1.88±0.33比10.80±1.23、(154±10)比(218±12)ng/L;F =591.86、659.16、118.37,均P<0.01].而对照病毒pGSadeno-GFP对软脂酸诱导的NF-κB p65结合活性和MCP-1表达均无明显影响.结论 TLR4/NF-κB信号通路介导了软脂酸诱导的人主动脉血管平滑肌细胞MCP-1基因表达.%Objective To investigate the role of toll like receptor 4(TLR4)pathway in regulation of monocyte chemoattractant protein-1(MCP-1)by palmitate in human aortic vascular smooth muscle cells (HA-VSMC).Methods To study the time course and dose dependent effects of palmitate on MCP-1 gene expression,HA-VSMC were cultured and treated with 100,200 or 400 μ mol/L of palmitate for 6,12 or 24 h,cells were then harvested at indicated time points,MCP-1 mRNA expression was analyzed with realtime polymerase chain reaction(RT-PCR)and the production of MCP-1 protein in cultural supernatant were tested using enzyme-linked immunosorbent assay(ELISA).To determine the involvement of signaling pathways in regulation of MCP-1 by palmitate,specific inhibitors that block protein kinase C(PKC),phosphotylinosital 3 kinase(PI3K),ceramide or nuclear factor(NF)-κB signaling were added to the serumfree media for 30 min followed by treatment with or without 400 μ mol/L of palmitate for additional 6 h,thereafter,the mRNA and protein expression of MCP-1 were studied.To further clarify the role of TLR4 pathway in induction of MCP-1

  17. 宫颈癌组织中硒结合蛋白1表达与肿瘤微环境中抗氧化酶活性有关%Selenium binding protein 1 expression in cervical cancer tissues associated to antioxidant enzyme activity in tumor microenvironment

    Institute of Scientific and Technical Information of China (English)

    王凤杰; 王科坤; 陈显兵; 刘锦红; 刘昕

    2016-01-01

    目的:探讨官颈癌患者血清和组织中谷胱甘肽过氧化物酶(Glutathione peroxidase,GPx)活性和宮颈组织中硒结合蛋白l (Selenium Binding Protein l,SBP1,SELENBPl)表达之间的相互关系,为SELENBP1在宫颈癌发生发展中的作用机制提供理论基础.方法:收集临床住院病人血清样本检测GPx活性,收集相应官颈组织样本检测GPx活性及采用Western blot方法检测组织内SELENBP1蛋白表达水平,用Spearman等级相关来分析其相关性.结果:官颈癌病人血清中GPx活性明显降低;与正常宫颈、CINⅢ级组织和相应癌旁组织相比,癌组织中GPx活性增强,SELENBP1蛋白表达也降低.结论:官颈癌组织中SELENBP1表达水平与肿瘤组织微环境中GPx活性呈负相关,而与病人血清中GPx活性无关,提示SELENBP1可能是通过肿瘤微环境中GPx来发挥抗肿瘤作用.

  18. Isolation and characterization of peptidoglycan recognition protein 1 from antler base of sika deer (Cervus nippon).

    Science.gov (United States)

    Jiang, Wei; Yin, Yongguang; Zhou, Yajun; He, Guidan; Qi, Yue

    2014-03-01

    Peptidoglycan recognition proteins (PGRPs) are secreted innate immunity pattern recognition molecules. In this study, a new peptidoglycan recognition protein 1 named cnPGRP1 was isolated from an antler base of sika deer Cervus nippon. The antler base antimicrobial proteins (AAP) were subjected to consecutive chromatographic methods connected to Sephadex G-25 gel filtration column (CM) anion-exchange column, and RP-HPLC. The molecular weight of cnPGRP1 was 17.2 kDa under SDS-PAGE, and peptide mass fingerprint analysis by MALDI-TOF-MS as peptidoglycan recognition protein 1 matched to Dasypus novemcinctus. The matched amino acids sequences were RLYEIIQKWPHYRA. Both Gram-positive and Gram-negative bacteria can be killed by cnPGRP1 in the 50-250 μg/mL range through in vitro. Furthermore, cnPGRP1 has been found to bind Gram-positive bacteria, Gram-negative bacteria, and even fungus.

  19. Identification of a Residue (Glu60) in TRAP Required for Inducing Efficient Transcription Termination at the trp Attenuator Independent of Binding Tryptophan and RNA.

    Science.gov (United States)

    McAdams, Natalie M; Patterson, Andrea; Gollnick, Paul

    2017-03-15

    Transcription of the tryptophan (trp) operon in Bacillus subtilis is regulated by an attenuation mechanism. Attenuation is controlled by the trpRNA-binding attenuation protein (TRAP). TRAP binds to a site in the 5' leader region of the nascent trp transcript in response to the presence of excess intracellular tryptophan. This binding induces transcription termination upstream of the structural genes of the operon. In prior attenuation models, the role of TRAP was only to alter the secondary structure of the leader region RNA so as to promote formation of the trp attenuator, which was presumed to function as an intrinsic terminator. However, formation of the attenuator alone has been shown to be insufficient to induce efficient termination, indicating that TRAP plays an additional role in this process. To further examine the function of TRAP, we performed a genetic selection for mutant TRAPs that bind tryptophan and RNA but show diminished termination at the trp attenuator. Five such TRAP mutants were obtained. Four of these have substitutions at Glu60, three of which are Lys (E60K) substitutions and the fourth of which is a Val (E60V) substitution. The fifth mutant obtained contains a substitution at Ile63, which is on the same β-strand of TRAP as Glu60. Purified E60K TRAP binds tryptophan and RNA with properties similar to those of the wild type but is defective at inducing termination at the trp attenuator in vitroIMPORTANCE Prior models for attenuation control of the B. subtilis trp operon suggested that the only role for TRAP is to bind to the leader region RNA and alter its folding to induce formation of an intrinsic terminator. However, several recent studies suggested that TRAP plays an additional role in the termination mechanism. We hypothesized that this function could involve residues in TRAP other than those required to bind tryptophan and RNA. Here we obtained TRAP mutants with alterations at Glu60 that are deficient at inducing termination in the

  20. Characterization of Plasminogen Binding to NB4 Promyelocytic Cells Using Monoclonal Antibodies against Receptor-Induced Binding Sites in Cell-Bound Plasminogen

    Directory of Open Access Journals (Sweden)

    Mercè Jardí

    2012-01-01

    Full Text Available The NB4 promyelocytic cell line exhibits many of the characteristics of acute promyelocytic leukemia blast cells, including the translocation (15 : 17 that fuses the PML gene on chromosome 15 to the RARα gene on chromosome 17. These cells have a very high fibrinolytic capacity. In addition to a high secretion of urokinase, NB4 cells exhibit a 10-fold higher plasminogen binding capacity compared with other leukemic cell lines. When tissue-type plasminogen activator was added to acid-treated cells, plasmin generation was 20–26-fold higher than that generated by U937 cells or peripheral blood neutrophils, respectively. We found that plasminogen bound to these cells can be detected by fluorescence-activated cell sorting using an antiplasminogen monoclonal antibody that specifically reacts with this antigen when it is bound to cell surfaces. All-trans retinoid acid treatment of NB4 cells markedly decreased the binding of this monoclonal antibody. This cell line constitutes a unique model to explore plasminogen binding and activation on cell surfaces that can be modulated by all-trans retinoid acid treatment.

  1. Neuropeptide Y-stimulated [(35) S]GTPγs functional binding is reduced in the hippocampus after kainate-induced seizures in mice

    DEFF Research Database (Denmark)

    Elbrønd-Bek, Heidi; Olling, Janne Damm; Gøtzsche, Casper René;

    2014-01-01

    Kainate-induced seizures constitute a model of temporal lobe epilepsy where prominent changes are observed in the hippocampal neuropeptide Y (NPY) system. However, little is known about the functional state and signal transduction of the NPY receptor population resulting from kainate exposure. Thus......, in this study, we explored functional NPY receptor activity in the mouse hippocampus and neocortex after kainate-induced seizures using NPY-stimulated [(35) S]GTPγS binding. Moreover, we also studied levels of [(125) I]-peptide YY (PYY) binding and NPY, Y1, Y2, and Y5 receptor mRNA in these kainate-treated mice....... Functional NPY binding was unchanged up to 12 h post-kainate, but decreased significantly in all hippocampal regions after 24 h and 1 week. Similarly, a decrease in [(125) I]-PYY binding was found in the dentate gyrus (DG) 1 week post-kainate. However, at 2 h, 6 h, and 12 h, [(125) I]-PYY binding...

  2. Cold-inducible RNA binding protein (CIRP, a novel XTcf-3 specific target gene regulates neural development in Xenopus

    Directory of Open Access Journals (Sweden)

    Wedlich Doris

    2008-08-01

    Full Text Available Abstract Background As nuclear mediators of wnt/β-catenin signaling, Lef/Tcf transcription factors play important roles in development and disease. Although it is well established, that the four vertebrate Lef/Tcfs have unique functional properties, most studies unite Lef-1, Tcf-1, Tcf-3 and Tcf-4 and reduce their function to uniformly transduce wnt/β-catenin signaling for activating wnt target genes. In order to discriminate target genes regulated by XTcf-3 from those regulated by XTcf-4 or Lef/Tcfs in general, we performed a subtractive screen, using neuralized Xenopus animal cap explants. Results We identified cold-inducible RNA binding protein (CIRP as novel XTcf-3 specific target gene. Furthermore, we show that knockdown of XTcf-3 by injection of an antisense morpholino oligonucleotide results in a general broadening of the anterior neural tissue. Depletion of XCIRP by antisense morpholino oligonucleotide injection leads to a reduced stability of mRNA and an enlargement of the anterior neural plate similar to the depletion of XTcf-3. Conclusion Distinct steps in neural development are differentially regulated by individual Lef/Tcfs. For proper development of the anterior brain XTcf-3 and the Tcf-subtype specific target XCIRP appear indispensable. Thus, regulation of anterior neural development, at least in part, depends on mRNA stabilization by the novel XTcf-3 target gene XCIRP.

  3. AKAP13 Rho-GEF and PKD-binding domain deficient mice develop normally but have an abnormal response to β-adrenergic-induced cardiac hypertrophy.

    Directory of Open Access Journals (Sweden)

    Matthew J Spindler

    Full Text Available BACKGROUND: A-kinase anchoring proteins (AKAPs are scaffolding molecules that coordinate and integrate G-protein signaling events to regulate development, physiology, and disease. One family member, AKAP13, encodes for multiple protein isoforms that contain binding sites for protein kinase A (PKA and D (PKD and an active Rho-guanine nucleotide exchange factor (Rho-GEF domain. In mice, AKAP13 is required for development as null embryos die by embryonic day 10.5 with cardiovascular phenotypes. Additionally, the AKAP13 Rho-GEF and PKD-binding domains mediate cardiomyocyte hypertrophy in cell culture. However, the requirements for the Rho-GEF and PKD-binding domains during development and cardiac hypertrophy are unknown. METHODOLOGY/PRINCIPAL FINDINGS: To determine if these AKAP13 protein domains are required for development, we used gene-trap events to create mutant mice that lacked the Rho-GEF and/or the protein kinase D-binding domains. Surprisingly, heterozygous matings produced mutant mice at Mendelian ratios that had normal viability and fertility. The adult mutant mice also had normal cardiac structure and electrocardiograms. To determine the role of these domains during β-adrenergic-induced cardiac hypertrophy, we stressed the mice with isoproterenol. We found that heart size was increased similarly in mice lacking the Rho-GEF and PKD-binding domains and wild-type controls. However, the mutant hearts had abnormal cardiac contractility as measured by fractional shortening and ejection fraction. CONCLUSIONS: These results indicate that the Rho-GEF and PKD-binding domains of AKAP13 are not required for mouse development, normal cardiac architecture, or β-adrenergic-induced cardiac hypertrophic remodeling. However, these domains regulate aspects of β-adrenergic-induced cardiac hypertrophy.

  4. [Effect of mutations and modifications of amino acid residues on zinc-induced interaction of the metal-binding domain of β-amyloid with DNA].

    Science.gov (United States)

    Khmeleva, S A; Mezentsev, Y V; Kozin, S A; Mitkevich, V A; Medvedev, A E; Ivanov, A S; Bodoev, N V; Makarov, A A; Radko, S P

    2015-01-01

    Interaction of intranuclear β-amyloid with DNA is considered to be a plausible mechanism of Alzheimer's disease pathogenesis. The interaction of single- and double-stranded DNA with synthetic peptides was analyzed using surface plasmon resonance. The peptides represent the metal-binding domain of β-amyloid (amino acids 1-16) and its variants with chemical modifications and point substitutions of amino acid residues which are associated with enhanced neurotoxicity of β-amyloid in cell tests. It has been shown that the presence of zinc ions is necessary for the interaction of the peptides with DNA in solution. H6R substitution has remarkably reduced the ability of domain 1-16 to bind DNA. This is in accordance with the supposition that the coordination of a zinc ion by amino acid residues His6, Glu11, His13, and His14 of the β-amyloid metal-binding domain results in the occurrence of an anion-binding site responsible for the interaction of the domain with DNA. Zinc-induced dimerization and oligomerization of domain 1-16 associated with phosphorylation of Ser8 and the presence of unblocked amino- and carboxy-terminal groups have resulted in a decrease of peptide concentrations required for detection of the peptide-DNA interaction. The presence of multiple anion-binding sites on the dimers and oligomers is responsible for the enhancement of the peptide-DNA interaction. A substitution of t