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Sample records for normogonadotropic women down-regulated

  1. Does prolonged pituitary down-regulation with gonadotropin-releasing hormone agonist improve the live-birth rate in in vitro fertilization treatment?

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    Ren, Jianzhi; Sha, Aiguo; Han, Dongmei; Li, Ping; Geng, Jie; Ma, Chaihui

    2014-07-01

    To evaluate the effects of a prolonged duration of gonadotropin-releasing hormone agonist (GnRH-a) in pituitary down-regulation for controlled ovarian hyperstimulation (COH) on the live-birth rate in nonendometriotic women undergoing in vitro fertilization and embryo transfer (IVF-ET). Retrospective cohort study. University-affiliated hospital. Normogonadotropic women undergoing IVF. Three hundred seventy-eight patients receiving a prolonged pituitary down-regulation with GnRH-a before ovarian stimulation and 422 patients receiving a GnRH-a long protocol. Live-birth rate per fresh ET. In comparison with the long protocol, the prolonged down-regulation protocol required a higher total dose of gonadotropins. A lower serum luteinizing hormone (LH) level on the starting day of gonadotropin and the day of human chorionic gonadotropin (hCG) and a fewer number of oocytes and embryos were observed in the prolonged down-regulation protocol. However, the duration of stimulation and number of high-quality embryos were comparable between the two groups. A statistically significantly higher implantation rate (50.27% vs. 39.69%), clinical pregnancy rate (64.02% vs. 56.87%) and live-birth rate per fresh transfer cycle (55.56% vs. 45.73%) were observed in the prolonged protocol. Prolonged down-regulation in a GnRH-a protocol might increase the live-birth rates in normogonadotropic women. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  2. Ovulation induction in normogonadotropic anovulation (PCOS)

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    van Santbrink, Evert J. P.; Fauser, Bart C. J. M.

    2006-01-01

    Treatment of normogonadotropic anovulatory infertility (World Health Organization class 2, or WHO2) is by induction of ovulation using clomiphene citrate (CC), followed by follicle-stimulating hormone (FSH) in cases of treatment failure. Not all patients will become ovulatory or will conceive with t

  3. PTGS2 down-regulation in cumulus cells of infertile women with endometriosis.

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    da Luz, Caroline M; da Broi, Michele G; Donabela, Flávia Cappello; Paro de Paz, Cláudia Cristina; Meola, Juliana; Navarro, Paula A

    2017-07-10

    A deleterious effect of endometriosis on oocyte quality has been proposed. Evidence suggests that cumulus cells could be used as indirect biomarkers of oocyte quality. The PTGS2 gene, which encodes cyclooxygenase 2 (COX-2), is deregulated in endometriotic lesions and plays a crucial role in the acquisition of oocyte competence. To date, research evaluating PTGS2 expression in cumulus cells of infertile patients with endometriosis has not been conducted. The aim this study was to compare the expression levels of PTGS2 in cumulus cells of infertile women, with and without endometriosis, undergoing ovarian stimulation for intracytoplasmic sperm injection (ICSI). Therefore, a case-control study compared PTGS2 gene expression in the cumulus cells of 38 infertile patients with endometriosis and 40 without, using real-time polymerase chain reaction. For the first time, decreased expression of PTGS2 was found in cumulus cells of infertile women with endometriosis compared with controls (7.2 ± 10.5 versus 12.4 ± 15.7), which might be related to reduced levels of COX-2 in the cumulus cells of women with the disease. Consequently, we hypothesize that lower transcript levels of PTGS2 in cumulus cells may be involved in the impairment of oocyte quality, suggesting a possible mechanism involved in disease-related infertility. Copyright © 2017 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  4. Limb immobilization induces a coordinate down-regulation of mitochondrial and other metabolic pathways in men and women.

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    Arkan Abadi

    Full Text Available Advancements in animal models and cell culture techniques have been invaluable in the elucidation of the molecular mechanisms that regulate muscle atrophy. However, few studies have examined muscle atrophy in humans using modern experimental techniques. The purpose of this study was to examine changes in global gene transcription during immobilization-induced muscle atrophy in humans and then explore the effects of the most prominent transcriptional alterations on protein expression and function. Healthy men and women (N = 24 were subjected to two weeks of unilateral limb immobilization, with muscle biopsies obtained before, after 48 hours (48 H and 14 days (14 D of immobilization. Muscle cross sectional area (approximately 5% and strength (10-20% were significantly reduced in men and women (approximately 5% and 10-20%, respectively after 14 D of immobilization. Micro-array analyses of total RNA extracted from biopsy samples at 48 H and 14 D uncovered 575 and 3,128 probes, respectively, which were significantly altered during immobilization. As a group, genes involved in mitochondrial bioenergetics and carbohydrate metabolism were predominant features at both 48 H and 14 D, with genes involved in protein synthesis and degradation significantly down-regulated and up-regulated, respectively, at 14 D of muscle atrophy. There was also a significant decrease in the protein content of mitochondrial cytochrome c oxidase, and the enzyme activity of cytochrome c oxidase and citrate synthase after 14 D of immobilization. Furthermore, protein ubiquitination was significantly increased at 48 H but not 14 D of immobilization. These results suggest that transcriptional and post-transcriptional suppression of mitochondrial processes is sustained throughout 14 D of immobilization, while protein ubiquitination plays an early but transient role in muscle atrophy following short-term immobilization in humans.

  5. Urinary follicle-stimulating hormone for normogonadotropic clomiphene-resistant anovulatory infertility: prospective, randomized comparison between low dose step-up and step-down dose regimens

    NARCIS (Netherlands)

    E.J. van Santbrink (Evert); B.C.J.M. Fauser (Bart)

    1997-01-01

    textabstractA low dose step-up and step-down regimen for induction of ovulation using urinary FSH was compared in a prospective randomized fashion in 37 normogonadotropic clomiphene-resistant oligo- or amenorrheic infertile women. The objectives was to assess potential

  6. Anti-Mullerian hormone serum concentrations in normoovulatory and anovulatory women of reproductive age

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    J.S.E. Laven (Joop); J.A. Visser (Jenny); A.P.N. Themmen (Axel); F.H. de Jong (Frank); B.C.J.M. Fauser (Bart); A.G.M.G.J. Mulders (Annemarie)

    2004-01-01

    textabstractAnti-Mullerian hormone (AMH) concentrations correlate with the number of antral follicles as well as age and constitute an endocrine marker for ovarian aging. In normogonadotropic anovulatory infertile women [World Health Organization (WHO) class 2], the number of early

  7. Ovarian response and pregnancy outcome related to mid-follicular LH levels in women undergoing assisted reproduction with GnRH agonist down-regulation and recombinant FSH stimulation

    DEFF Research Database (Denmark)

    Humaidan, P; Bungum, L; Bungum, M

    2002-01-01

    stimulation with recombinant FSH. METHODS: Blood samples were prospectively collected from a total of 207 normal women undergoing assisted reproduction and analysed retrospectively. Based on LH levels on stimulation day 8 patients were divided into four groups: 1.51 IU/l. RESULTS...

  8. miR-483-5p and miR-486-5p are down-regulated in cumulus cells of metaphase II oocytes from women with polycystic ovary syndrome.

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    Shi, Lin; Liu, Shan; Zhao, Wanqiu; Shi, Juanzi

    2015-10-01

    The aim of this study was to compare the expression of microRNAs (miRNAs) in cumulus cells from polycystic ovary syndrome (PCOS) and non-PCOS women. In the present study, miRNA expression profiles of the cumulus cell samples were determined by miRNA microarrays. Quantification of selected miRNAs and predicted target genes was performed using quantitative real-time PCR (qRT-PCR). The results showed that miR-483-5p and miR-486-5p are significantly decreased in cumulus cells of PCOS patients PCOS (fold change >2, false discovery rate <0.001). qRT-PCR found that four predicted genes, SOCS3, SRF, PTEN and FOXO1, were significantly increased in PCOS cumulus cells (all P < 0.001), and IGF2 (host gene of miR-483-5p) was significantly decreased in PCOS cumulus cells (P < 0.001). These results indicated that miR-483-5p might play an important role in reducing insulin resistance, and that miR-486-5p might promote cumulus cell proliferation through activation of PI3K/Akt. The findings from this study provided new insights into the complex molecular mechanisms involved in PCOS by revealing pathways possibly regulated by miRNAs. The differences in miRNAs (miR-483-5p, miR-486-5p) and their target gene expression in cumulus cells may provide clues for future research and help to explain aberrant follicular development and subfertility in women with PCOS.

  9. Down-regulated genes in mouse dental papillae and pulp.

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    Sasaki, H; Muramatsu, T; Kwon, H-J; Yamamoto, H; Hashimoto, S; Jung, H-S; Shimono, M

    2010-07-01

    Important factors involved in odontogenesis in mouse dental papillae disappear between the pre- and post-natal stages of development. Therefore, we hypothesized that certain genes involved in odontogenesis in dental papillae were subject to pre-/post-natal down-regulation. Our goal was to identify, by microarray analysis, which genes were down-regulated. Dental papillae were isolated from embryonic 16-day-, 18-day- (E16, E18), and post-natal 3-day-old (P3) murine first mandibular molar germs and analyzed by microarray. The number of down-regulated genes was 2269 between E16 and E18, and 3130 between E18 and P3. Drastic down-regulation (fold change > 10.0) of Adamts4, Aldha1a2, and Lef1 was observed at both E16 and E18, and quantitative RT-PCR revealed a post-natal reduction in their expression (Adamts4, 1/3; Aldh1a2, 1/13; and Lef1, 1/37). These results suggest that down-regulation of these three genes is an important factor in normal odontogenesis in dental papillae.

  10. Down-regulation of PERK enhances resistance to ionizing radiation

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    Oommen, Deepu, E-mail: oommen1978@gmail.com; Prise, Kevin M.

    2013-11-08

    Highlights: •PERK enhances the sensitivity of cancer cells to ionizing radiation. •Down-regulation of PERK results in enhanced DNA repair. •Ionizing radiation-induced apoptosis is inhibited in PERK-down regulated cancer cells. -- Abstract: Although, ionizing radiation (IR) has been implicated to cause stress in endoplasmic reticulum (ER), how ER stress signaling and major ER stress sensors modulate cellular response to IR is unclear. Protein kinase RNA-like endoplasmic reticulum kinase (PERK) is an ER transmembrane protein which initiates unfolded protein response (UPR) or ER stress signaling when ER homeostasis is disturbed. Here, we report that down-regulation of PERK resulted in increased clonogenic survival, enhanced DNA repair and reduced apoptosis in irradiated cancer cells. Our study demonstrated that PERK has a role in sensitizing cancer cells to IR.

  11. Optimal Down Regulation of mRNA Translation

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    Zarai, Yoram; Margaliot, Michael; Tuller, Tamir

    2017-01-01

    Down regulation of mRNA translation is an important problem in various bio-medical domains ranging from developing effective medicines for tumors and for viral diseases to developing attenuated virus strains that can be used for vaccination. Here, we study the problem of down regulation of mRNA translation using a mathematical model called the ribosome flow model (RFM). In the RFM, the mRNA molecule is modeled as a chain of n sites. The flow of ribosomes between consecutive sites is regulated by n + 1 transition rates. Given a set of feasible transition rates, that models the outcome of all possible mutations, we consider the problem of maximally down regulating protein production by altering the rates within this set of feasible rates. Under certain conditions on the feasible set, we show that an optimal solution can be determined efficiently. We also rigorously analyze two special cases of the down regulation optimization problem. Our results suggest that one must focus on the position along the mRNA molecule where the transition rate has the strongest effect on the protein production rate. However, this rate is not necessarily the slowest transition rate along the mRNA molecule. We discuss some of the biological implications of these results.

  12. Optimal Down Regulation of mRNA Translation

    Science.gov (United States)

    Zarai, Yoram; Margaliot, Michael; Tuller, Tamir

    2017-01-01

    Down regulation of mRNA translation is an important problem in various bio-medical domains ranging from developing effective medicines for tumors and for viral diseases to developing attenuated virus strains that can be used for vaccination. Here, we study the problem of down regulation of mRNA translation using a mathematical model called the ribosome flow model (RFM). In the RFM, the mRNA molecule is modeled as a chain of n sites. The flow of ribosomes between consecutive sites is regulated by n + 1 transition rates. Given a set of feasible transition rates, that models the outcome of all possible mutations, we consider the problem of maximally down regulating protein production by altering the rates within this set of feasible rates. Under certain conditions on the feasible set, we show that an optimal solution can be determined efficiently. We also rigorously analyze two special cases of the down regulation optimization problem. Our results suggest that one must focus on the position along the mRNA molecule where the transition rate has the strongest effect on the protein production rate. However, this rate is not necessarily the slowest transition rate along the mRNA molecule. We discuss some of the biological implications of these results. PMID:28120903

  13. DMBT1 expression is down-regulated in breast cancer

    DEFF Research Database (Denmark)

    Braidotti, P; Nuciforo, P G; Mollenhauer, J

    2004-01-01

    with anti DMBT1 antibody (DMBTh12) and sections from 36 samples, were double-stained also with anti MCM5, one of the 6 pre-replicative complex proteins with cell proliferation-licensing functions. DMBT1 gene expression at mRNA level was assessed by RT-PCR in frozen tissues samples from 39 patients. RESULTS...... expression was down-regulated in the cancerous lesions compared to the normal and/or hyperplastic epithelium adjacent to carcinomas (3/55 positive carcinomas versus 33/42 positive normal/hyperplastic epithelia; p = 0.0001). In 72% of cases RT-PCR confirmed immunohistochemical results. Most of normal...... and hyperplastic mammary cells positive with DMBTh12 were also MCM5-positive. CONCLUSIONS: The redistribution and up-regulation of DMBT1 in normal and hyperplastic tissues flanking malignant tumours and its down-regulation in carcinomas suggests a potential role in breast cancer. Moreover, the concomitant...

  14. Curcumin and emodin down-regulate TGF-β signaling pathway in human cervical cancer cells.

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    Pooja Chandrakant Thacker

    Full Text Available Cervical cancer is the major cause of cancer related deaths in women, especially in developing countries and Human Papilloma Virus infection in conjunction with multiple deregulated signaling pathways leads to cervical carcinogenesis. TGF-β signaling in later stages of cancer is known to induce epithelial to mesenchymal transition promoting tumor growth. Phytochemicals, curcumin and emodin, are effective as chemopreventive and chemotherapeutic compounds against several cancers including cervical cancer. The main objective of this work was to study the effect of curcumin and emodin on TGF-β signaling pathway and its functional relevance to growth, migration and invasion in two cervical cancer cell lines, SiHa and HeLa. Since TGF-β and Wnt/β-catenin signaling pathways are known to cross talk having common downstream targets, we analyzed the effect of TGF-β on β-catenin (an important player in Wnt/β-catenin signaling and also studied whether curcumin and emodin modulate them. We observed that curcumin and emodin effectively down regulate TGF-β signaling pathway by decreasing the expression of TGF-β Receptor II, P-Smad3 and Smad4, and also counterbalance the tumorigenic effects of TGF-β by inhibiting the TGF-β-induced migration and invasion. Expression of downstream effectors of TGF-β signaling pathway, cyclinD1, p21 and Pin1, was inhibited along with the down regulation of key mesenchymal markers (Snail and Slug upon curcumin and emodin treatment. Curcumin and emodin were also found to synergistically inhibit cell population and migration in SiHa and HeLa cells. Moreover, we found that TGF-β activates Wnt/β-catenin signaling pathway in HeLa cells, and curcumin and emodin down regulate the pathway by inhibiting β-catenin. Taken together our data provide a mechanistic basis for the use of curcumin and emodin in the treatment of cervical cancer.

  15. Down-regulation of CEACAM1 in breast cancer.

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    Yang, Changcheng; He, Pingqing; Liu, Yiwen; He, Yiqing; Yang, Cuixia; Du, Yan; Zhou, Muqing; Wang, Wenjuan; Zhang, Guoliang; Wu, Man; Gao, Feng

    2015-10-01

    Carcinoembryonic antigen-related adhesion molecule 1 (CEACAM1) is a type 1 transmembrane glycoprotein belonging to the CEA family, which has been found to exist as either soluble forms in body fluids or membrane-bound forms on the cell surface. Aberrant CEACAM1 expression is associated with tumor progression and has been found in a variety of human malignancies. Increasing interest has been devoted to the expression of CEACAM1 in breast cancer, but most of these findings are contradictory. The aim of this study was to investigate CEACAM1 expression in breast cancer in greater detail. Using immunohistochemical staining, we found that CEACAM1 expression was reduced or lost in breast cancer tissues compared with noncancerous breast tissues. In addition, soluble CEACAM1 levels in the culture medium of breast cancer cell lines were significantly lower than those in a nontumorigenic breast epithelial cell line. Immunofluorescence analysis consistently showed that breast cancer cell lines have relatively low expression of membrane-bound CEACAM1. Furthermore, CEACAM1 mRNA and protein expression levels were down-regulated in breast cancer cell lines as measured using real-time reverse transcriptase-polymerase chain reaction and western blot analysis, respectively. Taken together, our results demonstrate a systematic down-regulation of CEACAM1 in breast cancer and suggest that a strategy to restore CEACAM1 expression may be helpful for the treatment of breast cancer.

  16. Hypnosis and top-down regulation of consciousness.

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    Terhune, Devin B; Cleeremans, Axel; Raz, Amir; Lynn, Steven Jay

    2017-02-04

    Hypnosis is a unique form of top-down regulation in which verbal suggestions are capable of eliciting pronounced changes in a multitude of psychological phenomena. Hypnotic suggestion has been widely used both as a technique for studying basic science questions regarding human consciousness but also as a method for targeting a range of symptoms within a therapeutic context. Here we provide a synthesis of current knowledge regarding the characteristics and neurocognitive mechanisms of hypnosis. We review evidence from cognitive neuroscience, experimental psychopathology, and clinical psychology regarding the utility of hypnosis as an experimental method for modulating consciousness, as a model for studying healthy and pathological cognition, and as a therapeutic vehicle. We also highlight the relations between hypnosis and other psychological phenomena, including the broader domain of suggestion and suggestibility, and conclude by identifying the most salient challenges confronting the nascent cognitive neuroscience of hypnosis and outlining future directions for research on hypnosis and suggestion.

  17. TCR down-regulation controls T cell homeostasis

    DEFF Research Database (Denmark)

    Boding, Lasse; Bonefeld, Charlotte Menné; Nielsen, Bodil L

    2009-01-01

    was caused by the combination of reduced thymic output, decreased T cell apoptosis, and increased transition of naive T cells to memory T cells. Experiments with bone marrow chimeric mice confirmed that the CD3gammaLLAA mutation exerted a T cell intrinsic effect on T cell homeostasis that resulted...... in an increased transition of CD3gammaLLAA naive T cells to memory T cells and a survival advantage of CD3gammaLLAA T cells compared with wild-type T cells. The experimental observations were further supported by mathematical modeling of T cell homeostasis. Our study thus identifies an important role of CD3gamma......-mediated TCR down-regulation in T cell homeostasis....

  18. DMBT1 expression is down-regulated in breast cancer

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    Coggi G

    2004-08-01

    Full Text Available Abstract Background We studied the expression of DMBT1 (deleted in malignant brain tumor 1, a putative tumor suppressor gene, in normal, proliferative, and malignant breast epithelium and its possible relation to cell cycle. Methods Sections from 17 benign lesions and 55 carcinomas were immunostained with anti DMBT1 antibody (DMBTh12 and sections from 36 samples, were double-stained also with anti MCM5, one of the 6 pre-replicative complex proteins with cell proliferation-licensing functions. DMBT1 gene expression at mRNA level was assessed by RT-PCR in frozen tissues samples from 39 patients. Results Normal glands and hyperplastic epithelium in benign lesions displayed a luminal polarized DMBTh12 immunoreactivity. Normal and hyperplastic epithelium adjacent to carcinomas showed a loss of polarization, with immunostaining present in basal and perinuclear cytoplasmic compartments. DMBT1 protein expression was down-regulated in the cancerous lesions compared to the normal and/or hyperplastic epithelium adjacent to carcinomas (3/55 positive carcinomas versus 33/42 positive normal/hyperplastic epithelia; p = 0.0001. In 72% of cases RT-PCR confirmed immunohistochemical results. Most of normal and hyperplastic mammary cells positive with DMBTh12 were also MCM5-positive. Conclusions The redistribution and up-regulation of DMBT1 in normal and hyperplastic tissues flanking malignant tumours and its down-regulation in carcinomas suggests a potential role in breast cancer. Moreover, the concomitant expression of DMTB1 and MCM5 suggests its possible association with the cell-cycle regulation.

  19. Effects of coumarate 3-hydroxylase down-regulation on lignin structure

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    John Ralph; Takuya Akiyama; Hoon Kim; Fachuang Lu; Paul F. Schatz; Jane M. Marita; Sally A. Ralph; M.S. Srinivasa Reddy; Fang Chen; Richard A. Dixon

    2006-01-01

    Down-regulation of the gene encoding 4-coumarate 3-hydroxylase (C3H) in alfalfa massively but predictably increased the proportion of p-hydroxyphenyl (P) units relative to thenormally dominant guaiacyl (G) and syringyl (S) units Stem levels of up to ~65% P (from wild-type levels of ~1%) resulting from down-regulation of C3H were measured by traditional degradative...

  20. Down-regulation of CTLA-4 by HIV-1 Nef protein.

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    Mohamed El-Far

    Full Text Available HIV-1 Nef protein down-regulates several cell surface receptors through its interference with the cell sorting and trafficking machinery. Here we demonstrate for the first time the ability of Nef to down-regulate cell surface expression of the negative immune modulator CTLA-4. Down-regulation of CTLA-4 required the Nef motifs DD175, EE155 and LL165, all known to be involved in vesicle trafficking. Disruption of the lysosomal functions by pH-neutralizing agents prevented CTLA-4 down-regulation by Nef, demonstrating the implication of the endosomal/lysosomal compartments in this process. Confocal microscopy experiments visualized the co-localization between Nef and CTLA-4 in the early and recycling endosomes but not at the cell surface. Overall, our results provide a novel mechanism by which HIV-1 Nef interferes with the surface expression of the negative regulator of T cell activation CTLA-4. Down-regulation of CTLA-4 may contribute to the mechanisms by which HIV-1 sustains T cell activation, a critical step in viral replication and dissemination.

  1. Down-regulation of cell surface CXCR4 by HIV-1

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    Vigh Sandor

    2008-01-01

    Full Text Available Abstract Background CXC chemokine receptor 4 (CXCR4, a member of the G-protein-coupled chemokine receptor family, can serve as a co-receptor along with CD4 for entry into the cell of T-cell tropic X4 human immunodeficiency virus type 1 (HIV-1 strains. Productive infection of T-lymphoblastoid cells by X4 HIV-1 markedly reduces cell-surface expression of CD4, but whether or not the co-receptor CXCR4 is down-regulated has not been conclusively determined. Results Infection of human T-lymphoblastoid cell line RH9 with HIV-1 resulted in down-regulation of cell surface CXCR4 expression. Down-regulation of surface CXCR4 correlated temporally with the increase in HIV-1 protein expression. CXCR4 was concentrated in intracellular compartments in H9 cells after HIV-1 infection. Immunofluorescence microscopy studies showed that CXCR4 and HIV-1 glycoproteins were co-localized in HIV infected cells. Inducible expression of HIV-1 envelope glycoproteins also resulted in down-regulation of CXCR4 from the cell surface. Conclusion These results indicated that cell surface CXCR4 was reduced in HIV-1 infected cells, whereas expression of another membrane antigen, CD3, was unaffected. CXCR4 down-regulation may be due to intracellular sequestering of HIV glycoprotein/CXCR4 complexes.

  2. Paroxetine prevented the down-regulation of astrocytic L-Glu transporters in neuroinflammation

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    Koki Fujimori

    2015-01-01

    Full Text Available The extracellular L-glutamate (L-Glu concentration is elevated in neuroinflammation, thereby causing excitotoxicity. One of the mechanisms is down-regulation of astrocyte L-Glu transporters. Some antidepressants have anti-inflammatory effects. We therefore investigated effects of various antidepressants on the down-regulation of astrocyte L-Glu transporters in the in vitro neuroinflammation model. Among these antidepressants, only paroxetine was effective. We previously demonstrated that the down-regulation of astrocyte L-Glu transporters was caused by L-Glu released from activated microglia. We here clarified that only paroxetine inhibited L-Glu release from microglia. This is the novel action of paroxetine, which may bring advantages on the therapy of neuroinflammation.

  3. Down-regulation of microRNAs controlling tumourigenic factors in follicular thyroid carcinoma

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    Rossing, Maria; Helweg-Larsen, Rehannah Borup; Henao Giraldo, Ricardo

    2012-01-01

    ) and follicular carcinoma (FC). Comparison of carcinoma and adenoma with normal thyroid revealed 150 and 107 differentially expressed miRNAs. Most miRNAs were down-regulated and especially miR-199b-5p and miR-144 which were essentially lost in the carcinomas. Integration of the changed miRNAs with differentially...... expressed mRNAs demonstrated an enrichment of seed-sites among up-regulated transcripts encoding proteins implicated in thyroid tumourigenesis. This was substantiated by the demonstration that pre-miR-199b reduced proliferation when added to cultured follicular thyroid carcinoma cells. The down-regulated mi......RNAs in FC exhibited a substantial similarity with down-regulated miRNAs in anaplastic carcinoma and by gene set enrichment analysis, we observed a significant identity between target mRNAs in FC and transcripts up-regulated in anaplastic carcinoma. To examine the diagnostic potential of miRNA expression...

  4. Computer simulation of factors involved in the down-regulation of hormonal effects.

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    Kurbel, S; Kurbel, B; Dicić, M; Ugraji, V

    1996-03-01

    Down-regulation of hormonal effects is in the presented simulation related to the number of functional receptors and quantity of available hormonal stimulation. The former is in the model substituted with the quantity of stimulation able to produce a full down-regulation (Hs100) of target cells. The halftime (t1/2) of the hormonal effect recovery means the interval before the second hormonal stimulation can elicit half of the initial hormonal effect. Recovered hormonal effects are calculated after periods of two, three, four and five t1/2. The interval among hormonal stimulations varied from 1/2 to 5/2 of t1/2. Shorter than t1/2 intervals showed profound down-regulation even at weak hormonal stimulations (> 20% of Hs100). Stable levels of hormonal effects after frequent hormonal stimulations are found only in cases of very weak stimulations (Hs100). Intervals equalling t1/2 among weak stimulations (Hs100) produced stable hormonal effects. Further prolongation among repeated stimulations improved stability of hormonal effects and even strong stimulations (> 60% of Hs100) were followed with only temporary profound down-regulation. Hormone-binding receptors unable to activate target cells are in the model described as defective. Probability for the target cell to be stimulated is in the model defined as P. Relative quantity of hormonal stimulation per target cell needed to achieve certain P is calculated for cells bearing different proportions of defective receptors. Activation following weak hormone stimulations is highly probable (> 90%) for cells bearing less than 30% of defective receptors. With the proportion of defective receptors over 60%, the activation probability after weak hormone stimulations is reduced (< 66%). Down-regulation can be considered as a modulator of hormonal effects. In prediabetic patients, intense stimulation of pancreatic insulin secretion by frequent or increased ingestion of carbohydrates might lead to sustained hyperinsulinemia. A

  5. A herbivorous mite down-regulates plant defence and produces web to exclude competitors.

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    Sarmento, Renato A; Lemos, Felipe; Dias, Cleide R; Kikuchi, Wagner T; Rodrigues, Jean C P; Pallini, Angelo; Sabelis, Maurice W; Janssen, Arne

    2011-01-01

    Herbivores may interact with each other through resource competition, but also through their impact on plant defence. We recently found that the spider mite Tetranychus evansi down-regulates plant defences in tomato plants, resulting in higher rates of oviposition and population growth on previously attacked than on unattacked leaves. The danger of such down-regulation is that attacked plants could become a more profitable resource for heterospecific competitors, such as the two-spotted spider mite Tetranychus urticae. Indeed, T. urticae had an almost 2-fold higher rate of oviposition on leaf discs on which T. evansi had fed previously. In contrast, induction of direct plant defences by T. urticae resulted in decreased oviposition by T. evansi. Hence, both herbivores affect each other through induced plant responses. However, when populations of T. evansi and T. urticae competed on the same plants, populations of the latter invariably went extinct, whereas T. evansi was not significantly affected by the presence of its competitor. This suggests that T. evansi can somehow prevent its competitor from benefiting from the down-regulated plant defence, perhaps by covering it with a profuse web. Indeed, we found that T. urticae had difficulties reaching the leaf surface to feed when the leaf was covered with web produced by T. evansi. Furthermore, T. evansi produced more web when exposed to damage or other cues associated with T. urticae. We suggest that the silken web produced by T. evansi serves to prevent competitors from profiting from down-regulated plant defences.

  6. TCR down-regulation controls virus-specific CD8+ T cell responses

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    Bonefeld, Charlotte Menné; Haks, Mariëlle; Nielsen, Bodil

    2008-01-01

    molecule Bcl-2. This resulted in a 2-fold reduction in the clonal expansion of virus-specific CD8(+) T cells during the acute phase of vesicular stomatitis virus and lymphocytic choriomeningitis virus infections. These results identify an important role of CD3gamma-mediated TCR down-regulation in virus...

  7. Rapid male-specific regulatory divergence and down regulation of spermatogenesis genes in Drosophila species hybrids.

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    Jennifer Ferguson

    Full Text Available In most crosses between closely related species of Drosophila, the male hybrids are sterile and show postmeiotic abnormalities. A series of gene expression studies using genomic approaches have found significant down regulation of postmeiotic spermatogenesis genes in sterile male hybrids. These results have led some to suggest a direct relationship between down regulation in gene expression and hybrid sterility. An alternative explanation to a cause-and-effect relationship between misregulation of gene expression and male sterility is rapid divergence of male sex regulatory elements leading to incompatible interactions in an interspecies hybrid genome. To test the effect of regulatory divergence in spermatogenesis gene expression, we isolated 35 fertile D. simulans strains with D. mauritiana introgressions in either the X, second or third chromosome. We analyzed gene expression in these fertile hybrid strains for a subset of spermatogenesis genes previously reported as significantly under expressed in sterile hybrids relative to D. simulans. We found that fertile autosomal introgressions can cause levels of gene down regulation similar to that of sterile hybrids. We also found that X chromosome heterospecific introgressions cause significantly less gene down regulation than autosomal introgressions. Our results provide evidence that rapid male sex gene regulatory divergence can explain misexpression of spermatogenesis genes in hybrids.

  8. Rapid male-specific regulatory divergence and down regulation of spermatogenesis genes in Drosophila species hybrids.

    Science.gov (United States)

    Ferguson, Jennifer; Gomes, Suzanne; Civetta, Alberto

    2013-01-01

    In most crosses between closely related species of Drosophila, the male hybrids are sterile and show postmeiotic abnormalities. A series of gene expression studies using genomic approaches have found significant down regulation of postmeiotic spermatogenesis genes in sterile male hybrids. These results have led some to suggest a direct relationship between down regulation in gene expression and hybrid sterility. An alternative explanation to a cause-and-effect relationship between misregulation of gene expression and male sterility is rapid divergence of male sex regulatory elements leading to incompatible interactions in an interspecies hybrid genome. To test the effect of regulatory divergence in spermatogenesis gene expression, we isolated 35 fertile D. simulans strains with D. mauritiana introgressions in either the X, second or third chromosome. We analyzed gene expression in these fertile hybrid strains for a subset of spermatogenesis genes previously reported as significantly under expressed in sterile hybrids relative to D. simulans. We found that fertile autosomal introgressions can cause levels of gene down regulation similar to that of sterile hybrids. We also found that X chromosome heterospecific introgressions cause significantly less gene down regulation than autosomal introgressions. Our results provide evidence that rapid male sex gene regulatory divergence can explain misexpression of spermatogenesis genes in hybrids.

  9. Expression of NDRG2 is down-regulated in high-risk adenomas and colorectal carcinoma

    DEFF Research Database (Denmark)

    Lorentzen, Anders; Vogel, Lotte K.; Lewinsky, Rikke H;

    2007-01-01

    BACKGROUND: It has recently been shown that NDRG2 mRNA is down-regulated or undetectable in several human cancers and cancer cell-lines. Although the function of NDRG2 is unknown, high NDRG2 expression correlates with improved prognosis in high-grade gliomas. The aim of this study has been to exa...

  10. Oxytocin ameliorates the immediate myocardial injury in heart transplant through down regulation of the neutrophil dependent myocardial apoptosis

    Directory of Open Access Journals (Sweden)

    F Fadhil Al-Amran

    2014-01-01

    Conclusion: Oxytocin ameliorates myocardial injury in heart transplant through down-regulation the myocardial inflammatory response, reactive oxygen species, and neutrophil-dependant myocardial apoptosis.

  11. Down-regulation of Flt-1 gene expression by the proteasome inhibitor MG262.

    Science.gov (United States)

    Mezquita, J; Mezquita, B; Pau, M; Mezquita, C

    2003-08-15

    The mechanisms involved in the anti-angiogenic actions of the proteasome inhibitors are poorly understood. Here, we report that the gene expression of the VEGF receptor Flt-1 (vascular endothelial growth factor receptor 1) was down-regulated by the reversible proteasome inhibitor MG262 in explant cultures of the developing chicken pecten oculi, a vascular organ consisting of endothelial cells, pericytes, and macrophages. In addition, the inhibitor prevented the induction of Flt-1 by lipopolysaccharide (LPS) in macrophages and down-regulated the expression of Flt-1 after LPS induction. Flt-1 gene expression was also down regulated by MG262 in cultures of human microvascular endothelial cells. Interestingly, a transcript of Flt-1, coding for a soluble form of the receptor (sFlt-1) with anti-angiogenic properties, was not down-regulated in the same extent. Only a small decrease in the expression of VEGF and Ang-2 was detected in the pecten oculi upon inhibition of the proteasome, while no major changes were observed in the expression of other angiogenic molecules, such as KDR or Ang-1. Since recent experiments have demonstrated the importance of anti-Flt-1 therapy in the inhibition of tumor angiogenesis, retinal angiogenesis, arthritis, and atherosclerosis (Luttun et al. [2002]: Nat Med 8:831-840), our observation on down-regulation of Flt-1 in microvascular endothelial cells and macrophages by MG262 supports the postulated role of the proteasome inhibitors as potential candidates for therapeutic modulation of angiogenesis and inflammation. Copyright 2003 Wiley-Liss, Inc.

  12. Down regulation of ribosomal protein mRNAs during neuronal differentiation of human NTERA2 cells.

    Science.gov (United States)

    Bévort, M; Leffers, H

    2000-10-01

    We have analysed the expression of 32 ribosomal protein (RP) mRNAs during retinoic acid induced neuronal differentiation of human NTERA2 cells. Except for a new S27 variant (S27v), all were down regulated both in selectively replated differentiated neurons and the most differentiated continuous cultures, i.e., non-replated cultures. However, the expression profiles of the individual RP mRNAs were different, most (L3, L7, L8, L10, L13, L23a, L27a, L36a, L39, P0, S2, S3, S3a, S4X, S6, S9, S12, S13, S16, S19, S20, S23, and S27a) exhibited a constant down regulation, whereas a few were either initially constant (L11, L32, S8, and S11) or up regulated (L6, L15, L17, L31, and S27y) and then down regulated. The expression of S27v remained elevated in the most differentiated continuous cultures but was down regulated in replated differentiated neurons. The down regulation of RP mRNAs was variable: the expression levels in differentiated replated neurons were between 10% (S3) and 90% (S11) of the levels in undifferentiated cells. The ratio between rRNA and RP mRNA changed during the differentiation; in differentiated neurons there were, on average, about half the number of RP mRNAs per rRNA as compared to undifferentiated cells. The expression profiles of a few translation-related proteins were also determined. EF1alpha1, EF1beta1, and EF1delta were down regulated, whereas the expression of the neuron and muscle specific EF1alpha2 increased. The reduction in the expression of RP mRNAs was coordinated with a reduction in the expression level of the proliferation marker PCNA. The expression levels of most RP mRNAs were lower in purified differentiated post-mitotic neurons than in the most differentiated continuous cultures, despite similar levels of PCNA, suggesting that both the differentiation state and the proliferative status of the cells affect the expression of RP mRNAs.

  13. SAMHD1 is down regulated in lung cancer by methylation and inhibits tumor cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jia-lei [Department of Medical Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032 (China); Lu, Fan-zhen [Department of Thoracic Surgery, The Huadong Hospital, Fudan University, Shanghai 200040 (China); Shen, Xiao-Yong, E-mail: shengxiaoyong_sh@163.com [Department of Thoracic Surgery, The Huadong Hospital, Fudan University, Shanghai 200040 (China); Wu, Yun, E-mail: WuYun_hd@163.com [Department of Thoracic Surgery, The Huadong Hospital, Fudan University, Shanghai 200040 (China); Zhao, Li-ting [Department of Thoracic Surgery, The Huadong Hospital, Fudan University, Shanghai 200040 (China)

    2014-12-12

    Highlights: • SAMHD1 expression level is down regulated in lung adenocarcinoma. • The promoter of SAMHD1 is methylated in lung adenocarcinoma. • Over expression of SAMHD1 inhibits the proliferation of lung cancer cells. - Abstract: The function of dNTP hydrolase SAMHD1 as a viral restriction factor to inhibit the replication of several viruses in human immune cells was well established. However, its regulation and function in lung cancer have been elusive. Here, we report that SAMHD1 is down regulated both on protein and mRNA levels in lung adenocarcinoma compared to adjacent normal tissue. We also found that SAMHD1 promoter is highly methylated in lung adenocarcinoma, which may inhibit its gene expression. Furthermore, over expression of the SAMHD1 reduces dNTP level and inhibits the proliferation of lung tumor cells. These results reveal the regulation and function of SAMHD1 in lung cancer, which is important for the proliferation of lung tumor cells.

  14. TCR down-regulation boosts T-cell-mediated cytotoxicity and protection against poxvirus infections

    DEFF Research Database (Denmark)

    Hansen, Ann Kathrine; Regner, Matthias; Bonefeld, Charlotte Menne

    2011-01-01

    Cytotoxic T (Tc) cells play a key role in the defense against virus infections. Tc cells recognize infected cells via the T-cell receptor (TCR) and subsequently kill the target cells by one or more cytotoxic mechanisms. Induction of the cytotoxic mechanisms is finely tuned by the activation signals...... from the TCR. To determine whether TCR down-regulation affects the cytotoxicity of Tc cells, we studied TCR down-regulation-deficient CD3¿LLAA mice. We found that Tc cells from CD3¿LLAA mice have reduced cytotoxicity due to a specific deficiency in exocytosis of lytic granules. To determine whether......-regulation critically increases Tc cell cytotoxicity and protection against poxvirus infection....

  15. Down Regulation of Gene Expression by the Vaccinia Virus D10 Protein

    OpenAIRE

    Shors, Teri; Keck, James G.; Moss, Bernard

    1999-01-01

    Vaccinia virus genes are expressed in a sequential fashion, suggesting a role for negative as well as positive regulatory mechanisms. A potential down regulator of gene expression was mapped by transfection assays to vaccinia virus open reading frame D10, which encodes a protein with no previously known function. Inhibition was independent of the promoter type used for the reporter gene, indicating that the mechanism did not involve promoter sequence recognition. The inhibition was overcome, ...

  16. A herbivorous mite down-regulates plant defence and produces web to exclude competitors.

    Directory of Open Access Journals (Sweden)

    Renato A Sarmento

    Full Text Available Herbivores may interact with each other through resource competition, but also through their impact on plant defence. We recently found that the spider mite Tetranychus evansi down-regulates plant defences in tomato plants, resulting in higher rates of oviposition and population growth on previously attacked than on unattacked leaves. The danger of such down-regulation is that attacked plants could become a more profitable resource for heterospecific competitors, such as the two-spotted spider mite Tetranychus urticae. Indeed, T. urticae had an almost 2-fold higher rate of oviposition on leaf discs on which T. evansi had fed previously. In contrast, induction of direct plant defences by T. urticae resulted in decreased oviposition by T. evansi. Hence, both herbivores affect each other through induced plant responses. However, when populations of T. evansi and T. urticae competed on the same plants, populations of the latter invariably went extinct, whereas T. evansi was not significantly affected by the presence of its competitor. This suggests that T. evansi can somehow prevent its competitor from benefiting from the down-regulated plant defence, perhaps by covering it with a profuse web. Indeed, we found that T. urticae had difficulties reaching the leaf surface to feed when the leaf was covered with web produced by T. evansi. Furthermore, T. evansi produced more web when exposed to damage or other cues associated with T. urticae. We suggest that the silken web produced by T. evansi serves to prevent competitors from profiting from down-regulated plant defences.

  17. Apoptosis regulators Fau and Bcl-G are down-regulated in prostate cancer.

    Science.gov (United States)

    Pickard, Mark R; Edwards, Sandra E; Cooper, Colin S; Williams, Gwyn T

    2010-10-01

    The molecular control of cell death through apoptosis is compromised in prostate cancer cells, resulting in inappropriate cell survival and resistance to cytotoxic therapy. Reduced expression of the functionally connected apoptosis-regulators and candidate tumor suppressors Fau and Bcl-G has recently been implicated in oncogenesis in other tissues. The present study examines the hypothesis that reduced expression of these genes may be involved in prostate cancer. Fau and Bcl-G mRNA levels were determined by real time RT-PCR in two independent prostate tissue collections. In experiments in vitro, Fau and Bcl-G levels in prostate cancer cell lines were reduced using RNA interference and the effects on sensitivity to UVC irradiation were determined. Fau and Bcl-G mRNA levels were both lower in prostate cancer tissue than in normal prostate and Benign Prostate Hyperplasia. Active down-regulation of Fau and Bcl-G expression in vitro resulted in decreased sensitivity to UVC-induced cytotoxicity. Simultaneous down-regulation of Fau and Bcl-G produced a decrease in sensitivity which was similar to either gene alone. Fau and Bcl-G mRNA levels are both decreased in prostate cancer. In prostate cancer cell lines in vitro such down-regulation results in reduced sensitivity to UVC-induced cytotoxicity, consistent with the putative roles of these genes as candidate prostate tumor suppressors. The absence of an additive effect when Fau and Bcl-G were down-regulated simultaneously is consistent with the two genes acting in the same apoptosis pathway, for example, with the pro-apoptotic effects of Fau being mediated through modulation of Bcl-G. (c) 2010 Wiley-Liss, Inc.

  18. Down-regulated miR-9 and miR-433 in human gastric carcinoma

    Directory of Open Access Journals (Sweden)

    Nie Na

    2009-06-01

    Full Text Available Abstract Background MircoRNAs(miRNAs are short, endogenously non-coding RNAs. The abnormal expression of miRNAs may be valuable for the diagnosis and treatment of tumors. Methods To screening the special miRNAs in gastric carcinoma, expression level of miRNAs in gastric carcinoma and normal gaster samples were detected by miRNA gene chip. Then, the expressions of miR-9 and miR-433 in gastric carcinoma tissue and SGC7901 cell line were validated by qRT-PCR. GRB2 and RAB34, targets of miR-433 and miR-9 respectively, were detected by Western blot. Results We found 19 miRNAs and 7 miRNAs were down-regulated and up-regulated respectively. Compared with normal gaster samples, our data showed that miR-9 and miR-433 were down-regulated in gastric carcinoma. Meanwhile, we also found that miR-433 and miR-9 regulated the expression levels of GRB2 and RAB34 respectively. Conclusion Our data show miR-9 and miR-433 was down-regulated in gastric carcinoma. The targets of miR-433 and miR-9 were tumor-associated proteins GRB2 and RAB34 respectively. This result provided the related information of miRNAs in gastric carcinoma.

  19. Down-regulation of stathmin expression is required for megakaryocyte maturation and platelet production.

    Science.gov (United States)

    Iancu-Rubin, Camelia; Gajzer, David; Tripodi, Joseph; Najfeld, Vesna; Gordon, Ronald E; Hoffman, Ronald; Atweh, George F

    2011-04-28

    The final stages of of megakaryocyte (MK) maturation involve a series of steps, including polyploidization and proplatelet formation. Although these processes are highly dependent on dynamic changes in the microtubule (MT) cytoskeleton, the mechanisms responsible for regulation of MTs in MKs remain poorly defined. Stathmin is a highly conserved MT-regulatory protein that has been suggested to play a role in MK differentiation of human leukemic cell lines. However, previous studies defining this relationship have reached contradictory conclusions. In this study, we addressed this controversy and investigated the role of stathmin in primary human MKs. To explore the importance of stathmin down-regulation during megakaryocytopoiesis, we used a lentiviral-mediated gene delivery system to prevent physiologic down-regulation of stathmin in primary MKs. We demonstrated that sustained expression of constitutively active stathmin delayed cytoplasmic maturation (ie, glycoprotein GPIb and platelet factor 4 expression) and reduced the ability of MKs to achieve high levels of ploidy. Moreover, platelet production was impaired in MKs in which down-regulation of stathmin expression was prevented. These studies indicate that suppression of stathmin is biologically important for MK maturation and platelet production and support the importance of MT regulation during the final stages of thrombopoiesis.

  20. TCR Down-Regulation Controls Virus-Specific CD8+ T Cell Responses

    DEFF Research Database (Denmark)

    Bonefeld, Charlotte Menné; Haks, Mariëlle; Nielsen, Bodil

    2008-01-01

    The CD3gamma di-leucine-based motif plays a central role in TCR down-regulation. However, little is understood about the role of the CD3gamma di-leucine-based motif in physiological T cell responses. In this study, we show that the expansion in numbers of virus-specific CD8(+) T cells is impaired...... in mice with a mutated CD3gamma di-leucine-based motif. The CD3gamma mutation did not impair early TCR signaling, nor did it compromise recruitment or proliferation of virus-specific T cells, but it increased the apoptosis rate of the activated T cells by increasing down-regulation of the antiapoptotic...... molecule Bcl-2. This resulted in a 2-fold reduction in the clonal expansion of virus-specific CD8(+) T cells during the acute phase of vesicular stomatitis virus and lymphocytic choriomeningitis virus infections. These results identify an important role of CD3gamma-mediated TCR down-regulation in virus...

  1. Pathological implications of Cx43 down-regulation in human colon cancer.

    Science.gov (United States)

    Ismail, Rehana; Rashid, Rabiya; Andrabi, Khurshid; Parray, Fazl Q; Besina, Syed; Shah, Mohd Amin; Ul Hussain, Mahboob

    2014-01-01

    Connexin 43 is an important gap junction protein in vertebrates and is known for its tumor suppressive properties. Cx43 is abundantly expressed in the human intestinal epithelial cells and muscularis mucosae. To explore the role of Cx43 in the genesis of human colon cancer, we performed the expression analysis of Cx43 in 80 cases of histopathologically confirmed and clinically diagnosed human colon cancer samples and adjacent control tissue and assessed correlations with clinicopathological variables. Western blotting using anti-Cx43 antibody indicated that the expression of Cx43 was significantly down regulated (75%) in the cancer samples as compared to the adjacent control samples. Moreover, immunohistochemical analysis of the tissue samples confirmed the down regulation of the Cx43 in the intestinal epithelial cells. Cx43 down regulation showed significant association (pcancer. Our data demonstrated that loss of Cx43 may be an important event in colon carcinogenesis and tumor progression, providing significant insights about the tumor suppressive properties of the Cx43 and its potential as a diagnostic marker for colon cancer.

  2. Down-regulation of rat kidney calcitonin receptors by salmon calcitonin infusion evidence by autoradiography

    Energy Technology Data Exchange (ETDEWEB)

    Bouizar, Z.; Rostene, W.H.; Milhaud, G.

    1987-08-01

    In treating age-related osteoporosis and Paget disease of bone, it is of major importance to avoid an escape phenomenon that would reduce effectiveness of the treatment. The factors involved in the loss of therapeutic efficacy with administration of large pharmacological doses of the hormone require special consideration. Down-regulation of the hormone receptors could account for the escape phenomenon. Specific binding sites for salmon calcitonin (sCT) were characterized and localized by autoradiography on rat kidney sections incubated with /sup 125/I-labeled sCT. Autoradiograms demonstrated a heterogeneous distribution of /sup 125/I-labeled sCT binding sites in the kidney, with high densities in both the superficial layer of the cortex and the outer medulla. Infusion of different doses of unlabeled sCT by means of Alzet minipumps for 7 days produced rapid changes in plasma calcium, phosphate, and magnesium levels, which were no longer observed after 2 or 6 days of treatment. Besides, infusion of high doses of sCT induced down-regulation of renal sCT binding sites located mainly in the medulla, where calcitonin (CT) has been shown to exert it physiological effects on water and ion reabsorption. These data suggest that the resistance to high doses of sCT often observed during long-term treatment of patients may be the consequence of not only bone-cell desensitization but also down-regulation of CT-sensitive kidney receptor sites.

  3. Hepatitis B virus down-regulates expressions of MHC class I molecules on hepatoplastoma cell line.

    Science.gov (United States)

    Chen, Yongyan; Cheng, Min; Tian, Zhigang

    2006-10-01

    Chronic HBV infection is associated with a 100-fold high risk of developing hepatocellular carcinoma. Tumor recognition is of the most importance during the immune surveillance process that prevents cancer development in humans. In the present study, the expressions of MHC class I molecules on hepatoplastoma cell line HepG2.2.15 were investigated to indicate the possible effects of HBV on the immune recognition during HBV-associated hepatocellular carcinoma. It was found that the expressions of MHC class I molecules HLA-ABC, HLA-E and MICA were much lower in HepG2.2.15 cells compared with HepG2 cells. The expressing HBV in human hepatoplastoma cell line significantly down-regulated the expressions of MHC class I molecules. Additionally, it was observed that in murine chronic HBsAg carriers the expression of classical MHC-I molecule on hepatocytes was down-regulated. These results demonstrated that HBV might affect the immune recognition during HBV-associated hepatocellular carcinoma such as the recognition of CD8+ T, NK-CTL and NK cells and prevent the immune surveillance against tumors. However, the effects of HBV down-regulation of MHC class I molecules on the target cells in vivo should be further studied.

  4. CHIP mediates down-regulation of nucleobindin-1 in preosteoblast cell line models.

    Science.gov (United States)

    Xue, Fuying; Wu, Yanping; Zhao, Xinghui; Zhao, Taoran; Meng, Ying; Zhao, Zhanzhong; Guo, Junwei; Chen, Wei

    2016-08-01

    Nucleobindin-1 (NUCB1), also known as Calnuc, is a highly conserved, multifunctional protein widely expressed in tissues and cells. It contains two EF-hand motifs which have been shown to play a crucial role in binding Ca(2+) ions. In this study, we applied comparative two-dimensional gel electrophoresis to characterize differentially expressed proteins in HA-CHIP over-expressed and endogenous CHIP depleted MC3T3-E1 stable cell lines, identifying NUCB1 as a novel CHIP/Stub1 targeted protein. NUCB1 interacts with and is down-regulated by CHIP by both proteasomal dependent and independent pathways, suggesting that CHIP-mediated down-regulation of nucleobindin-1 might play a role in osteoblast differentiation. The chaperone protein Hsp70 was found to be important for CHIP and NUCB1 interaction as well as CHIP-mediated NUCB1 down-regulation. Our findings provide new insights into understanding the stability regulation of NUCB1.

  5. Down-regulation of lignin biosynthesis in transgenic Leucaena leucocephala harboring O-methyltransferase gene.

    Science.gov (United States)

    Rastogi, Smita; Dwivedi, Upendra Nath

    2006-01-01

    In the present study, a 0.47 kb OMT gene construct from aspen, encoding for an enzyme O-methyltransferase (OMT, EC 2.1.1.6), in antisense orientation was used to down-regulate lignin biosynthesis in Leucaena leucocephala. The plants were transformed with Agrobacterium tumefaciens strain harboring the antisense gene, and the transformation was confirmed by PCR amplification of the npt II gene. The integration of a heterologous antisense OMT gene construct in transformed plants led to a maximum of 60% reduction in OMT activity relative to control. The evaluation of total lignin content by the Klason method revealed a maximum of 28% reduction. Histochemical analyses of stem sections depicted a reduction in lignin content and normal xylem development. The results also suggested a probable increase in aldehyde levels and a decrease in syringyl units. Lignin down-regulation was accompanied by an increase in methanol soluble phenolics to an extent that had no impact on wood discoloration, and the plants displayed a normal phenotype. Concomitantly, an increase of up to 9% in cellulose content was also observed. Upon alkali extraction, modified lignin was more extractable as evident from reduced Klason lignin in saponified residue and increased alkali soluble phenolics. The results together suggested that the extent of down-regulation of OMT activity achieved may lead to quality amelioration of Leucaena with respect to its applicability in pulp and paper manufacture as well as nutritive and easily digestible forage production.

  6. Down-Regulation of miR-3928 Promoted Osteosarcoma Growth

    Directory of Open Access Journals (Sweden)

    Haidong Xu

    2014-05-01

    Full Text Available Background: Osteosarcoma is the most common primary bone malignancy in children and young adults. Most failures of osteosarcoma treatment were due to resistance to chemotherapy. Development of new therapy required elucidation underlying molecular mechanism. Many miRNAs have been proved to be involved in the pathogenesis of osteosarcoma. Methods: MiR-3928 expression level was assayed by qRT-PCR. MiRNA mimics or ASO were transfected for up-regulation or down-regulation of miR-3928 expression. Cell proliferation was assayed by formazan test. Apoptosis and cell cycle were assayed by FACS. MiR-3928 targeted genes were predicated by bioinformatics algorithm (TargetScanHuman. The correlation between targeted gene and miR-3928 was analyzed by Pearson's correlation coefficient analysis. Results: MiR-3928 was down-regulated in osteosarcoma tissues. Over-expression of miR-3928 inhibited tumor growth, induced cell apoptosis, increased the percent of cells in G1 phrase and decreased the percent of cells in S phrase. Down-regulation of miR-3928 promoted cell proliferation. ERBB3, IL-6R and CDK6 may be the targeted genes of miR-3928. Conclusions: Down-expression of miR-3928 in osteosarcoma promoted tumor growth by targeting ERBB3, IL-6R and CDK6. MiR-3928 may be a potential therapy target worth further investigation.

  7. Adipose Genes Down-Regulated During Experimental Endotoxemia Are Also Suppressed in Obesity

    Science.gov (United States)

    Hinkle, Christine C.; Haris, Lalarukh; Shah, Rhia; Mehta, Nehal N.; Putt, Mary E.; Reilly, Muredach P.

    2012-01-01

    Context: Adipose inflammation is a crucial link between obesity and its metabolic complications. Human experimental endotoxemia is a controlled model for the study of inflammatory cardiometabolic responses in vivo. Objective: We hypothesized that adipose genes down-regulated during endotoxemia would approximate changes observed with obesity-related inflammation and reveal novel candidates in cardiometabolic disease. Design, Subjects, and Intervention: Healthy volunteers (n = 14) underwent a 3 ng/kg endotoxin challenge; adipose biopsies were taken at 0, 4, 12, and 24 h for mRNA microarray. A priority list of highly down-regulated and biologically relevant genes was validated by RT-PCR in an independent sample of adipose from healthy subjects (n = 7) undergoing a subclinical 0.6 ng/kg endotoxemia protocol. Expression of validated genes was screened in adipose of lean and severely obese individuals (n = 11 per group), and cellular source was probed in cultured adipocytes and macrophages. Results: Endotoxemia (3 ng/kg) suppressed expression of 353 genes (to <67% of baseline; P < 1 × 10−5) of which 68 candidates were prioritized for validation. In low-dose (0.6 ng/kg) endotoxin validation, 22 (32%) of these 68 genes were confirmed. Functional classification revealed that many of these genes are involved in cell development and differentiation. Of validated genes, 59% (13 of 22) were down-regulated more than 1.5-fold in primary human adipocytes after treatment with endotoxin. In human macrophages, 59% (13 of 22) were up-regulated during differentiation to inflammatory M1 macrophages whereas 64% (14 of 22) were down-regulated during transition to homeostatic M2 macrophages. Finally, in obese vs. lean adipose, 91% (20 of 22) tended to have reduced expression (χ2 = 10.72, P < 0.01) with 50% (11 of 22) reaching P < 0.05 (χ2 = 9.28, P < 0.01). Conclusions: Exploration of down-regulated mRNA in adipose during human endotoxemia revealed suppression of genes involved in

  8. hZIP1 zinc uptake transporter down regulation and zinc depletion in prostate cancer

    Directory of Open Access Journals (Sweden)

    Kajdacsy-Balla André

    2005-09-01

    Full Text Available Abstract Background The genetic and molecular mechanisms responsible for and associated with the development and progression of prostate malignancy are largely unidentified. The peripheral zone is the major region of the human prostate gland where malignancy develops. The normal peripheral zone glandular epithelium has the unique function of accumulating high levels of zinc. In contrast, the ability to accumulate zinc is lost in the malignant cells. The lost ability of the neoplastic epithelial cells to accumulate zinc is a consistent factor in their development of malignancy. Recent studies identified ZIP1 (SLC39A1 as an important zinc transporter involved in zinc accumulation in prostate cells. Therefore, we investigated the possibility that down-regulation of hZIP1 gene expression might be involved in the inability of malignant prostate cells to accumulate zinc. To address this issue, the expression of hZIP1 and the depletion of zinc in malignant versus non-malignant prostate glands of prostate cancer tissue sections were analyzed. hZIP1 expression was also determined in malignant prostate cell lines. Results hZIP1 gene expression, ZIP1 transporter protein, and cellular zinc were prominent in normal peripheral zone glandular epithelium and in benign hyperplastic glands (also zinc accumulating glands. In contrast, hZIP1 gene expression and transporter protein were markedly down-regulated and zinc was depleted in adenocarcinomatous glands and in prostate intra-epithelial neoplastic foci (PIN. These changes occur early in malignancy and are sustained during its progression in the peripheral zone. hZIP1 is also expressed in the malignant cell lines LNCaP, PC-3, DU-145; and in the nonmalignant cell lines HPr-1 and BPH-1. Conclusion The studies clearly establish that hZIP1 gene expression is down regulated and zinc is depleted in adenocarcinomatous glands. The fact that all the malignant cell lines express hZIP1 indicates that the down-regulation

  9. Modified super-long down-regulation protocol improves fertilization and pregnancy in patients with poor ovarian responses

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hui-juan; SONG Xue-ru; L(U) Rui; XUE Feng-xia

    2012-01-01

    Background The successful end-point of in vitro fertilization (IVF) treatment is for a woman to give live birth.This outcome is based on various factors including adequate number of retrieved eggs.Failure to recruit adequate follicles,from which the eggs are retrieved,is called a "poor response".How to improve the clinical pregnancy rates of poor responders was one of the tough problems for IVF.Methods The study involved 51 patients who responded poorly to high dose gonadotropin treatment in their previous cycles at our reproductive center,between April 2010 and February 2012.The previous cycle (group A) received routine long protocol; the subsequent cycle (group B) received modified super-long down-regulation protocol.The primary outcome of the study was the number of oocytes fertilized.The increase in the pregnancy rate was the secondary outcome.Differences between the groups were assessed by using Student's t test and x2 test where appropriate.Results The patients' average age was (36.64±3.85) years.The mean duration of ovarian stimulation cycles of the group A patients was longer than those of the group B patients.The total dose of follicle-stimulating hormone (FSH) was significantly lower in the subsequent cycle.The peak value of serum estradiol on human chorionic gonadotrophin (hCG) day was lower in group A as compared with group B.The number of metaphase Ⅱ oocytes recovered was significantly higher in group B.The cleavage rate in group A was significantly lower than in group B,49 patients in group B reached embryo transfer stage,while 46 patients in group A reached this stage.Patients in group B received significantly more embryos per transfer as compared with group A.More pregnancies and more clinical pregnancies with fetal heart activity were achieved in group B.Conclusions This comparative trial shows that poor responder women undergoing repeated assisted reproduction treatment using modified super-long down-regulation protocol achieve more oocytes

  10. Down regulation of sodium channels in the central nervous system of hibernating snails.

    Science.gov (United States)

    Kiss, T; Battonyai, I; Pirger, Z

    2014-05-28

    Hibernation, as behavior, is an evolutionary mode of adaptation of animal species to unfavorable environmental conditions. It is generally characterized by suppressed metabolism, which also includes down regulation of the energy consuming ion-channel functioning. Experimental data regarding decreased ion-channel function are scarce. Therefore, our goal was to study the possible down regulation of voltage-gated sodium channel (NaV) subtypes in the neurons of hibernating snails. Our immunohistochemical experiments revealed that the expression of NaV1.8-like channels in the central nervous system was substantially down regulated in hibernating animals. In contrast to NaV1.8-like, the NaV1.9-like channels were present in neurons independently from hibernating and non-hibernating states. Our western blot data supported the immunohistochemical results according to which the band of the NaV1.8-like channel protein was less intensively labeled in the homogenate of the hibernating snails. The NaV1.9-like immunoreactivity was equally present both in hibernating and active snails. Micro-electrophysiological experiments show that in hibernating snails both NaV1.8- and NaV1.9-like currents are substantially decreased compared to that of the active snails. The contradictory electrophysiological and immunohistochemical or western blot data suggest that the molecular mechanisms of the "channel arrest" could be different in diverse NaV channel subtypes. Climate changes will affect temperature extremes and a question is how different species beyond their physiological tolerance will or able to adapt to changing environment. Hibernation is an important mode of adaptation to extreme climatic variations, and pursuant to this the present results may contribute to the study of the behavioral ecology.

  11. [BMMSC from blastic phase CML down-regulate leukemia cell apoptosis].

    Science.gov (United States)

    Wang, Ying; Han, Yu-Xiang; Niu, Zhi-Yun; Wang, Xing-Zhe; Hua, Huan; Shang, Yin-Tao; Wang, Fu-Xu; Zhang, Xue-Jun; Luo, Jian-Min

    2014-10-01

    The purpose of this study was to investigate the effect of bone marrow mesenchymal stem cells (BMMSC) from patients with chronic myeloid leukemia (CML) in blastic phase (Bp) on K562 cells and the primary CML-Bp cells, and to explore its potential mechanisms. K562 cells and primary CML-Bp cells were co-cultured with BMMSC of different groups; the cell proliferation was detected by MTT method, the cell apoptosis rate and mitochondrial membrane potential were measured by flow cytometry, the expression levels of Caspase-8, Caspase-9, and activated Caspase-3 in cells were measured by Western blot. The results showed that the CML-Bp BMMSC could enhance the survival rate of K562 cells treated with adviamycin (ADM) and display protective effect on K562 cells and primary CML-Bp mononuctear cells, inhibited ADM-induced leukimia cell apoptosis (P < 0.05); as compared with CML-chronic phase (CML-Cp) BMMSC and normal BMMSC, the CML-Bp BMMSC showed the highest protective effect on leukemic cells, the mitochondrial membrane potential of co-cultured cells slightly droped (P < 0.05). In the CML-Bp BMMSC cultured with K562 cells, the expression level of caspase-3 was more down-regulated than that in K562 alone plus ADM group, while the expression of caspase-9 significantly increased (P < 0.05). It is concluded that the CML-Bp BMMSC down-regulates ADM-induced leukemia cell appoptosis, its mechanism may relate with the inhibition of mitochondrial membrane potential drop, the stabilization of unactive expression of caspase-9 and down-regulation of caspase-3 expression.

  12. Down-regulation of BK channel expression in the pilocarpine model of temporal lobe epilepsy.

    Science.gov (United States)

    Pacheco Otalora, Luis F; Hernandez, Eder F; Arshadmansab, Massoud F; Francisco, Sebastian; Willis, Michael; Ermolinsky, Boris; Zarei, Masoud; Knaus, Hans-Guenther; Garrido-Sanabria, Emilio R

    2008-03-20

    In the hippocampus, BK channels are preferentially localized in presynaptic glutamatergic terminals including mossy fibers where they are thought to play an important role regulating excessive glutamate release during hyperactive states. Large conductance calcium-activated potassium channels (BK, MaxiK, Slo) have recently been implicated in the pathogenesis of genetic epilepsy. However, the role of BK channels in acquired mesial temporal lobe epilepsy (MTLE) remains unknown. Here we used immunohistochemistry, laser scanning confocal microscopy (LSCM), Western immunoblotting and RT-PCR to investigate the expression pattern of the alpha-pore-forming subunit of BK channels in the hippocampus and cortex of chronically epileptic rats obtained by the pilocarpine model of MTLE. All epileptic rats experiencing recurrent spontaneous seizures exhibited a significant down-regulation of BK channel immunostaining in the mossy fibers at the hilus and stratum lucidum of the CA3 area. Quantitative analysis of immunofluorescence signals by LSCM revealed a significant 47% reduction in BK channel immunofluorescent signals in epileptic rats when compared to age-matched non-epileptic control rats. These data correlate with a similar reduction in BK channel protein levels and transcripts in the cortex and hippocampus. Our data indicate a seizure-related down-regulation of BK channels in chronically epileptic rats. Further functional assays are necessary to determine whether altered BK channel expression is an acquired channelopathy or a compensatory mechanism affecting the network excitability in MTLE. Moreover, seizure-mediated BK down-regulation may disturb neuronal excitability and presynaptic control at glutamatergic terminals triggering exaggerated glutamate release and seizures.

  13. Protein kinase B/Akt1 inhibits autophagy by down-regulating UVRAG expression

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Wonseok; Ju, Ji-hyun; Lee, Kyung-min; Nam, KeeSoo; Oh, Sunhwa [Department of Life Science, College of Natural Science, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Shin, Incheol, E-mail: incheol@hanyang.ac.kr [Department of Life Science, College of Natural Science, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of)

    2013-02-01

    Autophagy, or autophagocytosis, is a selective intracellular degradative process involving the cell's own lysosomal apparatus. An essential component in cell development, homeostasis, repair and resistance to stress, autophagy may result in either cell death or survival. The targeted region of the cell is sequestered within a membrane structure, the autophagosome, for regulation of the catabolic process. A key factor in both autophagosome formation and autophagosome maturation is a protein encoded by the ultraviolet irradiation resistance-associated gene (UVRAG). Conversely, the serine/threonine-specific protein kinase B (PKB, also known as Akt), which regulates survival in various cancers, inhibits autophagy through mTOR activation. We found that Akt1 may also directly inhibit autophagy by down-regulating UVRAG both in a 293T transient transfection system and breast cancer cells stably expressing Akt1. The UVRAG with mutations at putative Akt1-phosphorylation sites were still inhibited by Akt1, and dominant-negative Akt1 also inhibited UVRAG expression, suggesting that Akt1 down-regulates UVRAG by a kinase activity-independent mechanism. We showed that Akt1 overexpression in MDA-MB-231 breast cancer cells down-regulated UVRAG transcription. Cells over-expressing Akt1 were more resistant than control cells to ultraviolet light-induced autophagy and exhibited the associated reduction in cell viability. Levels of the autophagosome indicator protein LC3B-II and mRFP-GFP-LC3 were reduced in cells that over-expressing Akt1. Inhibiting Akt1 by siRNA or reintroducing UVRAG gene rescued the level of LC3B-II in UV-irradiation. Altogether, these data suggest that Akt1 may inhibit autophagy by decreasing UVRAG expression, which also sensitizes cancer cells to UV irradiation.

  14. Keratin 8 absence down-regulates colonocyte HMGCS2 and modulates colonic ketogenesis and energy metabolism.

    Science.gov (United States)

    Helenius, Terhi O; Misiorek, Julia O; Nyström, Joel H; Fortelius, Lina E; Habtezion, Aida; Liao, Jian; Asghar, M Nadeem; Zhang, Haiyan; Azhar, Salman; Omary, M Bishr; Toivola, Diana M

    2015-06-15

    Simple-type epithelial keratins are intermediate filament proteins important for mechanical stability and stress protection. Keratin mutations predispose to human liver disorders, whereas their roles in intestinal diseases are unclear. Absence of keratin 8 (K8) in mice leads to colitis, decreased Na/Cl uptake, protein mistargeting, and longer crypts, suggesting that keratins contribute to intestinal homeostasis. We describe the rate-limiting enzyme of the ketogenic energy metabolism pathway, mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2), as a major down-regulated protein in the K8-knockout (K8(-/-)) colon. K8 absence leads to decreased quantity and activity of HMGCS2, and the down-regulation is not dependent on the inflammatory state, since HMGCS2 is not decreased in dextran sulfate sodium-induced colitis. Peroxisome proliferator-activated receptor α, a transcriptional activator of HMGCS2, is similarly down-regulated. Ketogenic conditions-starvation or ketogenic diet-increase K8(+/+) HMGCS2, whereas this response is blunted in the K8(-/-) colon. Microbiota-produced short-chain fatty acids (SCFAs), substrates in the colonic ketone body pathway, are increased in stool, which correlates with decreased levels of their main transporter, monocarboxylate transporter 1 (MCT1). Microbial populations, including the main SCFA-butyrate producers in the colon, were not altered in the K8(-/-). In summary, the regulation of the SCFA-MCT1-HMGCS2 axis is disrupted in K8(-/-) colonocytes, suggesting a role for keratins in colonocyte energy metabolism and homeostasis.

  15. Male sex interspecies divergence and down regulation of expression of spermatogenesis genes in Drosophila sterile hybrids.

    Science.gov (United States)

    Sundararajan, Vignesh; Civetta, Alberto

    2011-01-01

    Male sex genes have shown a pattern of rapid interspecies divergence at both the coding and gene expression level. A common outcome from crosses between closely-related species is hybrid male sterility. Phenotypic and genetic studies in Drosophila sterile hybrid males have shown that spermatogenesis arrest is postmeiotic with few exceptions, and that most misregulated genes are involved in late stages of spermatogenesis. Comparative studies of gene regulation in sterile hybrids and parental species have mainly used microarrays providing a whole genome representation of regulatory problems in sterile hybrids. Real-time PCR studies can reject or reveal differences not observed in microarray assays. Moreover, differences in gene expression between samples can be dependant on the source of RNA (e.g., whole body vs. tissue). Here we survey expression in D. simulans, D. mauritiana and both intra and interspecies hybrids using a real-time PCR approach for eight genes expressed at the four main stages of sperm development. We find that all genes show a trend toward under expression in the testes of sterile hybrids relative to parental species with only the two proliferation genes (bam and bgcn) and the two meiotic class genes (can and sa) showing significant down regulation. The observed pattern of down regulation for the genes tested can not fully explain hybrid male sterility. We discuss the down regulation of spermatogenesis genes in hybrids between closely-related species within the contest of rapid divergence experienced by the male genome, hybrid sterility and possible allometric changes due to subtle testes-specific developmental abnormalities.

  16. Down-regulation of lipoxygenase gene reduces degradation of carotenoids of golden rice during storage.

    Science.gov (United States)

    Gayen, Dipak; Ali, Nusrat; Sarkar, Sailendra Nath; Datta, Swapan K; Datta, Karabi

    2015-07-01

    Down-regulation of lipoxygenase enzyme activity reduces degradation of carotenoids of bio-fortified rice seeds which would be an effective tool to reduce huge post-harvest and economic losses of bio-fortified rice seeds during storage. Bio-fortified provitamin A-enriched rice line (golden rice) expressing higher amounts of β-carotene in the rice endosperm provides vitamin A for human health. However, it is already reported that degradation of carotenoids during storage is a major problem. The gene responsible for degradation of carotenoids during storage has remained largely unexplored till now. In our previous study, it has been shown that r9-LOX1 gene is responsible for rice seed quality deterioration. In the present study, we attempted to investigate if r9-LOX1 gene has any role in degradation of carotenoids in rice seeds during storage. To establish our hypothesis, the endogenous lipoxygenase (LOX) activity of high-carotenoid golden indica rice seed was silenced by RNAi technology using aleurone layer and embryo-specific Oleosin-18 promoter. To check the storage stability, LOX enzyme down-regulated high-carotenoid T3 transgenic rice seeds were subjected to artificial aging treatment. The results obtained from biochemical assays (MDA, ROS) also indicated that after artificial aging, the deterioration of LOX-RNAi lines was considerably lower compared to β-carotene-enriched transgenic rice which had higher LOX activity in comparison to LOX-RNAi lines. Furthermore, it was also observed by HPLC analysis that down-regulation of LOX gene activity decreases co-oxidation of β-carotene in LOX-RNAi golden rice seeds as compared to the β-carotene-enriched transgenic rice, after artificial aging treatment. Therefore, our study substantially establishes and verifies that LOX is a key enzyme for catalyzing co-oxidation of β-carotene and has a significant role in deterioration of β-carotene levels in the carotenoid-enriched golden rice.

  17. Ultrafine carbon particles down-regulate CYP1B1 expression in human monocytes

    Directory of Open Access Journals (Sweden)

    Ziegler-Heitbrock Loems

    2009-10-01

    Full Text Available Abstract Background Cytochrome P450 monoxygenases play an important role in the defence against inhaled toxic compounds and in metabolizing a wide range of xenobiotics and environmental contaminants. In ambient aerosol the ultrafine particle fraction which penetrates deeply into the lungs is considered to be a major factor for adverse health effects. The cells mainly affected by inhaled particles are lung epithelial cells and cells of the monocyte/macrophage lineage. Results In this study we have analyzed the effect of a mixture of fine TiO2 and ultrafine carbon black Printex 90 particles (P90 on the expression of cytochrome P450 1B1 (CYP1B1 in human monocytes, macrophages, bronchial epithelial cells and epithelial cell lines. CYP1B1 expression is strongly down-regulated by P90 in monocytes with a maximum after P90 treatment for 3 h while fine and ultrafine TiO2 had no effect. CYP1B1 was down-regulated up to 130-fold and in addition CYP1A1 mRNA was decreased 13-fold. In vitro generated monocyte-derived macrophages (MDM, epithelial cell lines, and primary bronchial epithelial cells also showed reduced CYP1B1 mRNA levels. Benzo[a]pyrene (BaP is inducing CYB1B1 but ultrafine P90 can still down-regulate gene expression at 0.1 μM of BaP. The P90-induced reduction of CYP1B1 was also demonstrated at the protein level using Western blot analysis. Conclusion These data suggest that the P90-induced reduction of CYP gene expression may interfere with the activation and/or detoxification capabilities of inhaled toxic compounds.

  18. Rapamycin up-regulates triglycerides in hepatocytes by down-regulating Prox1.

    Science.gov (United States)

    Kwon, Sora; Jeon, Ji-Sook; Kim, Su Bin; Hong, Young-Kwon; Ahn, Curie; Sung, Jung-Suk; Choi, Inho

    2016-02-27

    Although the prolonged use of rapamycin may cause unwanted side effects such as hyperlipidemia, the underlying mechanism remains unknown. Prox1 is a transcription factor responsible for the development of several tissues including lymphatics and liver. There is growing evidences that Prox1 participates in metabolism in addition to embryogenesis. However, whether Prox1 is directly related to lipid metabolism is currently unknown. HepG2 human hepatoma cells were treated with rapamycin and total lipids were analyzed by thin layer chromatography. The effect of rapamycin on the expression of Prox1 was determined by western blotting. To investigate the role of Prox1 in triglycerides regulation, siRNA and overexpression system were employed. Rapamycin was injected into mice for 2 weeks and total lipids and proteins in liver were measured by thin layer chromatography and western blot analysis, respectively. Rapamycin up-regulated the amount of triglyceride and down-regulated the expression of Prox1 in HepG2 cells by reducing protein half-life but did not affect its transcript. The loss-of-function of Prox1 was coincident with the increase of triglycerides in HepG2 cells treated with rapamycin. The up-regulation of triglycerides by rapamycin in HepG2 cells reverted to normal levels by the compensation of Prox1 using the overexpression system. Rapamycin also down-regulated Prox1 expression but increased triglycerides in mouse liver. This study suggests that rapamycin can increase the amount of triglycerides by down-regulating Prox1 expression in hepatocytes, which means that the mammalian target of rapamycin (mTOR) signaling is important for the regulation of triglycerides by maintaining Prox1 expression.

  19. Ciliary genes are down-regulated in bronchial tissue of primary ciliary dyskinesia patients.

    Directory of Open Access Journals (Sweden)

    Maciej Geremek

    Full Text Available Primary ciliary dyskinesia (PCD is a rare, genetically heterogeneous disease characterized by recurrent respiratory tract infections, sinusitis, bronchiectasis and male infertility. The pulmonary phenotype in PCD is caused by the impaired motility of cilia in the respiratory epithelium, due to ultrastructural defects of these organelles. We hypothesized that defects of multi-protein ciliary complexes should be reflected by gene expression changes in the respiratory epithelium. We have previously found that large group of genes functionally related to cilia share highly correlated expression pattern in PCD bronchial tissue. Here we performed an explorative analysis of differential gene expression in the bronchial tissue from six PCD patients and nine non-PCD controls, using Illumina HumanRef-12 Whole Genome BeadChips. We observed 1323 genes with at least 2-fold difference in the mean expression level between the two groups (t-test p-value <0.05. Annotation analysis showed that the genes down-regulated in PCD biopsies (602 were significantly enriched for terms related to cilia, whereas the up-regulated genes (721 were significantly enriched for terms related to cell cycle and mitosis. We assembled a list of human genes predicted to encode ciliary proteins, components of outer dynein arms, inner dynein arms, radial spokes, and intraflagellar transport proteins. A significant down-regulation of the expression of genes from all the four groups was observed in PCD, compared to non-PCD biopsies. Our data suggest that a coordinated down-regulation of the ciliome genes plays an important role in the molecular pathomechanism of PCD.

  20. Down-regulation of Wnt10a affects odontogenesis and proliferation in mesenchymal cells

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yang, E-mail: Ly10160624@163.com; Han, Dong, E-mail: Donghan@bjmu.edu.cn; Wang, Lei, E-mail: wanglei_dentist@163.com; Feng, Hailan, E-mail: kqfenghl@bjmu.edu.cn

    2013-05-17

    Highlights: •Down-regulation of Wnt10a in dental mesenchymal cells impairs odontogenesis of reassociated tooth germs. •Dspp is down- and up-regulated after Wnt10a-knockdown and overexpression in dental mesenchymal cells. •Down-regulation of Wnt10a inhibits proliferation of dental mesenchymal cells. -- Abstract: The WNT10a mutation has been found in patients with abnormal odontogenesis. In mice, Wnt10a expression is found in the tooth germ, but its role has not yet been elucidated. We aimed to investigate the role of Wnt10a in odontogenesis. Mesenchymal cells of the first mandibular molar germ at the bell stage were isolated, transfected with Wnt10a SiRNA or plasmid, and reassociated with epithelial part of the molar germ. Scrambled SiRNA or empty vector was used in the control group. The reassociated tooth germs were transplanted into mice subrenal capsules. After gene modification, dental mesenchymal cells cultured in vitro were checked for cell proliferation and the expression of Dspp was examined. All 12 reassociated tooth germs in the control group resumed odontogenesis, while only 5 of 12 in the Wnt10a knockdown group developed into teeth. After Wnt10a knockdown, the mesenchymal cells cultured in vitro presented repressed proliferation. Wnt10a knockdown and overexpression led to both down- and up-regulation of Dspp. We conclude that the down-regulation of Wnt10a impairs odontogensis and cell proliferation, and that Wnt10a regulates Dspp expression in mesenchymal cells. These findings help to elucidate the mechanism of abnormal tooth development in patients with the WNT10A mutation.

  1. miR-297 modulates multidrug resistance in human colorectal carcinoma by down-regulating MRP-2.

    Science.gov (United States)

    Xu, Ke; Liang, Xin; Shen, Ke; Cui, Daling; Zheng, Yuanhong; Xu, Jianhua; Fan, Zhongze; Qiu, Yanyan; Li, Qi; Ni, Lei; Liu, Jianwen

    2012-09-01

    Colorectal carcinoma is a frequent cause of cancer-related death in men and women. miRNAs (microRNAs) are endogenous small non-coding RNAs that regulate gene expression negatively at the post-transcriptional level. In the present study we investigated the possible role of microRNAs in the development of MDR (multidrug resistance) in colorectal carcinoma cells. We analysed miRNA expression levels between MDR colorectal carcinoma cell line HCT116/L-OHP cells and their parent cell line HCT116 using a miRNA microarray. miR-297 showed lower expression in HCT116/L-OHP cells compared with its parental cells. MRP-2 (MDR-associated protein 2) is an important MDR protein in platinum-drug-resistance cells and is a predicted target of miR-297. Additionally miR-297 was down-regulated in a panel of human colorectal carcinoma tissues and negatively correlated with expression levels of MRP-2. Furthermore, we found that ectopic expression of miR-297 in MDR colorectal carcinoma cells reduced MRP-2 protein level and sensitized these cells to anti-cancer drugs in vitro and in vivo. Taken together, our findings suggest that miR-297 could play a role in the development of MDR in colorectal carcinoma cells, at least in part by modulation of MRP-2.

  2. Andrographolide inhibits osteopontin expression and breast tumor growth through down regulation of PI3 kinase/Akt signaling pathway.

    Science.gov (United States)

    Kumar, S; Patil, H S; Sharma, P; Kumar, D; Dasari, S; Puranik, V G; Thulasiram, H V; Kundu, G C

    2012-09-01

    Breast cancer is one of the most common cancers among women in India and around the world. Despite recent advancement in the treatment of breast cancer, the results of chemotherapy to date remain unsatisfactory, prompting a need to identify natural agents that could target cancer efficiently with least side effects. Andrographolide (Andro) is one such molecule which has been shown to possess inhibitory effect on cancer cell growth. In this study, Andro, a natural diterpenoid lactone isolated from Andrographis paniculata has been shown to inhibit breast cancer cell proliferation, migration and arrest cell cycle at G2/M phase and induces apoptosis through caspase independent pathway. Our experimental evidences suggest that Andro attenuates endothelial cell motility and tumor-endothelial cell interaction. Moreover, Andro suppresses breast tumor growth in orthotopic NOD/SCID mice model. The anti-tumor activity of Andro in both in vitro and in vivo model was correlated with down regulation of PI3 kinase/Akt activation and inhibition of pro-angiogenic molecules such as OPN and VEGF expressions. Collectively, these results demonstrate that Andro may act as an effective anti-tumor and anti-angiogenic agent for the treatment of breast cancer.

  3. Do we live in a largely top-down regulated world?

    Science.gov (United States)

    Banse, Karl

    2007-06-01

    Based on a review of mostly recent literature for a public lecture, the question is discussed whether we live in a largely "top-down" regulated world rather than one formed "bottom-up" by the resources for plant and animal growth. Of course, the top-down mechanism is predicated by bottom-up production, especially by the plants. Examples for the effects of grazing and predation for the land and the open sea, but including coral reefs, are discussed. The answer to the question posed by the title is affirmative. Ecosystems altered by man and urgent needs for marine conservation are briefly treated.

  4. Possible Power Estimation of Down-Regulated Offshore Wind Power Plants

    DEFF Research Database (Denmark)

    Gögmen, Tuhfe

    The penetration of offshore wind power is continuously increasing in the Northern European grids. To assure safety in the operation of the power system, wind power plants are required to provide ancillary services, including reserve power attained through down-regulating the wind farm from its...... power plant. The developed procedure, the PossPOW algorithm, can also be used in the wind farm control as it yields a real-time wind farm power curve. The modern wind turbines have a possible power signal at the turbine level and the current state of the art is to aggregate those signals to achieve...

  5. Diabetic HDL is dysfunctional in stimulating endothelial cell migration and proliferation due to down regulation of SR-BI expression.

    Science.gov (United States)

    Pan, Bing; Ma, Yijing; Ren, Hui; He, Yubin; Wang, Yongyu; Lv, Xiaofeng; Liu, Donghui; Ji, Liang; Yu, Baoqi; Wang, Yuhui; Chen, Y Eugene; Pennathur, Subramaniam; Smith, Jonathan D; Liu, George; Zheng, Lemin

    2012-01-01

    Diabetic HDL had diminished capacity to stimulate endothelial cell (EC) proliferation, migration, and adhesion to extracellular matrix. The mechanism of such dysfunction is poorly understood and we therefore sought to determine the mechanistic features of diabetic HDL dysfunction. We found that the dysfunction of diabetic HDL on human umbilical vein endothelial cells (HUVECs) was associated with the down regulation of the HDL receptor protein, SR-BI. Akt-phosphorylation in HUVECs was induced in a biphasic manner by normal HDL. While diabetic HDL induced Akt phosphorylation normally after 20 minutes, the phosphorylation observed 24 hours after diabetic HDL treatment was reduced. To determine the role of SR-BI down regulation on diminished EC responses of diabetic HDL, Mouse aortic endothelial cells (MAECs) were isolated from wild type and SR-BI (-/-) mice, and treated with normal and diabetic HDL. The proliferative and migratory effects of normal HDL on wild type MAECs were greatly diminished in SR-BI (-/-) cells. In contrast, response to diabetic HDL was impaired in both types suggesting diminished effectiveness of diabetic HDL on EC proliferation and migration might be due to the down regulation of SR-BI. Additionally, SR-BI down regulation diminishes diabetic HDL's capacity to activate Akt chronically. Diabetic HDL was dysfunctional in promoting EC proliferation, migration, and adhesion to matrix which was associated with the down-regulation of SR-BI. Additionally, SR-BI down regulation diminishes diabetic HDL's capacity to activate Akt chronically.

  6. microRNA-143 down-regulates Hexokinase 2 in colon cancer cells

    DEFF Research Database (Denmark)

    Gregersen, Lea Haarup; Jacobsen, Anders; Frankel, Lisa

    2012-01-01

    a significant enrichment of miR-143 seed sites in their 3' UTRs. Here we report the identification of Hexokinase 2 (HK2) as a direct target of miR-143. We show that re-introduction of miR-143 in the colon cancer cell line DLD-1 results in a decreased lactate secretion. CONCLUSION: We have identified......ABSTRACT: BACKGROUND: MicroRNAs (miRNAs) are well recognized as gene regulators and have been implicated in the regulation of development as well as human diseases. miR-143 is located at a fragile site on chromosome 5 frequently deleted in cancer, and has been reported to be down......-regulated in several cancers including colon cancer. METHODS: To gain insight into the role of miR-143 in colon cancer, we used a microarray-based approach in combination with seed site enrichment analysis to identify miR-143 targets. RESULTS: As expected, transcripts down-regulated upon miR-143 overexpression had...

  7. Down-regulation of ALKBH2 increases cisplatin sensitivity in H1299 lung cancer cells

    Institute of Scientific and Technical Information of China (English)

    Shuang-shuang WU; Wei XU; Shan LIU; Bo CHEN; Xue-li WANG; Yan WANG; Shi-feng LIU; Jian-qing WU

    2011-01-01

    Aim: To elucidate the combined effect of alkylated DNA repair protein alkB homolog 2 (ALKBH2)-targeting gene therapy and cisplatin (cDDP) chemotherapy on the non-small cell lung cancer (NSCLC)H1299 cell line.Methods: ALKBH2 was down-regulated in H1299 cells by lentivirus-mediated RNA interference (RNAi). Changes in ALKBH2 expression were determined using real-time RT-PCR and Western blotting. Cell viability was evaluated using MTT assay. DNA synthesis in proliferating cells was determined using BrdU incorporation assay. Cell apoptosis was determined using flow cytometry.Results: Lentivirus-mediated ALKBH2 silencing alone did not induce apoptosis or attenuate the growth potential of H1299 cells within five days post-infection. Combined treatment modalities with lentivirus-mediated ALKBH2 down-regulation and cDDP (333 μmol/L)were significantly more potent in inhibiting cell growth and inducing apoptosis than mono-chemotherapy.Conclusion: Combined treatment modalities of ALKBH2 knockdown and cDDP chemotherapy have the potential to improve the efficacy in the treatment of NSCLC.

  8. Protamine sulfate down-regulates thrombin generation by inhibiting factor V activation.

    LENUS (Irish Health Repository)

    Ni Ainle, Fionnuala

    2009-08-20

    Protamine sulfate is a positively charged polypeptide widely used to reverse heparin-induced anticoagulation. Paradoxically, prospective randomized trials have shown that protamine administration for heparin neutralization is associated with increased bleeding, particularly after cardiothoracic surgery with cardiopulmonary bypass. The molecular mechanism(s) through which protamine mediates this anticoagulant effect has not been defined. In vivo administration of pharmacologic doses of protamine to BALB\\/c mice significantly reduced plasma thrombin generation and prolonged tail-bleeding time (from 120 to 199 seconds). Similarly, in pooled normal human plasma, protamine caused significant dose-dependent prolongations of both prothrombin time and activated partial thromboplastin time. Protamine also markedly attenuated tissue factor-initiated thrombin generation in human plasma, causing a significant decrease in endogenous thrombin potential (41% +\\/- 7%). As expected, low-dose protamine effectively reversed the anticoagulant activity of unfractionated heparin in plasma. However, elevated protamine concentrations were associated with progressive dose-dependent reduction in thrombin generation. To assess the mechanism by which protamine mediates down-regulation of thrombin generation, the effect of protamine on factor V activation was assessed. Protamine was found to significantly reduce the rate of factor V activation by both thrombin and factor Xa. Protamine mediates its anticoagulant activity in plasma by down-regulation of thrombin generation via a novel mechanism, specifically inhibition of factor V activation.

  9. Androgen Depletion Induces Senescence in Prostate Cancer Cells through Down-regulation of Skp2

    Directory of Open Access Journals (Sweden)

    Zuzana Pernicová

    2011-06-01

    Full Text Available Although the induction of senescence in cancer cells is a potent mechanism of tumor suppression, senescent cells remain metabolically active and may secrete a broad spectrum of factors that promote tumorigenicity in neighboring malignant cells. Here we show that androgen deprivation therapy (ADT, a widely used treatment for advanced prostate cancer, induces a senescence-associated secretory phenotype in prostate cancer epithelial cells, indicated by increases in senescence-associated β-galactosidase activity, heterochromatin protein 1β foci, and expression of cathepsin B and insulin-like growth factor binding protein 3. Interestingly, ADT also induced high levels of vimentin expression in prostate cancer cell lines in vitro and in human prostate tumors in vivo. The induction of the senescence-associated secretory phenotype by androgen depletion was mediated, at least in part, by down-regulation of S-phase kinase-associated protein 2, whereas the neuroendocrine differentiation of prostate cancer cells was under separate control. These data demonstrate a previously unrecognized link between inhibition of androgen receptor signaling, down-regulation of S-phase kinase-associated protein 2, and the appearance of secretory, tumor-promoting senescent cells in prostate tumors. We propose that ADT may contribute to the development of androgen-independent prostate cancer through modulation of the tissue microenvironment by senescent cells.

  10. microRNA-143 down-regulates Hexokinase 2 in colon cancer cells

    DEFF Research Database (Denmark)

    Gregersen, Lea Haarup; Jacobsen, Anders; Frankel, Lisa;

    2012-01-01

    -regulated in several cancers including colon cancer. METHODS: To gain insight into the role of miR-143 in colon cancer, we used a microarray-based approach in combination with seed site enrichment analysis to identify miR-143 targets. RESULTS: As expected, transcripts down-regulated upon miR-143 overexpression had...... a significant enrichment of miR-143 seed sites in their 3' UTRs. Here we report the identification of Hexokinase 2 (HK2) as a direct target of miR-143. We show that re-introduction of miR-143 in the colon cancer cell line DLD-1 results in a decreased lactate secretion. CONCLUSION: We have identified...... and validated HK2 as a miR-143 target. Furthermore, our results indicate that miR-143 mediated down-regulation of HK2 affects glucose metabolism in colon cancer cells. We hypothesize that loss of miR-143-mediated repression of HK2 can promote glucose metabolism in cancer cells, contributing to the shift towards...

  11. Phosphorylation-dependent down-regulation of apolipoprotein A5 by insulin

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, Maxine; Helleboid-Chapman, Audrey; Jakel, Heidelinde; Rommens, Corinne; Martin, Genevieve; Duran-Sandoval, Daniel; Staels, Bart; Rubin, Edward M.; Pennacchio, Len A.; Taskinen, Marja-Riitta; Fruchart-Najib, Jamila; Fruchart, Jean-Charles

    2004-02-15

    The apolipoprotein A5 (APOA5) gene has been shown to be important in lowering plasma triglyceride levels. Since several studies have shown that hyperinsulinemia is associated with hypertriglyceridemia, we sought to determine whether APOA5 gene is regulated by insulin. We show here that cell and mouse treatments with insulin down-regulated APOA5 expression in a dose-dependent manner. Furthermore, we determined that insulin decreases APOA5 promoter activity and subsequent deletion analyses revealed an E-box-containing fragment. We showed that Upstream Stimulatory Factors, USF1/USF2, bind to the identified E-box in the APOA5 promoter. Moreover, in cotransfection studies, USF1 stimulates APOA5 promoter activity. The treatment with insulin reduces the binding of USF1/USF2 to APOA5 promoter. The inhibition of PI3K pathway with wortmannin abolished the insulin s effect on APOA5 gene transcription. Using oligoprecipitation method of USF from nuclear extracts, we demonstrated that phosphorylated USF1 failed to bind to APOA5 promoter. This indicates that the APOA5 gene transrepression by insulin involves a phosphorylation of USF through PI3K, that modulate their binding to APOA5 promoter and results in APOA5 down-regulation. The effect of exogenous hyperinsulinemia in healthy men shows a decrease of the plasma ApoAV level. These data suggest a potential mechanism involving APOA5 gene in hypertriglyceridemia associated with hyperinsulinemia.

  12. Glucosamine Modulates T Cell Differentiation through Down-regulating N-Linked Glycosylation of CD25.

    Science.gov (United States)

    Chien, Ming-Wei; Lin, Ming-Hong; Huang, Shing-Hwa; Fu, Shin-Huei; Hsu, Chao-Yuan; Yen, B Lin-Ju; Chen, Jiann-Torng; Chang, Deh-Ming; Sytwu, Huey-Kang

    2015-12-04

    Glucosamine has immunomodulatory effects on autoimmune diseases. However, the mechanism(s) through which glucosamine modulates different T cell subsets and diseases remain unclear. We demonstrate that glucosamine impedes Th1, Th2, and iTreg but promotes Th17 differentiation through down-regulating N-linked glycosylation of CD25 and subsequently inhibiting its downstream Stat5 signaling in a dose-dependent manner. The effect of glucosamine on T helper cell differentiation was similar to that induced by anti-IL-2 treatment, further supporting an IL-2 signaling-dependent modulation. Interestingly, excess glucose rescued this glucosamine-mediated regulation, suggesting a functional competition between glucose and glucosamine. High-dose glucosamine significantly decreased Glut1 N-glycosylation in Th1-polarized cells. This finding suggests that both down-regulated IL-2 signaling and Glut1-dependent glycolytic metabolism contribute to the inhibition of Th1 differentiation by glucosamine. Finally, glucosamine treatment inhibited Th1 cells in vivo, prolonged the survival of islet grafts in diabetic recipients, and exacerbated the severity of EAE. Taken together, our results indicate that glucosamine interferes with N-glycosylation of CD25, and thereby attenuates IL-2 downstream signaling. These effects suggest that glucosamine may be an important modulator of T cell differentiation and immune homeostasis.

  13. Tolerization with BLP down-regulates HMGB1 a critical mediator of sepsis-related lethality.

    LENUS (Irish Health Repository)

    Coffey, J Calvin

    2012-02-03

    Tolerization with bacterial lipoprotein (BLP) affords a significant survival benefit in sepsis. Given that high mobility group box protein-1 (HMGB1) is a recognized mediator of sepsis-related lethality, we determined if tolerization with BLP leads to alterations in HMGB1. In vitro, BLP tolerization led to a reduction in HMGB1 gene transcription. This was mirrored at the protein level, as HMGB1 protein expression and release were reduced significantly in BLP-tolerized human THP-1 monocytic cells. BLP tolerance in vivo led to a highly significant, long-term survival benefit following challenge with lethal dose BLP in C57BL\\/6 mice. This was associated with an attenuation of HMGB1 release into the circulation, as evidenced by negligible serum HMGB1 levels in BLP-tolerized mice. Moreover, HMGB1 levels in peritoneal macrophages from BLP-tolerized mice were reduced significantly. Hence, tolerization with BLP leads to a down-regulation of HMGB1 protein synthesis and release. The improved survival associated with BLP tolerance could thus be explained by a reduction in HMGB1, were the latter associated with lethality in BLP-related sepsis. In testing this hypothesis, it was noted that neutralization of HMGB1, using anti-HMGB1 antibodies, abrogated BLP-associated lethality almost completely. To conclude, tolerization with BLP leads to a down-regulation of HMGB1, thus offering a novel means of targeting the latter. HMGB1 is also a mediator of lethality in BLP-related sepsis.

  14. Sprouty2 down-regulation promotes axon growth by adult sensory neurons.

    Science.gov (United States)

    Hausott, Barbara; Vallant, Natalie; Auer, Maria; Yang, Lin; Dai, Fangping; Brand-Saberi, Beate; Klimaschewski, Lars

    2009-12-01

    Fibroblast growth factors (FGFs) play a prominent role in axonal growth during development and repair. Treatment with FGF-2 or overexpression of FGF receptors promotes peripheral axon regeneration mainly by activation of extracellular signal-regulated kinase (ERK). The Ras/Raf/ERK pathway is under the control of Sprouty proteins acting as negative feedback inhibitors. We investigated the expression of Sprouty isoforms in adult sensory neurons of dorsal root ganglia (DRG) as well as the effects of Sprouty inhibition on axon growth by small interfering RNAs (siRNAs). Sprouty2 revealed the highest expression level in DRG neurons. Down-regulation of Sprouty2 promoted elongative axon growth by adult sensory neurons accompanied by enhanced FGF-2-induced activation of ERK and Ras, whereas Sprouty2 overexpression inhibited axon growth. Sprouty2 was not regulated in vivo in response to a sciatic nerve lesion. Together, our results imply that Sprouty2 is highly expressed in adult peripheral neurons and its down-regulation strongly promotes elongative axon growth by activation of the Ras/Raf/ERK pathway.

  15. High glucose induces dysfunction of airway epithelial barrier through down-regulation of connexin 43.

    Science.gov (United States)

    Yu, Hongmei; Yang, Juan; Zhou, Xiangdong; Xiao, Qian; Lü, Yang; Xia, Li

    2016-03-01

    The airway epithelium is a barrier to the inhaled antigens and pathogens. Connexin 43 (Cx43) has been found to play critical role in maintaining the function of airway epithelial barrier and be involved in the pathogenesis of the diabetic retinal vasculature, diabetes nephropathy and diabetes skin. Hyperglycemia has been shown to be an independent risk factor for respiratory infections. We hypothesize that the down-regulation of Cx43 induced by HG alters the expression of tight junctions (zonula occludens-1 (ZO-1) and occludin) and contributes to dysfunction of airway epithelial barrier, and Cx43 plays a critical role in the process in human airway epithelial cells (16 HBE). We show that high glucose (HG) decreased the expression of ZO-1 and occludin, disassociated interaction between Cx43 and tight junctions, and then increased airway epithelial transepithelial electrical resistance (TER) and permeability by down-regulation of Cx43 in human airway epithelial cells. These observations demonstrate an important role for Cx43 in regulating HG-induced dysfunction of airway epithelial barrier. These findings may bring new insights into the molecular pathogenesis of pulmonary infection related to diabetes mellitus and lead to novel therapeutic intervention for the dysfunction of airway epithelial barrier in chronic inflammatory airway diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Down-regulation of p73 correlates with high histological grade in Japanese with breast carcinomas

    Institute of Scientific and Technical Information of China (English)

    DU Cai-wen; Izo Kimijima; Toru Otake; Rikiya Abe; Seiichi Takenoshita; ZHANG Guo-jun

    2011-01-01

    Background p73, a homologue of p53, has been located at chromosome 1 p36-33, a region of frequently observed loss of heterozygosity in breast cancers. The objective of the present study was to investigate the function of p73 in Japanese with breast cancers. Methods Sixty Japanese patients with breast cancer were assessed by polymerase chain reaction single strand confirmation polymorphism analysis and direct sequencing to detect the p73 allele. p73 mRNA levels were also determined in 40 out of 60 patients by reverse-transcriptional polymerase chain reaction. Results We analyzed the entire open reading frame of the p73 gene by polymerase chain reaction single strand confirmation polymorphism and sequencing, and failed to identify any mutations of p73 in the encoding regions detected.Loss of heterozygosity of p73 was infrequent and only found in 9% of breast carcinomas. We revealed a few polymorphisms with a frequency of 13%-29%, which had been reported previously. Down-regulation of p73 mRNA expression was observed in tumor tissues in comparison to the normal breast tissues. A significant inverse correlation was found between p73 transcripts and high histological grade, suggesting that down-regulated p73 expression could be related to poor prognosis in those patients. Conclusion Our results suggest that p73 may serve as a tumor suppressor gene and its expression plays a role in tumorigenesis in Japanese patients with breast cancer.

  17. Effects of p21 Gene Down-Regulation through RNAi on Antler Stem Cells In Vitro.

    Science.gov (United States)

    Guo, Qianqian; Wang, Datao; Liu, Zhen; Li, Chunyi

    2015-01-01

    Cell cycle is an integral part of cell proliferation, and consists mainly of four phases, G1, S, G2 and M. The p21 protein, a cyclin dependent kinase inhibitor, plays a key role in regulating cell cyclevia G1 phase control. Cells capable of epimorphic regeneration have G2/M accumulation as their distinctive feature, whilst the majority of somatic cells rest at G1 phase. To investigate the role played byp21 in antler regeneration, we studied the cell cycle distribution of antler stem cells (ASCs), via down-regulation of p21 in vitro using RNAi. The results showed that ASCs had high levels of p21 mRNA expression and rested at G1 phase, which was comparable to the control somatic cells. Down-regulation of p21 did not result in ASC cell cycle re-distribution toward G2/M accumulation, but DNA damage and apoptosis of the ASCs significantly increased and the process of cell aging was slowed. These findings suggest that the ASCs may have evolved to use an alternative, p21-independent cell cycle regulation mechanism. Also a unique p21-dependent inhibitory effect may control DNA damage as a protective mechanism to ensure the fast proliferating ASCs do not become dysplastic/cancerous. Understanding of the mechanism underlying the role played by p21 in the ASCs could give insight into a mammalian system where epimorphic regeneration is initiated whilst the genome stability is effectively maintained.

  18. Down-Regulation of Lipocalin 2 Expression in Mouse Testis after Exposure to Electromagnetic Field

    Directory of Open Access Journals (Sweden)

    Amaneh Mohammadi Roushandeh

    2009-12-01

    Full Text Available Background: The effects of electromagnetic field (EMF onreproductive system have been of critical concern for a longtime. It has been shown that the EMF can adversely affect testicularcells and tissue and decrease male fertility. The mostimportant determinants of male fertility are sperm developmentand motility, which are affected by changes in several factorsincluding lipocalin 2 proteins. In the present study, we investigatedthe effects of exposure to EMF on testis tissue and expressionof lipocalin 2 gene.Methods: Male BALB/c mice (8 weeks old were exposed to 3mT EMF for 8 weeks, 4 hours/day. Control group (10 micedid not receive EMF exposure. After the experimental period,the mice were sacrificed, and their testis tissues were examinedby using light microscopy after hematoxylin-eosin staining.Additionally, total RNA and proteins were extracted from testistissue and used to study the lipocalin 2 expression by realtime RT-PCR and Western blot analysis.Results: The histological changes observed in the testes of experimentalgroup included increased number of spermatocytesand Leydig cells, and increased thickness of basement membranecompared with the control group. The mRNA and proteinstudies showed that expression of lipocalin 2 gene wasdown regulated in testes of the mice exposed to EMF.Conclusion: Our study showed that EMF down regulates theexpression of lipocalin 2, a cytoprotective molecule, in testis tissue.This down regulation can be one of the mechanisms that contributeto the decreased fertility observed after exposure to EMF

  19. Down-regulation of Rab5 decreases characteristics associated with maintenance of cell transformation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Patricio; Soto, Nicolás [Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago (Chile); Díaz, Jorge [Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago (Chile); Center for Molecular Studies of the Cell, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, Universidad de Chile, Santiago (Chile); Mendoza, Pablo [Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago (Chile); Díaz, Natalia [Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago (Chile); Center for Molecular Studies of the Cell, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, Universidad de Chile, Santiago (Chile); Quest, Andrew F.G. [Center for Molecular Studies of the Cell, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, Universidad de Chile, Santiago (Chile); Advanced Center for Chronic Diseases (ACCDiS), Faculty of Medicine, Universidad de Chile, Santiago (Chile); Torres, Vicente A., E-mail: vatorres@med.uchile.cl [Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago (Chile); Advanced Center for Chronic Diseases (ACCDiS), Faculty of Medicine, Universidad de Chile, Santiago (Chile)

    2015-08-21

    The early endosomal protein Rab5 is highly expressed in tumor samples, although a causal relationship between Rab5 expression and cell transformation has not been established. Here, we report the functional effects of targeting endogenous Rab5 with specific shRNA sequences in different tumor cell lines. Rab5 down-regulation in B16-F10 cells decreased tumor formation by subcutaneous injection into C57/BL6 mice. Accordingly, Rab5 targeting in B16-F10 and A549, but not MDA-MB-231 cells was followed by decreased cell proliferation, increased apoptosis and decreased anchorage-independent growth. These findings suggest that Rab5 expression is required to maintain characteristics associated with cell transformation. - Highlights: • Rab5 is important to the maintenance of cell transformation characteristics. • Down-regulation of Rab5 decreases cell proliferation and increases apoptosis in different cancer cells. • Rab5 is required for anchorage-independent growth and tumorigenicity in-vivo.

  20. Effects of p21 Gene Down-Regulation through RNAi on Antler Stem Cells In Vitro.

    Directory of Open Access Journals (Sweden)

    Qianqian Guo

    Full Text Available Cell cycle is an integral part of cell proliferation, and consists mainly of four phases, G1, S, G2 and M. The p21 protein, a cyclin dependent kinase inhibitor, plays a key role in regulating cell cyclevia G1 phase control. Cells capable of epimorphic regeneration have G2/M accumulation as their distinctive feature, whilst the majority of somatic cells rest at G1 phase. To investigate the role played byp21 in antler regeneration, we studied the cell cycle distribution of antler stem cells (ASCs, via down-regulation of p21 in vitro using RNAi. The results showed that ASCs had high levels of p21 mRNA expression and rested at G1 phase, which was comparable to the control somatic cells. Down-regulation of p21 did not result in ASC cell cycle re-distribution toward G2/M accumulation, but DNA damage and apoptosis of the ASCs significantly increased and the process of cell aging was slowed. These findings suggest that the ASCs may have evolved to use an alternative, p21-independent cell cycle regulation mechanism. Also a unique p21-dependent inhibitory effect may control DNA damage as a protective mechanism to ensure the fast proliferating ASCs do not become dysplastic/cancerous. Understanding of the mechanism underlying the role played by p21 in the ASCs could give insight into a mammalian system where epimorphic regeneration is initiated whilst the genome stability is effectively maintained.

  1. Effects of p21 Gene Down-Regulation through RNAi on Antler Stem Cells In Vitro

    Science.gov (United States)

    Guo, Qianqian; Wang, Datao; Liu, Zhen; Li, Chunyi

    2015-01-01

    Cell cycle is an integral part of cell proliferation, and consists mainly of four phases, G1, S, G2 and M. The p21 protein, a cyclin dependent kinase inhibitor, plays a key role in regulating cell cyclevia G1 phase control. Cells capable of epimorphic regeneration have G2/M accumulation as their distinctive feature, whilst the majority of somatic cells rest at G1 phase. To investigate the role played byp21 in antler regeneration, we studied the cell cycle distribution of antler stem cells (ASCs), via down-regulation of p21 in vitro using RNAi. The results showed that ASCs had high levels of p21 mRNA expression and rested at G1 phase, which was comparable to the control somatic cells. Down-regulation of p21 did not result in ASC cell cycle re-distribution toward G2/M accumulation, but DNA damage and apoptosis of the ASCs significantly increased and the process of cell aging was slowed. These findings suggest that the ASCs may have evolved to use an alternative, p21-independent cell cycle regulation mechanism. Also a unique p21-dependent inhibitory effect may control DNA damage as a protective mechanism to ensure the fast proliferating ASCs do not become dysplastic/cancerous. Understanding of the mechanism underlying the role played by p21 in the ASCs could give insight into a mammalian system where epimorphic regeneration is initiated whilst the genome stability is effectively maintained. PMID:26308075

  2. EGFRvIII escapes down-regulation due to impaired internalization and sorting to lysosomes.

    Science.gov (United States)

    Grandal, Michael V; Zandi, Roza; Pedersen, Mikkel W; Willumsen, Berthe M; van Deurs, Bo; Poulsen, Hans S

    2007-07-01

    EGFRvIII is a mutant variant of the epidermal growth factor receptor (EGFR) found exclusively in various cancer types. EGFRvIII lacks a large part of the extracellular domain and is unable to bind ligands; however, the receptor is constitutively phosphorylated and able to activate downstream signaling pathways. Failure to attenuate signaling by receptor down-regulation could be one of the major mechanisms by which EGFRvIII becomes oncogenic. Using a cell system expressing either EGFR or EGFRvIII with no expression of other EGFR family members and with endogenous levels of key degradation proteins, we have investigated the down-regulation of EGFRvIII and compared it to that of EGFR. We show that, in contrast to EGFR, EGFRvIII is inefficiently degraded. EGFRvIII is internalized, but the internalization rate of the mutated receptor is significantly less than that of unstimulated EGFR. Moreover, internalized EGFRvIII is recycled rather than delivered to lysosomes. EGFRvIII binds the ubiquitin ligase c-Cbl via Grb2, whereas binding via phosphorylated tyrosine residue 1045 seems to be limited. Despite c-Cbl binding, the receptor fails to become effectively ubiquitinylated. Thus, our results suggest that the long lifetime of EGFRvIII is caused by inefficient internalization and impaired sorting to lysosomes due to lack of effective ubiquitinylation.

  3. Down-regulation of MiR-127 facilitates hepatocyte proliferation during rat liver regeneration.

    Directory of Open Access Journals (Sweden)

    Chuanyong Pan

    Full Text Available Liver regeneration (LR after partial hepatectomy (PH involves the proliferation and apoptosis of hepatocytes, and microRNAs have been shown to post-transcriptionally regulate genes involved in the regulation of these processes. To explore the role of miR-127 during LR, the expression patterns of miR-127 and its related proteins were investigated. MiR-127 was introduced into a rat liver cell line to examine its effects on the potential target genes Bcl6 and Setd8, and functional studies were undertaken. We discovered that miR-127 was down-regulated and inversely correlated with the expression of Bcl6 and Setd8 at 24 hours after PH, a time at which hypermethylation of the promoter region of the miR-127 gene was detected. Furthermore, in BRL-3A rat liver cells, we observed that overexpression of miR-127 significantly suppressed cell growth and directly inhibited the expression of Bcl6 and Setd8. The results suggest that down-regulation of miR-127 may be due to the rapid methylation of its promoter during the first 24 h after PH, and this event facilitates hepatocyte proliferation by releasing Bcl6 and Setd8. These findings support a miRNA-mediated negative regulation pattern in LR and implicate an anti-proliferative role for miR-127 in liver cells.

  4. Down-regulation of tissue N:P ratios in terrestrial plants by elevated CO2.

    Science.gov (United States)

    Deng, Qi; Hui, Dafeng; Luo, Yiqi; Elser, James; Wang, Ying-ping; Loladze, Irakli; Zhang, Quanfa; Dennis, Sam

    2015-12-01

    Increasing atmospheric CO2 concentrations generally alter element stoichiometry in plants. However, a comprehensive evaluation of the elevated CO2 impact on plant nitrogen: phosphorus (N:P) ratios and the underlying mechanism has not been conducted. We synthesized the results from 112 previously published studies using meta-analysis to evaluate the effects of elevated CO2 on the N:P ratio of terrestrial plants and to explore the underlying mechanism based on plant growth and soil P dynamics. Our results show that terrestrial plants grown under elevated CO2 had lower N:P ratios in both above- and belowground biomass across different ecosystem types. The response ratio for plant N:P was negatively correlated with the response ratio for plant growth in croplands and grasslands, and showed a stronger relationship for P than for N. In addition, the CO2-induced down-regulation of plant N:P was accompanied by 19.3% and 4.2% increases in soil phosphatase activity and labile P, respectively, and a 10.1% decrease in total soil P. Our results show that down-regulation of plant N:P under elevated CO2 corresponds with accelerated soil P cycling. These findings should be useful for better understanding of terrestrial plant stoichiometry in response to elevated CO2 and of the underlying mechanisms affecting nutrient dynamics under climate change.

  5. Down-regulation of endogenous KLHL1 decreases voltage-gated calcium current density.

    Science.gov (United States)

    Perissinotti, Paula P; Ethington, Elizabeth G; Cribbs, Leanne; Koob, Michael D; Martin, Jody; Piedras-Rentería, Erika S

    2014-05-01

    The actin-binding protein Kelch-like 1 (KLHL1) can modulate voltage-gated calcium channels in vitro. KLHL1 interacts with actin and with the pore-forming subunits of Cav2.1 and CaV3.2 calcium channels, resulting in up-regulation of P/Q and T-type current density. Here we tested whether endogenous KLHL1 modulates voltage gated calcium currents in cultured hippocampal neurons by down-regulating the expression of KLHL1 via adenoviral delivery of shRNA targeted against KLHL1 (shKLHL1). Control adenoviruses did not affect any of the neuronal properties measured, yet down-regulation of KLHL1 resulted in HVA current densities ~68% smaller and LVA current densities 44% smaller than uninfected controls, with a concomitant reduction in α(1A) and α(1H) protein levels. Biophysical analysis and western blot experiments suggest Ca(V)3.1 and 3.3 currents are also present in shKLHL1-infected neurons. Synapsin I levels, miniature postsynaptic current frequency, and excitatory and inhibitory synapse number were reduced in KLHL1 knockdown. This study corroborates the physiological role of KLHL1 as a calcium channel modulator and demonstrates a novel, presynaptic role.

  6. Interleukin-1 as an Injury Signal Mobilizes Retinyl Esters in Hepatic Stellate Cells through Down Regulation of Lecithin Retinol Acyltransferase

    Science.gov (United States)

    Kida, Yujiro; Xia, Zanxian; Zheng, Sujun; Mordwinkin, Nicholas M.; Louie, Stan G.; Zheng, Song Guo; Feng, Min; Shi, Hongbo; Duan, Zhongping; Han, Yuan-Ping

    2011-01-01

    Retinoids are mostly stored as retinyl esters in hepatic stellate cells (HSCs) through esterification of retinol and fatty acid, catalyzed by lecithin-retinol acyltransferase (LRAT). This study is designated to address how retinyl esters are mobilized in liver injury for tissue repair and wound healing. Initially, we speculated that acute inflammatory cytokines may act as injury signal to mobilize retinyl esters by down-regulation of LRAT in HSCs. By examining a panel of cytokines we found interleukin-1 (IL-1) can potently down-regulate mRNA and protein levels of LRAT, resulting in mobilization of retinyl esters in primary rat HSCs. To simulate the microenvironment in the space of Disse, HSCs were embedded in three-dimensional extracellular matrix, by which HSCs retaine quiescent phenotypes, indicated by up-regulation of LRAT and accumulation of lipid droplets. Upon IL-1 stimulation, LRAT expression went down together with mobilization of lipid droplets. Secreted factors from Kupffer cells were able to suppress LRAT expression in HSCs, which was neutralized by IL-1 receptor antagonist. To explore the underlying mechanism we noted that the stability of LRAT protein is not significantly regulated by IL-1, indicating the regulation is likely at transcriptional level. Indeed, we found that IL-1 failed to down-regulate recombinant LRAT protein expressed in HSCs by adenovirus, while transcription of endogenous LRAT was promptly decreased. Following liver damage, IL-1 was promptly elevated in a close pace with down-regulation of LRAT transcription, implying their causative relationship. After administration of IL-1, retinyl ester levels in the liver, as measured by LC/MS/MS, decreased in association with down-regulation of LRAT. Likewise, IL-1 receptor knockout mice were protected from injury-induced down-regulation of LRAT. In summary, we identified IL-1 as an injury signal to mobilize retinyl ester in HSCs through down-regulation of LRAT, implying a mechanism governing

  7. Impaired down-regulation of negative emotion in self-referent social situations in bipolar disorder

    DEFF Research Database (Denmark)

    Kjærstad, Hanne L; Vinberg, Maj; Goldin, Philippe R

    2016-01-01

    Emotion dysregulation is a core feature of bipolar disorder (BD) that persists into periods of remission. Neuroimaging studies show aberrant neural responses during emotion regulation (ER) in patients with BD relative to healthy controls, but behavioural evidence for ER deficits is sparse...... naturally or dampen their emotional response to positive and negative social scenarios and associated self-beliefs. They were also given an established experimental task for comparison, involving reappraisal of negative affective picture stimuli, as well as a questionnaire of habitual ER strategies. BD...... patients showed reduced ability to down-regulate emotional responses in negative, but not positive, social scenarios relative to healthy controls and UD patients. In contrast, there were no between-group differences in the established ER task or in self-reported habitual reappraisal strategies. Findings...

  8. Overexpression of hsa-miR-939 follows by NGFR down-regulation and apoptosis reduction

    Indian Academy of Sciences (India)

    FAHIMEH HOSSEINI AGHDAEI; BAHRAM M SOLTANI; SADAT DOKANEHIIFARD; SEYED JAVAD MOWLA; MASOUD SOLEIMANI

    2017-03-01

    Neurotrophin receptors play a crucial role in neuronal survival, differentiation and regeneration. Nerve growthfactor receptor (NGFR) or P75NTR is a neurotrophin receptor that is involved in many pathological conditionsincluding cancers. Genetic factors that are involved in regulation of neurotrophin receptors are under intenseinvestigation. MiRNAs are novel regulators of signalling pathways that are candidates for regulation ofneurotrophin receptors. Computational programs predicted that NGFR gene is a bona fide target for hsa-miR-939. RT-qPCR, Western analysis and dual luciferase assay evidences indicated that NGFR transcript is targetedby hsa-miR-939. Also, hsa-miR-939 overexpression brought about down-regulation of NGFR expression in U87cell line, followed by cell death rate reduction, detected by flow cytometry. Taken together, here for the first time,hsa-miR-939 is introduced as a novel key regulator of NGFR expression and its involvement in cell death/survivalprocesses is suggested.

  9. Resistin does not down-regulate the transcription of insulin receptor promoter

    Institute of Scientific and Technical Information of China (English)

    Xiao-zhi QIAO; Xian-feng WANG; Zhe-rong XU; Yun-mei YANG

    2008-01-01

    Objective: To detect the effect of resistin on the transcription of insulin receptor promoter. Methods: Luciferase reporter gene was fused downstream of human insulin receptor promoter and the enzymatic activity of luciferase was determined in the presence or absence of resistin. The resistin expressed with plasmid was stained with antibody against Myc tag which was in frame fused with resistin coding sequence, and then imaged with confocal microscopy. Results: The treatment of pIRP-LUC transfected cells with recombinant resistin did not result in significant difference in the enzymatic activity of luciferase compared to the untreated cells. Cell staining showed that green fluorescence could be observed in the cytoplasm, but not in the nucleus. Conclusion: The results suggest that the endogenous resistin may functionally locate in the cytoplasm, but does not enter the nucleus and not down-regulate the transcription of insulin receptor promoter.

  10. Study of traits and recalcitrance reduction of field-grown COMT down-regulated switchgrass

    Energy Technology Data Exchange (ETDEWEB)

    Li, Mi; Pu, Yunqiao; Yoo, Chang Geun; Gjersing, Erica; Decker, Stephen R.; Doeppke, Crissa; Shollenberger, Todd; Tschaplinski, Timothy J.; Engle, Nancy L.; Sykes, Robert W.; Davis, Mark F.; Baxter, Holly L.; Mazarei, Mitra; Fu, Chunxiang; Dixon, Richard A.; Wang, Zeng-Yu; Neal Stewart, C.; Ragauskas, Arthur J.

    2017-01-03

    The native recalcitrance of plants hinders the biomass conversion process using current biorefinery techniques. Down-regulation of the caffeic acid O-methyltransferase (COMT) gene in the lignin biosynthesis pathway of switchgrass reduced the thermochemical and biochemical conversion recalcitrance of biomass. Due to potential environmental influences on lignin biosynthesis and deposition, studying the consequences of physicochemical changes in field-grown plants without pretreatment is essential to evaluate the performance of lignin-altered plants. We determined the chemical composition, cellulose crystallinity and the degree of its polymerization, molecular weight of hemicellulose, and cellulose accessibility of cell walls in order to better understand the fundamental features of why biomass is recalcitrant to conversion without pretreatment. The most important is to investigate whether traits and features are stable in the dynamics of field environmental effects over multiple years.

  11. Down-regulation of vimentin expression inhibits carcinoma cell migration and adhesion.

    Science.gov (United States)

    McInroy, Lorna; Määttä, Arto

    2007-08-17

    Vimentin is a type III Intermediate filament protein that is expressed frequently in epithelial carcinomas correlating with invasiveness and poor prognosis. We have analysed migration and adhesion to collagenous matrix of a panel of carcinoma cell lines. In vitro invasiveness was highest in vimentin-positive SW480 colon cancer and MDA-MB-231 breast cancer cells and the role of vimentin in these cell lines was investigated by RNA interference. Down-regulation of vimentin expression resulted in impaired migration in both scratch-wound experiments and in invasion assays through cell culture inserts coated with collagen gel. Compromised migration was observed in both cell lines, whereas cell attachment assays revealed impaired adhesion to fibrillar collagen in MDA-MB-231 cells while the adhesion of vimentin-ablated SW480 cells, that express both vimentin and keratin intermediate filaments was not affected. In conclusion, ablation of vimentin expression inhibits migration and invasion of colon and breast cancer cell lines.

  12. Lithium Down-regulates Histone Deacetylase 1 (HDAC1) and Induces Degradation of Mutant Huntingtin*

    Science.gov (United States)

    Wu, Shuai; Zheng, Shui-Di; Huang, Hong-Ling; Yan, Li-Chong; Yin, Xiao-Fei; Xu, Hai-Neng; Zhang, Kang-Jian; Gui, Jing-Hua; Chu, Liang; Liu, Xin-Yuan

    2013-01-01

    Lithium is an effective mood stabilizer that has been clinically used to treat bipolar disorder for several decades. Recent studies have suggested that lithium possesses robust neuroprotective and anti-tumor properties. Thus far, a large number of lithium targets have been discovered. Here, we report for the first time that HDAC1 is a target of lithium. Lithium significantly down-regulated HDAC1 at the translational level by targeting HDAC1 mRNA. We also showed that depletion of HDAC1 is essential for the neuroprotective effects of lithium and for the lithium-mediated degradation of mutant huntingtin through the autophagic pathway. Our studies explain the multiple functions of lithium and reveal a novel mechanism for the function of lithium in neurodegeneration. PMID:24165128

  13. Vitamin A induces inhibitory histone methylation modifications and down-regulates trained immunity in human monocytes

    DEFF Research Database (Denmark)

    Arts, Rob J W; Blok, Bastiaan A; van Crevel, Reinout

    2015-01-01

    Epidemiologic studies suggest that VAS has long-lasting immunomodulatory effects. We hypothesized that ATRA inhibits inflammatory cytokines in a model of trained immunity in monocytes by inducing epigenetic reprogramming through histone modifications. We used an previously described in vitro model...... of trained immunity, in which adherent monocytes of healthy volunteers were incubated for 24 h with BCG in the presence or absence of ATRA. After washing the cells, they were incubated for an additional 6 d in culture medium and restimulated with microbial ligands, and cytokine production was assessed. ATRA...... cytokine production. In addition to H3K9me3, the stimulatory histone mark H3K4me3 was down-regulated by ATRA at several promoter locations of cytokine genes. Therefore, we can conclude that ATRA inhibits cytokine production in models of direct stimulation or BCG-induced trained immunity...

  14. Natural polyphenols down-regulate universal stress protein in Mycobacterium tuberculosis: An in-silico approach

    Directory of Open Access Journals (Sweden)

    M Vijey Aanandhi

    2014-01-01

    Full Text Available Universal stress protein (USP is a novel target to overcome the tuberculosis resistance. Our present study enlightens the possibilities of some natural polyphenols as an antioxidant for USP. The study has shown some molecular simulations of some selected natural antioxidants with USP. We have considered USP (Rv1636 strain for homology modeling and the selected template was taken for the docking study. Curcumin, catechin, reservetrol has shown ARG 136 (1.8Ε hydrogen bonding and two ionic bonding with carboxyl group of curcumin with LEU 130 (3.3Ε and ASN 144 (3.4Ε respectively. INH was taken for the standard molecule to perform molecular simulation. It showed poor binding interaction with the target, that is, −5.18 kcal, and two hydrogen bonding with SER 140 (1.887Ε, ARG 147 (2.064Ε respectively. The study indicates possible new generation curcumin analogue for future therapy to down-regulate USP.

  15. Hydrogen peroxide down-regulates inositol 1,4,5-trisphosphate receptor content through proteasome activation.

    Science.gov (United States)

    Martín-Garrido, A; Boyano-Adánez, M C; Alique, M; Calleros, L; Serrano, I; Griera, M; Rodríguez-Puyol, D; Griendling, K K; Rodríguez-Puyol, M

    2009-11-15

    Hydrogen peroxide (H(2)O(2)) is implicated in the regulation of signaling pathways leading to changes in vascular smooth muscle function. Contractile effects produced by H(2)O(2) are due to the phosphorylation of myosin light chain kinase triggered by increases in intracellular calcium (Ca(2+)) from intracellular stores or influx of extracellular Ca(2+). One mechanism for mobilizing such stores involves the phosphoinositide pathway. Inositol 1,4,5-trisphosphate (IP(3)) mobilizes intracellular Ca(2+) by binding to a family of receptors (IP(3)Rs) on the endoplasmic-sarcoplasmic reticulum that act as ligand-gated Ca(2+) channels. IP(3)Rs can be rapidly ubiquitinated and degraded by the proteasome, causing a decrease in cellular IP(3)R content. In this study we show that IP(3)R(1) and IP(3)R(3) are down-regulated when vascular smooth muscle cells (VSMC) are stimulated by H(2)O(2), through an increase in proteasome activity. Moreover, we demonstrate that the decrease in IP(3)R by H(2)O(2) is accompanied by a reduction in calcium efflux induced by IP(3) in VSMC. Also, we observed that angiotensin II (ANGII) induces a decrease in IP(3)R by activation of NADPH oxidase and that preincubation with H(2)O(2) decreases ANGII-mediated calcium efflux and planar cell surface area in VSMC. The decreased IP(3) receptor content observed in cells was also found in aortic rings, which exhibited a decreased ANGII-dependent contraction after treatment with H(2)O(2). Altogether, these results suggest that H(2)O(2) mediates IP(3)R down-regulation via proteasome activity.

  16. Steatogenesis in adult-onset type II citrullinemia is associated with down-regulation of PPARα.

    Science.gov (United States)

    Komatsu, Michiharu; Kimura, Takefumi; Yazaki, Masahide; Tanaka, Naoki; Yang, Yang; Nakajima, Takero; Horiuchi, Akira; Fang, Zhong-Ze; Joshita, Satoru; Matsumoto, Akihiro; Umemura, Takeji; Tanaka, Eiji; Gonzalez, Frank J; Ikeda, Shu-Ichi; Aoyama, Toshifumi

    2015-03-01

    SLC25A13 (citrin or aspartate-glutamate carrier 2) is located in the mitochondrial membrane in the liver and its genetic deficiency causes adult-onset type II citrullinemia (CTLN2). CTLN2 is one of the urea cycle disorders characterized by sudden-onset hyperammonemia due to reduced argininosuccinate synthase activity. This disorder is frequently accompanied with hepatosteatosis in the absence of obesity and ethanol consumption. However, the precise mechanism of steatogenesis remains unclear. The expression of genes associated with fatty acid (FA) and triglyceride (TG) metabolism was examined using liver samples obtained from 16 CTLN2 patients and compared with 7 healthy individuals. Although expression of hepatic genes associated with lipogenesis and TG hydrolysis was not changed, the mRNAs encoding enzymes/proteins involved in FA oxidation (carnitine palmitoyl-CoA transferase 1α, medium- and very-long-chain acyl-CoA dehydrogenases, and acyl-CoA oxidase 1), very-low-density lipoprotein secretion (microsomal TG transfer protein), and FA transport (CD36 and FA-binding protein 1), were markedly suppressed in CTLN2 patients. Serum concentrations of ketone bodies were also decreased in these patients, suggesting reduced mitochondrial β-oxidation activity. Consistent with these findings, the expression of peroxisome proliferator-activated receptor α (PPARα), a master regulator of hepatic lipid metabolism, was significantly down-regulated. Hepatic PPARα expression was inversely correlated with severity of steatosis and circulating ammonia and citrulline levels. Additionally, phosphorylation of c-Jun-N-terminal kinase was enhanced in CTLN2 livers, which was likely associated with lower hepatic PPARα. Collectively, down-regulation of PPARα is associated with steatogenesis in CTLN2 patients. These findings provide a novel link between urea cycle disorder, lipid metabolism, and PPARα.

  17. Down-regulation of NDRG1 promotes migration of cancer cells during reoxygenation.

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    Liang-Chuan Lai

    Full Text Available One characteristic of tumor microenvironment is oxygen fluctuation, which results from hyper-proliferation and abnormal metabolism of tumor cells as well as disorganized neo-vasculature. Reoxygenation of tumors can induce oxidative stress, which leads to DNA damage and genomic instability. Although the cellular responses to hypoxia are well known, little is known about the dynamic response upon reoxygenation. In order to investigate the transcriptional responses of tumor adaptation to reoxygenation, breast cancer MCF-7 cells were cultured under 0.5% oxygen for 24 h followed by 24 h of reoxygenation in normoxia. Cells were harvested at 0, 1, 4, 8, 12, and 24 h during reoxygenation. The transcriptional profile of MCF-7 cells upon reoxygenation was examined using Illumina Human-6 v3 BeadChips. We identified 127 differentially expressed genes, of which 53.1% were up-regulated and 46.9% were down-regulated upon reoxygenation. Pathway analysis revealed that the HIF-1-alpha transcription factor network and validated targets of C-MYC transcriptional activation were significantly enriched in these differentially expressed genes. Among these genes, a subset of interest genes was further validated by quantitative reverse-transcription PCR. In particular, human N-MYC down-regulated gene 1 (NDRG1 was highly suppressed upon reoxygenation. NDRG1 is associated with a variety of stress and cell growth-regulatory conditions. To determine whether NDRG1 plays a role in reoxygenation, NDRG1 protein was overexpressed in MCF-7 cells. Upon reoxygenation, overexpression of NDRG1 significantly inhibited cell migration. Our results revealed the dynamic nature of gene expression in MCF-7 cells upon reoxygenation and demonstrated that NDRG1 is involved in tumor adaptation to reoxygenation.

  18. In vitro ischemia triggers a transcriptional response to down-regulate synaptic proteins in hippocampal neurons.

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    Joana Fernandes

    Full Text Available Transient global cerebral ischemia induces profound changes in the transcriptome of brain cells, which is partially associated with the induction or repression of genes that influence the ischemic response. However, the mechanisms responsible for the selective vulnerability of hippocampal neurons to global ischemia remain to be clarified. To identify molecular changes elicited by ischemic insults, we subjected hippocampal primary cultures to oxygen-glucose deprivation (OGD, an in vitro model for global ischemia that resulted in delayed neuronal death with an excitotoxic component. To investigate changes in the transcriptome of hippocampal neurons submitted to OGD, total RNA was extracted at early (7 h and delayed (24 h time points after OGD and used in a whole-genome RNA microarray. We observed that at 7 h after OGD there was a general repression of genes, whereas at 24 h there was a general induction of gene expression. Genes related with functions such as transcription and RNA biosynthesis were highly regulated at both periods of incubation after OGD, confirming that the response to ischemia is a dynamic and coordinated process. Our analysis showed that genes for synaptic proteins, such as those encoding for PICK1, GRIP1, TARPγ3, calsyntenin-2/3, SAPAP2 and SNAP-25, were down-regulated after OGD. Additionally, OGD decreased the mRNA and protein expression levels of the GluA1 AMPA receptor subunit as well as the GluN2A and GluN2B subunits of NMDA receptors, but increased the mRNA expression of the GluN3A subunit, thus altering the composition of ionotropic glutamate receptors in hippocampal neurons. Together, our results present the expression profile elicited by in vitro ischemia in hippocampal neurons, and indicate that OGD activates a transcriptional program leading to down-regulation in the expression of genes coding for synaptic proteins, suggesting that the synaptic proteome may change after ischemia.

  19. Down-regulated CFTR During Aging Contributes to Benign Prostatic Hyperplasia.

    Science.gov (United States)

    Xie, Chen; Sun, Xiao; Chen, Jing; Ng, Chi Fai; Lau, Kin Mang; Cai, Zhiming; Jiang, Xiaohua; Chan, Hsiao Chang

    2015-08-01

    Benign prostatic hyperplasia (BPH) is a hyper-proliferative disease of the aging prostate; however, the exact mechanism underlying the development of BPH remains incompletely understood. The present study investigated the possible involvement of the cystic fibrosis transmembrane conductance regulator (CFTR), which has been previously shown to negatively regulate nuclear factor-κB (NF-κB)/cyclooxygenase 2 (COX2)/prostaglandin E2 (PGE2) pathway, in the pathogenesis of BPH. Our results showed decreasing CFTR and increasing COX2 expression in rat prostate tissues with aging. Furthermore, suppression of CFTR led to increased expression of COX2 and over-production of PGE2 in a normal human prostate epithelial cell line (PNT1A) with elevated NF-κB activity. PGE2 stimulated the proliferation of primary rat prostate stromal cells but not epithelial cells, with increased PCNA expression. In addition, the condition medium from PNT1A cells after inhibition or knockdown of CFTR promoted cell proliferation of prostate stromal cells which could be reversed by COX2 or NF-κB inhibitor. More importantly, the involvement of CFTR in BPH was further demonstrated by the down-regulation of CFTR and up-regulation of COX2/NF-κB in human BPH samples. The present results suggest that CFTR may be involved in regulating PGE2 production through its negative regulation on NF-κB/COX2 pathway in prostate epithelial cells, which consequently stimulates cell growth of prostate stromal cells. The overstimulation of prostate stromal cell proliferation by down-regulation of CFTR-enhanced PGE2 production and release during aging may contribute to the development of BPH.

  20. Microbial symbionts in insects influence down-regulation of defense genes in maize.

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    Kelli L Barr

    Full Text Available Diabrotica virgifera virgifera larvae are root-feeding insects and significant pests to maize in North America and Europe. Little is known regarding how plants respond to insect attack of roots, thus complicating the selection for plant defense targets. Diabrotica virgifera virgifera is the most successful species in its genus and is the only Diabrotica beetle harboring an almost species-wide Wolbachia infection. Diabrotica virgifera virgifera are infected with Wolbachia and the typical gut flora found in soil-living, phytophagous insects. Diabrotica virgifera virgifera larvae cannot be reared aseptically and thus, it is not possible to observe the response of maize to effects of insect gut flora or other transient microbes. Because Wolbachia are heritable, it is possible to investigate whether Wolbachia infection affects the regulation of maize defenses. To answer if the success of Diabrotica virgifera virgifera is the result of microbial infection, Diabrotica virgifera virgifera were treated with antibiotics to eliminate Wolbachia and a microarray experiment was performed. Direct comparisons made between the response of maize root tissue to the feeding of antibiotic treated and untreated Diabrotica virgifera virgifera show down-regulation of plant defenses in the untreated insects compared to the antibiotic treated and control treatments. Results were confirmed via QRT-PCR. Biological and behavioral assays indicate that microbes have integrated into Diabrotica virgifera virgifera physiology without inducing negative effects and that antibiotic treatment did not affect the behavior or biology of the insect. The expression data and suggest that the pressure of microbes, which are most likely Wolbachia, mediate the down-regulation of many maize defenses via their insect hosts. This is the first report of a potential link between a microbial symbiont of an insect and a silencing effect in the insect host plant. This is also the first expression

  1. Hyperinsulinaemia down-regulates TLR4 expression in the mammalian heart

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    Melody ede Laat

    2014-07-01

    Full Text Available Toll-like receptors (TLR are key regulators of innate immune and inflammatory responses and their activation is linked to impaired glucose metabolism during metabolic disease. Determination of whether TLR4 signalling can be activated in the heart by insulin may shed light on the pathogenesis of diabetic cardiomyopathy, a process that is often complicated by obesity and insulin resistance. The aim of the current study was to determine if supraphysiological insulin concentrations alter the expression of TLR4, markers of TLR4 signalling and glucose transporters (GLUTs in the heart. First, the effect of insulin on TLR4 protein expression was investigated in vitro in isolated rat cardiac myocytes. Secondly, protein expression of TLR4, the pro-inflammatory cytokines IL-6 and TNF-α, suppressor of cytokine signalling 3 and GLUTs (1, 4, 8, 12 were examined in the equine ventricular myocardium following a prolonged, euglycaemic hyperinsulinaemic clamp. Down-regulation of TLR4 in plasma membrane-rich fractions of rat cardiac myocytes was observed after incubation with a supraphysiologic concentration of insulin as well as in the equine myocardium after prolonged insulin infusion. Further, cardiac TLR4 expression was negatively correlated with serum insulin concentration. Markers of cardiac TLR4 signalling and GLUT expression were not affected by hyperinsulinaemia and concomitant TLR4 down-regulation. Since TLRs are major determinants of the inflammatory response, our findings suggest that insulin infusion exerts an anti-inflammatory effect in the hearts of non-obese individuals. Understanding the regulation of cardiac TLR4 signalling during metabolic dysfunction will facilitate improved management of cardiac sequelae to metabolic syndrome and diabetes.

  2. BMP4 and LGL1 are Down Regulated in an Ovine Model of Congenital Diaphragmatic Hernia

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    Heather eEmmerton-Coughlin

    2014-11-01

    Full Text Available Background/Purpose: The molecular pathophysiology of lung hypoplasia in congenital diaphragmatic hernia (CDH remains poorly understood. The Wnt signaling pathway and downstream targets, such as bone morphogenetic proteins (BMP 4 and other factors such as late gestation lung protein 1 (LGL1, are essential to normal lung development. Nitrofen-induced hypoplastic CDH rodent lungs demonstrate down regulation of the Wnt pathway including BMP4 and reduced LGL1 expression. The aim of the current study was to examine the molecular pathophysiology associated with a surgically induced CDH in an ovine model. Methods: Left thoracotomy was performed at 80 days in 14 fetal sheep; CDH was created in 7 experimental animals. Lungs were harvested at 136 days (term=145d. Lung weight and mean terminal bronchiole density (MTBD were measured to determine the degree of pulmonary hypoplasia. Quantitative real time PCR was undertaken to analyze Wnt2, Wnt7b, BMP4 and LGL1 mRNA expression. Results: Total lung weight was decreased while MTBD was increased in the CDH group (p<0.05, confirming pulmonary hypoplasia. BMP4 and LGL1 mRNA was significantly reduced in CDH lungs (p<0.05. Wnt2 mRNA was decreased, although not significantly (p<0.06. Conclusions: For the first time, down regulation of BMP4 and Lgl1 are reported in an ovine CDH model. In contrast to other animal models, these changes are persistent to near term. These findings suggest that mechanical compression from herniated viscera may play a more important role in causing pulmonary hypoplasia in CDH, rather than a primary defect in lung organogenesis.

  3. PGC-1alpha down-regulation affects the antioxidant response in Friedreich's ataxia.

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    Daniele Marmolino

    Full Text Available BACKGROUND: Cells from individuals with Friedreich's ataxia (FRDA show reduced activities of antioxidant enzymes and cannot up-regulate their expression when exposed to oxidative stress. This blunted antioxidant response may play a central role in the pathogenesis. We previously reported that Peroxisome Proliferator Activated Receptor Gamma (PPARgamma Coactivator 1-alpha (PGC-1alpha, a transcriptional master regulator of mitochondrial biogenesis and antioxidant responses, is down-regulated in most cell types from FRDA patients and animal models. METHODOLOGY/PRINCIPAL FINDINGS: We used primary fibroblasts from FRDA patients and the knock in-knock out animal model for the disease (KIKO mouse to determine basal superoxide dismutase 2 (SOD2 levels and the response to oxidative stress induced by the addition of hydrogen peroxide. We measured the same parameters after pharmacological stimulation of PGC-1alpha. Compared to control cells, PGC-1alpha and SOD2 levels were decreased in FRDA cells and did not change after addition of hydrogen peroxide. PGC-1alpha direct silencing with siRNA in control fibroblasts led to a similar loss of SOD2 response to oxidative stress as observed in FRDA fibroblasts. PGC-1alpha activation with the PPARgamma agonist (Pioglitazone or with a cAMP-dependent protein kinase (AMPK agonist (AICAR restored normal SOD2 induction. Treatment of the KIKO mice with Pioglitazone significantly up-regulates SOD2 in cerebellum and spinal cord. CONCLUSIONS/SIGNIFICANCE: PGC-1alpha down-regulation is likely to contribute to the blunted antioxidant response observed in cells from FRDA patients. This response can be restored by AMPK and PPARgamma agonists, suggesting a potential therapeutic approach for FRDA.

  4. PGC-1alpha Down-Regulation Affects the Antioxidant Response in Friedreich's Ataxia

    Science.gov (United States)

    Marmolino, Daniele; Manto, Mario; Acquaviva, Fabio; Vergara, Paola; Ravella, Ajay; Monticelli, Antonella; Pandolfo, Massimo

    2010-01-01

    Background Cells from individuals with Friedreich's ataxia (FRDA) show reduced activities of antioxidant enzymes and cannot up-regulate their expression when exposed to oxidative stress. This blunted antioxidant response may play a central role in the pathogenesis. We previously reported that Peroxisome Proliferator Activated Receptor Gamma (PPARγ) Coactivator 1-alpha (PGC-1α), a transcriptional master regulator of mitochondrial biogenesis and antioxidant responses, is down-regulated in most cell types from FRDA patients and animal models. Methodology/Principal Findings We used primary fibroblasts from FRDA patients and the knock in-knock out animal model for the disease (KIKO mouse) to determine basal superoxide dismutase 2 (SOD2) levels and the response to oxidative stress induced by the addition of hydrogen peroxide. We measured the same parameters after pharmacological stimulation of PGC-1α. Compared to control cells, PGC-1α and SOD2 levels were decreased in FRDA cells and did not change after addition of hydrogen peroxide. PGC-1α direct silencing with siRNA in control fibroblasts led to a similar loss of SOD2 response to oxidative stress as observed in FRDA fibroblasts. PGC-1α activation with the PPARγ agonist (Pioglitazone) or with a cAMP-dependent protein kinase (AMPK) agonist (AICAR) restored normal SOD2 induction. Treatment of the KIKO mice with Pioglitazone significantly up-regulates SOD2 in cerebellum and spinal cord. Conclusions/Significance PGC-1α down-regulation is likely to contribute to the blunted antioxidant response observed in cells from FRDA patients. This response can be restored by AMPK and PPARγ agonists, suggesting a potential therapeutic approach for FRDA. PMID:20383327

  5. Cholesterol Down-Regulates BK Channels Stably Expressed in HEK 293 Cells

    Science.gov (United States)

    Deng, Xiu-Ling; Sun, Hai-Ying; Li, Gui-Rong

    2013-01-01

    Cholesterol is one of the major lipid components of the plasma membrane in mammalian cells and is involved in the regulation of a number of ion channels. The present study investigates how large conductance Ca2+-activated K+ (BK) channels are regulated by membrane cholesterol in BK-HEK 293 cells expressing both the α-subunit hKCa1.1 and the auxiliary β1-subunit or in hKCa1.1-HEK 293 cells expressing only the α-subunit hKCa1.1 using approaches of electrophysiology, molecular biology, and immunocytochemistry. Membrane cholesterol was depleted in these cells with methyl-β-cyclodextrin (MβCD), and enriched with cholesterol-saturated MβCD (MβCD-cholesterol) or low-density lipoprotein (LDL). We found that BK current density was decreased by cholesterol enrichment in BK-HEK 293 cells, with a reduced expression of KCa1.1 protein, but not the β1-subunit protein. This effect was fully countered by the proteasome inhibitor lactacystin or the lysosome function inhibitor bafilomycin A1. Interestingly, in hKCa1.1-HEK 293 cells, the current density was not affected by cholesterol enrichment, but directly decreased by MβCD, suggesting that the down-regulation of BK channels by cholesterol depends on the auxiliary β1-subunit. The reduced KCa1.1 channel protein expression was also observed in cultured human coronary artery smooth muscle cells with cholesterol enrichment using MβCD-cholesterol or LDL. These results demonstrate the novel information that cholesterol down-regulates BK channels by reducing KCa1.1 protein expression via increasing the channel protein degradation, and the effect is dependent on the auxiliary β1-subunit. PMID:24260325

  6. Additional nitrogen fertilization at heading time of rice down-regulates cellulose synthesis in seed endosperm.

    Science.gov (United States)

    Midorikawa, Keiko; Kuroda, Masaharu; Terauchi, Kaede; Hoshi, Masako; Ikenaga, Sachiko; Ishimaru, Yoshiro; Abe, Keiko; Asakura, Tomiko

    2014-01-01

    The balance between carbon and nitrogen is a key determinant of seed storage components, and thus, is of great importance to rice and other seed-based food crops. To clarify the influence of the rhizosphere carbon/nitrogen balance during the maturation stage of several seed components, transcriptome analysis was performed on the seeds from rice plants that were provided additional nitrogen fertilization at heading time. As a result, it was assessed that genes associated with molecular processes such as photosynthesis, trehalose metabolism, carbon fixation, amino acid metabolism, and cell wall metabolism were differentially expressed. Moreover, cellulose and sucrose synthases, which are involved in cellulose synthesis, were down-regulated. Therefore, we compared cellulose content of mature seeds that were treated with additional nitrogen fertilization with those from control plants using calcofluor staining. In these experiments, cellulose content in endosperm from plants receiving additional nitrogen fertilization was less than that in control endosperm. Other starch synthesis-related genes such as starch synthase 1, starch phosphorylase 2, and branching enzyme 3 were also down-regulated, whereas some α-amylase and β-amylase genes were up-regulated. On the other hand, mRNA expression of amino acid biosynthesis-related molecules was up-regulated. Moreover, additional nitrogen fertilization caused accumulation of storage proteins and up-regulated Cys-poor prolamin mRNA expression. These data suggest that additional nitrogen fertilization at heading time changes the expression of some storage substance-related genes and reduces cellulose levels in endosperm.

  7. Mechanism of Wnt signaling induced down regulation of mrhl long non-coding RNA in mouse spermatogonial cells

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    Akhade, Vijay Suresh; Dighe, Shrinivas Nivrutti; Kataruka, Shubhangini; Rao, Manchanahalli R. Satyanarayana

    2016-01-01

    Long non coding RNAs (lncRNAs) have emerged as important regulators of various biological processes. LncRNAs also behave as response elements or targets of signaling pathway(s) mediating cellular function. Wnt signaling is important in regulating mammalian spermatogenesis. Mrhl RNA negatively regulates canonical Wnt pathway and gets down regulated upon Wnt signaling activation in mouse spermatogonial cells. Also, mrhl RNA regulates expression of genes pertaining to Wnt pathway and spermatogenesis by binding to chromatin. In the present study, we delineate the detailed molecular mechanism of Wnt signaling induced mrhl RNA down regulation in mouse spermatogonial cells. Mrhl RNA has an independent transcription unit and our various experiments like Chromatin Immunoprecipitation (in cell line as well as mouse testis) and shRNA mediated down regulation convincingly show that β-catenin and TCF4, which are the key effector proteins of the Wnt signaling pathway are required for down regulation of mrhl RNA. We have identified Ctbp1 as the co-repressor and its occupancy on mrhl RNA promoter depends on both β-catenin and TCF4. Upon Wnt signaling activation, Ctbp1 mediated histone repression marks increase at the mrhl RNA promoter. We also demonstrate that Wnt signaling induced mrhl RNA down regulation results in an up regulation of various meiotic differentiation marker genes. PMID:26446991

  8. Simvastatin induces NFκB/p65 down-regulation and JNK1/c-Jun/ATF-2 activation, leading to matrix metalloproteinase-9 (MMP-9) but not MMP-2 down-regulation in human leukemia cells.

    Science.gov (United States)

    Chen, Ying-Jung; Chang, Long-Sen

    2014-12-15

    The aim of the present study was to explore the signaling pathways associated with the effect of simvastatin on matrix metalloproteinase-2 (MMP-2)/MMP-9 expression in human leukemia K562 cells. In sharp contrast to its insignificant effect on MMP-2, simvastatin down-regulated MMP-9 protein expression and mRNA levels in K562 cells. Simvastatin-induced Pin1 down-regulation evoked NFκB/p65 degradation. Meanwhile, simvastatin induced JNK-mediated c-Jun and ATF-2 activation. Over-expression of Pin1 suppressed simvastatin-induced MMP-9 down-regulation. Treatment with SP600125 (a JNK inhibitor) or knock-down of JNK1 reduced MMP-2 expression in simvastatin-treated cells. Simvastatin enhanced the binding of c-Jun/ATF-2 with the MMP-2 promoter. Down-regulation of c-Jun or ATF-2 by siRNA revealed that c-Jun/ATF-2 activation was crucial for MMP-2 expression. Suppression of p65 activation or knock-down of Pin1 by shRNA reduced MMP-2 and MMP-9 expression in K562 cells. Over-expression of constitutively active JNK1 rescued MMP-2 expression in Pin1 shRNA-transfected cells. Simvastatin treatment also suppressed MMP-9 but not MMP-2 expression in human leukemia U937 and KU812 cells. Taken together, our data indicate that simvastatin-induced p65 instability leads to MMP-9 down-regulation in leukemia cells, while simvastatin-induced JNK1/c-Jun/ATF-2 activation maintains the MMP-2 expression underlying p65 down-regulation. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Genetically Determined Insulin Resistance is Characterized by Down-Regulation of Mitochondrial Oxidative Metabolism in Human Skeletal Muscle

    DEFF Research Database (Denmark)

    Kristensen, Jonas M; Skov, Vibe; Wojtaszewski, Jørgen

    2010-01-01

    Transcriptional profiling of skeletal muscle from patients with type 2 diabetes and high-risk individuals have demonstrated a co-ordinated down-regulation of oxidative phosphorylation (OxPhos) genes, suggesting a link between insulin resistance and mitochondrial dysfunction. However, whether...... mitochondrial dysfunction is a cause or consequence of insulin resistance remains to be clarified. In the present study, we tested the hypothesis that mitochondrial oxidative metabolism was down-regulated in skeletal muscle of patients with genetically determined insulin resistance. Skeletal muscle biopsies.......02), and complex V (ATP5B; p=0.005). Our data demonstrate that genetically determined insulin resistance is associated with a co-ordinated down-regulation of OxPhos components both at the transcriptional and translational level. These findings suggest that an impaired biological response to insulin in skeletal...

  10. miR-191 regulates mouse erythroblast enucleation by down-regulating Riok3 and Mxi1.

    Science.gov (United States)

    Zhang, Lingbo; Flygare, Johan; Wong, Piu; Lim, Bing; Lodish, Harvey F

    2011-01-15

    Using RNA-seq technology, we found that the majority of microRNAs (miRNAs) present in CFU-E erythroid progenitors are down-regulated during terminal erythroid differentiation. Of the developmentally down-regulated miRNAs, ectopic overexpression of miR-191 blocks erythroid enucleation but has minor effects on proliferation and differentiation. We identified two erythroid-enriched and developmentally up-regulated genes, Riok3 and Mxi1, as direct targets of miR-191. Knockdown of either Riok3 or Mxi1 blocks enucleation, and either physiological overexpression of miR-191 or knockdown of Riok3 or Mxi1 blocks chromatin condensation. Thus, down-regulation of miR-191 is essential for erythroid chromatin condensation and enucleation by allowing up-regulation of Riok3 and Mxi1.

  11. CDK Inhibitors Roscovitine and CR8 Trigger Mcl-1 Down-Regulation and Apoptotic Cell Death in Neuroblastoma Cells.

    Science.gov (United States)

    Bettayeb, Karima; Baunbæk, Dianne; Delehouze, Claire; Loaëc, Nadège; Hole, Alison J; Baumli, Sonja; Endicott, Jane A; Douc-Rasy, Setha; Bénard, Jean; Oumata, Nassima; Galons, Hervé; Meijer, Laurent

    2010-04-01

    Neuroblastoma (NB), the most frequent extracranial solid tumor of children accounting for nearly 15% of all childhood cancer mortality, displays overexpression of antiapoptotic Bcl-2 and Mcl-1 in aggressive forms of the disease. The clinical phase 2 drug roscovitine (CYC202, seliciclib), a relatively selective inhibitor of cyclin-dependent kinases (CDKs), and CR8, a recently developed and more potent analog, induce concentration-dependent apoptotic cell death of NB cells (average IC(50) values: 24.2 µM and 0.4 µM for roscovitine and CR8, respectively). Both roscovitine and CR8 trigger rapid down-regulation of the short-lived survival factor Mcl-1 in the 9 investigated human NB cell lines. This effect was further analyzed in the human SH-SY5Y NB cell line. Down-regulation of Mcl-1 appears to depend on inhibition of CDKs rather than on interaction of roscovitine and CR8 with their secondary targets. CR8 is an adenosine triphosphate-competitive inhibitor of CDK9, and the structure of a CDK9/cyclin T/CR8 complex is described. Mcl-1 down-regulation occurs both at the mRNA and protein levels. This effect can be accounted for by a reduction in Mcl-1 protein synthesis, under stable Mcl-1 degradation conditions. Mcl-1 down-regulation is accompanied by a transient increase in free Noxa, a proapoptotic factor. Mcl-1 down-regulation occurs independently of the presence or up-regulation of p53 and of the MYCN status. Taken together, these results suggest that the clinical drug roscovitine and its novel analog CR8 induce apoptotic tumor cell death by down-regulating Mcl-1, a key survival factor expressed in all NB cell lines. CDK inhibition may thus constitute a new approach to treat refractory high-risk NB.

  12. Diabetic HDL Is Dysfunctional in Stimulating Endothelial Cell Migration and Proliferation Due to Down Regulation of SR-BI Expression

    Science.gov (United States)

    Pan, Bing; Ma, Yijing; Ren, Hui; He, Yubin; Wang, Yongyu; Lv, Xiaofeng; Liu, Donghui; Ji, Liang; Yu, Baoqi; Wang, Yuhui; Chen, Y. Eugene; Pennathur, Subramaniam; Smith, Jonathan D.; Liu, George; Zheng, Lemin

    2012-01-01

    Background Diabetic HDL had diminished capacity to stimulate endothelial cell (EC) proliferation, migration, and adhesion to extracellular matrix. The mechanism of such dysfunction is poorly understood and we therefore sought to determine the mechanistic features of diabetic HDL dysfunction. Methodology/Principal Findings We found that the dysfunction of diabetic HDL on human umbilical vein endothelial cells (HUVECs) was associated with the down regulation of the HDL receptor protein, SR-BI. Akt-phosphorylation in HUVECs was induced in a biphasic manner by normal HDL. While diabetic HDL induced Akt phosphorylation normally after 20 minutes, the phosphorylation observed 24 hours after diabetic HDL treatment was reduced. To determine the role of SR-BI down regulation on diminished EC responses of diabetic HDL, Mouse aortic endothelial cells (MAECs) were isolated from wild type and SR-BI (−/−) mice, and treated with normal and diabetic HDL. The proliferative and migratory effects of normal HDL on wild type MAECs were greatly diminished in SR-BI (−/−) cells. In contrast, response to diabetic HDL was impaired in both types suggesting diminished effectiveness of diabetic HDL on EC proliferation and migration might be due to the down regulation of SR-BI. Additionally, SR-BI down regulation diminishes diabetic HDL’s capacity to activate Akt chronically. Conclusions/Significance Diabetic HDL was dysfunctional in promoting EC proliferation, migration, and adhesion to matrix which was associated with the down-regulation of SR-BI. Additionally, SR-BI down regulation diminishes diabetic HDL’s capacity to activate Akt chronically. PMID:23133640

  13. Protein Kinase C-{delta} mediates down-regulation of heterogeneous nuclear ribonucleoprotein K protein: involvement in apoptosis induction

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Feng-Hou [NO.3 People' s Hospital affiliated to Shanghai Jiao-Tong University School of Medicine (SJTU-SM), Shanghai 201900 (China); The Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of National Ministry of Education, Shanghai Jiao-Tong University School of Medicine (SJTU-SM), Shanghai 200025 (China); Wu, Ying-Li [The Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of National Ministry of Education, Shanghai Jiao-Tong University School of Medicine (SJTU-SM), Shanghai 200025 (China); Zhao, Meng [Institute of Health Science, SJTU-SM/Shanghai Institutes for Biological Science, Chinese Academy of Sciences, Shanghai (China); Liu, Chuan-Xu; Wang, Li-Shun [The Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of National Ministry of Education, Shanghai Jiao-Tong University School of Medicine (SJTU-SM), Shanghai 200025 (China); Chen, Guo-Qiang, E-mail: chengq@shsmu.edu.cn [The Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of National Ministry of Education, Shanghai Jiao-Tong University School of Medicine (SJTU-SM), Shanghai 200025 (China); Institute of Health Science, SJTU-SM/Shanghai Institutes for Biological Science, Chinese Academy of Sciences, Shanghai (China)

    2009-11-15

    We reported previously that NSC606985, a camptothecin analogue, induces apoptosis of acute myeloid leukemia (AML) cells through proteolytic activation of protein kinase C delta ({Delta}PKC-{delta}). By subcellular proteome analysis, heterogeneous nuclear ribonucleoprotein K (hnRNP K) was identified as being significantly down-regulated in NSC606985-treated leukemic NB4 cells. HnRNP K, a docking protein for DNA, RNA, and transcriptional or translational molecules, is implicated in a host of processes involving the regulation of gene expression. However, the molecular mechanisms of hnRNP K reduction and its roles during apoptosis are still not understood. In the present study, we found that, following the appearance of the {Delta}PKC-{delta}, hnRNP K protein was significantly down-regulated in NSC606985, doxorubicin, arsenic trioxide and ultraviolet-induced apoptosis. We further provided evidence that {Delta}PKC-{delta} mediated the down-regulation of hnRNP K protein during apoptosis: PKC-{delta} inhibitor could rescue the reduction of hnRNP K; hnRNP K failed to be decreased in PKC-{delta}-deficient apoptotic KG1a cells; conditional induction of {Delta}PKC-{delta} in U937T cells directly down-regulated hnRNP K protein. Moreover, the proteasome inhibitor also inhibited the down-regulation of hnRNP K protein by apoptosis inducer and the conditional expression of {Delta}PKC-{delta}. More intriguingly, the suppression of hnRNP K with siRNA transfection significantly induced apoptosis. To our knowledge, this is the first demonstration that proteolytically activated PKC-{delta} down-regulates hnRNP K protein in a proteasome-dependent manner, which plays an important role in apoptosis induction.

  14. 垂体降调节方案的比较%Comparison between different pituitary down-regulation protocols

    Institute of Scientific and Technical Information of China (English)

    黄孙兴; 周灿权

    2012-01-01

    Pituitary down-regulation plays an important role in the development of assisted reproductive technology. It significantly improves the outcome of in vitro fertilization (IVF) and promotes relevant basic research in reproductive physiology. Since the emergence of this technique, many studies have been done to investigate the clinic effect of the different protocols. It took more than 20 years to identify some optimal protocols with the GnRH analogues in IVF, including long protocol, short protocol and GnRH antagonist protocol. Comparison of the difference among these classic protocols can provide theoretical basis for establishing the individual down-regulation protocol, as well as relevant clinical experience.

  15. Role of calcium signaling in down-regulation of aggrecan induced by cyclic tensile strain in annulus fibrosus cells

    Institute of Scientific and Technical Information of China (English)

    GUO Zhi-liang; ZHOU Yue; LI Hua-zhuang; CAO Guo-yong; TENG Hai-jun

    2006-01-01

    Objective:To study the role of intracellular calcium signal pathway in the down-regulation of aggrecan induced by cyclic tensile strain in the annulus fibrosus cells. Methods :The expression of aggrecan mRNA and core protein were respectively detected with RT-PCR and western blot after the channels transmitting calcium ions were blocked with EGTA, gadolinium and verapamil. Results:EGTA, gadolinium and verapamil partially prevented the effects of cyclic tensile strain on the expression of aggrecan in annulus fibrosus cells. Conclusion:The calcium signaling is involved in the down-regulation of proteoglycan resulting from cyclic tensile strain in the annulus fibrosus cells.

  16. Down-regulation of progesterone receptor membrane component 1 (PGRMC1 in peripheral nucleated blood cells associated with premature ovarian failure (POF and polycystic ovary syndrome (PCOS

    Directory of Open Access Journals (Sweden)

    Karlström Per-Olof

    2010-06-01

    Full Text Available Abstract Background Progesterone receptor membrane component 1 (PGRMC1 is a member of a progesterone-binding complex implicated in female reproduction. We aimed i to determine the natural expression of PGRMC1 in peripheral nucleated blood cells throughout the menstrual cycle and ii to investigate any association between PGRMC1 levels in leukocytes and conditions characterized by reduced fertility. Methods We analyzed PGRMC1 expression in peripheral leukocytes from 15 healthy cycling women over four weeks. Additionally, we determined PGRMC1 levels in samples from patients with premature ovarian failure (POF and polycystic ovary syndrome (PCOS as well as in healthy postmenopausal women and male controls. The levels of PGRMC1 protein in nucleated peripheral blood cells were quantified by Western blot analysis. Results PGRMC1 levels did not vary significantly throughout the menstrual cycle. We observed a significant down-regulation of PGRMC1 in postmenopausal women and in patients with premature ovarian failure (POF and polycystic ovary syndrome (PCOS when compared to early follicular phase of healthy women. Conclusion This study suggests that reduced levels of PGRMC1 in peripheral leukocytes are associated with perturbed ovulatory function.

  17. HIV-1 infection causes a down-regulation of genes involved in ribosome biogenesis.

    Directory of Open Access Journals (Sweden)

    Claudia L Kleinman

    Full Text Available HIV-1 preferentially infects CD4+ T cells, causing fundamental changes that eventually lead to the release of new viral particles and cell death. To investigate in detail alterations in the transcriptome of the CD4+ T cells upon viral infection, we sequenced polyadenylated RNA isolated from Jurkat cells infected or not with HIV-1. We found a marked global alteration of gene expression following infection, with an overall trend toward induction of genes, indicating widespread modification of the host biology. Annotation and pathway analysis of the most deregulated genes showed that viral infection produces a down-regulation of genes associated with the nucleolus, in particular those implicated in regulating the different steps of ribosome biogenesis, such as ribosomal RNA (rRNA transcription, pre-rRNA processing, and ribosome maturation. The impact of HIV-1 infection on genes involved in ribosome biogenesis was further validated in primary CD4+ T cells. Moreover, we provided evidence by Northern Blot experiments, that host pre-rRNA processing in Jurkat cells might be perturbed during HIV-1 infection, thus strengthening the hypothesis of a crosstalk between nucleolar functions and viral pathogenesis.

  18. Down-regulation of Risa improves insulin sensitivity by enhancing autophagy.

    Science.gov (United States)

    Wang, Yuangao; Hu, Yanan; Sun, Chenxia; Zhuo, Shu; He, Zhishui; Wang, Hui; Yan, Menghong; Liu, Jun; Luan, Yi; Dai, Changgui; Yang, Yonggang; Huang, Rui; Zhou, Ben; Zhang, Fang; Zhai, Qiwei

    2016-09-01

    It has been reported that some small noncoding RNAs are involved in the regulation of insulin sensitivity. However, whether long noncoding RNAs also participate in the regulation of insulin sensitivity is still largely unknown. We identified and characterized a long noncoding RNA, regulator of insulin sensitivity and autophagy (Risa), which is a poly(A)(+) cytoplasmic RNA. Overexpression of Risa in mouse primary hepatocytes or C2C12 myotubes attenuated insulin-stimulated phosphorylation of insulin receptor, Akt, and Gsk3β, and knockdown of Risa alleviated insulin resistance. Further studies showed that overexpression of Risa in hepatocytes or myotubes decreased autophagy, and knockdown of Risa up-regulated autophagy. Moreover, knockdown of Atg7 or -5 significantly inhibited the effect of knockdown of Risa on insulin resistance, suggesting that knockdown of Risa alleviated insulin resistance via enhancing autophagy. In addition, tail vein injection of adenovirus to knock down Risa enhanced insulin sensitivity and hepatic autophagy in both C57BL/6 and ob/ob mice. Taken together, the data demonstrate that Risa regulates insulin sensitivity by affecting autophagy and suggest that Risa is a potential target for treating insulin-resistance-related diseases.-Wang, Y., Hu, Y., Sun, C., Zhuo, S., He, Z., Wang, H., Yan, M., Liu, J., Luan, Y., Dai, C., Yang, Y., Huang, R., Zhou, B., Zhang, F., Zhai, Q. Down-regulation of Risa improves insulin sensitivity by enhancing autophagy. © FASEB.

  19. Dioscin enhances methotrexate absorption by down-regulating MDR1 in vitro and in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lijuan, E-mail: jlwang1979@163.com [Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Dalian, Liaoning (China); Wang, Changyuan, E-mail: wangcyuan@163.com [Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Dalian, Liaoning (China); Provincial Key Laboratory for Pharmacokinetics and Transport, Liaoning, Dalian Medical University, Dalian, Liaoning (China); Peng, Jinyong, E-mail: jinyongpeng2005@163.com [Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Dalian, Liaoning (China); Provincial Key Laboratory for Pharmacokinetics and Transport, Liaoning, Dalian Medical University, Dalian, Liaoning (China); Liu, Qi, E-mail: llaqii@yahoo.com.cn [Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Dalian, Liaoning (China); Provincial Key Laboratory for Pharmacokinetics and Transport, Liaoning, Dalian Medical University, Dalian, Liaoning (China); Meng, Qiang, E-mail: mengq531@yahoo.cn [Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Dalian, Liaoning (China); Provincial Key Laboratory for Pharmacokinetics and Transport, Liaoning, Dalian Medical University, Dalian, Liaoning (China); Sun, Huijun, E-mail: sunhuijun@hotmail.com [Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Dalian, Liaoning (China); Provincial Key Laboratory for Pharmacokinetics and Transport, Liaoning, Dalian Medical University, Dalian, Liaoning (China); Huo, Xiaokui, E-mail: huoxiaokui@163.com [Department of Clinical Pharmacology, College of Pharmacy, Dalian Medical University, Dalian, Liaoning (China); Provincial Key Laboratory for Pharmacokinetics and Transport, Liaoning, Dalian Medical University, Dalian, Liaoning (China); and others

    2014-06-01

    The purpose of this study was to investigate the enhancing effect of dioscin on the absorption of methotrexate (MTX) and clarify the molecular mechanism involved in vivo and in vitro. Dioscin increased MTX chemosensitivity and transepithelial flux in the absorptive direction, significantly inhibiting multidrug resistance 1 (MDR1) mRNA and protein expression and MDR1 promoter and nuclear factor κ-B (NF-κB) activities in Caco-2 cells. Moreover, inhibitor κB-α (IκB-α) degradation was inhibited by dioscin. Dioscin enhanced the intracellular concentration of MTX by down-regulating MDR1 expression through a mechanism that involves NF-κB signaling pathway inhibition in Caco-2 cells. Dioscin strengthened MTX absorption by inhibiting MDR1 expression in rat intestine. In addition, even though MTX is absorbed into the enterocytes, there was no increase in toxicity observed, and that, in fact, decreased toxicity was seen. - Highlights: • Dioscin raised MTX concentration by inhibiting MDR1 in Caco-2 cells. • Dioscin suppresses MDR1 by inhibiting NF-κB signaling pathway in Caco-2 cells. • Dioscin can enhance MTX absorption via inhibiting MDR1 in vivo and in vitro. • Dioscin did not increase MTX-induced gastrointestinal mucosal toxicity.

  20. Down-regulation of Stathmin Is Required for the Phenotypic Changes and Classical Activation of Macrophages.

    Science.gov (United States)

    Xu, Kewei; Harrison, Rene E

    2015-07-31

    Macrophages are important cells of innate immunity with specialized capacity for recognition and elimination of pathogens and presentation of antigens to lymphocytes for adaptive immunity. Macrophages become activated upon exposure to pro-inflammatory cytokines and pathogenic stimuli. Classical activation of macrophages with interferon-γ (IFNγ) and lipopolysaccharide (LPS) triggers a wide range of signaling events and morphological changes to induce the immune response. Our previous microtubule (MT) proteomic work revealed that the stathmin association with MTs is considerably reduced in activated macrophages, which contain significantly more stabilized MTs. Here, we show that there is a global decrease in stathmin levels, an MT catastrophe protein, in activated macrophages using both immunoblotting and immunofluorescent microscopy. This is an LPS-specific response that induces proteasome-mediated degradation of stathmin. We explored the functions of stathmin down-regulation in activated macrophages by generating a stable cell line overexpressing stathmin-GFP. We show that stathmin-GFP overexpression impacts MT stability, impairs cell spreading, and reduces activation-associated phenotypes. Furthermore, overexpressing stathmin reduces complement receptor 3-mediated phagocytosis and cellular activation, implicating a pivotal inhibitory role for stathmin in classically activated macrophages.

  1. Prion pathogenesis is unaltered following down-regulation of SIGN-R1.

    Science.gov (United States)

    Bradford, Barry M; Brown, Karen L; Mabbott, Neil A

    2016-10-01

    Prion diseases are infectious neurodegenerative disorders characterised by accumulations of abnormal prion glycoprotein in affected tissues. Following peripheral exposure, many prion strains replicate upon follicular dendritic cells (FDC) in lymphoid tissues before infecting the brain. An intact splenic marginal zone is important for the efficient delivery of prions to FDC. The marginal zone contains a ring of specific intercellular adhesion molecule-3-grabbing non-integrin related 1 (SIGN-R1)-expressing macrophages. This lectin binds dextran and capsular pneumococcal polysaccharides, and also enhances the clearance of apoptotic cells via interactions with complement components. Since prions are acquired as complement-opsonized complexes we determined the role of SIGN-R1 in disease pathogenesis. We show that transient down-regulation of SIGN-R1 prior to intravenous prion exposure had no effect on the early accumulation of prions upon splenic FDC or their subsequent spread to the brain. Thus, SIGN-R1 expression by marginal zone macrophages is not rate-limiting for peripheral prion disease pathogenesis.

  2. Minocycline down-regulates topical mucosal inflammation during the application of microbicide candidates.

    Directory of Open Access Journals (Sweden)

    Liangzhu Li

    Full Text Available An effective anti-human immunodeficiency virus-1 (HIV-1 microbicide should exert its action in the absence of causing aberrant activation of topical immunity that will increase the risk of HIV acquisition. In the present study, we demonstrated that the vaginal application of cellulose sulfate (CS gel induced topical mucosal inflammatory responses; the addition of minocycline to CS gel could significantly attenuate the inflammation in a mice model. The combined gel of CS plus minocycline not only reduced the production of inflammatory cytokines in cervicovaginal lavages (CVLs, also down-regulated the activation of CD4+ T cells and the recruitment of other immune cells including HIV target cells into vaginal tissues. Furthermore, an In vitro HIV-1 pseudovirus infection inhibition assay showed that the combined gel decreased the infection efficacy of different subtypes of HIV-1 pseudoviruses compared with that of CS gel alone. These results implicate that minocycline could be integrated into microbicide formulation to suppress the aberrant activation of topical mucosal immunity and enhance the safety profile during the application of microbicides.

  3. Down-Regulation of NDUFB9 Promotes Breast Cancer Cell Proliferation, Metastasis by Mediating Mitochondrial Metabolism.

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    Liang-Dong Li

    Full Text Available Despite advances in basic and clinical research, metastasis remains the leading cause of death in breast cancer patients. Genetic abnormalities in mitochondria, including mutations affecting complex I and oxidative phosphorylation, are found in breast cancers and might facilitate metastasis. Genes encoding complex I components have significant breast cancer prognostic value. In this study, we used quantitative proteomic analyses to compare a highly metastatic cancer cell line and a parental breast cancer cell line; and observed that NDUFB9, an accessory subunit of the mitochondrial membrane respiratory chain NADH dehydrogenase (complex I, was down-regulated in highly metastatic breast cancer cells. Furthermore, we demonstrated that loss of NDUFB9 promotes MDA-MB-231 cells proliferation, migration, and invasion because of elevated levels of mtROS, disturbance of the NAD+/NADH balance, and depletion of mtDNA. We also showed that, the Akt/mTOR/p70S6K signaling pathway and EMT might be involved in this mechanism. Thus, our findings contribute novel data to support the hypothesis that misregulation of mitochondrial complex I NADH dehydrogenase activity can profoundly enhance the aggressiveness of human breast cancer cells, suggesting that complex I deficiency is a potential and important biomarker for further basic research or clinical application.

  4. MARCH1 down-regulation in IL-10-activated B cells increases MHC class II expression.

    Science.gov (United States)

    Galbas, Tristan; Steimle, Viktor; Lapointe, Réjean; Ishido, Satoshi; Thibodeau, Jacques

    2012-07-01

    IL-10 is vastly studied for its anti-inflammatory properties on most immune cells. However, it has been reported that IL-10 activates B cells, up-regulates their MHC class II molecules and prevents apoptosis. As MARCH1 was shown to be responsible for the intracellular sequestration of MHC class II molecules in dendritic cells and monocytes in response to IL-10, we set out to clarify the role of this ubiquitin ligase in B cells. Here, we demonstrate in mice that splenic follicular B cells represent the major cell population that up-regulate MHC II molecules in the presence of IL-10. Activation of these cells through TLR4, CD40 or the IL-10 receptor caused the down-regulation of MARCH1 mRNA. Accordingly, B cells from MARCH1-deficient mice do not up-regulate I-A(b) in response to IL-10. In all, our results demonstrate that IL-10 can have opposite effects on MARCH1 regulation in different cell types.

  5. Chronic exposure to hexachlorobenzene results in down-regulation of connexin43 in the breast.

    Science.gov (United States)

    Delisle, Ariane; Ferraris, Emanuelle; Plante, Isabelle

    2015-11-01

    Decreased expression of connexins has been associated with cancer, but the underlying mechanisms are poorly understood. We have previously shown that a 5 day exposure to hexachlorobenzene (HCB) resulted in decreased connexins expression in hepatocytes 45 days later, and that this down-regulation was linked to activation of Akt through the ILK pathway. Because HCB promotes cancer in both the liver and breast, the present study aimed to determine if the mechanisms are similar in both tissues. MCF-12A breast cells were thus transfected with vectors coding for either Akt or a constitutively active form of Akt. In those cells, activation of Akt was correlated with decreased Cx43 levels. Female rats were then exposed to HCB by gavage either following the same protocol used previously for the liver or through a chronic exposure. While no changes were observed after the 5 days exposure protocol, chronic exposure to HCB resulted in increased Akt levels and decreased Cx43 levels in breast cells. In vitro, Akt was activated in MCF-12A cells exposed to HCB either for 7 days or chronically, but no changes were observed in junctional proteins. Together, these results suggested that, while activation of Akt can decrease Cx43 expression in breast cells in vitro, other mechanisms are involved during HCB exposure, leading to a decrease in Cx43 levels in a model- and duration-dependent manner. Finally, we showed that HCB effects are tissue specific, as we did not observe the same results in breast and liver tissues.

  6. Down-Regulation of Bcl-2 Protein Sensitizes NCI 460 Cells to Radiotherapy-Induced Apoptosis

    Institute of Scientific and Technical Information of China (English)

    Dongmei He; Yuan Zhang; Gexiu Liu

    2006-01-01

    OBJECTIVE To determine whether Bcl-2 protein down-regulation can render NCI-460 cells more susceptible to gamma radiation-induced apoptosis by treatment with antisense oligonucleotide (ASODN) against the coding region of Bcl-2 mRNA.METHODS Cell survival was determined using the trypan blue dye exclusion. Expression of the Bcl-2 protein was assayed using immunofluorescence labeling with fluoresce isothiocyanate. Apoptosis was determined by Giemsa staining and flow cytomertry.RESULTS It was found that Bcl-2 ASODN combined with radiation significantly reduced the number of viable cells (P<0.05). There was no difference in cell survival between a nonsense oligodeoxynucleotide/radiation combination and cells treated with radiation alone. Bcl-2 ASODN combined with radiation significantly inhibited expression of the Bcl-2protein in the NCI-H460 cells (P<0.05). Using Giemsa staining, cells treated with Bcl-2 ASODN combined with radiation at 72 h displayed classic apoptotic changes. Apoptotic rates of the NCI-H460 cells treated with Bcl-2 ASODN combined with radiation significantly increased (P<0.05), compared with either a nonsense oligodeoxynucleotide/radiation combination or radiation-treatment cells alone.CONCLUSION ASODN against the coding region of Bcl-2 mRNA increases radiation-induced apoptosis in NCI-H460 cells.

  7. Treatment of CIA Mice with FGF21 Down-regulates TH17-IL-17 Axis.

    Science.gov (United States)

    Li, Si-ming; Yu, Yin-hang; Li, Lu; Wang, Wen-fei; Li, De-shan

    2016-02-01

    Recently, FGF21 was reported to play an important role in anti-inflammation. The aim of the study is to explore the mechanism for FGF21 alleviating inflammation of CIA. CIA mice were injected with FGF21 once a day for 28 days after first booster immunization. The results showed that FGF21 alleviates arthritis severity and decreases serum anti-CII antibodies levels in CIA mice. Compared with CIA model, the number of the splenic TH17 cells was significantly decreased in FGF21-treated mice. FGF21 treatment reduced the mRNA expression of IL-17, TNF-α, IL-1β, IL-6, IL-8, and MMP3 and increased level of IL-10 in the spleen tissue. The expression of STAT3 and phosphorylated STAT3 was suppressed in FGF21-treated group. The mRNA expression of RORγt and IL-23 also decreased. In conclusion, these findings suggest that the beneficial effects of FGF21 on CIA mice were achieved by down-regulating Th17-IL-17 axis through STAT3/RORγt pathway. Modulating of Th17-mediated inflammatory response may be one of the mechanisms for FGF21 attenuating inflammation in CIA.

  8. Down-regulation of the cardiac sarcoplasmic reticulum ryanodine channel in severely food-restricted rats

    Directory of Open Access Journals (Sweden)

    V.A. Vizotto

    2007-01-01

    Full Text Available We have shown that myocardial dysfunction induced by food restriction is related to calcium handling. Although cardiac function is depressed in food-restricted animals, there is limited information about the molecular mechanisms that lead to this abnormality. The present study evaluated the effects of food restriction on calcium cycling, focusing on sarcoplasmic Ca2+-ATPase (SERCA2, phospholamban (PLB, and ryanodine channel (RYR2 mRNA expressions in rat myocardium. Male Wistar-Kyoto rats, 60 days old, were submitted to ad libitum feeding (control rats or 50% diet restriction for 90 days. The levels of left ventricle SERCA2, PLB, and RYR2 were measured using semi-quantitative RT-PCR. Body and ventricular weights were reduced in 50% food-restricted animals. RYR2 mRNA was significantly decreased in the left ventricle of the food-restricted group (control = 5.92 ± 0.48 vs food-restricted group = 4.84 ± 0.33, P < 0.01. The levels of SERCA2 and PLB mRNA were similar between groups (control = 8.38 ± 0.44 vs food-restricted group = 7.96 ± 0.45, and control = 1.52 ± 0.06 vs food-restricted group = 1.53 ± 0.10, respectively. Down-regulation of RYR2 mRNA expressions suggests that chronic food restriction promotes abnormalities in sarcoplasmic reticulum Ca2+ release.

  9. Classical swine fever virus down-regulates endothelial connexin 43 gap junctions.

    Science.gov (United States)

    Hsiao, Hsiang-Jung; Liu, Pei-An; Yeh, Hung-I; Wang, Chi-Young

    2010-07-01

    Classical swine fever is a contagious disease of pigs characterized by fatal hemorrhagic fever. Classical swine fever virus (CSFV) induces the expression of pro-inflammatory and pro-coagulant factors of vascular endothelial cells and establishes a long-term infection. This study aimed to understand the effect of CSFV on endothelial connexin 43 (Cx43) expression and gap junctional intercellular coupling (GJIC). Porcine aortic endothelial cells were infected with CSFV at different multiplicity of infection for 48 h. Semi-quantitative RT-PCR, immunoconfocal microscopy, and Western blotting showed that the transcription and translation of Cx43 were reduced, and this was associated with an attenuation of GJIC. This decrease occurred in a time-dependent manner. An ERK inhibitor (PD98059), a JNK inhibitor (SP600125), and proteasome/lysosome inhibitors all significantly reversed the reduction in Cx43 protein levels without any influence on the titer of progeny virus. In addition, CSFV activated ERK and JNK in a time-dependent manner and down-regulated Cx43 promoter activity, mainly through decreased AP2 binding. This effect was primarily caused by the replication of CSFV rather than a consequence of cytokines being induced by CSFV infection of endothelial cells.

  10. Bax Inhibitor-1 down-regulation in the progression of chronic liver diseases

    Directory of Open Access Journals (Sweden)

    Burra Patrizia

    2010-04-01

    Full Text Available Abstract Background Bax inhibitor-1 (BI-1 is an evolutionary conserved endoplasmic reticulum protein that, when overexpressed in mammalian cells, suppresses the apoptosis induced by Bax, a pro-apoptotic member of the Bcl-2 family. The aims of this study were: (1 to clarify the role of intrinsic anti- and pro-apoptotic mediators, evaluating Bax and BI-1 mRNA and protein expressions in liver tissues from patients with different degrees of liver damage; (2 to determine whether HCV and HBV infections modulate said expression. Methods We examined 62 patients: 39 with chronic hepatitis (CH (31 HCV-related and 8 HBV-related; 7 with cirrhosis (6 HCV-related and 1 HBV-related; 13 with hepatocellular carcinoma (HCC [7 in viral cirrhosis (6 HCV- and 1 HBV-related, 6 in non-viral cirrhosis]; and 3 controls. Bax and BI-1 mRNAs were quantified by real-time PCR, and BI-1 protein expression by Western blot. Results CH tissues expressed significantly higher BI-1 mRNA levels than cirrhotic tissues surrounding HCC (P Conclusions BI-1 expression is down-regulated as liver damage progresses. The high BI-1 mRNAs levels observed in early liver disease may protect virus-infected cells against apoptosis, while their progressive downregulation may facilitate hepatocellular carcinogenesis. HCV genotype seems to have a relevant role in Bax transcript expression.

  11. Lygodium flexuosum extract down regulates the expression of proinflammatory cytokines in CCl4 -induced hepatotoxicity

    Institute of Scientific and Technical Information of China (English)

    Pallara Janardhanan Wills; Velikkakathu Vasumathi Asha

    2012-01-01

    Objective:To examine the downregulation of proinflammatory cytokines in a time dependant manner on carbon tetrachloride induced toxicity in experimental animals.Methods:CCl4(150 μL/100 g) was dissolved in corn oil(1:1 v/v%) and administered orally.GroupI was treated as normal control and received corn oil on8th day.GroupII was toxic control and was given a single dose ofCCl4 on8th days.GroupIII wastreated withLygodium flexuosum(L. flexuosum)n-hexane extract(200 mg/kg) for8 days and on8th day a single dose ofCCl4 was received.GroupIV(negative control) receivedL. flexuosumn-hexane extract(200 mg/kg) alone for8 days.Results:Treatment withn-hexane extract prior to the administration ofCCl4 significantly prevented an increase in serumAST,ALT,LDH activity and lipid peroxidation and prevented the depletion of glutathione (GSH).Rats treated withL. flexuosum had reduced mRNA levels ofTGF-β1,TNF-α andIL-1βgenes in liver ofCCl4 intoxicated rats when compared toCCl4 control as evidenced byRT-PCR. Conclusions:The data suggest that L. flexuosum, a widely available fern, significantly reduces CCl4 induced acute hepatotoxicity by down-regulating the expression of pro-inflammatory cytokines in rats.

  12. Carnosine reverses the aging-induced down regulation of brain regional serotonergic system.

    Science.gov (United States)

    Banerjee, Soumyabrata; Ghosh, Tushar K; Poddar, Mrinal K

    2015-12-01

    The purpose of the present investigation was to study the role of carnosine, an endogenous dipeptide biomolecule, on brain regional (cerebral cortex, hippocampus, hypothalamus and pons-medulla) serotonergic system during aging. Results showed an aging-induced brain region specific significant (a) increase in Trp (except cerebral cortex) and their 5-HIAA steady state level with an increase in their 5-HIAA accumulation and declination, (b) decrease in their both 5-HT steady state level and 5-HT accumulation (except cerebral cortex). A significant decrease in brain regional 5-HT/Trp ratio (except cerebral cortex) and increase in 5-HIAA/5-HT ratio were also observed during aging. Carnosine at lower dosages (0.5-1.0μg/Kg/day, i.t. for 21 consecutive days) didn't produce any significant response in any of the brain regions, but higher dosages (2.0-2.5μg/Kg/day, i.t. for 21 consecutive days) showed a significant response on those aging-induced brain regional serotonergic parameters. The treatment with carnosine (2.0μg/Kg/day, i.t. for 21 consecutive days), attenuated these brain regional aging-induced serotonergic parameters and restored towards their basal levels that observed in 4 months young control rats. These results suggest that carnosine attenuates and restores the aging-induced brain regional down regulation of serotonergic system towards that observed in young rats' brain regions.

  13. Down-regulation of KCa2.3 channels causes erectile dysfunction in mice

    DEFF Research Database (Denmark)

    Comerma Steffensen, Simon Gabriel; Hedegaard, Elise; Kun, Attila

    2017-01-01

    in transgenic mice with overexpression (KCa2.3T/T(−Dox)) or down-regulation (KCa2.3T/T(+Dox)) of the KCa2.3 channels and wild-type C57BL/6-mice (WT). QPCR revealed that KCa2.3 and KCa1.1 channels were the most abundant in mouse corpus cavernosum. KCa2.3 channels were found by immunoreactivity and electron...... microscopy in the apical-lateral membrane of endothelial cells in the corpus cavernosum. Norepinephrine contraction was enhanced in the corpus cavernosum of KCa2.3T/T(+Dox)versus KCa2.3T/T(−Dox) mice, while acetylcholine relaxation was only reduced at 0.3 µM and relaxations in response to the nitric oxide...... donor sodium nitroprusside were unaltered. An opener of KCa2 channels, NS309 induced concentration-dependent relaxations of corpus cavernosum. Mean arterial pressure was lower in KCa2.3T/T(−Dox) mice compared with WT and KCa2.3T/T(+Dox) mice. In anesthetized mice, cavernous nerve stimulation augmented...

  14. Down-regulation of the beacon gene expression in the regenerating rat adrenal cortex.

    Science.gov (United States)

    Ziolkowska, Agnieszka; Rucinski, Marcin; Tyczewska, Marianna; Belloni, Anna Sandra; Nowak, Magdalena; Nussdorfer, Gastone G; Malendowicz, Ludwik K

    2006-12-01

    Beacon, a hypothalamic peptide involved in the regulation of food intake, has been recently shown to be expressed in the adrenal cortex, and to inhibit its secretion and growth. To further characterize the role of beacon in the control of adrenal growth, we investigated the level of beacon gene expression in the regenerating rat adrenal cortex. Conventional reverse transcription-polymerase chain reaction (PCR) and immunocytochemistry demonstrated the expression of beacon mRNA and protein in the adrenals at both days 5 and 8 of regeneration after enucleation and contralateral adrenalectomy. Semiquantitative real time-PCR revealed a net down-regulation of beacon mRNA in the regenerating glands, as compared to the intact adrenal cortex of sham-operated animals. Beacon gene expression was higher at day 8 than at day 5 of regeneration. Mitotic index, as assayed by the stachmokinetic method with vincristin, was negligible in the intact adrenal, but greatly elevated in regenerating gland, with a higher index found at day 5 than at day 8 after surgery. Taken together our findings indicate that the level of beacon gene expression is inversely correlated with the proliferative activity of adrenocortical cells, and suggest that beacon might act as an endogenous inhibitor of adrenocortical growth in the rat.

  15. Nutlin-3 down-regulates retinoblastoma protein expression and inhibits muscle cell differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Erica M. [Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118 (United States); Niu, MengMeng; Bergholz, Johann [Center of Growth, Metabolism and Aging, College of Life Sciences, Sichuan University, Chengdu, 610014 China (China); Jim Xiao, Zhi-Xiong, E-mail: jxiao@bu.edu [Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118 (United States); Center of Growth, Metabolism and Aging, College of Life Sciences, Sichuan University, Chengdu, 610014 China (China)

    2015-05-29

    The p53 tumor suppressor gene plays a critical role in regulation of proliferation, cell death and differentiation. The MDM2 oncoprotein is a major negative regulator for p53 by binding to and targeting p53 for proteasome-mediated degradation. The small molecule inhibitor, nutlin-3, disrupts MDM2-p53 interaction resulting in stabilization and activation of p53 protein. We have previously shown that nutlin-3 activates p53, leading to MDM2 accumulation as concomitant of reduced retinoblastoma (Rb) protein stability. It is well known that Rb is important in muscle development and myoblast differentiation and that rhabdomyosarcoma (RMS), or cancer of the skeletal muscle, typically harbors MDM2 amplification. In this study, we show that nutlin-3 inhibited myoblast proliferation and effectively prevented myoblast differentiation, as evidenced by lack of expression of muscle differentiation markers including myogenin and myosin heavy chain (MyHC), as well as a failure to form multinucleated myotubes, which were associated with dramatic increases in MDM2 expression and decrease in Rb protein levels. These results indicate that nutlin-3 can effectively inhibit muscle cell differentiation. - Highlights: • Nutlin-3 inhibits myoblast proliferation and prevents differentiation into myotubes. • Nutlin-3 increases MDM2 expression and down-regulates Rb protein levels. • This study has implication in nutlin-3 treatment of rhabdomyosarcomas.

  16. Capsaicin protects cortical neurons against ischemia/reperfusion injury via down-regulating NMDA receptors.

    Science.gov (United States)

    Huang, Ming; Cheng, Gen; Tan, Han; Qin, Rui; Zou, Yimin; Wang, Yun; Zhang, Ying

    2017-09-01

    Capsaicin, the ingredient responsible for the pungent taste of hot chili peppers, is widely used in the study and management of pain. Recently, its neuroprotective effect has been described in multiple studies. Herein, we investigated the underlying mechanisms for the neuroprotective effect of capsaicin. Direct injection of capsaicin (1 or 3nmol) into the peri-infarct area reduced the infarct volume and improved neurological behavioral scoring and motor coordination function in the middle cerebral artery occlusion (MCAO)/reperfusion model in rats. The time window of the protective effect of capsaicin was within 1h after reperfusion, when excitotoxicity is the main reason of cell death. In cultured cortical neurons, administration of capsaicin attenuated glutamate-induced excitotoxic injury. With respect to the mechanisms of the neuroprotective effect of capsaicin, reduced calcium influx after glutamate stimulation was observed following capsaicin pretreatment in cortical neurons. Trpv1 knock-out abolished the inhibitory effect of capsaicin on glutamate-induced calcium influx and subsequent neuronal death. Reduced expression of GluN1 and GluN2B, subunits of NMDA receptor, was examined after capsaicin treatment in cortical neurons. In summary, our studies reveal that the neuroprotective effect of capsaicin in cortical neurons is TRPV1-dependent and down-regulation of the expression and function of NMDA receptors contributes to the protection afforded by capsaicin. Copyright © 2017. Published by Elsevier Inc.

  17. Down-regulation of Wnt10a affects odontogenesis and proliferation in mesenchymal cells.

    Science.gov (United States)

    Liu, Yang; Han, Dong; Wang, Lei; Feng, Hailan

    2013-05-17

    The WNT10a mutation has been found in patients with abnormal odontogenesis. In mice, Wnt10a expression is found in the tooth germ, but its role has not yet been elucidated. We aimed to investigate the role of Wnt10a in odontogenesis. Mesenchymal cells of the first mandibular molar germ at the bell stage were isolated, transfected with Wnt10a SiRNA or plasmid, and reassociated with epithelial part of the molar germ. Scrambled SiRNA or empty vector was used in the control group. The reassociated tooth germs were transplanted into mice subrenal capsules. After gene modification, dental mesenchymal cells cultured in vitro were checked for cell proliferation and the expression of Dspp was examined. All 12 reassociated tooth germs in the control group resumed odontogenesis, while only 5 of 12 in the Wnt10a knockdown group developed into teeth. After Wnt10a knockdown, the mesenchymal cells cultured in vitro presented repressed proliferation. Wnt10a knockdown and overexpression led to both down- and up-regulation of Dspp. We conclude that the down-regulation of Wnt10a impairs odontogensis and cell proliferation, and that Wnt10a regulates Dspp expression in mesenchymal cells. These findings help to elucidate the mechanism of abnormal tooth development in patients with the WNT10A mutation. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Down-regulation of a manganese transporter in the face of metal toxicity.

    Science.gov (United States)

    Jensen, Laran T; Carroll, Mark C; Hall, Matthew D; Harvey, Christopher J; Beese, Sara E; Culotta, Valeria C

    2009-06-01

    The yeast Smf1p Nramp manganese transporter is posttranslationally regulated by environmental manganese. Smf1p is stabilized at the cell surface with manganese starvation, but is largely degraded in the vacuole with physiological manganese through a mechanism involving the Rsp5p adaptor complex Bsd2p/Tre1p/Tre2p. We now describe an additional level of Smf1p regulation that occurs with toxicity from manganese, but not other essential metals. This regulation is largely Smf1p-specific. As with physiological manganese, toxic manganese triggers vacuolar degradation of Smf1p by trafficking through the multivesicular body. However, regulation by toxic manganese does not involve Bsd2p/Tre1p/Tre2p. Toxic manganese triggers both endocytosis of cell surface Smf1p and vacuolar targeting of intracellular Smf1p through the exocytic pathway. Notably, the kinetics of vacuolar targeting for Smf1p are relatively slow with toxic manganese and require prolonged exposures to the metal. Down-regulation of Smf1p by toxic manganese does not require transport activity of Smf1p, whereas such transport activity is needed for Smf1p regulation by manganese starvation. Furthermore, the responses to manganese starvation and manganese toxicity involve separate cellular compartments. We provide evidence that manganese starvation is sensed within the lumen of the secretory pathway, whereas manganese toxicity is sensed within an extra-Golgi/cytosolic compartment of the cell.

  19. Down-regulation of ABCG2, a urate exporter, by parathyroid hormone enhances urate accumulation in secondary hyperparathyroidism.

    Science.gov (United States)

    Sugimoto, Ryusei; Watanabe, Hiroshi; Ikegami, Komei; Enoki, Yuki; Imafuku, Tadashi; Sakaguchi, Yoshiaki; Murata, Michiya; Nishida, Kento; Miyamura, Shigeyuki; Ishima, Yu; Tanaka, Motoko; Matsushita, Kazutaka; Komaba, Hirotaka; Fukagawa, Masafumi; Otagiri, Masaki; Maruyama, Toru

    2017-03-01

    Hyperuricemia occurs with increasing frequency among patients with hyperparathyroidism. However, the molecular mechanism by which the serum parathyroid hormone (PTH) affects serum urate levels remains unknown. This was studied in uremic rats with secondary hyperparathyroidism where serum urate levels were found to be increased and urate excretion in the intestine and kidney decreased, presumably due to down-regulation of the expression of the urate exporter ABCG2 in intestinal and renal epithelial membranes. These effects were prevented by administration of the calcimimetic cinacalcet, a PTH suppressor, suggesting that PTH may down-regulate ABCG2 expression. This was directly tested in intestinal Caco-2 cells where the expression of ABCG2 on the plasma membrane was down-regulated by PTH (1-34) while its mRNA level remained unchanged. Interestingly, an inactive PTH derivative (13-34) had no effect, suggesting that a posttranscriptional regulatory system acts through the PTH receptor to regulate ABCG2 plasma membrane expression. As found in an animal study, additional clinical investigations showed that treatment with cinacalcet resulted in significant reductions in serum urate levels together with decreases in PTH levels in patients with secondary hyperparathyroidism undergoing dialysis. Thus, PTH down-regulates ABCG2 expression on the plasma membrane to suppress intestinal and renal urate excretion, and the effects of PTH can be prevented by cinacalcet treatment.

  20. Fucoidan induces apoptosis of HepG2 cells by down-regulating p-Stat3.

    Science.gov (United States)

    Roshan, Sadia; Liu, Yun-yi; Banafa, Amal; Chen, Hui-jie; Li, Ke-xiu; Yang, Guang-xiao; He, Guang-yuan; Chen, Ming-jie

    2014-06-01

    Fucoidan is one of the main bioactive components of polysaccharides. The current study was focused on the anti-tumor effects of fucoidan on human heptoma cell line HepG2 and the possible mechanisms. Fucoidan treatment resulted in cell cycle arrest and apoptosis of HepG2 cells in a dose-dependent manner detected by MTT assay, flow cytometry and fluorescent microscopy. The results of flow cytometric analysis revealed that fucoidan induced G2/M arrest in the cell cycle progression. Hoechst 33258 and Annexin V/PI staining results showed that the apoptotic cell number was increased, which was associated with a dose-dependent up-regulation of Bax and down-regulation of Bcl-2 and p-Stat3. In parallel, the up-regulation of p53 and the increase in reactive oxygen species were also observed, which may play important roles in the inhibition of HepG2 growth by fucoidan. In the meantime, Cyclin B1 and CDK1 were down-regulated by fucoidan treatment. Down-regulation of p-Stat3 by fucoidan resulted in apoptosis and an increase in ROS in response to fucoidan exposure. We therefore concluded that fucoidan induces apoptosis through the down-regulation of p-Stat3. These results suggest that fucoidan may be used as a novel anti-cancer agent for hepatocarcinoma.

  1. Antisense down-regulation of 4CL expression alters lignification, tree growth, and saccharification potential of field-grown poplar

    Science.gov (United States)

    Steven L. Voelker; Barbara Lachenbruch; Frederick C. Meinzer; Michael Jourdes; Chanyoung Ki; Ann M. Patten; Laurence B. Davin; Norman G. Lewis; Gerald A. Tuskan; Lee Gunter; Stephen R. Decker; Michael J. Selig; Robert Sykes; Michael E. Himmel; Peter Kitin; Olga Shevchenko; Steven H. Strauss

    2010-01-01

    Transgenic down-regulation of the Pt4CL1 gene family encoding 4-coumarate:coenzyme A ligase (4CL) has been reported as a means for reducing lignin content in cell walls and increasing overall growth rates, thereby improving feedstock quality for paper and bioethanol production. Using hybrid poplar (Populus tremula...

  2. Investigation of (E)-3-[4-(2-Oxo-3-aryl-chromen-4-yl)oxyphenyl]acrylic Acids as Oral Selective Estrogen Receptor Down-Regulators.

    Science.gov (United States)

    Degorce, Sébastien L; Bailey, Andrew; Callis, Rowena; De Savi, Chris; Ducray, Richard; Lamont, Gillian; MacFaul, Philip; Maudet, Mickael; Martin, Scott; Morgentin, Rémy; Norman, Richard A; Peru, Aurélien; Pink, Jennifer H; Plé, Patrick A; Roberts, Bryan; Scott, James S

    2015-04-23

    A novel estrogen receptor down-regulator, 7-hydroxycoumarin (5, SS5020), has been reported with antitumor effects against chemically induced mammary tumors. Here, we report on our own investigation of 7-hydroxycoumarins as potential selective estrogen receptor down-regulators, which led us to the discovery of potent down-regulating antagonists, such as 33. Subsequent optimization and removal of the 7-hydroxy group led to coumarin 59, which had increased potency and improved rat bioavailability relative to SS5020.

  3. CD36 deficiency leads to choroidal involution via COX2 down-regulation in rodents.

    Directory of Open Access Journals (Sweden)

    Marianne Houssier

    2008-02-01

    Full Text Available BACKGROUND: In the Western world, a major cause of blindness is age-related macular degeneration (AMD. Recent research in angiogenesis has furthered the understanding of choroidal neovascularization, which occurs in the "wet" form of AMD. In contrast, very little is known about the mechanisms of the predominant, "dry" form of AMD, which is characterized by retinal atrophy and choroidal involution. The aim of this study is to elucidate the possible implication of the scavenger receptor CD36 in retinal degeneration and choroidal involution, the cardinal features of the dry form of AMD. METHODS AND FINDINGS: We here show that deficiency of CD36, which participates in outer segment (OS phagocytosis by the retinal pigment epithelium (RPE in vitro, leads to significant progressive age-related photoreceptor degeneration evaluated histologically at different ages in two rodent models of CD36 invalidation in vivo (Spontaneous hypertensive rats (SHR and CD36-/- mice. Furthermore, these animals developed significant age related choroidal involution reflected in a 100%-300% increase in the avascular area of the choriocapillaries measured on vascular corrosion casts of aged animals. We also show that proangiogenic COX2 expression in RPE is stimulated by CD36 activating antibody and that CD36-deficient RPE cells from SHR rats fail to induce COX2 and subsequent vascular endothelial growth factor (VEGF expression upon OS or antibody stimulation in vitro. CD36-/- mice express reduced levels of COX2 and VEGF in vivo, and COX2-/- mice develop progressive choroidal degeneration similar to what is seen in CD36 deficiency. CONCLUSIONS: CD36 deficiency leads to choroidal involution via COX2 down-regulation in the RPE. These results show a novel molecular mechanism of choroidal degeneration, a key feature of dry AMD. These findings unveil a pathogenic process, to our knowledge previously undescribed, with important implications for the development of new therapies.

  4. Stathmin mediates hepatocyte resistance to death from oxidative stress by down regulating JNK.

    Science.gov (United States)

    Zhao, Enpeng; Amir, Muhammad; Lin, Yu; Czaja, Mark J

    2014-01-01

    Stathmin 1 performs a critical function in cell proliferation by regulating microtubule polymerization. This proliferative function is thought to explain the frequent overexpression of stathmin in human cancer and its correlation with a bad prognosis. Whether stathmin also functions in cell death pathways is unclear. Stathmin regulates microtubules in part by binding free tubulin, a process inhibited by stathmin phosphorylation from kinases including c-Jun N-terminal kinase (JNK). The involvement of JNK activation both in stathmin phosphorylation, and in hepatocellular resistance to oxidative stress, led to an examination of the role of stathmin/JNK crosstalk in oxidant-induced hepatocyte death. Oxidative stress from menadione-generated superoxide induced JNK-dependent stathmin phosphorylation at Ser-16, Ser-25 and Ser-38 in hepatocytes. A stathmin knockdown sensitized hepatocytes to both apoptotic and necrotic cell death from menadione without altering levels of oxidant generation. The absence of stathmin during oxidative stress led to JNK overactivation that was the mechanism of cell death as a concomitant knockdown of JNK1 or JNK2 blocked death. Hepatocyte death from JNK overactivation was mediated by the effects of JNK on mitochondria. Mitochondrial outer membrane permeabilization occurred in stathmin knockdown cells at low concentrations of menadione that triggered apoptosis, whereas mitochondrial β-oxidation and ATP homeostasis were compromised at higher, necrotic menadione concentrations. Stathmin therefore mediates hepatocyte resistance to death from oxidative stress by down regulating JNK and maintaining mitochondrial integrity. These findings demonstrate a new mechanism by which stathmin promotes cell survival and potentially tumor growth.

  5. Stathmin mediates hepatocyte resistance to death from oxidative stress by down regulating JNK.

    Directory of Open Access Journals (Sweden)

    Enpeng Zhao

    Full Text Available Stathmin 1 performs a critical function in cell proliferation by regulating microtubule polymerization. This proliferative function is thought to explain the frequent overexpression of stathmin in human cancer and its correlation with a bad prognosis. Whether stathmin also functions in cell death pathways is unclear. Stathmin regulates microtubules in part by binding free tubulin, a process inhibited by stathmin phosphorylation from kinases including c-Jun N-terminal kinase (JNK. The involvement of JNK activation both in stathmin phosphorylation, and in hepatocellular resistance to oxidative stress, led to an examination of the role of stathmin/JNK crosstalk in oxidant-induced hepatocyte death. Oxidative stress from menadione-generated superoxide induced JNK-dependent stathmin phosphorylation at Ser-16, Ser-25 and Ser-38 in hepatocytes. A stathmin knockdown sensitized hepatocytes to both apoptotic and necrotic cell death from menadione without altering levels of oxidant generation. The absence of stathmin during oxidative stress led to JNK overactivation that was the mechanism of cell death as a concomitant knockdown of JNK1 or JNK2 blocked death. Hepatocyte death from JNK overactivation was mediated by the effects of JNK on mitochondria. Mitochondrial outer membrane permeabilization occurred in stathmin knockdown cells at low concentrations of menadione that triggered apoptosis, whereas mitochondrial β-oxidation and ATP homeostasis were compromised at higher, necrotic menadione concentrations. Stathmin therefore mediates hepatocyte resistance to death from oxidative stress by down regulating JNK and maintaining mitochondrial integrity. These findings demonstrate a new mechanism by which stathmin promotes cell survival and potentially tumor growth.

  6. Quantitative cell signalling analysis reveals down-regulation of MAPK pathway activation in colorectal cancer.

    LENUS (Irish Health Repository)

    Gulmann, Christian

    2009-08-01

    Mitogen-activated protein kinases (MAPK) are considered to play significant roles in colonic carcinogenesis and kinase inhibitor therapy has been proposed as a potential tool in the treatment of this disease. Reverse-phase microarray assays using phospho-specific antibodies can directly measure levels of phosphorylated protein isoforms. In the current study, samples from 35 cases of untreated colorectal cancer colectomies were laser capture-microdissected to isolate epithelium and stroma from cancer as well as normal (i.e. uninvolved) mucosa. Lysates generated from these four tissue types were spotted onto reverse-phase protein microarrays and probed with a panel of antibodies to ERK, p-ERK, p38, p-p38, p-JNK, MEK and p-MEK. Whereas total protein levels were unchanged, or slightly elevated (p38, p = 0.0025) in cancers, activated isoforms, including p-ERK, p-p38 and p-JNK, were decreased two- to four-fold in cancers compared with uninvolved mucosa (p < 0.0023 in all cases except for p-JNK in epithelium, where decrement was non-significant). This was backed up by western blotting. Dukes\\' stage B and C cancers displayed lower p-ERK and p-p38 expression than Dukes\\' stage A cancers, although this was not statistically significant. It is concluded that MAPK activity may be down-regulated in colorectal cancer and that further exploration of inhibitory therapy in this system should be carefully evaluated if this finding is confirmed in larger series.

  7. Ectodermal-neural cortex 1 down-regulates Nrf2 at the translational level.

    Directory of Open Access Journals (Sweden)

    Xiao-Jun Wang

    Full Text Available The transcription factor Nrf2 is the master regulator of a cellular defense mechanism against environmental insults. The Nrf2-mediated antioxidant response is accomplished by the transcription of a battery of genes that encode phase II detoxifying enzymes, xenobiotic transporters, and antioxidants. Coordinated expression of these genes is critical in protecting cells from toxic and carcinogenic insults and in maintaining cellular redox homeostasis. Activation of the Nrf2 pathway is primarily controlled by Kelch-like ECH-associated protein 1 (Keap1, which is a molecular switch that turns on or off the Nrf2 signaling pathway according to intracellular redox conditions. Here we report our finding of a novel Nrf2 suppressor ectodermal-neural cortex 1 (ENC1, which is a BTB-Kelch protein and belongs to the same family as Keap1. Transient expression of ENC1 reduced steady-state levels of Nrf2 and its downstream gene expression. Although ENC1 interacted with Keap1 indirectly, the ENC1-mediated down-regulation of Nrf2 was independent of Keap1. The negative effect of ENC1 on Nrf2 was not due to a change in the stability of Nrf2 because neither proteasomal nor lysosomal inhibitors had any effects. Overexpression of ENC1 did not result in a change in the level of Nrf2 mRNA, rather, it caused a decrease in the rate of Nrf2 protein synthesis. These results demonstrate that ENC1 functions as a negative regulator of Nrf2 through suppressing Nrf2 protein translation, which adds another level of complexity in controlling the Nrf2 signaling pathway.

  8. Endothelial progenitor cell down-regulation in a mouse model of Kawasaki disease

    Institute of Scientific and Technical Information of China (English)

    LIU Jun-feng; DU Zhong-dong; CHEN Zhi; LU Dun-xiang; LI Li; GUAN Yun-qian; WAN Sui-gui

    2012-01-01

    Background Cardiovascular complications of Kawasaki disease (KD) are a common cause of heart disease in pediatric populations.Previous studies have suggested a role for endothelial progenitor cells (EPCs) in coronary artery lesions associated with KD.However,long-term observations of EPCs during the natural progression of this disorder are lacking.Using an experimental model of KD,we aimed to determine whether the coronary artery lesions are associated with down-regulation of EPCs.Methods To induce KD,C57BL/6 mice were administered an intraperitoneal injection of Lactobacillus casei cell wall extract (LCWE; phosphate buffered saline used as control vehicle).Study groups included:group A (14 days following LCWE injection),group B (56 days following LCWE injection) and group C (controls).Numbers of circulating EPCs (positively staining for both CD34 and FIk-1 while staining negative for CD45) were evaluated using flow cytometry.Bone marrow mononuclear cells were cultured in vitro to expand EPCs for functional analysis.In vitro EPC proliferation,adhesion and migration were assessed.Results The model was shown to exhibit similar coronary artery lesions to KD patients with coronary aneurysms.Numbers of circulating EPCs decreased significantly in the KD models (groups A and B) compared to controls ((0.017±0.008)% VS.(0.028±0.007)%,P<0.05 and (0.016±0.007)% vs.(0.028±0.007)%,P <0.05).Proliferative,adhesive and migratory properties of EPCs were markedly impaired in groups A and B.Conclusion Coronary artery lesions in KD occur as a consequence of impaired vascular injury repair,resulting from excess consumption of EPCs together with a functional impairment of bone marrow EPCs and their precursors.

  9. RETINOIC ACID DOWN-REGULATES BONE MORPHOGENETIC PROTEIN 7 EXPRESSION IN RAT WITH CLEFT PALATE

    Institute of Scientific and Technical Information of China (English)

    Lei Guo; Yu-yan Zhao; Shi-liang Zhang; Kui Liu; Xiao-yu Gao

    2008-01-01

    Objective To evaluate the effects of retinoic acid (RA) on expression of bone morphogenetic protein 7 (BMP-7)in rat fetus with cleft palate, and the effects of RA on proliferation and apoptosis of osteoblasts. Methods All-trans RA (ATRA) was used to induce congenital cleft palate in Wistar rat. BMP-7 mRNA expres-sion in maxillary bone tissue of fetal rats was measured by Northern blotting analysis. Flow cytometry and MTT assay were used to measure the apoptosis and proliferation of ATRA-treated MC-3T3-E1 cells. BMP-7 mRNA and protein ex-pressions in ATRA-treated MC-3T3-E1 cells were detected by RT-PCR and Western blotting analysis.Results ATRA could induce cleft palate of rat fetus. The incidence rate of cleft palate induced by 100 mg/kg AT-RA (45.5%) was significantly higher than 50 mg/kg ATRA (12.5%, P<0.05). BMP-7 mRNA expression de-creased in maxillary bone tissue of rat fetus with cleft palate. MC-3T3-E1 cells proliferation treated with 1 × 10-6 mol/L ATRA decreased by 60%, the cell apoptosis increased by 2 times. BMP-7 mR.NA and protein levels in MC-3T3-E1cells treated with 1 × 10-6 mol/L ATRA decreased by 60% and 80%, respectively, compared with ATRA-untreated ceils (P<0.05).Conclusions BMP-7 may play an important role in embryonic palate development RA may possess the ability to down-regulate cell proliferation through regulation of BMP-7 gene expression.

  10. Irradiation of protoporphyric mice induces down-regulation of epidermal eicosanoid metabolism

    Energy Technology Data Exchange (ETDEWEB)

    He, D.; Lim, H.W. (Department of Veterans Affairs Medical Center, New York, NY (USA))

    1991-09-01

    This study investigated the effect of radiation on clinical and histologic changes, and on cutaneous eicosanoid metabolism, in Skh:HR-1 hairless albino mice rendered protoporphyric by the administration of collidine. At 0.1-18 h after exposure to 12 kJ/m2 of 396-406 nm irradiation, thicknesses of back skin and ears were measured, and histologic changes were evaluated by using hematoxylin and eosin (H-E) and Giemsa's stains. Activities of eicosanoid-metabolizing enzymes in epidermal and dermal homogenates were assessed by incubating the tissue homogenates with 3H-AA, followed by quantitation of the eicosanoids generated by radio-TLC. In irradiated protoporphyric mice, an increase of back-skin thickness was noted at 0.1 h, reaching a peak at 18 h, whereas maximal increase in ear thickness was observed at 12 h. Histologic changes included dermal edema, increased mast cell degranulation, and mononuclear cells in the dermis. In these irradiated protoporphyric animals, generations of 6 keto-PGF1a, PGF2a, PGE2, PGD2, and HETE by epidermal eicosanoid-metabolizing enzymes were markedly suppressed at all the timepoints studied. Dermal eicosanoid-metabolizing enzymes of irradiated protoporphyric mice generated increased amounts of PGE2 and HETE at 18 h, probably reflecting the presence of dermal cellular infiltrates. The suppression of the activities of epidermal eicosanoid-metabolizing enzymes was prevented by intraperitoneal injection of WR-2721, a sulfhydryl group generator, prior to irradiation, suggesting that the suppression was secondary to photo-oxidative damage of the enzymes during the in vivo phototoxic response. These results suggest that the effect of protoporphyrin and radiation on cutaneous eicosanoid metabolism in this animal model in vivo is that of a down regulation of the activities of epidermal eicosanoid-metabolizing enzymes.

  11. Down-regulation of CDH1 is associated with expression of SNAI1 in colorectal adenomas.

    Directory of Open Access Journals (Sweden)

    Feride Kroepil

    Full Text Available INTRODUCTION: Down-regulation of E-cadherin (CDH1 and epithelial-mesenchymal transition (EMT are considered critical events for invasion and metastasis of colorectal carcinoma. Here we tested whether the important regulators of E-cadherin expression SNAI1 and TWIST1 are already detectable in human colorectal adenomas. METHODS: RNA was extracted from a set of randomly selected formalin-fixed and paraffin-embedded (FFPE colorectal adenomas (n = 41 and normal colon mucosa (n = 10. Subsequently mRNA expression of CDH1, CDH2, SNAI1 and TWIST1 was analysed by quantitative RT-PCR analysis. CDH1 as well as SNAI1 protein expression were assessed by immunohistochemistry (IHC. RESULTS: SNAI1 mRNA was expressed in 78% (n = 32/41, TWIST1 mRNA in 41% (n = 17/41 and CDH2 mRNA in 41% (n = 17/41 of the colorectal adenoma tissue, while normal colon mucosa was negative for these transcription factors. We found a significant correlation between reduced CDH1 and the presence of SNAI1 mRNA expression and for combined SNAI1 and TWIST1 mRNA expression, respectively. A correlation between CDH2 mRNA expression and reduced CDH1 expression was not observed. We confirmed the relationship between SNAI1 expression and reduced E-cadherin expression on the protein level via IHC. CONCLUSION: Our data show that SNAI1 and Twist1 are already expressed in benign precursor lesions of colorectal cancer and that SNAI1 expression was significantly correlated with lower expression of CDH1. Whether these findings reflect true EMT and/or are a sign of a more aggressive biology need to be investigated in further studies.

  12. Strategic down-regulation of attentional resources as a mechanism of proactive response inhibition.

    Science.gov (United States)

    Langford, Zachary D; Krebs, Ruth M; Talsma, Durk; Woldorff, Marty G; Boehler, C N

    2016-08-01

    Efficiently avoiding inappropriate actions in a changing environment is central to cognitive control. One mechanism contributing to this ability is the deliberate slowing down of responses in contexts where full response cancellation might occasionally be required, referred to as proactive response inhibition. The present electroencephalographic (EEG) study investigated the role of attentional processes in proactive response inhibition in humans. To this end, we compared data from a standard stop-signal task, in which stop signals required response cancellation ('stop-relevant'), to data where possible stop signals were task-irrelevant ('stop-irrelevant'). Behavioral data clearly indicated the presence of proactive slowing in the standard stop-signal task. A novel single-trial analysis was used to directly model the relationship between response time and the EEG data of the go-trials in both contexts within a multilevel linear models framework. We found a relationship between response time and amplitude of the attention-related N1 component in stop-relevant blocks, a characteristic that was fully absent in stop-irrelevant blocks. Specifically, N1 amplitudes were lower the slower the response time, suggesting that attentional resources were being strategically down-regulated to control response speed. Drift diffusion modeling of the behavioral data indicated that multiple parameters differed across the two contexts, likely suggesting the contribution from independent brain mechanisms to proactive slowing. Hence, the attentional mechanism of proactive response control we report here might coexist with known mechanisms that are more directly tied to motoric response inhibition. As such, our study opens up new research avenues also concerning clinical conditions that feature deficits in proactive response inhibition.

  13. Down-regulation of Zac1 gene expression in rat white adipose tissue by androgens.

    Science.gov (United States)

    Mirowska, Agnieszka; Sledzinski, Tomasz; Smolenski, Ryszard T; Swierczynski, Julian

    2014-03-01

    ZAC1 is a zinc-finger protein transcription factor, a transcriptional cofactor for nuclear receptors, and a co-activator of nuclear receptors, which interacts with multiple signaling pathways affecting apoptosis, cell cycle arrest, and metabolism. Some data suggest that ZAC1 regulates the expression of genes associated with function of adipose tissue. Since there is no information about the levels of Zac1 gene expression in white adipose tissue (WAT), and the expression of several genes associated with metabolic function of WAT is significantly lower in male than female animals, we have examined: (a) the relative ZAC1 mRNA levels in some organs/tissues, including three main depots of WAT, in 3-month-old male rats; (b) the relative ZAC1 mRNA levels in WAT of male and female rats; (c) the effect of orchidectomy and orchidectomy with concomitant testosterone treatment on ZAC1 mRNA and protein levels; (d) the effect of ovariectomy and ovariectomy with concomitant 17β-estradiol treatment on ZAC1 mRNA levels; (e) the effect of dihydrotestosterone on ZAC1 mRNA levels in isolated adipocytes. Our results indicate that: (a) ZAC1 mRNA levels are relatively high in WAT in comparison with other organs/tissues; (b) ZAC1 mRNA levels in subcutaneous WAT are approximately 2-fold lower than in epididymal and retroperitoneal adipose tissue; (c) ZAC1 mRNA levels in WAT of adult female rats are approximately 2-fold higher than in male rats; (d) testosterone is inversely related to ZAC1 mRNA and protein levels in WAT of male rats; and (e) dihydrotestosterone decreases the ZAC1 mRNA levels in adipocytes in dose dependent manner. In conclusion, Zac1 gene is highly expressed in white adipose tissue of adult rats. Androgens could play an important role in down-regulation of the ZAC1 mRNA and protein levels in rats.

  14. [Enhanced chemosensitivity of Hep-2 through down-regulating expression of SOX2 by RNAi].

    Science.gov (United States)

    Yang, Ning; Hui, Lian; Yang, Huijun; Jiang, Xuejun

    2014-08-01

    To investigate the effect of SOX2 on chemotherapy sensitivity of human laryngeal epithelial cells Hep-2. We designed and synthesized RNAis for silencing the expression of SOX2 in Hep-2 cells and selected the most effective RNAi by Western blot analysis. Then the recombinant plasmids of pGCsi-H1-SOX2 and pGCsi-H1-NC were constructed and transfected into Hep-2 cells to build cell lines of psiSOX2-Hep-2 and psiNC-Hep-2. CCK-8 assay had been used to test the sensitivity of Hep-2 cells to 5-FU and PTX after silencing SOX2 expression. Hoechst staining had been used to exam the changes of Hep-2 cells apoptosis treatment by 5-FU and PTX after silencing SOX2 expression. Furthermore, the changes of apoptosis-related genes expressions were detected by Western blotting. The cell lines of psiSOX2-Hep-2 and psiNC-Hep-2 were successfully established, and the expression of SOX2 protein was decreased 78% in psiSOX2-Hep-2 cells compared with psiNC-Hep-2 cells. After reducing SOX2 expression, the sensitivity of Hep-2 cells to 5-FU and PTX were increased and the IC50 values for 48 h were decreased to 8.12 μg/ml and 5.16 μg/ml. Meanwhile, the apoptosis rate and the expression of apoptotic gene Bax and cleaved caspase-3 expression were dramatically increased and anti-apoptotic genes survivin and Bcl-2 were significantly decreased in psiSOX2-Hep-2 cells compared with psiNC-Hep-2 cells. Down-regulating the protein expression of SOX2 by RNAi will significantly enhance the sensitivity of human laryngeal epithelial cells Hep-2 to 5-FU and PTX.

  15. Down-regulation of intestinal drug transporters in chronic renal failure in rats.

    Science.gov (United States)

    Naud, Judith; Michaud, Josée; Boisvert, Caroline; Desbiens, Karine; Leblond, Francois A; Mitchell, Andrew; Jones, Christine; Bonnardeaux, Alain; Pichette, Vincent

    2007-03-01

    Chronic renal failure (CRF) is associated with an increased bioavailability of drugs by a poorly understood mechanism. One hypothesis is a reduction in the elimination of drugs by the intestine, i.e., drug elimination mediated by protein membrane transporters such as P-glycoprotein (Pgp) and multidrug-resistance-related protein (MRP) 2. The present study aimed to investigate the repercussions of CRF on intestinal transporters involved in drug absorption [organic anion-transportingpolypeptide (Oatp)] and those implicated in drug extrusion (Pgp and MRP2). Pgp, MRP2, MRP3, Oatp2, and Oatp3 protein expression and Pgp, MRP2, and Oatp3 mRNA expression were assessed in the intestine of CRF (induced by five-sixth nephrectomy) and control rats. Pgp and MRP2 activities were measured using the everted gut technique. Rat enterocytes and Caco-2 cells were incubated with sera from control and CRF rats to characterize the mechanism of transporters' down-regulation. Protein expression of Pgp, MRP2, and MRP3 were reduced by more than 40% (p CRF rats, whereas Oatp2 and Oatp3 expression remained unchanged. There was no difference in the mRNA levels assessed by real-time polymerase chain reaction. Pgp and MRP2 activities were decreased by 30 and 25%, respectively, in CRF rats compared with control (p CRF in rats is associated with a decrease in intestinal Pgp and MRP2 protein expression and function secondarily to serum uremic factors. This reduction could explain the increased bioavailability of drugs in CRF.

  16. Down-regulation of microRNA-26a promotes mouse hepatocyte proliferation during liver regeneration.

    Directory of Open Access Journals (Sweden)

    Jian Zhou

    Full Text Available BACKGROUND: Inadequate liver regeneration (LR is still an unsolved problem in major liver resection and small-for-size syndrome post-living donor liver transplantation. A number of microRNAs have been shown to play important roles in cell proliferation. Herein, we investigated the role of miR-26a as a pivotal regulator of hepatocyte proliferation in LR. METHODOLOGY/PRINCIPAL FINDINGS: Adult male C57BL/6J mice, undergoing 70% partial hepatectomy (PH, were treated with Ad5-anti-miR-26a-LUC or Ad5-miR-26a-LUC or Ad5-LUC vector via portal vein. The animals were subjected to in vivo bioluminescence imaging. Serum and liver samples were collected to test liver function, calculate liver-to-body weight ratio (LBWR, document hepatocyte proliferation (Ki-67 staining, and investigate potential targeted gene expression of miR-26a by quantitative real-time PCR and Western blot. The miR-26a level declined during LR after 70% PH. Down-regulation of miR-26a by anti-miR-26a expression led to enhanced proliferation of hepatocytes, and both LBWR and hepatocyte proliferation (Ki-67(+ cells % showed an increased tendency, while liver damage, indicated by aspartate aminotransferase (AST, alanine aminotransferase (ALT and total bilirubin (T-Bil, was reduced. Furthermore, CCND2 and CCNE2, as possible targeted genes of miR-26a, were up-regulated. In addition, miR-26a over-expression showed converse results. CONCLUSIONS/SIGNIFICANCE: MiR-26a plays crucial role in regulating the proliferative phase of LR, probably by repressing expressions of cell cycle proteins CCND2 and CCNE2. The current study reveals a novel miRNA-mediated regulation pattern during the proliferative phase of LR.

  17. Slug down-regulation by RNA interference inhibits invasion growth in human esophageal squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Zhang Shaoyan

    2011-05-01

    Full Text Available Abstract Background Esophageal squamous cell carcinoma (ESCC is one of the most aggressive carcinomas of the gastrointestinal tract. We assessed the relevance of Slug in measuring the invasive potential of ESCC cells in vitro and in vivo in immunodeficient mice. Methods We utilized RNA interference to knockdown Slug gene expression, and effects on survival and invasive carcinoma were evaluated using a Boyden chamber transwell assay in vitro. We evaluated the effect of Slug siRNA-transfection and Slug cDNA-transfection on E-cadherin and Bcl-2 expression in ESCC cells. A pseudometastatic model of ESCC in immunodeficient mice was used to assess the effects of Slug siRNA transfection on tumor metastasis development. Results The EC109 cell line was transfected with Slug-siRNA to knockdown Slug expression. The TE13 cell line was transfected with Slug-cDNA to increase Slug expression. EC109 and TE13 cell lines were tested for the expression of apoptosis-related genes bcl-2 and metastasis-related gene E-cadherin identified previously as Slug targets. Bcl-2 expression was increased and E-cadherin was decreased in Slug siRNA-transfected EC109 cells. Bcl-2 expression was increased and E-cadherin was decreased in Slug cDNA-transfected TE13 cells. Invasion of Slug siRNA-transfected EC109 cells was reduced and apoptosis was increased whereas invasion was greater in Slug cDNA-transfected cells. Animals injected with Slug siRNA-transfected EC109 cells exhihited fewer seeded nodes and demonstrated more apoptosis. Conclusions Slug down-regulation promotes cell apoptosis and decreases invasion capability in vitro and in vivo. Slug inhibition may represent a novel strategy for treatment of metastatic ESCC.

  18. SLX4-SLX1 Protein-independent Down-regulation of MUS81-EME1 Protein by HIV-1 Viral Protein R (Vpr).

    Science.gov (United States)

    Zhou, Xiaohong; DeLucia, Maria; Ahn, Jinwoo

    2016-08-12

    Evolutionarily conserved structure-selective endonuclease MUS81 forms a complex with EME1 and further associates with another endonuclease SLX4-SLX1 to form a four-subunit complex of MUS81-EME1-SLX4-SLX1, coordinating distinctive biochemical activities of both endonucleases in DNA repair. Viral protein R (Vpr), a highly conserved accessory protein in primate lentiviruses, was previously reported to bind SLX4 to mediate down-regulation of MUS81. However, the detailed mechanism underlying MUS81 down-regulation is unclear. Here, we report that HIV-1 Vpr down-regulates both MUS81 and its cofactor EME1 by hijacking the host CRL4-DCAF1 E3 ubiquitin ligase. Multiple Vpr variants, from HIV-1 and SIV, down-regulate both MUS81 and EME1. Furthermore, a C-terminally truncated Vpr mutant and point mutants R80A and Q65R, all of which lack G2 arrest activity, are able to down-regulate MUS81-EME1, suggesting that Vpr-induced G2 arrest is not correlated with MUS81-EME1 down-regulation. We also show that neither the interaction of MUS81-EME1 with Vpr nor their down-regulation is dependent on SLX4-SLX1. Together, these data provide new insight on a conserved function of Vpr in a host endonuclease down-regulation.

  19. Pyrrolidine dithiocarbamate inhibits enterovirus 71 replication by down-regulating ubiquitin-proteasome system.

    Science.gov (United States)

    Lin, Lexun; Qin, Ying; Wu, Heng; Chen, Yang; Wu, Shuo; Si, Xiaoning; Wang, Hui; Wang, Tianying; Zhong, Xiaoyan; Zhai, Xia; Tong, Lei; Pan, Bo; Zhang, Fengmin; Zhong, Zhaohua; Wang, Yan; Zhao, Wenran

    2015-01-02

    Enterovirus 71 (EV71) is the main causative pathogen of hand, foot, and mouth disease (HFMD). The severe neurological complications caused by EV71 infection and the lack of effective therapeutic medicine underline the importance of searching for antiviral substances. Pyrrolidine dithiocarbamate (PDTC), an antioxidant, has been reported to inhibit the replication of coxsackievirus B (CVB) through dysregulating ubiquitin-proteasome system (UPS). In this study, we demonstrated that PDTC exerted potent antiviral effect on EV71. Viral RNA synthesis, viral protein expression, and the production of viral progeny were significantly reduced by the treatment of PDTC in Vero cells infected with EV71. Similar to the previous report about the inhibitory effect of PDTC on UPS, we found that PDTC treatment led to decreased levels of polyubiquitinated proteins in EV71-infected cells. The inhibitory effect of PDTC on UPS was further confirmed by the increased accumulation of cell cycle regulatory proteins p21 and p53, which are normally degraded through UPS, while the expression levels of both proteins remained unchanged. We also showed that PDTC had no impact on the activity of proteasome. Thus, we demonstrated that the down-regulation of PDTC on UPS was the result of its inhibition on ubiquitination. More importantly, this study provides evidence that the inhibition on UPS was required for the antiviral activity of PDTC, since MG132, a potent proteasome inhibitor, significantly inhibited the cytopathic effect and viral protein synthesis in EV71-infected cells. We also found that the antioxidant property of PDTC did not contribute to its antiviral effect, since N-acetyl-l-cysteine, a potent antioxidant, could not inhibit viral replication. In addition, CPE and viral protein synthesis were not inhibited in the cells pretreated with PDTC 2h before viral infection and then cultured in the media with no PDTC supplement, while the antioxidant effect of PDTC was retained. PDTC also

  20. Lycium barbarum L. Polysaccharide (LBP Reduces Glucose Uptake via Down-Regulation of SGLT-1 in Caco2 Cell

    Directory of Open Access Journals (Sweden)

    Huizhen Cai

    2017-02-01

    Full Text Available Lycium barbarum L. polysaccharide (LBP is prepared from Lycium barbarum L. (L. barbarum, which is a traditional Chinese medicine. LPB has been shown to have hypoglycemic effects. In order to gain some mechanistic insights on the hypoglycemic effects of LBP, we investigated the uptake of LBP and its effect on glucose absorption in the human intestinal epithelial cell line Caco2 cell. The uptake of LBP through Caco2 cell monolayer was time-dependent and was inhibited by phloridzin, a competitive inhibitor of SGLT-1. LPB decreased the absorption of glucose in Caco2 cell, and down-regulated the expression of SGLT-1. These results suggest that LBP might be transported across the human intestinal epithelium through SGLT-1 and it inhibits glucose uptake via down-regulating SGLT-1.

  1. Down-regulation of adipogenesis of mesenchymal stem cells by oscillating high-gradient magnetic fields and mechanical vibration

    Science.gov (United States)

    Zablotskii, V.; Lunov, O.; Novotná, B.; Churpita, O.; Trošan, P.; HoláÅ, V.; Syková, E.; Dejneka, A.; Kubinová, Š.

    2014-09-01

    Nowadays, the focus in medicine on molecular genetics has resulted in a disregard for the physical basis of treatment even though many diseases originate from changes in cellular mechanics. Perturbations of the cellular nanomechanics promote pathologies, including cardiovascular disease and cancer. Furthermore, whilst the biological and therapeutic effects of magnetic fields are a well-established fact, to date the underlying mechanisms remain obscure. Here, we show that oscillating high-gradient magnetic field (HGMF) and mechanical vibration affect adipogenic differentiation of mesenchymal stem cells by the transmission of mechanical stress to the cell cytoskeleton, resulting in F-actin remodelling and subsequent down-regulation of adipogenic genes adiponectin, PPARγ, and AP2. Our findings propose an insight into the regulation of cellular nanomechanics, and provide a basis for better controlled down-regulation of stem cell adipogenesis by HGMF, which may facilitate the development of challenging therapeutic strategies suitable for the remote control of biological systems.

  2. Down-regulation of HSP27 sensitizes TRAIL-resistant tumor cell to TRAIL-induced apoptosis

    DEFF Research Database (Denmark)

    Zhuang, Hongqin; Jiang, Weiwei; Cheng, Wei

    2010-01-01

    oxygen species or anticancer drugs. Their elevated expressions facilitate cells to survive in stress circumstances. The HSP27 expression is enhanced in many tumor cells, implying that it is involved in tumor progression and the development of treatment resistance in various tumors, including lung cancer...... siRNA on drug sensitization of A549 cells to TRAIL treatment. The results showed that treatment of A549 cells with HSP27 siRNA down-regulated HSP27 expression but did not induce significant apoptosis. However, combination of HSP27 siRNA with TRAIL-induced significant apoptosis in TRAIL-resistant A549...... cells. In addition to inducing caspases activation and apoptosis, combined treatment with HSP27 siRNA and TRAIL also increased JNK and p53 expression and activity. Collectively, these findings provide a conclusion that siRNA targeting of the HSP27 gene specifically down-regulated HSP27 expression in A...

  3. Collagen I-induced dendritic cells activation is regulated by TNF- production through down-regulation of IRF4

    Indian Academy of Sciences (India)

    Barun Poudel; Hyeon-Hui Ki; Young-Mi Lee; Dae-Ki Kim

    2015-03-01

    Previously we have shown that collagen I enhances the maturation and function of dendritic cells (DCs). Inflammatory mediators such as tumour necrosis factor (TNF)-, interleukin (IL)-1 and lipopolysaccharide (LPS) are also known to activate DCs. Here we investigated the involvement of TNF- on the collagen I-induced DCs activation. TNF-a neutralization inhibited collagen I-induced IL-12 secretions by DCs. Additionally, we observed suppression of collagen I-induced costimulatory molecules expression along with down-regulation of genes involved in DCs activation pathway. Furthermore, TNF- inhibition upon collagen Istimulation up-regulated the expression of interferon regulatory transcription factor IRF4, when compared to collagen I only treated cells. Collectively, our data demonstrate that collagen I induce TNF- production, which is crucial for the activation and function of DCs, through down-regulation of IRF4, and implicates the importance in development of anti- TNF- therapeutics for several inflammatory diseases.

  4. Quercetin induces tumor-selective apoptosis through down-regulation of Mcl-1 and activation of Bax

    Science.gov (United States)

    Cheng, Senping; Gao, Ning; Zhang, Zhuo; Chen, Gang; Budhraja, Amit; Ke, Zunji; Son, Young-ok; Wang, Xin; Luo, Jia; Shi, Xianglin

    2010-01-01

    Purpose To investigate the in vivo antitumor efficacy of querctin in U937 xenografts and the functional role of Mcl-1 and Bax in quercetin-induced apoptosis in human leukemia cells. Experimental Design Leukemia cells were treated with quercetin, after which apoptosis, Mcl-1 expression, and Bax activation and translocation were evaluated. The efficacy of quercein, as well as Mcl-1 expression and Bax activation were investigated in xenografts of leukemia cells. Results Administration of quercetin caused pronounced apoptosis in both transformed and primary leukemia cells, but not in normal blood peripheral mononuclear cells. Quercetin-induced apoptosis was accompanied by Mcl-1 down-regulation and Bax conformational change and mitochondrial translocation which triggered cytochrome c release. Knockdown of Bax by siRNA reversed querctin-induced apoptosis. Knockout of Bax abrogated the activation of caspase and apoptosis. Ectopic expression of Mcl-1 attenuated quercetin-mediated Bax activation, translocation and cell death. Conversely, interruption of Mcl-1 by siRNA enhanced Bax activation and translocation, as well as lethality induced by quercetin. However, the absence of Bax had no effect on quercetin-mediated Mcl-1 down-regulation. Furthermore, in vivo administration of quercetin attenuated tumor growth in U937 xenografts. The TUNEL positive apoptotic cells in tumor sections increased in quercetin-treated mice as compared with controls. Mcl-1 down-regulation and Bax activation were observed in xenografts. Conclusions These data suggest that quercetin may be useful for the treatment of leukemia by preferentially inducing apoptosis in leukemia versus normal hematopoietic cells, through a process involving Mcl-1 down-regulation, which in turn potentiates Bax activation and mitochondrial translocation, culminating in apoptosis. PMID:21138867

  5. Sulforaphane down-regulates SKP2 to stabilize p27(KIP1) for inducing antiproliferation in human colon adenocarcinoma cells.

    Science.gov (United States)

    Chung, Yuan-Kai; Chi-Hung Or, Richard; Lu, Chien-Hsing; Ouyang, Wei-Ting; Yang, Shu-Yi; Chang, Chia-Che

    2015-01-01

    Sulforaphane is a cruciferous vegetable-derived isothiocyanate with promising chemopreventive and therapeutic activities. Induction of proliferation arrest and apoptosis principally contribute to sulforaphane's anticancer activity, but the precise molecular mechanisms remain elusive. The oncoprotein SKP2 is a key component of the SKP1-CULLIN1-F-box (SCF) E3 ligase complex and is responsible for directing SCF-mediated degradation of cyclin-dependent kinase inhibitor p27(KIP1) to promote cell proliferation. We herein provide the first evidence supporting the critical involvement of the SKP2-p27(KIP1) axis in sulforaphane-induced antiproliferation in various human colon adenocarcinoma cell lines. Specifically, sulforaphane markedly suppressed the levels of bromodeoxyuridine (BrdU) incorporation and clonogenicity in all tested cell lines, illustrating the antiproliferative effect of sulforaphane. Of note, sulforaphane-induced antiproliferation was accompanied with down-regulation of SKP2, leading to the stabilization and thus up-regulation of p27(KIP1). Additionally, sulforaphane was found to down-regulate SKP2 mainly through transcriptional repression, as sulforaphane lowered SKP2 mRNA expression and the SKP2 promoter activity. Furthermore, sulforaphane treatment led to the activation of both AKT and ERK, thus ruling out the possibility that sulforaphane down-regulates SKP2 by inhibiting AKT or ERK. Notably, sulforaphane-elicited suppression of BrdU incorporation and clonogenicity were significantly rescued in the context of SKP2 overexpression or p27(KIP1) depletion, therefore highlighting the important role of SKP2 down-regulation and the ensuing stabilization of p27(KIP1) in sulforaphane-induced antiproliferation. Collectively, these data expand our molecular understanding about how sulforaphane elicits proliferation arrest, but also implicate the application of sulforaphane in therapeutic modalities targeting SKP2. Copyright © 2014 The Society for Biotechnology

  6. Down-regulation of amygdala activation with real-time fMRI neurofeedback in a healthy female sample

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    Christian eParet

    2014-09-01

    Full Text Available Psychiatric conditions of emotion dysregulation are often characterized by difficulties in regulating the activity of limbic regions such as the amygdala. Real-time functional magnetic resonance imaging (rt-fMRI allows to feedback brain activation and opens the possibility to establish a neurofeedback (NF training of amygdala activation, e.g. for subjects suffering from emotion dysregulation.As a first step, we investigated whether feedback of the amygdala response to aversive scenes can improve down-regulation of amygdala activation. One group of healthy female participants received amygdala feedback (N=16 and a control group was presented with feedback from a control region located in the basal ganglia (N(sum=32. Subjects completed a one-session rt-fMRI-NF training where they viewed aversive pictures and received continuous visual feedback on brain activation (REGULATE condition. In a control condition, subjects were advised to respond naturally to aversive pictures (VIEW, and a neutral condition served as the non-affective control (NEUTRAL. In an adjacent run, subjects were presented with aversive pictures without feedback to test for transfer effects of learning.In a region of interest (ROI analysis, the VIEW and the REGULATE conditions were contrasted to estimate brain regulation success. The ROI analysis was complemented by an exploratory analysis of activations at the whole brain level. Both groups showed down-regulation of the amygdala response during training. Feedback from the amygdala but not from the control region was associated with down-regulation of the right amygdala in the transfer test. The whole-brain analysis did not detect significant group interactions. Results of the group whole-brain analyses are discussed.We present a proof-of-concept study using rt-fMRI-NF for amygdala down-regulation in the presence of aversive scenes. Results are in line with a potential benefit of neurofeedback training for amygdala regulation.

  7. Involvement of Oxidative Stress and Down-Regulation of Bcl-2 in Arachidonic Acid-Induced Apoptosis in HUVECs

    Institute of Scientific and Technical Information of China (English)

    WANG Bing-hua; WANG Yun; CHEN Li-da; CAO Jin-xiu; ZHOU Wen-jing

    2005-01-01

    Human umbilical vein endothelial cells (HUVECs) were treated with arachidonic acid (AA). After 24 h exposure to AA, typical morphological changes of apoptosis were observed by Giemsa stain and transmission electron microscopy. The apoptotic ratio in HUVECs treated with 50 μmol/L, 100 μmol/L and 150 μmol/L AA were (20.7±3.6) %, (38.6±4.3) % and (52.5±7.5) % respectively. Contrarily, low concentration of AA (≤25 μmol/L) exerted no influence on cell viability by MTT assay. Intracellular malondialdehyde increased significantly in a dose-dependent manner upon AA treatment and the opposite tendency was found for the reduced glutathione. Western Blots show that apoptosis triggered by AA was associated with the down-regulation of Bcl-2 expression, but not with Bax and p53. Pretreatment with 50 μmol/L α-tocopherol reduced AA-induced oxidative stress and apoptosis, also inhibited the down-regulation of Bcl-2/Bax ratio. These results suggested that high concentration of free AA could induce apoptosis in HUVECs probably via oxidative stress and down-regulation of Bcl-2.

  8. An ethanol extract of Piper betle Linn. mediates its anti-inflammatory activity via down-regulation of nitric oxide.

    Science.gov (United States)

    Ganguly, Sudipto; Mula, Soumyaditya; Chattopadhyay, Subrata; Chatterjee, Mitali

    2007-05-01

    The leaves of Piper betle (locally known as Paan) have long been in use in the Indian indigenous system of medicine for the relief of pain; however, the underlying molecular mechanisms of this effect have not been elucidated. The anti-inflammatory and immunomodulatory effects of an ethanolic extract of the leaves of P. betle (100 mg kg(-1); PB) were demonstrated in a complete Freund's adjuvant-induced model of arthritis in rats with dexamethasone (0.1 mg kg(-1)) as the positive control. At non-toxic concentrations of PB (5-25 microg mL(-1)), a dose-dependent decrease in extracellular production of nitric oxide in murine peritoneal macrophages was measured by the Griess assay and corroborated by flow cytometry using the nitric oxide specific probe, 4,5-diaminofluorescein-2 diacetate. This decreased generation of reactive nitrogen species was mediated by PB progressively down-regulating transcription of inducible nitric oxide synthase in macrophages, and concomitantly causing a dose-dependent decrease in the expression of interleukin-12 p40, indicating the ability of PB to down-regulate T-helper 1 pro-inflammatory responses. Taken together, the anti-inflammatory and anti-arthrotic activity of PB is attributable to its ability to down-regulate the generation of reactive nitrogen species, thus meriting further pharmacological investigation.

  9. Sensitization of multidrug-resistant human cancer cells to Hsp90 inhibitors by down-regulation of SIRT1.

    Science.gov (United States)

    Kim, Hak-Bong; Lee, Su-Hoon; Um, Jee-Hyun; Oh, Won Keun; Kim, Dong-Wan; Kang, Chi-Dug; Kim, Sun-Hee

    2015-11-03

    The effectiveness of Hsp90 inhibitors as anticancer agents was limited in multidrug-resistant (MDR) human cancer cells due to induction of heat shock proteins (Hsps) such as Hsp70/Hsp27 and P-glycoprotein (P-gp)-mediated efflux. In the present study, we showed that resistance to Hsp90 inhibitors of MDR human cancer cells could be overcome with SIRT1 inhibition. SIRT1 knock-down or SIRT1 inhibitors (amurensin G and EX527) effectively suppressed the resistance to Hsp90 inhibitors (17-AAG and AUY922) in several MDR variants of human lymphoblastic leukemia and human breast cancer cell lines. SIRT1 inhibition down-regulated the expression of heat shock factor 1 (HSF1) and subsequently Hsps and facilitated Hsp90 multichaperone complex disruption via hyperacetylation of Hsp90/Hsp70. These findings were followed by acceleration of ubiquitin ligase CHIP-mediated mutant p53 (mut p53) degradation and subsequent down-regulation of P-gp in 17-AAG-treated MDR cancer cells expressing P-gp and mut p53 after inhibition of SIRT1. Therefore, combined treatment with Hsp90 inhibitor and SIRT1 inhibitor could be a more effective therapeutic approach for Hsp90 inhibitor-resistant MDR cells via down-regulation of HSF1/Hsps, mut p53 and P-gp.

  10. MiR-217 is down-regulated in psoriasis and promotes keratinocyte differentiation via targeting GRHL2

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Haigang; Hou, Liyue; Liu, Jingjing; Li, Zhiming, E-mail: lizm_1001@sina.com

    2016-02-26

    MiR-217 is a well-known tumor suppressor, and its down-regulation has been shown in a wide range of solid and leukaemic cancers. However, the biological role of miR-217 in psoriasis pathogenesis, especially in keratinocyte hyperproliferation and differentiation, is not clearly understood. In this study, we found the expression of miR-217 was markedly down-regulated in psoriasis keratinocytes of psoriatic patients. In addition, overexpression of miR-217 inhibited the proliferation and promoted the differentiation of primary human keratinocytes. On the contrary, inhibition of endogenous miR-217 increased cell proliferation and delayed differentiation. Furthermore, Grainyhead-like 2 (GRHL2) was identified as a direct target of miR-217 by luciferase reporter assay. The expression of miR-217 and GRHL2 was inversely correlated in both transfected keratinocytes and in psoriasis lesional skin. Moreover, knocking down GRHL2 expression by siRNA enhanced keratinocyte differentiation. Taken together, our results demonstrate a role for miR-217 in the regulation of keratinocyte differentiation, partially through the regulation of GRHL2. - Highlights: • miR-217 is down-regulated in psoriasis skin lesions. • miR-217 inhibits the proliferation and promotes differentiation of keratinocytes. • GRHL2 is a novel target of miR-217 in keratinocytes. • GRHL2 is up-regulated and inversely correlated with miR-217 in psoriasis skin lesions.

  11. Internalization and down-regulation of the human epidermal growth factor receptor are regulated by the carboxyl-terminal tyrosines

    DEFF Research Database (Denmark)

    Helin, K; Beguinot, L

    1991-01-01

    with receptors in which 1, 2, or all 3 tyrosines were changed to phenylalanines. The triple point mutant EGF-R, expressed in NIH-3T3, exhibited low autophosphorylation in vivo, low biological and reduced kinase activities. Single and double point mutants were down-regulated, as well as wild type EGF-R......The C terminus of the epidermal growth factor receptor (EGF-R) contains three tyrosines (Y1068, Y1148, and Y1173) which correspond to the major autophosphorylation sites. To investigate the role of the tyrosines in internalization and down-regulation of the EGF-R, mutational analysis was performed...... in response to EGF showing a half-life of about 1 h. Degradation of the triple point mutant, however, was impaired and resulted in a half-life of 4 h in the presence of EGF. EGF-dependent down-regulation of surface receptors was decreased in the triple point mutant EGF-R as was internalization and degradation...

  12. Is telomerase reactivation associated with the down-regulation of TGF β receptor-II expression in human breast cancer?

    Directory of Open Access Journals (Sweden)

    Thomas Valene

    2003-07-01

    Full Text Available Abstract Background Telomerase is a ribonucleoprotein that synthesizes telomeres and plays an important role in chromosomal stability and cellular immortalisation. Telomerase activity is detectable in most human cancers but not in normal somatic cells. TGF beta (transforming growth factor beta is a member of a family of cytokines that are essential for cell survival and seems to be down-regulated in human cancer. Recent in vitro work using human breast cancer cell lines has suggested that TGF beta down-regulates the expression of hTERT (human telomerase reverse transcriptase : the catalytic subunit of telomerase. We have therefore hypothesised that telomerase reactivation is associated with reduced immunohisto-chemical expression of TGF beta type II receptor (RII in human breast cancer. Methods TGF beta RII immunohistochemical expression was determined in 24 infiltrating breast carcinomas with known telomerase activity (17 telomerase-positive and 7 telomerase-negative. Immunohistochemical expression of TGF beta RII was determined by a breast pathologist who was blinded to telomerase data. Results TGF beta RII was detected in all lesions. The percentage of stained cells ranged from 1–100%. The difference in TGF beta RII expression between telomerase positive and negative tumours was not statistically significant (p = 1.0. Conclusion The results of this pilot study suggest that there is no significant association between telomerase reactivation and TGF-beta RII down-regulation in human breast cancer.

  13. Fasting induces CART down-regulation in the zebrafish nervous system in a cannabinoid receptor 1-dependent manner.

    Science.gov (United States)

    Nishio, Shin-Ichi; Gibert, Yann; Berekelya, Liubov; Bernard, Laure; Brunet, Frédéric; Guillot, Etienne; Le Bail, Jean-Christophe; Sánchez, Juan Antonio; Galzin, Anne Marie; Triqueneaux, Gerard; Laudet, Vincent

    2012-08-01

    Central and peripheral mechanisms modulate food intake and energy balance in mammals and the precise role of the type 1 cannabinoid receptor (CB1) in these processes is still being explored. Using the zebrafish, Danio rerio, we show that rimonabant, a CB1-specific antagonist with an EC(50) of 5.15 × 10(-8) m, decreases embryonic yolk sac reserve use. We reveal a developmental overlap between CART genes and CB1 expression in the hypothalamus and medulla oblongata, two brain structures that play crucial roles in appetite regulation in mammals. We show that morpholino knockdown of CB1 or fasting decreases cocaine- and amphetamine-related transcript (CART)-3 expression. Strikingly, this down-regulation occurs only in regions coexpressing CB1 and CART3, reinforcing the link between CB1, CART, and appetite regulation. We show that rimonabant treatment impairs the fasting-induced down-regulation of CART expression in specific brain regions, whereas vehicle alone-treated embryos do not display this rescue of CART expression. Our data reveal that CB1 lies upstream of CART and signals the appetite through the down-regulation of CART expression. Thus, our results establish the zebrafish as a promising system to study appetite regulation.

  14. Ginsenoside Rg3 inhibits epithelial-mesenchymal transition (EMT) and invasion of lung cancer by down-regulating FUT4.

    Science.gov (United States)

    Tian, Lili; Shen, Dachuan; Li, Xiaodong; Shan, Xiu; Wang, Xiaoqi; Yan, Qiu; Liu, Jiwei

    2016-01-12

    The epithelial-mesenchymal transition (EMT) is an important factor in lung cancer metastasis, and targeting EMT is a potential therapeutic strategy. Fucosyltransferase IV (FUT4) and its synthetic cancer sugar antigen Lewis Y (LeY) was abnormally elevated in many cancers. In this study, a traditional Chinese medicine ginsenoside Rg3 was used to investigate whether its inhibition to EMT and invasion of lung cancer is by the glycobiology mechanism. We found that Rg3 treatment (25, 50, 100 μg/ml) inhibited cell migration and invasion by wound-healing and transwell assays. Rg3 could significantly alter EMT marker proteins with increased E-cadherin, but decreased Snail, N-cadherin and Vimentin expression. Rg3 also down-regulated FUT4 gene and protein expression in lung cancer cells by qPCR, Western blot and immunofluorescence. After FUT4 down-regulated with shFUT4, EMT was obviously inhibited. Furthermore, the activation of EGFR through decreased LeY biosynthesis was inhibited, which blocked the downstream MAPK and NF-κB signal pathways. In addition, Rg3 reduced tumor volume and weight in xenograft mouse model, and significantly decreased tumor metastasis nodules in lung tissues by tail vein injection. In conclusion, Rg3 inhibits EMT and invasion of lung cancer by down-regulating FUT4 mediated EGFR inactivation and blocking MAPK and NF-κB signal pathways. Rg3 may be a potentially effective agent for the treatment of lung cancer.

  15. Neuronal identity genes regulated by super-enhancers are preferentially down-regulated in the striatum of Huntington's disease mice.

    Science.gov (United States)

    Achour, Mayada; Le Gras, Stéphanie; Keime, Céline; Parmentier, Frédéric; Lejeune, François-Xavier; Boutillier, Anne-Laurence; Néri, Christian; Davidson, Irwin; Merienne, Karine

    2015-06-15

    Huntington's disease (HD) is a neurodegenerative disease associated with extensive down-regulation of genes controlling neuronal function, particularly in the striatum. Whether altered epigenetic regulation underlies transcriptional defects in HD is unclear. Integrating RNA-sequencing (RNA-seq) and chromatin-immunoprecipitation followed by massively parallel sequencing (ChIP-seq), we show that down-regulated genes in HD mouse striatum associate with selective decrease in H3K27ac, a mark of active enhancers, and RNA Polymerase II (RNAPII). In addition, we reveal that decreased genes in HD mouse striatum display a specific epigenetic signature, characterized by high levels and broad patterns of H3K27ac and RNAPII. Our results indicate that this signature is that of super-enhancers, a category of broad enhancers regulating genes defining tissue identity and function. Specifically, we reveal that striatal super-enhancers display extensive H3K27 acetylation within gene bodies, drive transcription characterized by low levels of paused RNAPII, regulate neuronal function genes and are enriched in binding motifs for Gata transcription factors, such as Gata2 regulating striatal identity genes. Together, our results provide evidence for preferential down-regulation of genes controlled by super-enhancers in HD striatum and indicate that enhancer topography is a major parameter determining the propensity of a gene to be deregulated in a neurodegenerative disease.

  16. Hepatitis B Virus Down-Regulates Expressions of MHC Class ⅠMolecules on Hepatoplastoma Cell Line

    Institute of Scientific and Technical Information of China (English)

    Yongyan Chen; Min Cheng; ,Zhigang Tian

    2006-01-01

    Chronic HBV infection is associated with a 100-fold high risk of developing hepatocellular carcinoma. Tumor recognition is of the most importance during the immune surveillance process that prevents cancer development in humans. In the present study, the expressions of MHC class Ⅰ molecules on hepatoplastoma cell line HepG2.2.15 were investigated to indicate the possible effects of HBV on the immune recognition during HBV-associated hepatocellular carcinoma. It was found that the expressions of MHC class Ⅰ molecules HLA-ABC, HLA-E and MICA were much lower in HepG2.2.15 cells compared with HepG2 cells. The expressing HBV in human hepatoplastoma cell line significantly down-regulated the expressions of MHC class Ⅰ molecules. Additionally, it was observed that in murine chronic HBsAg carriers the expression of classical MHC-Ⅰ molecule on hepatocytes was down-regulated. These results demonstrated that HBV might affect the immune recognition during HBV-associated hepatoceilular carcinoma such as the recognition of CD8+ T, NK-CTL and NK cells and prevent the immune surveillance against tumors. However, the effects of HBV down-regulation of MHC class Ⅰ molecules on the target cells in vivo should be further studied.

  17. Synergism between the mTOR inhibitor rapamycin and FAK down-regulation in the treatment of acute lymphoblastic leukemia

    Directory of Open Access Journals (Sweden)

    Pei-Jie Shi

    2016-02-01

    Full Text Available Abstract Background Acute lymphoblastic leukemia (ALL is an aggressive malignant disorder of lymphoid progenitor cells in both children and adults. Although improvements in contemporary therapy and development of new treatment strategies have led to dramatic increases in the cure rate in children with ALL, the relapse rate remains high and the prognosis of relapsed childhood ALL is poor. Molecularly targeted therapies have emerged as the leading treatments in cancer therapy. Multi-cytotoxic drug regimens have achieved success, yet many studies addressing targeted therapies have focused on only one single agent. In this study, we attempted to investigate whether the effect of the mammalian target of rapamycin (mTOR inhibitor rapamycin is synergistic with the effect of focal adhesion kinase (FAK down-regulation in the treatment of ALL. Methods The effect of rapamycin combined with FAK down-regulation on cell proliferation, the cell cycle, and apoptosis was investigated in the human precursor B acute lymphoblastic leukemia cells REH and on survival time and leukemia progression in a non-obese diabetic/severe combined immunodeficiency (NOD/SCID mouse model. Results When combined with FAK down-regulation, rapamycin-induced suppression of cell proliferation, G0/G1 cell cycle arrest, and apoptosis were significantly enhanced. In addition, REH cell-injected NOD/SCID mice treated with rapamycin and a short-hairpin RNA (shRNA to down-regulate FAK had significantly longer survival times and slower leukemia progression compared with mice injected with REH-empty vector cells and treated with rapamycin. Moreover, the B-cell CLL/lymphoma-2 (BCL-2 gene family was shown to be involved in the enhancement, by combined treatment, of REH cell apoptosis. Conclusions FAK down-regulation enhanced the in vitro and in vivo inhibitory effects of rapamycin on REH cell growth, indicating that the simultaneous targeting of mTOR- and FAK-related pathways might offer a novel

  18. The Cytoplasmic Domain of CD4 Is Sufficient for Its Down-Regulation from the Cell Surface by Human Immunodeficiency Virus Type 1 Nef

    OpenAIRE

    S. J. Anderson; Lenburg, M; Landau, N R; Garcia, J. V.

    1994-01-01

    Human immunodeficiency virus type 1 Nef down-regulates surface expression of murine and human CD4 but not human CD8. We recently reported that the cytoplasmic domain of CD4 is required for its down-regulation by Nef. Using a chimeric molecule composed of the extracellular and transmembrane domains of human CD8 fused to the cytoplasmic domain of human CD4, we show here that the cytoplasmic domain of CD4 is sufficient for down-regulation by Nef. Since the cytoplasmic domain of CD4 is also the s...

  19. Identification of phenylalanine 346 in the rat growth hormone receptor as being critical for ligand-mediated internalization and down-regulation

    DEFF Research Database (Denmark)

    Allevato, G; Billestrup, N; Goujon, L;

    1995-01-01

    in this domain revealed that phenylalanine 346 is required for internalization. Receptor down-regulation in transiently transfected COS-7 cells was also dependent upon the phenylalanine 346 residue of the GHR, since no GH-induced down-regulation was observed in cells expressing the F346A GHR mutant. In contrast......, the ability to stimulate transcription of the serine protease inhibitor 2.1 promoter by the GHR was not affected by the phenylalanine 346 to alanine mutation. These results demonstrate that phenylalanine 346 is essential for GHR internalization and down-regulation but not for transcriptional signaling...

  20. Down-Regulation of Notchl and NF-κB by Curcumin in Breast Cancer Cells MDA-MB-231

    Institute of Scientific and Technical Information of China (English)

    LONG Li; CAO You-de

    2008-01-01

    Objective:To test whether the down-regulation of Notch1 gene expression by curcumin could inhibit cell growth and induce apoptosis,which may be associated mechanistically with the down-regulation of NF-κB in breast cancer cells. Methods:Breast cancer cell lines MDA-MB-231 were cultured in vitro and treated with different dosages of curcumin(0,1.25,5.0,20.0μmol/L)for dose-dependent assay and different time(0,24,48,72 h)at the dosage of 5.0μmol/L for time course assay.The changes of the mRNA and protein expression of Notch1 and NF-κB were measured by RT-PCR and Western Blot,and MTT assay was used to measure the change of proliferation. Results:The mRNA and protein levels of Notch 1 and NF-κB were decreased significantly in human breast cancer cell line with the increase of dosage of curcumin(P<0.05),and with the extension of time course(P<0.05).These changes suggested a dose- and time-dependent manner.The proliferation rate of cells also was significantly inhibited(P<0.05). Conclusion:The current results show that the Notch-1 signaling pathway is associated mechanistically with NF-κB activity during curcumin-induced cell growth inhibition and apoptosis of breast cancer cells.These results suggest that the down-regulation of Notch signaling by curcumin may be a novel strategy for the treatment of patients with breast cancer.

  1. CDK/CK1 inhibitors roscovitine and CR8 down-regulate amplified MYCN in neuroblastoma cells

    Science.gov (United States)

    DELEHOUZE, Claire; GODL, Klaus; LOAEC, Nadège; BRUYERE, Céline; DESBAN, Nathalie; OUMATA, Nassima; GALONS, Hervé; ROUMELIOTIS, Theodoros I.; GIANNOPOULOU, Eugenia G.; GRENET, Jose; TWITCHELL, Devin; LAHTI, Jill; MOUCHET, Nicolas; GALIBERT, Marie-Dominique; GARBIS, Spiros D.; MEIJER, Laurent

    2014-01-01

    To understand the mechanisms of action of (R)-roscovitine and (S)-CR8, two related pharmacological inhibitors of cyclin-dependent kinases (CDKs), we applied a variety of ‘-omics’ techniques to the human neuroblastoma SH-SY5Y and IMR32 cell lines: [1] kinase interaction assays, [2] affinity competition on immobilized broad-spectrum kinase inhibitors, [3] affinity chromatography on immobilized (R)-roscovitine and (S)-CR8, [4] whole genome transcriptomics analysis and specific quantitative PCR studies, [5] global quantitative proteomics approach and Western blot analysis of selected proteins. Altogether the results show that the major direct targets of these two molecules belong to the CDKs (1, 2, 5, 7, 9, 12), DYRKs, CLKs, CK1s families. By inhibiting CDK7, CDK9 and CDK12, these inhibitors transiently reduce RNA polymerase 2 activity, which results in down-regulation of a large set of genes. Global transcriptomics and proteomics analysis converge to a central role of MYC transcription factors down-regulation. Indeed CDK inhibitors trigger rapid and massive down-regulation of MYCN expression in MYCN amplified neuroblastoma cells as well as in nude mice xenografted IMR32 cells. Inhibition of casein kinase 1 may also contribute to the antitumoral activity of (R)-roscovitine and (S)-CR8. This dual mechanism of action may be crucial in the use of these kinase inhibitors for the treatment of MYC-dependent cancers, in particular neuroblastoma where MYCN amplification is a strong predictor factor for high-risk disease. PMID:24317512

  2. Prevention of oxytosis-induced c-Raf down-regulation by (arylthio)cyclopentenone prostaglandins is neuroprotective.

    Science.gov (United States)

    Shibata, Shoko; Furuta, Kyoji; Oh-Hashi, Kentaro; Ueda, Hiroshi; Kiuchi, Kazutoshi; Hirata, Yoko

    2017-09-06

    Prolonged exposure to high concentrations of glutamate leads to cell type specific glutathione depletion and resulting oxidative stress, known as oxytosis. As a result of glutathione depletion, accumulation of reactive oxygen species and Ca(2+) influx are increased; however, the specific target of oxytosis has yet to be identified. In the present study, we focused on the effect of glutamate-induced oxidative stress on the extracellular-regulated protein kinase (ERK) pathway using the murine hippocampal HT22 cell line. Although the contribution of the ERK pathway to glutamate-induced oxytosis in HT22 cells is controversial, Western blot analysis revealed that glutamate caused down-regulation of mitogen-activated protein kinase kinase kinase (c-Raf) and a resulting decrease in the phosphorylation of c-Raf, as well as of mitogen-activated protein kinase kinase1/2 (MEK1/2) and ERK1/2, downstream components of the c-Raf/MEK/ERK pathway. Furthermore, neuroprotective (arylthio)cyclopentenone prostaglandins prevented glutamate-induced c-Raf down-regulation and consequently maintained the basal activity of c-Raf and its downstream signaling components. A pull-down assay using biotin-labeled cyclopentenone prostaglandins revealed that they preferentially bound to c-Raf relative to other signaling molecules of the ERK pathway, including Ras, MEK1/2, and ERK. These results suggest that neuroprotective (arylthio)cyclopentenone prostaglandins directly bind to c-Raf protein and protect cells from down-regulation of the c-Raf protein itself, resulting in neuroprotection against oxidative stress. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. MicroRNA-122 down-regulation is involved in phenobarbital-mediated activation of the constitutive androstane receptor.

    Science.gov (United States)

    Shizu, Ryota; Shindo, Sawako; Yoshida, Takemi; Numazawa, Satoshi

    2012-01-01

    Constitutive androstane receptor (CAR) is a nuclear receptor that regulates the transcription of target genes, including CYP2B and 3A. Phenobarbital activates CAR, at least in part, in an AMP-activated protein kinase (AMPK)-dependent manner. However, the precise mechanisms underlying phenobarbital activation of AMPK are still unclear. In the present study, it was demonstrated that phenobarbital administration to mice decreases hepatic miR-122, a liver-enriched microRNA involved in both hepatic differentiation and function. The time-course change in the phenobarbital-mediated down-regulation of miR-122 was inversely correlated with AMPK activation. Phenobarbital decreased primary miR-122 to approximately 25% of the basal level as early as 1 h and suppressed transactivity of mir-122 promoter in HuH-7 cells, suggesting that the down-regulation occurred at the transcriptional level. AMPK activation by metformin or 5-aminoimidazole-4-carboxamide 1-β-D-ribonucleoside had no evident effect on miR-122 levels. An inhibitory RNA specific for miR-122 increased activated AMPK and CAR-mediated trancactivation of the phenobarbital-responsive enhancer module in HepG2 cells. Conversely, the reporter activity induced by the ectopic CAR was almost completely suppressed by co-transfection with the miR-122 mimic RNA. GFP-tagged CAR was expressed in the cytoplasm in addition to the nucleus in the majority of HuH-7 cells in which miR-122 was highly expressed. Co-transfection of the mimic or the inhibitor RNA for miR-122 further increased or decreased, respectively, the number of cells that expressed GFP-CAR in the cytoplasm. Taken together, these results suggest that phenobarbital-mediated down-regulation of miR-122 is an early and important event in the AMPK-dependent CAR activation and transactivation of its target genes.

  4. Virtual Experiments Enable Exploring and Challenging Explanatory Mechanisms of Immune-Mediated P450 Down-Regulation.

    Directory of Open Access Journals (Sweden)

    Brenden K Petersen

    Full Text Available Hepatic cytochrome P450 levels are down-regulated during inflammatory disease states, which can cause changes in downstream drug metabolism and hepatotoxicity. Long-term, we seek sufficient new insight into P450-regulating mechanisms to correctly anticipate how an individual's P450 expressions will respond when health and/or therapeutic interventions change. To date, improving explanatory mechanistic insight relies on knowledge gleaned from in vitro, in vivo, and clinical experiments augmented by case reports. We are working to improve that reality by developing means to undertake scientifically useful virtual experiments. So doing requires translating an accepted theory of immune system influence on P450 regulation into a computational model, and then challenging the model via in silico experiments. We build upon two existing agent-based models-an in silico hepatocyte culture and an in silico liver-capable of exploring and challenging concrete mechanistic hypotheses. We instantiate an in silico version of this hypothesis: in response to lipopolysaccharide, Kupffer cells down-regulate hepatic P450 levels via inflammatory cytokines, thus leading to a reduction in metabolic capacity. We achieve multiple in vitro and in vivo validation targets gathered from five wet-lab experiments, including a lipopolysaccharide-cytokine dose-response curve, time-course P450 down-regulation, and changes in several different measures of drug clearance spanning three drugs: acetaminophen, antipyrine, and chlorzoxazone. Along the way to achieving validation targets, various aspects of each model are falsified and subsequently refined. This iterative process of falsification-refinement-validation leads to biomimetic yet parsimonious mechanisms, which can provide explanatory insight into how, where, and when various features are generated. We argue that as models such as these are incrementally improved through multiple rounds of mechanistic falsification and

  5. Down-regulation of seladin-1 increases BACE1 levels and activity through enhanced GGA3 depletion during apoptosis.

    Science.gov (United States)

    Sarajärvi, Timo; Haapasalo, Annakaisa; Viswanathan, Jayashree; Mäkinen, Petra; Laitinen, Marjo; Soininen, Hilkka; Hiltunen, Mikko

    2009-12-04

    Seladin-1 is a neuroprotective protein selectively down-regulated in brain regions affected in Alzheimer disease (AD). Seladin-1 protects cells against beta-amyloid (Abeta) peptide 42- and oxidative stress-induced apoptosis activated by caspase-3, a key mediator of apoptosis. Here, we have employed RNA interference to assess the molecular effects of seladin-1 down-regulation on the beta-secretase (BACE1) function and beta-amyloid precursor protein (APP) processing in SH-SY5Y human neuroblastoma cells in both normal and apoptotic conditions. Our results show that approximately 60% reduction in seladin-1 protein levels, resembling the decrease observed in AD brain, did not significantly affect APP processing or Abeta secretion in normal growth conditions. However, under apoptosis, seladin-1 small interfering RNA (siRNA)-transfected cells showed increased caspase-3 activity on average by 2-fold when compared with control siRNA-transfected cells. Increased caspase-3 activity coincided with a significant depletion of the BACE1-sorting protein, GGA3 (Golgi-localized gamma-ear-containing ADP-ribosylation factor-binding protein), and subsequently augmented BACE1 protein levels and activity. Augmented BACE1 activity in turn correlated with the enhanced beta-amyloidogenic processing of APP and ultimately increased Abeta production. These adverse changes associated with decreased cell viability in seladin-1 siRNA-transfected cells under apoptosis. No changes in GGA3 or BACE1 levels were found after seladin-1 knockdown in normal growth conditions. Collectively, our results suggest that under stress conditions, reduced seladin-1 expression results in enhanced GGA3 depletion, which further leads to augmented post-translational stabilization of BACE1 and increased beta-amyloidogenic processing of APP. These mechanistic findings related to seladin-1 down-regulation are important in the context of AD as the oxidative stress-induced apoptosis plays a key role in the disease

  6. High Silicon Accumulation in the Shoot is Required for Down-Regulating the Expression of Si Transporter Genes in Rice.

    Science.gov (United States)

    Mitani-Ueno, Namiki; Yamaji, Naoki; Ma, Jian Feng

    2016-12-01

    Rice requires high silicon (Si) for its high and sustainable yield. The efficient uptake of Si in rice is mediated by two transporters OsLsi1 and OsLsi2, which function as influx and efflux transporters, respectively. Our previous studies showed that the mRNA expression levels of these transporter genes were down-regulated by Si. Herein we investigated the mechanism underlying regulation of OsLsi1 and OsLsi2 expression. There was a negative correlation between the expression level of OsLsi1 and OsLsi2 and shoot Si accumulation when the rice seedlings were exposed to different Si supply conditions. A split root experiment showed that the expression of both OsLsi1 and OsLsi2 was also down-regulated in half the roots without direct Si exposure when the other half of the roots were exposed to Si. Analysis with transgenic rice carrying different lengths of OsLsi1 promoter regions fused with green fluorescent protein (GFP) as a reporter gene revealed that the region responsible for the Si response of OsLsi1 expression is present between -327 to -292 in the promoter. However, this region was not associated with the tissue and cellular localization of OsLsi1. In conclusion, the Si-induced down-regulation of Si transporter genes is controlled by shoot Si, not root Si, and the region between -327 and -292 in the OsLsi1 promoter is involved in this regulation of OsLsi1 expression in rice.

  7. Water deficit down-regulates miR398 and miR408 in pea (Pisum sativum L.).

    Science.gov (United States)

    Jovanović, Živko; Stanisavljević, Nemanja; Mikić, Aleksandar; Radović, Svetlana; Maksimović, Vesna

    2014-10-01

    MicroRNAs (miRNAs), recently recognized as important regulator of gene expression at posttranscriptional level, have been found to be involved in plant stress responses. The observation that some miRNAs are up- or down regulated by stress implies that they could play vital roles in plant resistance to abiotic and biotic stress. We investigated the effect of water stress treatment during 10 days on expression of conserved miRNAs-miR398a/b and miR408 in pea plants. This time frame reflects the changes as close as possible to the changes where water stress causes visible effects under field condition. It was observed that dehydration strongly down regulates the expression of both miR398a/b and miR408 in pea roots and shoots. The down-regulation of miR398a/b and the up-regulation of potential target genes - copper superoxide dismutase, CSD1, highlight the involvement of this miRNA in pea stress response. To the contrary, the mRNA level of cytochrome c oxidase subunit 5 (COX5b) did not change in roots and shoots of water-stressed plants, compared to control (well) hydrated plants. This suggests that COX5b is not the target of miR398, or that its expression is regulated by some other mechanism. P1B-ATPase expression increased during water deficit only in the shoots of pea; in the roots there were no changes in expression. Our results help to understand the possible role of investigated miRNAs and their contribution to pea capacity to cope with water deficit.

  8. SPAK and OSR1 Dependent Down-Regulation of Murine Renal Outer Medullary K+ Channel ROMK1

    Directory of Open Access Journals (Sweden)

    Bernat Elvira

    2014-09-01

    Full Text Available Background/Aims: The kinases SPAK (SPS1-related proline/alanine-rich kinase and OSR1 (oxidative stress-responsive kinase 1 participate in the regulation of the NaCl cotransporter NCC and the Na+,K+,2Cl- cotransporter NKCC2. The kinases are regulated by WNK (with-no-K[Lys] kinases. Mutations of genes encoding WNK kinases underly Gordon's syndrome, a monogenic disease leading to hypertension and hyperkalemia. WNK kinases further regulate the renal outer medullary K+ channel ROMK1. The present study explored, whether SPAK and/or OSR1 have similarly the potential to modify the activity of ROMK1. Methods: ROMK1 was expressed in Xenopus oocytes with or without additional expression of wild-type SPAK, constitutively active T233ESPAK, catalytically inactive D212ASPAK, wild-type OSR1, constitutively active T185EOSR1 and catalytically inactive D164AOSR1. Channel activity was determined utilizing dual electrode voltage clamp and ROMK1 protein abundance in the cell membrane utilizing chemiluminescence of ROMK1 containing an extracellular hemagglutinin epitope (ROMK1-HA. Results: ROMK1 activity and ROMK1-HA protein abundance were significantly down-regulated by wild-type SPAK and T233ESPAK, but not by D212ASPAK. Similarly, ROMK1 activity and ROMK1-HA protein abundance were significantly down-regulated by wild-type OSR1 and T185EOSR1, but not by D164AOSR1. Conclusion: ROMK1 protein abundance and activity are down-regulated by SPAK and OSR1.

  9. NUDT2 Disruption Elevates Diadenosine Tetraphosphate (Ap4A and Down-Regulates Immune Response and Cancer Promotion Genes.

    Directory of Open Access Journals (Sweden)

    Andrew S Marriott

    Full Text Available Regulation of gene expression is one of several roles proposed for the stress-induced nucleotide diadenosine tetraphosphate (Ap4A. We have examined this directly by a comparative RNA-Seq analysis of KBM-7 chronic myelogenous leukemia cells and KBM-7 cells in which the NUDT2 Ap4A hydrolase gene had been disrupted (NuKO cells, causing a 175-fold increase in intracellular Ap4A. 6,288 differentially expressed genes were identified with P < 0.05. Of these, 980 were up-regulated and 705 down-regulated in NuKO cells with a fold-change ≥ 2. Ingenuity® Pathway Analysis (IPA® was used to assign these genes to known canonical pathways and functional networks. Pathways associated with interferon responses, pattern recognition receptors and inflammation scored highly in the down-regulated set of genes while functions associated with MHC class II antigens were prominent among the up-regulated genes, which otherwise showed little organization into major functional gene sets. Tryptophan catabolism was also strongly down-regulated as were numerous genes known to be involved in tumor promotion in other systems, with roles in the epithelial-mesenchymal transition, proliferation, invasion and metastasis. Conversely, some pro-apoptotic genes were up-regulated. Major upstream factors predicted by IPA® for gene down-regulation included NFκB, STAT1/2, IRF3/4 and SP1 but no major factors controlling gene up-regulation were identified. Potential mechanisms for gene regulation mediated by Ap4A and/or NUDT2 disruption include binding of Ap4A to the HINT1 co-repressor, autocrine activation of purinoceptors by Ap4A, chromatin remodeling, effects of NUDT2 loss on transcript stability, and inhibition of ATP-dependent regulatory factors such as protein kinases by Ap4A. Existing evidence favors the last of these as the most probable mechanism. Regardless, our results suggest that the NUDT2 protein could be a novel cancer chemotherapeutic target, with its inhibition

  10. TNF-α-induced down-regulation of CDX2 suppresses MEP1A expression in colitis

    DEFF Research Database (Denmark)

    Coskun, Mehmet; Olsen, Anders Krüger; Holm, Thomas Lindebo

    2012-01-01

    High levels of pro-inflammatory cytokines are linked to inflammatory bowel disease (IBD). The transcription factor Caudal-related homeobox transcription factor 2 (CDX2) plays a crucial role in differentiation of intestinal epithelium and regulates IBD-susceptibility genes, including meprin 1A (ME......A). The aim was to investigate the expression of CDX2 and MEP1A in colitis; to assess if they are regulated by tumor necrosis factor-α (TNF-α), and finally to reveal if CDX2 is involved in a TNF-α-induced down-regulation of MEP1A....

  11. Ischemic heart disease down-regulates angiotensin type 1 receptor mRNA in human coronary arteries

    DEFF Research Database (Denmark)

    Wackenfors, Angelica; Emilson, Malin; Ingemansson, Richard;

    2004-01-01

    Angiotensin II is important in the development of cardiovascular disease. In the present study, angiotensin II receptor mRNA levels were quantified by real-time polymerase chain reaction (real-time PCR) in human coronary arteries from patients with ischemic heart disease and controls. Furthermore......, the suitability of artery culture for studying angiotensin receptor changes was evaluated by in vitro pharmacology and real-time PCR. The angiotensin type 1 (AT1) receptor mRNA levels were down-regulated in human coronary arteries from patients with ischemic heart disease as compared to controls (P

  12. [Role of calcineurin in down-regulation of left ventricular transmural voltage- dependent K(+) currents in mice with heart failure].

    Science.gov (United States)

    Shi, Chen-Xia; Dong, Fang; Chang, Yan-Chao; Wang, Xiao-Feng; Xu, Yan-Fang

    2015-08-25

    The aim of the present study was to investigate the role of calcineurin in the down-regulation of left ventricular transmural voltage-dependent K(+) currents in heart failure. Transverse aorta was banded by using microsurgical techniques to create mouse heart failure model. Sham-operated (Sham) or aorta banded (Band) mice were randomized to receive calcineurin inhibitor cyclosporine A (CsA) or vehicle. The densities and kinetic properties of voltage-dependent K(+) currents, as well as action potential (AP), of left ventricular subendocardial (Endo) and subepicardial (Epi) myocytes were determined by using whole-cell patch-clamp technique. The results showed that calcineurin activity was significant higher in Endo myocytes than that in Epi ones in all the groups. Compared with Sham group, Band mice showed significantly increased calcineurin activity both in Endo and Epi myocytes. CsA significantly reduced calcineurin activity in Band mice. CsA treatment in Band mice partially reversed the down-regulation of Ito density, completely reversed the down-regulation of IK,slow density both in Endo and Epi myocytes, and Iss density in Endo myocytes. In addition, CsA treatment in Band mice partially antagonized the prolongation of action potential duration (APD), and APD at 50% (APD50) and 90% repolarization (APD90) were significantly reduced. Because of non-parallel shortening of APD in Endo and Epi myocytes, the ratio of Endo/Epi APD90 was reduced from 4.8:1 in Band mice to 2.6:1 in CsA-treated mice, which was close to that in Sham mice. The results suggest that non-parallel activation of calcineurin in Endo and Epi myocytes contributes to the down-regulation of transmural voltage-dependent K(+) currents and the amplification of transmural dispersion of repolarization (TDR) in left ventricular failure hearts. Inhibition of calcineurin may be a potential new therapeutic strategy to prevent and cure arrhythmias and sudden death in heart failure.

  13. Down regulation of miR-203 in radiation-induced thymic lymphoma promoted cells proliferation and inhibited apoptosis%Down regulation of miR-203in radiation-induced thymic lymphoma promoted cells proliferation and inhibited apoptosis

    Institute of Scientific and Technical Information of China (English)

    Zhang Chaoxiong; Zhang Mingjian; Gao Fu; Zhou Chuanfeng; Zhang Pei; Cai Jianming; Liu Cong

    2015-01-01

    Objective To investigate the role of miR-203 in radiation-induced thymic lymphoma (RITL).Methods A 60Co irradiator was used for total-body irradiation.MicroRNAs(miRNAs) level was assayed by qRT-PCR.Cell proliferation was assayed by MTT assay.Cell apoptosis was examined by fluorescence activated cell sorter (FACS).Dual luciferase reporter assay system was used to detect the 3'UTR reporter.Results MiR-203 was down-regulated in RITL tissues.Overexpression of miR-203 strongly inhibited the proliferation of both NIH3T3 cells and EL4 cells and vice versa.MiR-203 inhibited cells proliferation and induced apoptosis via TANK-binding kinase (TBK1),SLUG (SNAI2) and Cyclin D1 (CCND1).Conclusions Radiation down-regulated the level of miR-203 in thymic,which promoted radiation-induced thymic lymphoma by targeting TBK1,SNAI2 and CCND1.

  14. Expression of Fragaria vesca PIP Aquaporins in Response to Drought Stress: PIP Down-Regulation Correlates with the Decline in Substrate Moisture Content

    OpenAIRE

    Nada Šurbanovski; Sargent, Daniel J.; Else, Mark A.; Simpson, David W.; Hanma Zhang; Grant, Olga M.

    2013-01-01

    PIP aquaporin responses to drought stress can vary considerably depending on the isoform, tissue, species or level of stress; however, a general down-regulation of these genes is thought to help reduce water loss and prevent backflow of water to the drying soil. It has been suggested therefore, that it may be necessary for the plant to limit aquaporin production during drought stress, but it is unknown whether aquaporin down-regulation is gradual or triggered by a particular intensity of the ...

  15. Urinary hMG versus recombinant FSH for controlled ovarian hyperstimulation following an agonist long down-regulation protocol in IVF or ICSI treatment: a systematic review and meta-analysis.

    Science.gov (United States)

    Coomarasamy, Arri; Afnan, Masoud; Cheema, Deepti; van der Veen, Fulco; Bossuyt, Patrick M M; van Wely, Madelon

    2008-02-01

    Since the most recent Cochrane review on hMG versus rFSH for controlled ovarian hyperstimulation following a long down-regulation protocol, several new trials have emerged. We conducted a systematic review and meta-analysis of randomized trials comparing the effectiveness of hMG versus rFSH following a long down-regulation protocol in IVF-ICSI cycles, on the primary outcome of live birth per woman randomized, as well as several other secondary outcomes. Searches were conducted in MEDLINE, EMBASE, Science Direct, Cochrane Library and databases of abstracts (last search January 2007). Seven randomized trials, consisting of a total of 2159 randomized women, were identified. A meta-analysis of these trials showed a significant increase in live birth rate with hMG when compared with rFSH (relative risk, RR = 1.18, 95% CI: 1.02-1.38, P = 0.03). The heterogeneity test was non-significant (P = 0.97), suggesting that there was no statistical inconsistency between the seven studies. The pooled risk difference (RD) for the outcome of live birth rate was 4% (95% CI: 1-7%) for these study populations. There was an increase in clinical pregnancy rates with hMG when compared with rFSH (RR = 1.17, 95% CI 1.03-1.34). No significant differences were noted for gonadotrophin use, spontaneous abortion, multiple pregnancy, cancellation and ovarian hyperstimulation syndrome rates. For the populations in the randomized trials, hMG was associated with a pooled 4% increase in live birth rate when compared with rFSH in IVF-ICSI treatment following a long down-regulation protocol.

  16. Expression of neurexin and neuroligin in the enteric nervous system and their down-regulated expression levels in Hirschsprung disease.

    Science.gov (United States)

    Zhang, Qiangye; Wang, Jian; Li, Aiwu; Liu, Hongzhen; Zhang, Wentong; Cui, Xinhai; Wang, Kelai

    2013-04-01

    To investigate the expression levels of neurexins and neuroligins in the enteric nervous system (ENS) in Hirschsprung Disease (HSCR). Longitudinal muscles with adherent mesenteric plexus were obtained by dissection of the fresh gut wall of mice, guinea pigs, and humans. Double labeling of neurexin I and Hu (a neuron marker), neuroligin 1 and Hu, neurexin I and synaptophysin (a presynaptic marker), and neuroligin 1 and PSD95 (a postsynaptic marker) was performed by immunofluorescence staining. Images were merged to determine the relative localizations of the proteins. Expression levels of neurexin and neuroligin in different segments of the ENS in HSCR were investigated by immunohistochemistry. Neurexin and neuroligin were detected in the mesenteric plexus of mice, guinea pigs, and humans with HSCR. Neurexin was located in the presynapse, whereas neuroligin was located in the postsynapse. Expression levels of neurexin and neuroligin were significant in the ganglionic colonic segment of HSCR, moderate in the transitional segment, and negative in the aganglionic colonic segment. The expressions of neurexin and neuroligin in the transitional segments were significantly down-regulated compared with the levels in the normal segments (P < 0.05). Expression levels of neurexin and neuroligin in ENS are significantly down-regulated in HSCR, which may be involved in the pathogenesis of HSCR.

  17. Down-regulation of msrb3 and destruction of normal auditory system development through hair cell apoptosis in zebrafish.

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    Shen, Xiaofang; Liu, Fei; Wang, Yingzhi; Wang, Huijun; Ma, Jing; Xia, Wenjun; Zhang, Jin; Jiang, Nan; Sun, Shaoyang; Wang, Xu; Ma, Duan

    2015-01-01

    Hearing defects can significantly influence quality of life for those who experience them. At this time, 177 deafness genes have been cloned, including 134 non-syndromic hearing-loss genes. The methionine sulfoxide reductase B3 (Ahmed et al., 2011) gene (also called DFNB74) is one such newly discovered hearing-loss gene. Within this gene c.265 T>G and c.55 T>C mutations are associated with autosomal recessive hearing loss. However, the biological role and mechanism underlying how it contributes to deafness is unclear. Thus, to better understand this mutation, we designed splicing morpholinos for the purpose of down-regulating msrb3 in zebrafish. Morphants exhibited small, tiny, fused, or misplaced otoliths and abnormal numbers of otoliths. Down-regulation of msrb3 also caused shorter, thinner, and more crowded cilia. Furthermore, L1-8 neuromasts were reduced and disordered in the lateral line system; hair cells in each neuromast underwent apoptosis. Co-injection with human MSRB3 mRNA partially rescued auditory system defects, but mutant MSRB3 mRNA could not. Thus, msrb3 is instrumental for auditory system development in zebrafish and MSRB3-related deafness may be caused by promotion of hair cell apoptosis.

  18. Histone Deacetylase (HDAC Inhibitors Down-Regulate Endothelial Lineage Commitment of Umbilical Cord Blood Derived Endothelial Progenitor Cells

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    Horia Maniu

    2012-11-01

    Full Text Available To test the involvement of histone deacetylases (HDACs activity in endothelial lineage progression, we investigated the effects of HDAC inhibitors on endothelial progenitors cells (EPCs derived from umbilical cord blood (UCB. Adherent EPCs, that expressed the endothelial marker proteins (PCAM-1, CD105, CD133, and VEGFR2 revealed by flow cytometry were treated with three HDAC inhibitors: Butyrate (BuA, Trichostatin A (TSA, and Valproic acid (VPA. RT-PCR assay showed that HDAC inhibitors down-regulated the expression of endothelial genes such as VE-cadherin, CD133, CXCR4 and Tie-2. Furthermore, flow cytometry analysis illustrated that HDAC inhibitors selectively reduce the expression of VEGFR2, CD117, VE-cadherin, and ICAM-1, whereas the expression of CD34 and CD45 remained unchanged, demonstrating that HDAC is involved in endothelial differentiation of progenitor cells. Real-Time PCR demonstrated that TSA down-regulated telomerase activity probably via suppression of hTERT expression, suggesting that HDAC inhibitor decreased cell proliferation. Cell motility was also decreased after treatment with HDAC inhibitors as shown by wound-healing assay. The balance of acethylation/deacethylation kept in control by the activity of HAT (histone acetyltransferases/HDAC enzymes play an important role in differentiation of stem cells by regulating proliferation and endothelial lineage commitment.

  19. Ginsenoside PPD’s Antitumor Effect via Down-Regulation of mTOR Revealed by Super-Resolution Imaging

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    Bo Teng

    2017-03-01

    Full Text Available Derived from Panax ginseng, the natural product 20(S-Protopanaxadiol (PPD has been reported for its cytotoxicity against several cancer cell lines. The molecular mechanism is, however, not well understood. Here we show that PPD significantly inhibits proliferation, induces apoptosis and causes G2/M cell cycle arrest in human laryngeal carcinoma cells (Hep-2 cells. PPD also decreases the levels of proteins related to cell proliferation. Moreover, PPD-induced apoptosis is characterized by a dose-dependent down-regulation of Bcl-2 expression and up-regulation of Bax, and is accompanied by the activation of Caspase-3 as well. Further molecular mechanism is revealed by direct stochastic optical reconstruction microscopy (dSTORM—a novel high-precision localization microscopy which enables effective resolution down to the order of 10 nm. It shows the expression and spatial arrangement of mTOR and its downstream effectors, demonstrating that this ginsenoside exerts its excellent anticancer effects via down-regulation of mTOR signaling pathway in Hep-2 cells. Taken together, our findings elucidate that the antitumor effect of PPD is associated with its regulation of mTOR expression and distribution, which encourages further studies of PPD as a promising therapeutic agent against laryngeal carcinoma.

  20. Down-regulation of sup 3 H-imipramine binding sites in rat cerebral cortex prenatal exposure to antidepressants

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    Montero, D.; de Ceballos, M.L. (Cajal Institute, Madrid (Spain)); Del Rio, J. (Univ. of Navarra, Pamplona (Spain))

    1990-01-01

    Several antidepressant drugs were given to pregnant rats in the last 15 days of gestation and {sup 3}H-imipramine binding ({sup 3}H-IMI) was subsequently measured in the cerebral cortex of the offspring. The selective serotonin (5-HT) uptake blockers chlorimipramine and fluoxetine as well as the selective monoamine oxidase (MAO) inhibitors clorgyline and deprenyl induced, after prenatal exposure, a down-regulation of {sup 3}H-IMI binding sites at postnatal day 25. The density of these binding sites was still reduced at postnatal day 90 in rats exposed in utero to the MAO inhibitors. The antidepressants desipramine and nomifensine were ineffective in this respect. After chronic treatment of adult animals, only chlorimipramine was able to down-regulate the {sup 3}H-IMI binding sites. Consequently, prenatal exposure of rats to different antidepressant drugs affecting predominantly the 5-HT systems induces more marked and long-lasting effects on cortical {sup 3}H-IMI binding sites. The results suggest that the developing brain is more susceptible to the actions of antidepressants.

  1. MiR-378 Promotes the Migration of Liver Cancer Cells by Down-Regulating Fus Expression

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    Jichun Ma

    2014-12-01

    Full Text Available Background: miR-378 regulates osteoblast differentiation and participates in tumor cell self-renewal and chemo-resistance. However, the function of miR-378 in liver cancer cell migration has not been reported to date. Methods: miR-378 expression was examined using real-time quantitative PCR. HepG2 cell migration and liver cell invasion were examined using wound-healing and cell invasion assays. Additionally, HepG2 cell metastasis was analyzed in nude mice. Results: miR-378 over-expression enhances HepG2 cell proliferation, migration and liver cell invasion. Typical metastatic lesions were found in the livers of mice injected with miR-378-transfected cells, and high levels of the CMV promoter were detected in the nodules, indicating that miR-378 promoted the metastasis of the tumor cells to the liver. We also demonstrated that miR-378 down-regulated Fus expression. Conclusions: Our results suggested that miR-378 enhanced cell migration and metastasis by down-regulating Fus expression.

  2. Overexpression of Insulin Degrading Enzyme could Greatly Contribute to Insulin Down-regulation Induced by Short-Term Swimming Exercise.

    Science.gov (United States)

    Kim, Min Sun; Goo, Jun Seo; Kim, Ji Eun; Nam, So Hee; Choi, Sun Il; Lee, Hye Ryun; Hwang, In Sik; Shim, Sun Bo; Jee, Seung Wan; Lee, Su Hae; Bae, Chang Joon; Cho, Jung Sik; Cho, Jun Yong; Hwang, Dae Youn

    2011-03-01

    Exercise training is highly correlated with the reduced glucose-stimulated insulin secretion (GSIS), although it enhanced insulin sensitivity, glucose uptake and glucose transporter expression to reduce severity of diabetic symptoms. This study investigated the impact of short-term swimming exercise on insulin regulation in the Goto-Kakizaki (GK) rat as a non-obese model of non-insulin-dependent diabetes mellitus. Wistar (W/S) and GK rats were trained 2 hours daily with the swimming exercise for 4 weeks, and then the changes in the metabolism of insulin and glucose were assessed. Body weight was markedly decreased in the exercised GK rats compare to their non-exercised counterpart, while W/S rats did not show any exercise-related changes. Glucose concentration was not changed by exercise, although impaired glucose tolerance was improved in GK rats 120 min after glucose injection. However, insulin concentration was decreased by swimming exercise as in the decrease of GSIS after running exercise. To identify the other cause for exercise-induced insulin down-regulation, the changes in the levels of key factors involved in insulin production (C-peptide) and clearance (insulin-degrading enzyme; IDE) were measured in W/S and GK rats. The C-peptide level was maintained while IDE expression increased markedly. Therefore, these results showed that insulin down-regulation induced by short-term swimming exercise likely attributes to enhanced insulin clearance via IDE over-expression than by altered insulin production.

  3. Distinct down-regulation of cardiac beta 1- and beta 2-adrenoceptors in different human heart diseases.

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    Steinfath, M; Geertz, B; Schmitz, W; Scholz, H; Haverich, A; Breil, I; Hanrath, P; Reupcke, C; Sigmund, M; Lo, H B

    1991-02-01

    Cardiac beta-adrenoceptor density and beta 1- and beta 2-subtype distribution were examined in human left ventricular myocardium from transplant donors serving as controls and from patients with mitral valve stenosis, aortic valve stenosis, idiopathic dilated cardiomyopathy, and ischaemic cardiomyopathy respectively. The total beta-adrenoceptor density was similar in transplant donors and patients with moderate heart failure (NYHA II-III) due to mitral valve stenosis, but was markedly reduced in all forms of severe heart failure (NYHA III-IV) studied. A reduction of both beta 1- and beta 2-adrenoceptors was found in patients with severe heart failure due to mitral valve stenosis or ischaemic cardiomyopathy. In contrast, a selective down-regulation of beta 1-adrenoceptors with unchanged beta 2-adrenoceptors and hence a relative increase in the latter was observed in idiopathic dilated cardiomyopathy and aortic valve stenosis. It is concluded that the extent of total beta-adrenoceptor down-regulation is related to the degree of heart failure. Selective loss of beta 1-adrenoceptors is not specific for idiopathic dilated cardiomyopathy but also occurs in aortic valve stenosis. Changes in beta 1- and beta 2-subtype distribution are rather related to the aetiology than to the clinical degree of heart failure.

  4. Down-regulation apoptosis signal-regulating kinase 1 gene reduced the Litopenaeus vannamei hemocyte apoptosis in WSSV infection.

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    Yuan, Feng-Hua; Chen, Yong-Gui; Zhang, Ze-Zhi; Yue, Hai-Tao; Bi, Hai-Tao; Yuan, Kai; Weng, Shao-Ping; He, Jian-Guo; Chen, Yi-Hong

    2016-03-01

    Apoptosis signal-regulating kinase 1 (ASK1), a mitogen-activated protein kinase kinase kinase, is crucial in various cellular responses. In the present study, we identified and characterized an ASK1 homolog from Litopenaeus vannamei (LvASK1). The full-length cDNA of LvASK1 was 5400 bp long, with an open reading frame encoding a putative 1420 amino acid protein. LvASK1 was highly expressed in muscle, hemocyte, eyestalk and heart. Real-time RT-PCR analysis showed that the expression of the LvASK1 was upregulated during the white spot syndrome virus (WSSV) challenge. The knocked-down expression of LvASK1 by RNA interference significantly reduced the apoptotic ratio of the hemocytes collected from WSSV-infected L. vannamei. Furthermore, the down-regulation of LvASK1 also decreased the cumulative mortality of WSSV-infected L. vannamei. These results suggested that down-regulation of LvASK1 decreased the apoptotic rate of hemocytes in WSSV-infected shrimp, and that it could contribute to the reduction of cumulative mortality in WSSV-infected L. vannamei.

  5. N-methylhemeanthidine chloride, a novel Amaryllidaceae alkaloid, inhibits pancreatic cancer cell proliferation via down-regulating AKT activation

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    Guo, Guoli; Yao, Guangmin; Zhan, Guanqun; Hu, Yufeng [Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei PR China (China); Yue, Ming [Hubei Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei (China); Cheng, Ling; Liu, Yaping; Ye, Qi [Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei PR China (China); Qing, Guoliang [Hubei Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei (China); Zhang, Yonghui, E-mail: zhangyh@mails.tjmu.edu.cn [Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei PR China (China); Liu, Hudan, E-mail: hudanliu@hust.edu.cn [Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei PR China (China)

    2014-11-01

    We previously reported the isolation of a novel Amaryllidaceae alkaloid, N-methylhemeanthidine chloride (NMHC), from Zephyranthes candida, which exhibits potent cytotoxicity in a spectrum of tumor cells. However, the mechanism of action remains unclear. Using multiple cell lines derived from human pancreatic cancer, one of the most mortal and refractory human malignancies, we further studied the NMHC-mediated cytotoxicity and found that it induced drastic cytotoxicity in pancreatic cancer cells whereas an insignificant effect on a noncancerous cell line. The NMHC-mediated growth inhibition was more severe than the first-line chemotherapeutic agent gemcitabine, leading to cell cycle arrest, apoptotic death and decreased glycolysis. NMHC exerted its function through down-regulating AKT activation, and the ectopic expression of activated AKT rescued the growth inhibition. Consistently, NMHC injections in a pancreatic cancer xenograft model manifested the anti-tumor effect in vivo. Engrafted tumor cells underwent AKT attenuation and apoptotic death upon treatments. As such, we here demonstrate the AKT inhibition may be one of the mechanisms by which NMHC decreases tumor cell survival rate in vitro and in vivo. Our data thereby suggest that NMHC holds great promise as a potent chemotherapeutic agent against pancreatic cancer and sheds new light on obtaining such agents from natural products toward therapeutic purposes. - Highlights: • N-methylhemeanthidine chloride (NMHC) is a novel Amaryllidaceae alkaloid. • NMHC exhibits potent anti-neoplastic activity. • NMHC leads to cell cycle arrest, apoptotic death and decreased metabolism. • NMHC down-regulates the AKT signaling pathway.

  6. Chelerythrine down regulates expression of VEGFA, BCL2 and KRAS by arresting G-Quadruplex structures at their promoter regions

    Science.gov (United States)

    Jana, Jagannath; Mondal, Soma; Bhattacharjee, Payel; Sengupta, Pallabi; Roychowdhury, Tanaya; Saha, Pranay; Kundu, Pallob; Chatterjee, Subhrangsu

    2017-01-01

    A putative anticancer plant alkaloid, Chelerythrine binds to G-quadruplexes at promoters of VEGFA, BCL2 and KRAS genes and down regulates their expression. The association of Chelerythrine to G-quadruplex at the promoters of these oncogenes were monitored using UV absorption spectroscopy, fluorescence anisotropy, circular dichroism spectroscopy, CD melting, isothermal titration calorimetry, molecular dynamics simulation and quantitative RT-PCR technique. The pronounced hypochromism accompanied by red shifts in UV absorption spectroscopy in conjunction with ethidium bromide displacement assay indicates end stacking mode of interaction of Chelerythrine with the corresponding G-quadruplex structures. An increase in fluorescence anisotropy and CD melting temperature of Chelerythrine-quadruplex complex revealed the formation of stable Chelerythrine-quadruplex complex. Isothermal titration calorimetry data confirmed that Chelerythrine-quadruplex complex formation is thermodynamically favourable. Results of quantative RT-PCR experiment in combination with luciferase assay showed that Chelerythrine treatment to MCF7 breast cancer cells effectively down regulated transcript level of all three genes, suggesting that Chelerythrine efficiently binds to in cellulo quadruplex motifs. MD simulation provides the molecular picture showing interaction between Chelerythrine and G-quadruplex. Binding of Chelerythrine with BCL2, VEGFA and KRAS genes involved in evasion, angiogenesis and self sufficiency of cancer cells provides a new insight for the development of future therapeutics against cancer.

  7. LAPTM4B Down Regulation Inhibits the Proliferation, Invasion and Angiogenesis of HeLa Cells In Vitro

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    Fanling Meng

    2015-09-01

    Full Text Available Background/Aims: LAPTM4B (lysosome-associated protein transmembrane 4 beta is a novel oncogene with important functions in aggressive human carcinomas, including cervical cancer. However, the specific functions and internal molecular mechanisms associated with this gene in the context of cervical cancer remain unclear. Methods: In this study, we explored the effects and mechanisms of LAPTM4B on tumor growth, metastasis and angiogenesis in vitro by depletion of LAPTM4B in Hela cell. RNA interference was used to induce down regulation of LAPTM4B gene expression in Hela cells. The motility, migration potential, and proliferation of the Hela cells were measured by flow cytometry, Transwell migration assays, wound healing assays, and Cell Counting Kit-8 assays. In addition, the cell cycle analysis utilized fluorescence-activated cell sorting. Results: In this study, RNAi-mediated LAPTM4B knockdown inhibited cell growth and angiogenesis. In vitro, HeLa cells with down regulated LAPTM4B also exhibited decreased migration and invasion activity as well as significantly reduced CDK12, HIF-1α, MMP-2, MMP-9 and VEGF expression. LAPTM4B blockade significantly decreased cord lengths and branch points in a tube formation assay. Conclusions: These results suggested that LAPTM4B inactivation could be a novel therapeutic target for cervical cancer.

  8. Establishment of an ovarian metastasis model and possible involvement of E-cadherin down-regulation in the metastasis.

    Science.gov (United States)

    Kuwabara, Yoshiko; Yamada, Taketo; Yamazaki, Ken; Du, Wen-Lin; Banno, Kouji; Aoki, Daisuke; Sakamoto, Michiie

    2008-10-01

    Clinical observations of cases of ovarian metastasis suggest that there may be a unique mechanism underlying ovarian-specific metastasis. This study was undertaken to establish an in vivo model of metastasis to the ovary, and to investigate the mechanism of ovarian-specific metastasis. We examined the capacity for ovarian metastasis in eight different human carcinoma cell lines by implantation in female NOD/SCID mice transvenously and intraperitoneally. By transvenous inoculation, only RERF-LC-AI, a poorly differentiated carcinoma cell line, frequently demonstrated ovarian metastasis. By intraperitoneal inoculation, four of the eight cell lines (HGC27, MKN-45, KATO-III, and RERF-LC-AI) metastasized to the ovary. We compared E-cadherin expression among ovarian metastatic cell lines and others. All of these four ovarian metastatic cell lines and HSKTC, a Krukenberg tumor cell line, showed E-cadherin down-regulation and others did not. E-cadherin was then forcibly expressed in RERF-LC-AI, and inhibited ovarian metastasis completely. The capacity for metastasizing to the other organs was not affected by E-cadherin expression. We also performed histological investigation of clinical ovarian-metastatic tumor cases. About half of all ovarian-metastatic tumor cases showed loss or reduction of E-cadherin expression. These data suggest that E-cadherin down-regulation may be involved in ovarian-specific metastasis.

  9. Endotoxin-induced basal respiration alterations of renal HK-2 cells: A sign of pathologic metabolism down-regulation

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    Quoilin, C., E-mail: cquoilin@ulg.ac.be [Laboratory of Biomedical Spectroscopy, Department of Physics, University of Liege, 4000 Liege (Belgium); Mouithys-Mickalad, A. [Center of Oxygen Research and Development, Department of Chemistry, University of Liege, 4000 Liege (Belgium); Duranteau, J. [Department of Anaesthesia and Surgical ICU, CHU Bicetre, University Paris XI Sud, 94275 Le Kremlin Bicetre (France); Gallez, B. [Biomedical Magnetic Resonance Group, Louvain Drug Research Institute, Universite catholique de Louvain, 1200 Brussels (Belgium); Hoebeke, M. [Laboratory of Biomedical Spectroscopy, Department of Physics, University of Liege, 4000 Liege (Belgium)

    2012-06-29

    Highlights: Black-Right-Pointing-Pointer A HK-2 cells model of inflammation-induced acute kidney injury. Black-Right-Pointing-Pointer Two oximetry methods: high resolution respirometry and ESR spectroscopy. Black-Right-Pointing-Pointer Oxygen consumption rates of renal cells decrease when treated with LPS. Black-Right-Pointing-Pointer Cells do not recover normal respiration when the LPS treatment is removed. Black-Right-Pointing-Pointer This basal respiration alteration is a sign of pathologic metabolism down-regulation. -- Abstract: To study the mechanism of oxygen regulation in inflammation-induced acute kidney injury, we investigate the effects of a bacterial endotoxin (lipopolysaccharide, LPS) on the basal respiration of proximal tubular epithelial cells (HK-2) both by high-resolution respirometry and electron spin resonance spectroscopy. These two complementary methods have shown that HK-2 cells exhibit a decreased oxygen consumption rate when treated with LPS. Surprisingly, this cellular respiration alteration persists even after the stress factor was removed. We suggested that this irreversible decrease in renal oxygen consumption after LPS challenge is related to a pathologic metabolic down-regulation such as a lack of oxygen utilization by cells.

  10. JNK/c-Jun signaling pathway mediates the fluoride-induced down-regulation of MMP-20 in vitro

    Science.gov (United States)

    Zhang, Yan; Li, Wu; Chi, Hae Sun; Chen, James; DenBesten, Pamela K.

    2008-01-01

    Delayed removal of amelogenins, which are initially hydrolyzed by matrix metalloproteinase MMP-20, is a characteristic of enamel fluorosis. In this study, we investigated the regulation of MMP-20 and possible effects of fluoride on MMP-20 expression in human ameloblast lineage cells. Protein expression and signaling pathways of human ameloblast lineage cells, exposed to 10 μM fluoride, were compared to control cells without fluoride exposure. The role of activator protein-1 in MMP-20 regulation was analyzed by DNA-protein affinity precipitation and luciferase reporter gene assays. MMP-20 protein levels in human ameloblast lineage cells decreased in the presence of fluoride, while amelogenin and TIMP-2 were not altered. Fluoride also decreased the transcription of a luciferase reporter gene driven by the MMP-20 promoter. Down-regulation of MMP-20 by fluoride was related to suppression of JNK/c-Jun phosphorylation. In contrast, the JNK activator elevated the expression of MMP-20. Three c-Jun binding sites on the MMP-20 promoter were identified for the first time, and were occupied by c-Jun as MMP-20 was induced. Deletion of any one of AP-1 binding sites on the MMP-20 promoter significantly reduced the transcription of downstream luciferase reporter. These in vitro findings suggest that c-Jun is a key regulatory element for MMP-20 expression, and human ameloblast lineage cells can respond to fluoride by down-regulating MMP-20 transcription through the JNK/c-Jun signaling pathway. PMID:17611094

  11. Transient down-regulation of the RNA silencing machinery increases efficiency of Agrobacterium-mediated transformation of Arabidopsis.

    Science.gov (United States)

    Bilichak, Andriy; Yao, Youli; Kovalchuk, Igor

    2014-06-01

    Agrobacterium tumefaciens is a plant pathogen that is widely used in plant transformation. As the process of transgenesis includes the delivery of single-stranded T-DNA molecule, we hypothesized that transformation rate may negatively correlate with the efficiency of the RNA-silencing machinery. Using mutants compromised in either the transcriptional or post-transcriptional gene-silencing pathways, two inhibitors of stable transformation were revealed-AGO2 and NRPD1a. Furthermore, an immunoprecipitation experiment has shown that NRPD1, a subunit of Pol IV, directly interacts with Agrobacterium T-DNA in planta. Using the Tobacco rattle virus (TRV)--based virus-induced gene silencing (VIGS) technique, we demonstrated that the transient down-regulation of the expression of either AGO2 or NRPD1a genes in reproductive organs of Arabidopsis, leads to an increase in transformation rate. We observed a 6.0- and 3.5-fold increase in transformation rate upon transient downregulation of either AGO2 or NRPD1a genes, respectively. This is the first report demonstrating the increase in the plant transformation rate via VIGS-mediated transient down-regulation of the components of epigenetic machinery in reproductive tissue.

  12. The GPCR-associated sorting protein 1 regulates ligand-induced down-regulation of GPR55.

    Science.gov (United States)

    Kargl, J; Balenga, N A; Platzer, W; Martini, L; Whistler, J L; Waldhoer, M

    2012-04-01

    Many GPCRs, including the CB(1) cannabinoid receptor, are down-regulated following prolonged agonist exposure by interacting with the GPCR-associated sorting protein-1 (GASP-1). The CB(1) receptor antagonist rimonabant has also recently been described to be an agonist at GPR55, a cannabinoid-related receptor. Here we investigated the post-endocytic properties of GPR55 after agonist exposure and tested whether GASP-1 is involved in this process. We evaluated the direct protein-protein interaction of GPR55 with GASP-1 using (i) GST-binding assays and (ii) co-immunoprecipitation assays in GPR55-HEK293 cells with endogenous GASP-1 expression. We further tested the internalization, recycling and degradation of GPR55 using confocal fluorescence microscopy and biotinylation assays in the presence and absence of GASP-1 (lentiviral small hairpin RNA knockdown of GASP-1) under prolonged agonist [rimonabant (RIM), lysophosphatidylinositol (LPI)] stimulation. We showed that the prolonged activation of GPR55 with rimonabant or LPI down-regulates GPR55 via GASP-1. GASP-1 binds to GPR55 in vitro, and this interaction was required for targeting GPR55 for degradation. Disrupting the GPR55-GASP-1 interaction prevented post-endocytic receptor degradation, and thereby allowed receptor recycling. These data implicate GASP-1 as an important regulator of ligand-mediated down-regulation of GPR55. By identifying GASP-1 as a key regulator of the trafficking and, by extension, functional expression of GPR55, we may be one step closer to gaining a better understanding of this receptor in response to cannabinoid drugs. This article is part of a themed section on Cannabinoids in Biology and Medicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-8. To view Part I of Cannabinoids in Biology and Medicine visit http://dx.doi.org/10.1111/bph.2011.163.issue-7. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological

  13. Herbal medicine Gamgungtang down-regulates autoimmunity through induction of TH2 cytokine production by lymphocytes in experimental thyroiditis model.

    Science.gov (United States)

    Sa, Eun-Ho; Jin, Un-Ho; Kim, Dong-Soo; Kang, Bong-Seok; Ha, Ki-Tae; Kim, June-Ki; Park, Won-Hwan; Kim, Cheorl-Ho

    2007-02-12

    The crude herbal formulation, Gamgungtang (GGT), has been shown to protect animals against a wide range of spontaneously developing or induced autoimmune diseases. We have previously reported that GGT shows marked down-regulation of several experimental autoimmune diseases. Although very effective at preventing thyroid infiltrates in mice immunized with mouse deglycosylated thyroglobulin and complete Freund's adjuvant and in spontaneous models of thyroiditis, it completely failed to modify experimental autoimmune thyroiditis (EAT) induced in mice immunized with mouse thyroglobulin and lipopolysaccharide. In this study, in an effort to elucidate the mechanisms by which GGT suppresses EAT, and autoimmunity in general, we investigated the in vivo effects of this drug on the Th1/Th2 lymphocyte balance, which is important for the induction or inhibition of autoreactivity. Naive SJL/J mice were treated orally for 5 days with GGT (80 mg/(kg day)). Spleen cells were obtained at various time points during the treatment period and were stimulated in vitro with concanavalin A. Interleukins IL-4, IL-10 and IL-12, transforming growth factor-beta (TGF-beta) and interferon-gamma (IFN-gamma) cytokine production was evaluated at the protein levels of the cytokines in the medium and mRNA expressions. A significant upregulation of IL-4, IL-10 and TGF-beta was observed following treatment with GGT, which peaked at day 5 (IL-10) or day 10 (IL-4). On the other hand, IL-12 and IFN-gamma production were either unchanged or decreased. It seems therefore that GGT induces in vivo a shift towards Th2 lymphocytes which may be one of the mechanisms of down-regulation of the autoimmune reactivity in EAT. Our observations indicate that down-regulation of TH1 cytokines (especially IL-12) and enhancement of Th2 cytokine production may play an important role in the control of T-cell-mediated autoimmunity. These data may contribute to the design of new immunomodulating treatments for a group of

  14. Necdin, a negative growth regulator, is a novel STAT3 target gene down-regulated in human cancer.

    Directory of Open Access Journals (Sweden)

    Rachel Haviland

    Full Text Available Cytokine and growth factor signaling pathways involving STAT3 are frequently constitutively activated in many human primary tumors, and are known for the transcriptional role they play in controlling cell growth and cell cycle progression. However, the extent of STAT3's reach on transcriptional control of the genome as a whole remains an important question. We predicted that this persistent STAT3 signaling affects a wide variety of cellular functions, many of which still remain to be characterized. We took a broad approach to identify novel STAT3 regulated genes by examining changes in the genome-wide gene expression profile by microarray, using cells expressing constitutively-activated STAT3. Using computational analysis, we were able to define the gene expression profiles of cells containing activated STAT3 and identify candidate target genes with a wide range of biological functions. Among these genes we identified Necdin, a negative growth regulator, as a novel STAT3 target gene, whose expression is down-regulated at the mRNA and protein levels when STAT3 is constitutively active. This repression is STAT3 dependent, since inhibition of STAT3 using siRNA restores Necdin expression. A STAT3 DNA-binding site was identified in the Necdin promoter and both EMSA and chromatin immunoprecipitation confirm binding of STAT3 to this region. Necdin expression has previously been shown to be down-regulated in a melanoma and a drug-resistant ovarian cancer cell line. Further analysis of Necdin expression demonstrated repression in a STAT3-dependent manner in human melanoma, prostate and breast cancer cell lines. These results suggest that STAT3 coordinates expression of genes involved in multiple metabolic and biosynthetic pathways, integrating signals that lead to global transcriptional changes and oncogenesis. STAT3 may exert its oncogenic effect by up-regulating transcription of genes involved in promoting growth and proliferation, but also by down-regulating

  15. Nucleolin down-regulation is involved in ADP-induced cell cycle arrest in S phase and cell apoptosis in vascular endothelial cells.

    Directory of Open Access Journals (Sweden)

    Wenmeng Wang

    Full Text Available High concentration of extracellular ADP has been reported to induce cell apoptosis, but the molecular mechanisms remain not fully elucidated. In this study, we found by serendipity that ADP treatment of human umbilical vein endothelial cells (HUVEC and human aortic endothelial cells (HAEC down-regulated the protein level of nucleolin in a dose- and time-dependent manner. ADP treatment did not decrease the transcript level of nucloelin, suggesting that ADP might induce nucleolin protein degradation. HUVEC and HAEC expressed ADP receptor P2Y13 receptor, but did not express P2Y1 or P2Y12 receptors. However, P2Y1, 12, 13 receptor antagonists MRS2179, PSB0739, MRS2211 did not inhibit ADP-induced down-regulation of nucleolin. Moreover, MRS2211 itself down-regulated nucleolin protein level. In addition, 2-MeSADP, an agonist for P2Y1, 12 and 13 receptors, did not down-regulate nucleolin protein. These results suggested that ADP-induced nucleolin down-regulation was not due to the activation of P2Y1, 12, or 13 receptors. We also found that ADP treatment induced cell cycle arrest in S phase, cell apoptosis and cell proliferation inhibition via nucleolin down-regulation. The over-expression of nucleolin by gene transfer partly reversed ADP-induced cell cycle arrest, cell apoptosis and cell proliferation inhibition. Furthermore, ADP sensitized HUVEC to cisplatin-induced cell death by the down-regulation of Bcl-2 expression. Taken together, we found, for the first time to our knowledge, a novel mechanism by which ADP regulates cell proliferation by induction of cell cycle arrest and cell apoptosis via targeting nucelolin.

  16. Down-regulation of Transducin-Like Enhancer of Split protein 4 in hepatocellular carcinoma promotes cell proliferation and epithelial-Mesenchymal-Transition

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    Wu, Xiao-cai; Xiao, Cui-cui; Li, Hua [Department of Hepatic Surgery, 3rd Affiliated Hospital of Sun Yat-sen University, Guangzhou (China); Guangdong Provincial Key Laboratory of Liver Disease Research, Guangzhou (China); Tai, Yan; Zhang, Qi [Guangdong Provincial Key Laboratory of Liver Disease Research, Guangzhou (China); Yang, Yang, E-mail: yysysu2@163.com [Department of Hepatic Surgery, 3rd Affiliated Hospital of Sun Yat-sen University, Guangzhou (China)

    2016-08-19

    Background: Transducin-Like Enhancer of Split protein 4 (TLE4) has been reported to be involved in some subsets of acute myeloid leukemia and colorectal cancer. In the present study, we aimed to explore the role of TLE4 in tumorigenesis and cancer progression in hepatocellular carcinoma (HCC). Methods: The expression pattern of TLE4 in HCC was determined by Western-blot and qRT-PCR, gain-of-function and loss-of-function was used to explore the biological role of TLE4 in HCC cells. A xenograft model was established to confirm its effects on proliferation. Results: The protein expression levels of TLE4 were significantly down-regulated in HCC tissues compared to matched adjacent normal liver tissues. In vitro, down-regulation of TLE4 in Huh7 or SMMC-7721 promoted cell proliferation and ectopical expression of TLE4 in Hep3B or Bel-7404 suppressed cell proliferation. In addition, the cell colony formation ability was enhanced after down-regulation of TLE4 expression in Huh-7 but suppressed after over-expression in Hep3B. Furthermore, down-regulation of TLE4 increased the cell invasion ability, as well as increased the expression level of Vimentin and decreased that of E-cadherin, indicating a phenotype of epithelial-mesenchymal transition (EMT) in HCC cells. On the contrary, ectopical expression of TLE4 in HCC cells decreased the cell invasion ability and inhibited EMT. In vivo, compared to control group, xenograft tumor volumes were significantly decreased in TLE4 overexpression group. Conclusions: These results demonstrated that TLE4 might play important regulatory roles in cellular proliferation and EMT process in HCC. - Highlights: • TLE4 is significantly down-regulated in HCC samples. • Down regulated of TLE4 in HCC cells promotes cell proliferation. • Down regulated of TLE4 in HCC cells promotes epithelial-to-mesenchymal transition.

  17. Hepatitis C virus Core protein stimulates cell growth by down-regulating p16 expression via DNA methylation.

    Science.gov (United States)

    Park, Sun-Hye; Lim, Joo Song; Lim, Su-Yeon; Tiwari, Indira; Jang, Kyung Lib

    2011-11-01

    Hepatitis C virus Core plays a vital role in the development of hepatocellular carcinoma; however, its action mechanism is still controversial. Here, we showed that Core down-regulated levels of p16, resulting in inactivation of Rb and subsequent activation of E2F1, which lead to growth stimulation of hepatocytes. For this effect, Core inhibited p16 expression by inducing promoter hypermethylation via up-regulation of DNA methyltransferase 1 (DNMT1) and DNMT3b. The growth stimulatory effect of Core was abolished when levels of p16 were restored by either exogenous complementation or treatment with 5-Aza-2'dC, indicating that the effect is critical for the stimulation of cell growth by Core. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  18. Down-regulated expression of NPM1 in IMS-M2 cell line by (-)-epigallocatechin-3-gallate

    Institute of Scientific and Technical Information of China (English)

    Hoang Thanh Chi; Bui Thi Kim Ly; Hoang Anh Vu; Yuko Sato; Phu Chi Dung; Phan Thi Xinh

    2014-01-01

    Objective: To investigate the inhibited effect of epigallocatechin-3-gallate (EGCG) on the expression of NPM1 in IMS-M2 cells harboring the NPM1 mutations.Methods:Cell proliferation assay was performed to test the effects of EGCG on cell growth of IMS-M2 cells harboring the NPM1 mutations. Western blot analysis were performed to test the protein expression of NPM1, AKT, those associated with apoptosis. Results: EGCG can down-regulate the expression of NPM1 in IMS-M2 cells harboring the NPM1 mutations. Moreover, EGCG also suppressed the cell proliferation and induced apoptosis in IMS-M2 cells.Conclusions:The results suggested that EGCG could be considered as a reagent for treatment of AML patients with NPM1 mutations.

  19. Picroside Ⅱ down-regulates matrix metalloproteinase-9 expression following cerebral ischemia/reperfusion injury in rats

    Institute of Scientific and Technical Information of China (English)

    Xiang Li; Xinying Xu; Zhen Li; Yunliang Guo; Qin Li; Xiaodan Li; Zhen Zhou

    2010-01-01

    Studies have shown that Picroside Ⅱ attenuates inflammatory reactions following brain ischemia through the inhibition of the TLR-4-NF-κB signal transduction pathway,and ameliorates cerebral edema through the reduction of aquaporin-4 expression.Matrix metalloproteinase-9(MMP-9),located downstream of the TLR-4-NF-κB signal transduction pathway,can degrade the neurovascular matrix,damage the blood-brain barrier to induce cerebral edema,and directly result in neuronal apoptosis and brain injury.Therefore,the present study further observed MMP-9expression in the brain tissues of rats with cerebral ischemia/reperfusion injury following Picroside Ⅱtreatment.Results demonstrated that Picroside Ⅱ significantly reduced MMP-9 expression in ischemic brain tissues,as well as neuronal apoptosis and brain infarct volume,suggesting PicrosideⅡ exhibits neuroprotection by down-regulating MMP-9 expression and inhibiting cell apoptosis.

  20. Down-regulation of the chemokine receptor CCR5 by activation of chemotactic formyl peptide receptor in human monocytes.

    Science.gov (United States)

    Shen, W; Li, B; Wetzel, M A; Rogers, T J; Henderson, E E; Su, S B; Gong, W; Le, Y; Sargeant, R; Dimitrov, D S; Oppenheim, J J; Wang, J M

    2000-10-15

    Interactions between cell surface receptors are important regulatory elements in the complex host responses to infections. In this study, it is shown that a classic chemotactic factor, the bacterial chemotactic peptide N-formyl-methionyl-leucylphenyl-alanine (fMLF), rapidly induced a protein-kinase-C-mediated serine phosphorylation and down-regulation of the chemokine receptor CCR5, which serves as a major human immunodeficiency virus (HIV)-1 coreceptor. The fMLF binding to its receptor, formyl peptide receptor (FPR), resulted in significant attenuation of cell responses to CCR5 ligands and in inhibition of HIV-1-envelope-glycoprotein-mediated fusion and infection of cells expressing CD4, CCR5, and FPR. The finding that the expression and function of CCR5 can be regulated by peptides that use an unrelated receptor may provide a novel approach to the design of anti-inflamatory and antiretroviral agents. (Blood. 2000;96:2887-2894)

  1. Down-regulation of the A3 adenosine receptor in human mast cells upregulates mediators of angiogenesis and remodeling.

    Science.gov (United States)

    Rudich, Noam; Dekel, Ornit; Sagi-Eisenberg, Ronit

    2015-05-01

    Adenosine activated mast cells have been long implicated in allergic asthma and studies in rodent mast cells have assigned the A3 adenosine receptor (A3R) a primary role in mediating adenosine responses. Here we analyzed the functional impact of A3R activation on genes that are implicated in tissue remodeling in severe asthma in the human mast cell line HMC-1 that shares similarities with lung derived human mast cells. Quantitative real time PCR demonstrated upregulation of IL6, IL8, VEGF, amphiregulin and osteopontin. Moreover, further upregulation of these genes was noted upon the addition of dexamethasone. Unexpectedly, activated A3R down regulated its own expression and knockdown of the receptor replicated the pattern of agonist induced gene upregulation. This study therefore identifies the human mast cell A3R as regulator of tissue remodeling gene expression in human mast cells and demonstrates a heretofore-unrecognized mode of feedback regulation that is exerted by this receptor.

  2. Hypoxia-induced 15-HETE enhances the constriction of internal carotid arteries by down-regulating potassium channels.

    Science.gov (United States)

    Zhu, Yanmei; Chen, Li; Liu, Wenjuan; Wang, Weizhi; Zhu, Daling; Zhu, Yulan

    2010-08-15

    Severe hypoxia induces the constriction of internal carotid arteries (ICA), which worsens ischemic stroke in the brain. A few metabolites are presumably involved in hypoxic vasoconstriction, however, less is known about how such molecules provoke this vasoconstriction. We have investigated the influence of 15-hydroxyeicosatetrienoic acid (15-HETE) produced by 15-lipoxygenase (15-LOX) on vasoconstriction during hypoxia. As showed in our results, 15-LOX level increases in ICA endothelia and smooth muscles. 15-HETE enhances the tension of ICA ring in a dose-dependent manner, as well as attenuates the activities and expression of voltage-gated potassium channels (Kv 1.5 and Kv 2.1). Therefore, the down-regulation of Kv channels by 15-HETE during hypoxia may weaken the repolarization of action potentials and causes a dominant influx of calcium ions to enhance smooth muscle tension and ICA constriction.

  3. Down-regulation of malignant potential by alpha linolenic acid in human and mouse colon cancer cells.

    Science.gov (United States)

    Chamberland, John P; Moon, Hyun-Seuk

    2015-03-01

    Omega-3 fatty acids (also called ω-3 fatty acis or n-3 fatty acid) are polyunsaturated fatty acids (PUFAs) with a double bond (C=C) at the third carbon atom from the end of the carbon chain. Numerous test tube and animal studies have shown that omega-3 fatty acids may prevent or inhibit the growth of cancers, suggesting that omega-3 fatty acids are important in cancer physiology. Alpha-linolenic acid (ALA) is one of an essential omega-3 fatty acid and organic compound found in seeds (chia and flaxseed), nuts (notably walnuts), and many common vegetable oils. ALA has also been shown to down-regulate cell proliferation of prostate, breast, and bladder cancer cells. However, direct evidence that ALA suppresses to the development of colon cancer has not been studied. Also, no previous studies have evaluated whether ALA may regulate malignant potential (adhesion, invasion and colony formation) in colon cancer cells. In order to address the questions above, we conducted in vitro studies and evaluated whether ALA may down-regulate malignant potential in human (HT29 and HCT116) and mouse (MCA38) colon cancer cell lines. We observed that treatment with 1-5 mM of ALA inhibits cell proliferation, adhesion and invasion in both human and mouse colon cancer cell lines. Interestingly, we observed that ALA did not decrease total colony numbers when compared to control. By contrast, we found that size of colony was significantly changed by ALA treatment when compared to control in all colon cancer cell lines. We suggest that our data enhance our current knowledge of ALA's mechanism and provide crucial information to further the development of new therapies for the management or chemoprevention of colon cancer.

  4. Antioxidants Abrogate Alpha-Tocopherylquinone-Mediated Down-Regulation of the Androgen Receptor in Androgen-Responsive Prostate Cancer Cells.

    Directory of Open Access Journals (Sweden)

    Alexandra M Fajardo

    Full Text Available Tocopherylquinone (TQ, the oxidation product of alpha-tocopherol (AT, is a bioactive molecule with distinct properties from AT. In this study, AT and TQ are investigated for their comparative effects on growth and androgenic activity in prostate cancer cells. TQ potently inhibited the growth of androgen-responsive prostate cancer cell lines (e.g., LAPC4 and LNCaP cells, whereas the growth of androgen-independent prostate cancer cells (e.g., DU145 cells was not affected by TQ. Due to the growth inhibitory effects induced by TQ on androgen-responsive cells, the anti-androgenic properties of TQ were examined. TQ inhibited the androgen-induced activation of an androgen-responsive reporter and inhibited the release of prostate specific antigen from LNCaP cells. TQ pretreatment was also found to inhibit AR activation as measured using the Multifunctional Androgen Receptor Screening assay. Furthermore, TQ decreased androgen-responsive gene expression, including TM4SF1, KLK2, and PSA over 5-fold, whereas AT did not affect the expression of androgen-responsive genes. Of importance, the antiandrogenic effects of TQ on prostate cancer cells were found to result from androgen receptor protein down-regulation produced by TQ that was not observed with AT treatment. Moreover, none of the androgenic endpoints assessed were affected by AT. The down-regulation of androgen receptor protein by TQ was abrogated by co-treatment with antioxidants. Overall, the biological actions of TQ were found to be distinct from AT, where TQ was found to be a potent inhibitor of cell growth and androgenic activity in androgen-responsive prostate cancer cells.

  5. SOD2 deficient erythroid cells up-regulate transferrin receptor and down-regulate mitochondrial biogenesis and metabolism.

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    Florent M Martin

    Full Text Available BACKGROUND: Mice irradiated and reconstituted with hematopoietic cells lacking manganese superoxide dismutase (SOD2 show a persistent hemolytic anemia similar to human sideroblastic anemia (SA, including characteristic intra-mitochondrial iron deposition. SA is primarily an acquired, clonal marrow disorder occurring in individuals over 60 years of age with uncertain etiology. METHODOLOGY/PRINCIPAL FINDINGS: To define early events in the pathogenesis of this murine model of SA, we compared erythroid differentiation of Sod2⁻/⁻ and normal bone marrow cells using flow cytometry and gene expression profiling of erythroblasts. The predominant transcriptional differences observed include widespread down-regulation of mitochondrial metabolic pathways and mitochondrial biogenesis. Multiple nuclear encoded subunits of complexes I-IV of the electron transport chain, ATP synthase (complex V, TCA cycle and mitochondrial ribosomal proteins were coordinately down-regulated in Sod2⁻/⁻ erythroblasts. Despite iron accumulation within mitochondria, we found increased expression of transferrin receptor, Tfrc, at both the transcript and protein level in SOD2 deficient cells, suggesting deregulation of iron delivery. Interestingly, there was decreased expression of ABCb7, the gene responsible for X-linked hereditary SA with ataxia, a component required for iron-sulfur cluster biogenesis. CONCLUSIONS/SIGNIFICANCE: These results indicate that in erythroblasts, mitochondrial oxidative stress reduces expression of multiple nuclear genes encoding components of the respiratory chain, TCA cycle and mitochondrial protein synthesis. An additional target of particular relevance for SA is iron:sulfur cluster biosynthesis. By decreasing transcription of components of cluster synthesis machinery, both iron utilization and regulation of iron uptake are impacted, contributing to the sideroblastic phenotype.

  6. The Cell Surface Estrogen Receptor, G Protein- Coupled Receptor 30 (GPR30, is Markedly Down Regulated During Breast Tumorigenesis

    Directory of Open Access Journals (Sweden)

    Indira Poola

    2008-01-01

    Full Text Available Background: GPR30 is a cell surface estrogen receptor that has been shown to mediate a number of non-genomic rapid effects of estrogen and appear to balance the signaling of estrogen and growth factors. In addition, progestins appear to use GPR30 for their actions. Therefore, GPR30 could play a critical role in hormonal regulation of breast epithelial cell integrity. Deregulation of the events mediated by GPR30 could contribute to tumorigenesis.Methods: To understand the role of GPR30 in the deregulation of estrogen signaling processes during breast carcinogenesis, we have undertaken this study to investigate its expression at mRNA levels in tumor tissues and their matched normal tissues. We compared its expression at mRNA levels by RT quantitative real-time PCR relative to GAPDH in ERα”—positive (n = 54 and ERα”—negative (n = 45 breast cancer tissues to their matched normal tissues.Results: We report here, for the first time, that GPR30 mRNA levels were significantly down-regulated in cancer tissues in comparison with their matched normal tissues (p 0.0001 by two sided paired t-test. The GPR30 expression levels were significantly lower in tumor tissues from patients (n = 29 who had lymph node metastasis in comparison with tumors from patients (n = 53 who were negative for lymph node metastasis (two sample t-test, p 0.02, but no association was found with ERα, PR and other tumor characteristics.Conclusions: Down-regulation of GPR30 could contribute to breast tumorigenesis and lymph node metastasis.

  7. [Grape seed proanthocyanidins extract inhibits pancreatic cancer cell growth through down-regulation of miR-27a expression].

    Science.gov (United States)

    Ma, Jia; Fang, Binbin; Zeng, Fanpeng; Pang, Haijie; Ma, Cong; Xia, Jun

    2015-01-01

    To explore the eff ect of grape seed proanthocyanidins extract (GSPE) on the growth of pancreatic cancer cells and the underlying mechanisms. The pancreatic cancer AsPC-1 cells were cultured in vitro. The effects of GSPE on cell proliferation, apoptosis and migration were analyzed by MTT, Annexin V-FITC/PI and Transwell migration assay, respectively. The expression of miR-27a and FOXO1 in AsPC-1 cells was determined by real-time RT-PCR and Western blot, respectively. The miR-27a inhibitors were applied to verify the role of miR-27a in mediation of GSPE effects. GSPE inhibited cell growth in a dose-dependent manner. This inhibitory effect was significant when the dosage of GSPE was more than 50 μg/mL (P<0.05 vs control). GSPE also could induce apoptosis and inhibit cell migration. MiR-27a expression was notably down-regulated when the dosage of GSPE was 75 μg/mL (P<0.01 vs control). Compared with the control group, cell proliferation inhibition was significantly increased in the miR-27a inhibitor group, the GSPE group and the miR-27a inhibitor plus GSPE group (P<0.01), while cell migration was significantly decreased (P<0.01). Compared with the GSPE or the miR-27a inhibitor group, the growth and migration inhibitory effects in the miR-27a inhibitor plus GSPE group were more obviously (P<0.01). Both GSPE and miR-27a inhibitor alone could up-regulate FOXO1 expression. But these effects were more apparent when they are applied in combination. GSPE inhibites AsPC-1 cells' growth and migration partly through down-regulation of miR-27a expression.

  8. miR-125b suppresses the proliferation and migration of osteosarcoma cells through down-regulation of STAT3

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Li-hong; Li, Hui; Li, Jin-ping; Zhong, Hui; Zhang, Han-chon; Chen, Jia [Department of Orthopedics, The Second Xiangya Hospital of Central South University, Changsha 410010 (China); Xiao, Tao, E-mail: xiaotaoxyl@163.com [Department of Orthopedics, The Second Xiangya Hospital of Central South University, Changsha 410010 (China)

    2011-12-09

    Highlights: Black-Right-Pointing-Pointer miR-125b is frequently down-regulated in osteosarcoma samples and human osteosarcoma cell lines. Black-Right-Pointing-Pointer Ectopic restoration of miR-125b suppresses cell proliferation and migration in vitro. Black-Right-Pointing-Pointer STAT3 is the direct and functional downstream target of miR-125b. Black-Right-Pointing-Pointer STAT3 can bind to the promoter region of miR-125b and serves as a transactivator. -- Abstract: There is accumulating evidence that microRNAs are involved in multiple processes in development and tumor progression. Abnormally expressed miR-125b was found to play a fundamental role in several types of cancer; however, whether miR-125b participates in regulating the initiation and progress of osteosarcoma still remains unclear. Here we demonstrate that miR-125b is frequently down-regulated in osteosarcoma samples and human osteosarcoma cell lines. The ectopic restoration of miR-125b expression in human osteosarcoma cells suppresses proliferation and migration in vitro and inhibits tumor formation in vivo. We further identified signal transducer and activator of transcription 3 (STAT3) as the direct and functional downstream target of miR-125b. Interestingly, we discovered that the expression of miR-125b is regulated by STAT3 at the level of transcription. STAT3 binds to the promoter region of miR-125b in vitro and serves as a transactivator. Taken together, our findings point to an important role in the molecular etiology of osteosarcoma and suggest that miR-125b is a potential target in the treatment of osteosarcoma.

  9. HPV16 E2 could act as down-regulator in cellular genes implicated in apoptosis, proliferation and cell differentiation

    Directory of Open Access Journals (Sweden)

    Valencia-Hernández Armando

    2011-05-01

    Full Text Available Abstract Background Human Papillomavirus (HPV E2 plays several important roles in the viral cycle, including the transcriptional regulation of the oncogenes E6 and E7, the regulation of the viral genome replication by its association with E1 helicase and participates in the viral genome segregation during mitosis by its association with the cellular protein Brd4. It has been shown that E2 protein can regulate negative or positively the activity of several cellular promoters, although the precise mechanism of this regulation is uncertain. In this work we constructed a recombinant adenoviral vector to overexpress HPV16 E2 and evaluated the global pattern of biological processes regulated by E2 using microarrays expression analysis. Results The gene expression profile was strongly modified in cells expressing HPV16 E2, finding 1048 down-regulated genes, and 581 up-regulated. The main cellular pathway modified was WNT since we found 28 genes down-regulated and 15 up-regulated. Interestingly, this pathway is a convergence point for regulating the expression of genes involved in several cellular processes, including apoptosis, proliferation and cell differentiation; MYCN, JAG1 and MAPK13 genes were selected to validate by RT-qPCR the microarray data as these genes in an altered level of expression, modify very important cellular processes. Additionally, we found that a large number of genes from pathways such as PDGF, angiogenesis and cytokines and chemokines mediated inflammation, were also modified in their expression. Conclusions Our results demonstrate that HPV16 E2 has regulatory effects on cellular gene expression in HPV negative cells, independent of the other HPV proteins, and the gene profile observed indicates that these effects could be mediated by interactions with cellular proteins. The cellular processes affected suggest that E2 expression leads to the cells in to a convenient environment for a replicative cycle of the virus.

  10. N-MYC down-regulated-like proteins regulate meristem initiation by modulating auxin transport and MAX2 expression.

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    Yashwanti Mudgil

    Full Text Available BACKGROUND: N-MYC down-regulated-like (NDL proteins interact with the Gβ subunit (AGB1 of the heterotrimeric G protein complex and play an important role in AGB1-dependent regulation of lateral root formation by affecting root auxin transport, auxin gradients and the steady-state levels of mRNA encoding the PIN-FORMED 2 and AUXIN 1 auxin transport facilitators. Auxin transport in aerial tissue follows different paths and utilizes different transporters than in roots; therefore, in the present study, we analyzed whether NDL proteins play an important role in AGB1-dependent, auxin-mediated meristem development. METHODOLOGY/PRINCIPAL FINDINGS: Expression levels of NDL gene family members need to be tightly regulated, and altered expression (both over-expression and down-regulation confers ectopic growth. Over-expression of NDL1 disrupts vegetative and reproductive organ development. Reduced expression of the NDL gene family members results in asymmetric leaf emergence, twinning of rosette leaves, defects in leaf formation, and abnormal silique distribution. Reduced expression of the NDL genes in the agb1-2 (null allele mutant rescues some of the abnormal phenotypes, such as silique morphology, silique distribution, and peduncle angle, suggesting that proper levels of NDL proteins are maintained by AGB1. We found that all of these abnormal aerial phenotypes due to altered NDL expression were associated with increases in basipetal auxin transport, altered auxin maxima and altered MAX2 expression within the inflorescence stem. CONCLUSION/SIGNIFICANCE: NDL proteins, together with AGB1, act as positive regulators of meristem initiation and branching. AGB1 and NDL1 positively regulate basipetal inflorescence auxin transport and modulate MAX2 expression in shoots, which in turn regulates organ and lateral meristem formation by the establishment and maintenance of auxin gradients.

  11. Micheliolide provides protection of mice against Staphylococcus aureus and MRSA infection by down-regulating inflammatory response

    Science.gov (United States)

    Jiang, Xinru; Wang, Yuli; Qin, Yifei; He, Weigang; Benlahrech, Adel; Zhang, Qingwen; Jiang, Xin; Lu, Zhenhui; Ji, Guang; Zheng, Yuejuan

    2017-01-01

    A major obstacle to therapy in intensive care units is sepsis caused by severe infection. In recent years gram-positive (G+) bacteria, most commonly staphylococci, are thought to be the main pathogens. Micheliolide (MCL) was demonstrated to provide a therapeutic role in rheumatoid arthritis, inflammatory intestinal disease, colitis-associated cancer, and lipopolysaccharide (LPS, the main component of G− bacterial cell wall) induced septic shock. We proved here that MCL played an anti-inflammatory role in Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA) induced peritonitis. It inhibited the expression of inflammatory cytokines and chemokines in macrophages and dendritic cells upon stimulation with peptidoglycan (PGN, the main cell wall composition of G+ bacteria). PI3K/Akt and NF-κB pathways account for the anti-inflammatory role of MCL after PGN stimulation. MCL reduced IL-6 secretion through down-regulating NF-κB activation and improved the survival status in mice challenged with a lethal dose of S. aureus. In MRSA infection mouse model, MCL down-regulated the expression of IL-6, TNF-α, MCP-1/CCL2 and IFN-γ in sera, and ameliorated the organ damage of liver and kidney. In conclusion, MCL can help maintain immune equilibrium and decrease PGN, S. aureus and MRSA-triggered inflammatory response. These provide the rationality for the potential usage of MCL in sepsis caused by G+ bacteria (e.g., S. aureus) and antibiotic-resistant bacteria (e.g., MRSA). PMID:28165033

  12. The role of E-cadherin down-regulation in oral cancer: CDH1 gene expression and epigenetic blockage.

    Science.gov (United States)

    Pannone, G; Santoro, A; Feola, A; Bufo, P; Papagerakis, P; Lo Muzio, L; Staibano, S; Ionna, F; Longo, F; Franco, R; Aquino, G; Contaldo, M; De Maria, S; Serpico, R; De Rosa, A; Rubini, C; Papagerakis, S; Giovane, A; Tombolini, V; Giordano, A; Caraglia, M; Di Domenico, M

    2014-01-01

    The prognosis of the oral squamous cell carcinoma (OSCC) patients remains very poor, mainly due to their high propensity to invade and metastasize. E-cadherin reduced expression occurs in the primary step of oral tumour progression and gene methylation is a mode by which the expression of this protein is regulated in cancers. In this perspective, we investigated E-cadherin gene (CDH1) promoter methylation status in OSCC and its correlation with Ecadherin protein expression, clinicopathological characteristics and patient outcome. Histologically proven OSCC and paired normal mucosa were analyzed for CDH1 promoter methylation status and E-cadherin protein expression by methylation-specific polymerase chain reaction and immunohistochemistry. Colocalization of E-cadherin with epidermal growth factor (EGF) receptor (EGFR) was evidenced by confocal microscopy and by immunoprecipitation analyses. This study indicated E-cadherin protein down-regulation in OSCC associated with protein delocalization from membrane to cytoplasm. Low E-cadherin expression correlated to aggressive, poorly differentiated, high grade carcinomas and low patient survival. Moreover, protein down-regulation appeared to be due to E-cadherin mRNA downregulation and CDH1 promoter hypermethylation. In an in vitro model of OSCC the treatment with EGF caused internalization and co-localization of E-cadherin with EGFR and the addition of demethylating agents increased E-cadherin expression. Low E-Cadherin expression is a negative prognostic factor of OSCC and is likely due to the hypermethylation of CDH1 promoter. The delocalization of E-cadherin from membrane to cytoplasm could be also due to the increased expression of EGFR in OSCC and the consequent increase of E-cadherin co-internalization with EGFR.

  13. Symplocos cochinchinensis enhances insulin sensitivity via the down regulation of lipogenesis and insulin resistance in high energy diet rat model.

    Science.gov (United States)

    Antu, Kalathookunnel Antony; Riya, Mariam Philip; Nair, Anupama; Mishra, Arvind; Srivastava, Arvind K; Raghu, Kozhiparambil Gopalan

    2016-12-04

    This plant has been utilized in Indian system of medicine for treatment of diabetes. This is clearly evident from the composition of Ayurvedic preparation for diabetes 'Nisakathakadi Kashayam' where this is one of the main ingredients of this preparation AIM OF THE STUDY: The study aims in elucidating the molecular mechanisms underlying the insulin sensitizing effects of Symplocos cochinchinensis ethanol extract (SCE) using a high fructose and saturated fat (HFS) fed insulin resistant rat model. Experimental groups consisted of normal diet (ND), ND+SCE 500mg/kg bwd, HFS+vehicle, HFS+metformin 100mg/kg bwd, HFS+SCE 250/500mg/kg bwd. Initially the animals were kept under HFS diet for 8 weeks, and at the end of 8 week period, animals were found to develop insulin resistance and dyslipidemia. Post-administration of SCE, metformin or vehicle were carried out for 3 weeks. Gene and protein expressions relevant to insulin signalling pathway were analysed. HFS significantly altered the normal physiology of animals via proteins and genes relevant to metabolism like stearoyl-CoA desaturase (SCD1), sterol regulatory element binding protein 1 (SREBP-1c), fatty acid synthase (FAS), glucose 6 phosphatase (G6Pase), phosphoenol pyruvate carboxykinase (PEPCK), glucose transporter 2 (GLUT2), protein tyrosine phosphatse 1B (PTP1B), peroxisome proliferator activated receptor alpha (PPAR alpha), sirtuin 1 (SIRT1) and glucokinase. SCE administration attenuates the insulin resistance in HFS rat by the down regulation of SCD1 gene expression that modulates SREBP-1c dependent and independent hepatic lipid accumulation. SCE enhances insulin sensitivity via the down regulation of lipogenesis and insulin resistance in HFS rat model. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  14. Triptolide inhibits the proliferation of prostate cancer cells and down-regulates SUMO-specific protease 1 expression.

    Directory of Open Access Journals (Sweden)

    Weiwei Huang

    Full Text Available Recently, traditional Chinese medicine and medicinal herbs have attracted more attentions worldwide for its anti-tumor efficacy. Celastrol and Triptolide, two active components extracted from the Chinese herb Tripterygium wilfordii Hook F (known as Lei Gong Teng or Thunder of God Vine, have shown anti-tumor effects. Celastrol was identified as a natural 26 s proteasome inhibitor which promotes cell apoptosis and inhibits tumor growth. The effect and mechanism of Triptolide on prostate cancer (PCa is not well studied. Here we demonstrated that Triptolide, more potent than Celastrol, inhibited cell growth and induced cell death in LNCaP and PC-3 cell lines. Triptolide also significantly inhibited the xenografted PC-3 tumor growth in nude mice. Moreover, Triptolide induced PCa cell apoptosis through caspases activation and PARP cleavage. Unbalance between SUMOylation and deSUMOylation was reported to play an important role in PCa progression. SUMO-specific protease 1 (SENP1 was thought to be a potential marker and therapeutical target of PCa. Importantly, we observed that Triptolide down-regulated SENP1 expression in both mRNA and protein levels in dose-dependent and time-dependent manners, resulting in an enhanced cellular SUMOylation in PCa cells. Meanwhile, Triptolide decreased AR and c-Jun expression at similar manners, and suppressed AR and c-Jun transcription activity. Furthermore, knockdown or ectopic SENP1, c-Jun and AR expression in PCa cells inhibited the Triptolide anti-PCa effects. Taken together, our data suggest that Triptolide is a natural compound with potential therapeutic value for PCa. Its anti-tumor activity may be attributed to mechanisms involving down-regulation of SENP1 that restores SUMOylation and deSUMOyaltion balance and negative regulation of AR and c-Jun expression that inhibits the AR and c-Jun mediated transcription in PCa.

  15. Down-regulation of MicroRNA-126 in Glioblastoma and its Correlation with Patient Prognosis: A Pilot Study.

    Science.gov (United States)

    Han, In Bo; Kim, Minsoo; Lee, Soo Hong; Kim, Jin Kwon; Kim, Se Hoon; Chang, Jong Hee; Teng, Yang D

    2016-12-01

    Glioblastoma is the most common primary malignant tumor of the adult human brain. Although microRNA-126 (miR-126) has been reported to exhibit expression abnormalities in various types of cancer, to date very few studies have examined changes in miR-126 level in glioblastoma. In this pilot study, we investigated the changes in miR-126 expression in newly-dissected primary glioblastoma to explore possible roles of miR-126 in patient prognosis. Total RNA was extracted from tumoral and adjacent non-cancerous tissues from 14 patients' paired frozen specimens. Using an established quantitative reverse transcriptase-PCR protocol, the levels of miR-126 in glioblastoma and adjacent non-tumor brain tissues were compared against small nucleolar RNA U48 (RNU48) as a reference gene. The expression of miR-126 in glioblastoma samples was significantly lower than in paired non-tumoral controls (pglioblastoma patients with higher relative intratumoral miR-126 expression (i.e. 53-79% relative to that of the control tissue; n=7) had significantly improved survival duration than patients whose miR-126 levels were lower (i.e. 12-48%, n=7; stratified log-rank analysis p=0.011 when the dividing threshold was set at ≥51%; total: n=14, male: 8; female: 6). Thus, intraglioblastoma miR-126 may be down-regulated relative to normal tissue and patients with less down-regulation of intratumoral miR-126 expression could have improved postsurgical prognosis. Future clinical studies with larger sample sizes should be performed to validate this observation.

  16. Shoot-Specific Down-Regulation of Protein Farnesyltransferase (α-Subunit) for Yield Protection against Drought in Canola

    Institute of Scientific and Technical Information of China (English)

    Yang Wang; Michelle Beaith; Maryse Chalifoux; Jifeng Ying; Tina Uchacz; Carlene Sarvas; Rebecca Griffiths; Monika Kuzma; Jiangxin Wan; Yafan Huang

    2009-01-01

    Canola (Brassica napus L.) is one of the most important oilseed crops in the world and its seed yield and quality are significantly affected by drought stress. As an innate and adaptive response to water deficit, land plants avoid potential damage by rapid biosynthesis of the phytohormone abscisic acid (ABA), which triggers stomatal closure to reduce transpirational water loss. The ABA-mediated stomatal response is a dosage-dependent process; thus, one genetic engineering approach for achieving drought avoidance could be to sensitize the guard cell's responsiveness to this hormone.Recent genetic studies have pinpointed protein farnesyltransferase as a key negative regulator controlling ABA sensitivity in the guard cells. We have previously shown that down-regulation of the gene encoding Arabidopsis β-subunit of farnesyltransferase (ERA1) enhances the plant's sensitivity to ABA and drought tolerance. Although the α-subunit of famesyltransferase (AtFTA) is also implicated in ABA sensing, the effectiveness of using such a gene target for improving drought tolerance in a crop plant has not been validated. Here, we report the identification and characterization of the promoter of Arabidopsis hydroxypyruvate reductase (AtHPR1), which expresses specifically in the shoot and not in non-photosynthetic tissues such as root. The promoter region of AtHPR1 contains the core motif of the well characterized dehydration-responsive cis-acting element and we have confirmed that AtHPR1 expression is inducible by drought stress. Conditional and specific down-regulation of FTA in canola using the AtHPR1 promoter driving an RNAi construct resulted in yield protection against drought stress in the field. Using this molecular strategy, we have made significant progress in engineering drought tolerance in this important crop species.

  17. CRM 1-mediated degradation and agonist-induced down-regulation of beta-adrenergic receptor mRNAs.

    Science.gov (United States)

    Bai, Ying; Lu, Huafei; Machida, Curtis A

    2006-10-01

    The beta1-adrenergic receptor (beta1-AR) mRNAs are post-transcriptionally regulated at the level of mRNA stability and undergo accelerated agonist-mediated degradation via interaction of its 3' untranslated region (UTR) with RNA binding proteins, including the HuR nuclear protein. In a previous report [Kirigiti et al. (2001). Mol. Pharmacol. 60:1308-1324], we examined the agonist-mediated down-regulation of the rat beta1-AR mRNAs, endogenously expressed in the rat C6 cell line and ectopically expressed in transfectant hamster DDT1MF2 and rat L6 cells. In this report, we determined that isoproterenol treatment of neonatal rat cortical neurons, an important cell type expressing beta1-ARs in the brain, results in significant decreases in beta1-AR mRNA stability, while treatment with leptomycin B, an inhibitor of the nuclear export receptor CRM 1, results in significant increases in beta1-AR mRNA stability and nuclear retention. UV-crosslinking/immunoprecipitation and glycerol gradient fractionation analyses indicate that the beta1-AR 3' UTR recognize complexes composed of HuR and multiple proteins, including CRM 1. Cell-permeable peptides containing the leucine-rich nuclear export signal (NES) were used as inhibitors of CRM 1-mediated nuclear export. When DDT1MF2 transfectants were treated with isoproterenol and peptide inhibitors, only the co-addition of the NES inhibitor reversed the isoproterenol-induced reduction of beta1-AR mRNA levels. Our results suggest that CRM 1-dependent NES-mediated mechanisms influence the degradation and agonist-mediated down-regulation of the beta1-AR mRNAs.

  18. Down-regulated CBS/H2S pathway is involved in high-salt-induced hypertension in Dahl rats.

    Science.gov (United States)

    Huang, Pan; Chen, Siyao; Wang, Yuan; Liu, Jia; Yao, Qiuyu; Huang, Yaqian; Li, Hongxia; Zhu, Mingzhu; Wang, Suxia; Li, Lin; Tang, Chaoshu; Tao, Yinghong; Yang, Guosheng; Du, Junbao; Jin, Hongfang

    2015-04-30

    The study was designed to explore the significance of endogenous H2S in the development of high-salt-induced hypertension in rats. High-salt-induced hypertension rat model was made by feeding Dahl rat high-salt diet containing 8% NaCl for 8 weeks with SD rats as control. SBP and aorta structure in rats were observed. Endogenous H2S content and expression of cystathionine β-lyase (CBS), cystathionine γ-lyase and mercaptopyruvate sulfurtransferase in renal tissues were detected. Mechanisms for the impact of high-salt on CBS/H2S in renal tissues were studied, targeting HIF-1α pathway. The effect of H2S on RAS in serum and renal tissue of rats were tested. High-salt reduced endogenous H2S content and inhibited the expression of CBS in renal tissue in salt-sensitive Dahl rats. H2S donor, however, inhibited salt-sensitive hypertension, reversed aortic structural remodeling and inhibited activation of the RAS system in renal tissues in Dahl rats. Expression of HIF-1α was decreased but expression of PHD2 was increased in renal tissue of Dahl rats with high-salt diet, whereas they did not alter in renal tissue of SD rats with high-salt diet. Ex vivo experiment showed that inhibitor of HIF-1α degradation could rescue down-regulated CBS/H2S pathway in renal tissue of Dahl rats with high-salt. In contrast, inhibitor of HIF-1α activity decreased the CBS/H2S pathway in the renal tissue of SD rats treated with high-salt. Down-regulated CBS/H2S pathway in renal tissues under high-salt insult might be an important pathogenesis of salt-sensitive hypertension. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Bryostatin 1 down-regulates mdr1 and potentiates vincristine cytotoxicity in diffuse large cell lymphoma xenografts.

    Science.gov (United States)

    Al-Katib, A M; Smith, M R; Kamanda, W S; Pettit, G R; Hamdan, M; Mohamed, A N; Chelladurai, B; Mohammad, R M

    1998-05-01

    The down-regulation of multidrug resistance (mdr1) gene expression as detected by competitive reverse transcription-PCR and the antitumor activity of bryostatin 1 (Bryo1) are investigated in a newly established cell line from a patient with relapsed diffuse large cell lymphoma (DLCL). The cell line (WSU-DLCL2) grows in liquid culture and forms s.c. tumors in mice with severe combined immune deficiency. WSU-DLCL2 is a mature B-cell line (IgG lambda) that is negative for EBV nuclear antigen, expresses the multidrug resistance phenotype, and has t(14;18)(q32;q21) plus other chromosomal aberrations. Exposure of the WSU-DLCL2 cells to Bryo1 in culture reversed the multidrug resistance phenotype within 24 h. A functional assay revealed a 4-fold increase in [3H]vincristine accumulation in Bryo1-treated cells compared with control. Vincristine (VCR), doxorubicin, Bryo1, and 1-beta-D-arabinofuranosylcytosine showed no clinically significant activity when given alone to WSU-DLCL2-bearing severe combined immune deficiency mice. However, when given 24 h before each cytotoxic agent, Bryo1 substantially increased the antitumor activity of VCR but not 1-beta-D-arabinofuranosylcytosine. There was a statistically significant (P animals compared with untreated controls. In vivo, a competitive reverse transcription-PCR assay revealed decreased mdr1 RNA expression 24 h after Bryo1 treatment. These findings taken together indicate that Bryo1-induced down-regulation of mdr1 might be one mechanism by which Bryo1 potentiates VCR activity. The sequential use of both agents resulted in clinically significant antitumor activity in this lymphoma model.

  20. Down-regulation of the oncogene PTTG1 via the KLF6 tumor suppressor during induction of myeloid differentiation.

    Directory of Open Access Journals (Sweden)

    Pei-Yi Chen

    Full Text Available The aberrant expression of proto-oncogenes is involved in processes that are responsible for cellular proliferation and the inhibition of myeloid differentiation in acute myeloid leukemia (AML. Pituitary Tumor-Transforming gene 1 (PTTG1, an oncogenic transcription factor, is abundantly expressed in various human cancers and hematopoietic malignancies. However, its expression in normal leukocytes and most normal tissues is very low or undetectable. The mechanism by which PTTG1 overexpression modifies myeloid cell development and promotes leukemogenesis remain unclear. To investigate the mechanistic links between PTTG1 overexpression and leukemia cell differentiation, we utilized phorbol 12-myristate 13-acetate (PMA, a well-known agent that triggers monocyte/macrophage differentiation, to analyze the expression patterns of PTTG1 in PMA-induced myeloid differentiation. We found that PTTG1 is down-regulated at the transcriptional level in PMA-treated HL-60 and THP1 cells. In addition, we identified a binding site for a tumor suppressor protein, Kruppel-like factor 6 (KLF6, in the PTTG1 promoter. We found that KLF6 could directly bind and repress PTTG1 expression. In HL-60 and THP1 cells, KLF6 mRNA and protein levels are up-regulated with a concordant reduction of PTTG1 expression upon treatment with PMA. Furthermore, KLF6 knockdown by shRNA abolished the suppression of PTTG1 and reduced the activation of the differentiation marker CD11b in PMA-primed cells. The protein kinase C (PKC inhibitor and the MAPK/ERK kinase (MEK inhibitor significantly blocked the potentiation of PMA-mediated KLF6 induction and the down-regulation of PTTG1, indicating that PTTG1 is suppressed via the activation of PKC/ERK/KLF6 pathway. Our findings suggest that drugs that increase the KLF6 inhibition of PTTG1 may have a therapeutic application in AML treatment strategies.

  1. Disruption of mechanical stress in extracellular matrix is related to Stanford type A aortic dissection through down-regulation of Yes-associated protein

    Science.gov (United States)

    Jiang, Wen-Jian; Ren, Wei-Hong; Liu, Xu-Jie; Liu, Yan; Wu, Fu-Jian; Sun, Li-Zhong; Lan, Feng; Du, Jie; Zhang, Hong-Jia

    2016-01-01

    In this study, we assessed whether the down-regulation of Yes-associated protein (YAP) is involved in the pathogenesis of extracellular matrix (ECM) mechanical stress-induced Stanford type A aortic dissection (STAAD). Human aortic samples were obtained from heart transplantation donors as normal controls and from STAAD patients undergoing surgical replacement of the ascending aorta. Decreased maximum aortic wall velocity, ECM disorders, increased VSMC apoptosis, and YAP down-regulation were identified in STAAD samples. In a mouse model of STAAD, YAP was down-regulated over time during the development of ECM damage, and increased VSMC apoptosis was also observed. YAP knockdown induced VSMC apoptosis under static conditions in vitro, and the change in mechanical stress induced YAP down-regulation and VSMC apoptosis. This study provides evidence that YAP down-regulation caused by the disruption of mechanical stress is associated with the development of STAAD via the induction of apoptosis in aortic VSMCs. As STAAD is among the most elusive and life-threatening vascular diseases, better understanding of the molecular pathogenesis of STAAD is critical to improve clinical outcome. PMID:27608489

  2. Disruption of mechanical stress in extracellular matrix is related to Stanford type A aortic dissection through down-regulation of Yes-associated protein.

    Science.gov (United States)

    Jiang, Wen-Jian; Ren, Wei-Hong; Liu, Xu-Jie; Liu, Yan; Wu, Fu-Jian; Sun, Li-Zhong; Lan, Feng; Du, Jie; Zhang, Hong-Jia

    2016-09-05

    In this study, we assessed whether the down-regulation of Yes-associated protein (YAP) is involved in the pathogenesis of extracellular matrix (ECM) mechanical stress-induced Stanford type A aortic dissection (STAAD). Human aortic samples were obtained from heart transplantation donors as normal controls and from STAAD patients undergoing surgical replacement of the ascending aorta. Decreased maximum aortic wall velocity, ECM disorders, increased VSMC apoptosis, and YAP down-regulation were identified in STAAD samples. In a mouse model of STAAD, YAP was down-regulated over time during the development of ECM damage, and increased VSMC apoptosis was also observed. YAP knockdown induced VSMC apoptosis under static conditions in vitro, and the change in mechanical stress induced YAP down-regulation and VSMC apoptosis. This study provides evidence that YAP down-regulation caused by the disruption of mechanical stress is associated with the development of STAAD via the induction of apoptosis in aortic VSMCs. As STAAD is among the most elusive and life-threatening vascular diseases, better understanding of the molecular pathogenesis of STAAD is critical to improve clinical outcome.

  3. Stress conditions promote yeast Gap1 permease ubiquitylation and down-regulation via the arrestin-like Bul and Aly proteins.

    Science.gov (United States)

    Crapeau, Myriam; Merhi, Ahmad; André, Bruno

    2014-08-01

    Gap1, the yeast general amino acid permease, is a convenient model for studying how the intracellular traffic of membrane transporters is regulated. Present at the plasma membrane under poor nitrogen supply conditions, it undergoes ubiquitylation, endocytosis, and degradation upon activation of the TORC1 kinase complex in response to an increase in internal amino acids. This down-regulation is stimulated by TORC1-dependent phosphoinhibition of the Npr1 kinase, resulting in activation by dephosphorylation of the arrestin-like Bul1 and Bul2 adaptors recruiting the Rsp5 ubiquitin ligase to Gap1. We report here that Gap1 is also down-regulated when cells are treated with the TORC1 inhibitor rapamycin or subjected to various stresses and that a lack of the Tco89 subunit of TORC1 causes constitutive Gap1 down-regulation. Both the Bul1 and Bul2 and the Aly1 and Aly2 arrestin-like adaptors of Rsp5 promote this down-regulation without undergoing dephosphorylation. Furthermore, they act via the C-terminal regions of Gap1 not involved in ubiquitylation in response to internal amino acids, whereas a Gap1 mutant altered in the N-terminal tail and resistant to ubiquitylation by internal amino acids is efficiently down-regulated under stress via the Bul and Aly adaptors. Although the Bul proteins mediate Gap1 ubiquitylation of two possible lysines, Lys-9 and Lys-16, the Aly proteins promote ubiquitylation of the Lys-16 residue only. This stress-induced pathway of Gap1 down-regulation targets other permeases as well, and it likely allows cells facing adverse conditions to retrieve amino acids from permease degradation.

  4. Editor's Highlight: Neonatal Activation of the Xenobiotic-Sensors PXR and CAR Results in Acute and Persistent Down-regulation of PPARα-Signaling in Mouse Liver.

    Science.gov (United States)

    Li, Cindy Yanfei; Cheng, Sunny Lihua; Bammler, Theo K; Cui, Julia Yue

    2016-10-01

    Safety concerns have emerged regarding the potential long-lasting effects due to developmental exposure to xenobiotics. The pregnane X receptor (PXR) and constitutive androstane receptor (CAR) are critical xenobiotic-sensing nuclear receptors that are highly expressed in liver. The goal of this study was to test our hypothesis that neonatal exposure to PXR- or CAR-activators not only acutely but also persistently regulates the expression of drug-processing genes (DPGs). A single dose of the PXR-ligand PCN (75 mg/kg), CAR-ligand TCPOBOP (3 mg/kg), or vehicle (corn oil) was administered intraperitoneally to 3-day-old neonatal wild-type mice. Livers were collected 24 h post-dose or from adult mice at 60 days of age, and global gene expression of these mice was determined using Affymetrix Mouse Transcriptome Assay 1.0. In neonatal liver, PCN up-regulated 464 and down-regulated 449 genes, whereas TCPOBOP up-regulated 308 and down-regulated 112 genes. In adult liver, there were 15 persistently up-regulated and 22 persistently down-regulated genes following neonatal exposure to PCN, as well as 130 persistently up-regulated and 18 persistently down-regulated genes following neonatal exposure to TCPOBOP. Neonatal exposure to both PCN and TCPOBOP persistently down-regulated multiple Cyp4a members, which are prototypical-target genes of the lipid-sensor PPARα, and this correlated with decreased PPARα-binding to the Cyp4a gene loci. RT-qPCR, western blotting, and enzyme activity assays in livers of wild-type, PXR-null, and CAR-null mice confirmed that the persistent down-regulation of Cyp4a was PXR and CAR dependent. In conclusion, neonatal exposure to PXR- and CAR-activators both acutely and persistently regulates critical genes involved in xenobiotic and lipid metabolism in liver.

  5. LIN28 expression in malignant germ cell tumors down-regulates let-7 and increases oncogene levels

    Science.gov (United States)

    Murray, Matthew J.; Saini, Harpreet K.; Siegler, Charlotte A.; Hanning, Jennifer E.; Barker, Emily M.; van Dongen, Stijn; Ward, Dawn M.; Raby, Katie L.; Groves, Ian J.; Scarpini, Cinzia G.; Pett, Mark R.; Thornton, Claire M.; Enright, Anton J.; Nicholson, James C.; Coleman, Nicholas

    2013-01-01

    Despite their clinico-pathologic heterogeneity, malignant germ-cell-tumors (GCTs) share molecular abnormalities that are likely to be functionally important. In this study, we investigated the potential significance of down-regulation of the let-7 family of tumor-suppressor microRNAs in malignant-GCTs. Microarray results from pediatric and adult samples (n=45) showed that LIN28, the negative-regulator of let-7 biogenesis, was abundant in malignant-GCTs, regardless of patient age, tumor site or histologic subtype. Indeed, a strong negative-correlation existed between LIN28 and let-7 levels in specimens with matched datasets. Low let-7 levels were biologically significant, since the sequence complementary to the 2-7nt common let-7 seed ‘GAGGUA’ was enriched in the 3′untranslated regions of mRNAs up-regulated in pediatric and adult malignant-GCTs, compared with normal gonads (a mixture of germ cells and somatic cells). We identified 27 mRNA targets of let-7 that were up-regulated in malignant-GCT cells, confirming significant negative-correlations with let-7 levels. Among 16 mRNAs examined in a largely independent set of specimens by qRT-PCR, we defined negative-associations with let-7e levels for six oncogenes, including MYCN, AURKB, CCNF, RRM2, MKI67 and C12orf5 (when including normal control tissues). Importantly, LIN28 depletion in malignant-GCT cells restored let-7 levels and repressed all of these oncogenic let-7 mRNA targets, with LIN28 levels correlating with cell proliferation and MYCN levels. Conversely, ectopic expression of let-7e was sufficient to reduce proliferation and down-regulate MYCN, AURKB and LIN28, the latter via a double-negative feedback loop. We concluded that the LIN28/let-7 pathway has a critical pathobiological role in malignant-GCTs and therefore offers a promising target for therapeutic intervention. PMID:23774216

  6. Down-regulation of PPARgamma1 suppresses cell growth and induces apoptosis in MCF-7 breast cancer cells

    Directory of Open Access Journals (Sweden)

    Wallis Natalie K

    2008-12-01

    Full Text Available Abstract Background Peroxisome proliferator-activated receptor gamma (PPARγ is a member of the nuclear hormone receptor superfamily and is highly expressed in many human tumors including breast cancer. PPARγ has been identified as a potential target for breast cancer therapy based on the fact that its activation by synthetic ligands affects the differentiation, proliferation, and apoptosis of cancer cells. However, the controversial nature of current studies and disappointing results from clinical trials raise questions about the contribution of PPARγ signaling in breast cancer development in the absence of stimulation by exogenous ligands. Recent reports from both in vitro and in vivo studies are inconsistent and suggest that endogenous activation of PPARγ plays a much more complex role in initiation and progression of cancer than previously thought. Results We have previously demonstrated that an increase in expression of PPARγ1 in MCF-7 breast cancer cells is driven by a tumor-specific promoter. Myc-associated zinc finger protein (MAZ was identified as a transcriptional mediator of PPARγ1 expression in these cells. In this study, using RNA interference (RNAi to inhibit PPARγ1 expression directly or via down-regulation of MAZ, we report for the first time that a decrease in PPARγ1 expression results in reduced cellular proliferation in MCF-7 breast cancer cells. Furthermore, we demonstrate that these changes in proliferation are associated with a significant decrease in cell transition from G1 to the S phase. Using a dominant-negative mutant of PPARγ1, Δ462, we confirmed that PPARγ1 acts as a pro-survival factor and showed that this phenomenon is not limited to MCF-7 cells. Finally, we demonstrate that down-regulation of PPARγ1 expression leads to an induction of apoptosis in MCF-7 cells, confirmed by analyzing Bcl-2 expression and PARP-1 cleavage. Conclusion Thus, these findings suggest that an increase in PPARγ1 signaling

  7. Down-regulation of the caffeic acid O-methyltransferase gene in switchgrass reveals a novel monolignol analog

    Directory of Open Access Journals (Sweden)

    Tschaplinski Timothy J

    2012-09-01

    Full Text Available Abstract Background Down-regulation of the caffeic acid 3-O-methyltransferase EC 2.1.1.68 (COMT gene in the lignin biosynthetic pathway of switchgrass (Panicum virgatum resulted in cell walls of transgenic plants releasing more constituent sugars after pretreatment by dilute acid and treatment with glycosyl hydrolases from an added enzyme preparation and from Clostridium thermocellum. Fermentation of both wild-type and transgenic switchgrass after milder hot water pretreatment with no water washing showed that only the transgenic switchgrass inhibited C. thermocellum. Gas chromatography–mass spectrometry (GCMS-based metabolomics were undertaken on cell wall aqueous extracts to determine the nature of the microbial inhibitors. Results GCMS confirmed the increased concentration of a number of phenolic acids and aldehydes that are known inhibitors of microbial fermentation. Metabolomic analyses of the transgenic biomass additionally revealed the presence of a novel monolignol-like metabolite, identified as trans-3, 4-dimethoxy-5-hydroxycinnamyl alcohol (iso-sinapyl alcohol in both non-pretreated, as well as hot water pretreated samples. iso-Sinapyl alcohol and its glucoside were subsequently generated by organic synthesis and the identity of natural and synthetic materials were confirmed by mass spectrometric and NMR analyses. The additional novel presence of iso-sinapic acid, iso-sinapyl aldehyde, and iso-syringin suggest the increased activity of a para-methyltransferase, concomitant with the reduced COMT activity, a strict meta-methyltransferase. Quantum chemical calculations were used to predict the most likely homodimeric lignans generated from dehydration reactions, but these products were not evident in plant samples. Conclusions Down-regulation of COMT activity in switchgrass resulted in the accumulation of previously undetected metabolites resembling sinapyl alcohol and its related metabolites, but that are derived from para

  8. KCNK5 is Functionally Down-Regulated Upon Long-Term Hypotonicity in Ehrlich Ascites Tumor Cells

    DEFF Research Database (Denmark)

    Kirkegaard, S. S.; Wulff, Tune; Gammeltoft, S.

    2013-01-01

    Background/Aims: Regulatory volume decrease (RVD) in response to acute cell swelling is well described and KCNK5 (also known as TASK-2 or K2P5.1) has been shown to be the volume sensitive K+ channel in Ehrlich cells. Very little is, on the other hand, known about the effects of long-term hypotoni......Background/Aims: Regulatory volume decrease (RVD) in response to acute cell swelling is well described and KCNK5 (also known as TASK-2 or K2P5.1) has been shown to be the volume sensitive K+ channel in Ehrlich cells. Very little is, on the other hand, known about the effects of long......-term hypotonicity on expression and function of KCNK5, thus we have investigated the effect of long-term hypotonicity (24h - 48h) on KCNK5 in Ehrlich cells on the mRNA, protein and physiological levels. Methods: Physiological effects of long-term hypotonicity were measured using patch-clamp and Coulter counter...... physiological impairment of KCNK5 in Ehrlich cells after long-term hypotonic stimulation is predominantly due to down-regulation of the KCNK5 protein synthesis.© 2013 S. Karger AG, Basel...

  9. Curcumin inhibits cell growth and invasion and induces apoptosis through down-regulation of Skp2 in pancreatic cancer cells

    Science.gov (United States)

    Su, Jingna; Zhou, Xiuxia; Wang, Lixia; Yin, Xuyuan; Wang, Zhiwei

    2016-01-01

    Natural polyphenol compound curcumin has been found to exhibit its anticancer activity in a variety of human malignancies including pancreatic cancer (PC). However, the underlying mechanism has not been fully understood. Accumulating evidence has demonstrated that Skp2 (S-phase kinase associated protein 2) plays an oncogenic role in the development and progression of human cancers. In this study, we aim to explore the molecular basis of curcumin-induced cell growth inhibition in PC cells.Multiple methods such as CTG assay, Flow cytometry, clonogenic assay, wound healing assay, Transwell invasion assay, Western blotting, and transfection were performed to validate the oncogenic role of curcumin in PC cells. We found that curcumin suppressed cell growth, clonogenic potential, migration and invasion, and induced cell apoptosis and cell cycle arrest. Moreover, we observed thatover-expression of Skp2 significantly promoted cell growth, whereas down-regulation of Skp2 with siRNAs inhibited cell growth. The molecular basis of curcumin-mediated cell growth inhibition we identified is that curcumin significantly suppressed Skp2 expression and subsequently induced p21 expression. These findings suggested thattargeting Skp2 by curcumin could be a promising therapeutic strategy for the treatment of PC patients.

  10. Systemic down-regulation of delta-9 desaturase promotes muscle oxidative metabolism and accelerates muscle function recovery following nerve injury.

    Directory of Open Access Journals (Sweden)

    Ghulam Hussain

    Full Text Available The progressive deterioration of the neuromuscular axis is typically observed in degenerative conditions of the lower motor neurons, such as amyotrophic lateral sclerosis (ALS. Neurodegeneration in this disease is associated with systemic metabolic perturbations, including hypermetabolism and dyslipidemia. Our previous gene profiling studies on ALS muscle revealed down-regulation of delta-9 desaturase, or SCD1, which is the rate-limiting enzyme in the synthesis of monounsaturated fatty acids. Interestingly, knocking out SCD1 gene is known to induce hypermetabolism and stimulate fatty acid beta-oxidation. Here we investigated whether SCD1 deficiency can affect muscle function and its restoration in response to injury. The genetic ablation of SCD1 was not detrimental per se to muscle function. On the contrary, muscles in SCD1 knockout mice shifted toward a more oxidative metabolism, and enhanced the expression of synaptic genes. Repressing SCD1 expression or reducing SCD-dependent enzymatic activity accelerated the recovery of muscle function after inducing sciatic nerve crush. Overall, these findings provide evidence for a new role of SCD1 in modulating the restorative potential of skeletal muscles.

  11. Onset of Quiescence Following p53 Mediated Down-Regulation of H2AX in Normal Cells

    Science.gov (United States)

    Inase, Aki; Shinohe, Keitaro; Yoshioka, Yoshiko; Shikanai, Mima; Ichijima, Yosuke; Unno, Junya; Mizutani, Shuki; Tsuchiya, Naoto; Hippo, Yoshitaka; Nakagama, Hitoshi; Masutani, Mitsuko; Teraoka, Hirobumi; Yoshioka, Ken-ichi

    2011-01-01

    Normal cells, both in vivo and in vitro, become quiescent after serial cell proliferation. During this process, cells can develop immortality with genomic instability, although the mechanisms by which this is regulated are unclear. Here, we show that a growth-arrested cellular status is produced by the down-regulation of histone H2AX in normal cells. Normal mouse embryonic fibroblast cells preserve an H2AX diminished quiescent status through p53 regulation and stable-diploidy maintenance. However, such quiescence is abrogated under continuous growth stimulation, inducing DNA replication stress. Because DNA replication stress-associated lesions are cryptogenic and capable of mediating chromosome-bridge formation and cytokinesis failure, this results in tetraploidization. Arf/p53 module-mutation is induced during tetraploidization with the resulting H2AX recovery and immortality acquisition. Thus, although cellular homeostasis is preserved under quiescence with stable diploidy, tetraploidization induced under growth stimulation disrupts the homeostasis and triggers immortality acquisition. PMID:21858116

  12. Onset of quiescence following p53 mediated down-regulation of H2AX in normal cells.

    Directory of Open Access Journals (Sweden)

    Yuko Atsumi

    Full Text Available Normal cells, both in vivo and in vitro, become quiescent after serial cell proliferation. During this process, cells can develop immortality with genomic instability, although the mechanisms by which this is regulated are unclear. Here, we show that a growth-arrested cellular status is produced by the down-regulation of histone H2AX in normal cells. Normal mouse embryonic fibroblast cells preserve an H2AX diminished quiescent status through p53 regulation and stable-diploidy maintenance. However, such quiescence is abrogated under continuous growth stimulation, inducing DNA replication stress. Because DNA replication stress-associated lesions are cryptogenic and capable of mediating chromosome-bridge formation and cytokinesis failure, this results in tetraploidization. Arf/p53 module-mutation is induced during tetraploidization with the resulting H2AX recovery and immortality acquisition. Thus, although cellular homeostasis is preserved under quiescence with stable diploidy, tetraploidization induced under growth stimulation disrupts the homeostasis and triggers immortality acquisition.

  13. The excreted polysaccharide of Pleurotus eryngii inhibits the foam-cell formation via down-regulation of CD36.

    Science.gov (United States)

    Chen, Jingjing; Yong, Yangyang; Xia, Xian; Wang, Zeliang; Liang, Youxing; Zhang, Shizhu; Lu, Ling

    2014-11-04

    Previous study has verified the polysaccharide from the fruiting body of Pleurotus eryngii (PEPE) is capable of decreasing the lipid content in both of cell-line and mouse model. However, little is known about underlying mechanisms and whether this bioactive polysaccharide exists in submerged culture. Here, we verified the excreted polysaccharides EP and EP-1 from submersion culture of P. eryngii have the remarkable inhibitory effects on lipid accumulation in macrophage-derived foam cells. Structure analysis indicates EP-1 consists of D-types of glucose, galactose and mannose with the main β(1 → 3)-glucan glycosidic linkage branched at O-6 by α-D-glucose while EP digested by β-1,3-glucanase fails to decrease the lipid accumulation, suggesting that the special structure is essential for its function. Expression analysis suggests that EP is able to cause the down-regulation of the scavenger receptor-CD36 on both transcription and protein levels. Most importantly, EP can be obtained by fermentation in a mass-production.

  14. Berberine Induces Apoptosis in p53-Null Leukemia Cells by Down-Regulating XIAP at the Post-Transcriptional Level

    Directory of Open Access Journals (Sweden)

    Jian Liu

    2013-11-01

    Full Text Available Background: Berberine exerts anticancer activities both in vitro and in vivo through different mechanisms. However, the underlying molecular mechanisms of berberine induced p53-independent apoptosis remain unclear. Methods: The p53-null leukemia cell line EU-4 cells were exposed to berberine. Then the cell viability and apoptosis were determined. Western blot and PCR were employed to detect the expression of apoptosis related protein, XIAP and MDM2. Small interfering RNA (siRNA was applied to knock down endogenous expression of MDM2 and XIAP. Results: Berberine induced p53-independent, XIAP-mediated apoptotic cell death in p53-null leukemia cells. Treatment with berberine resulted in suppression of XIAP protein in a dose- and time- dependent manner. Berberine induced down-regulation of XIAP protein involving inhibition of MDM2 expression and a proteasome-dependent pathway. Moreover, inhibition of XIAP by berberine or siRNA increased the sensitivity of leukemia cells to doxorubicin-induced apoptosis. Conclusion: Our findings characterize the molecular mechanisms of berberine-induced caspase activation and subsequent apoptosis, and berberine may be a novel candidate inducer of apoptosis in leukemia cells, which normally lack p53 expression.

  15. Induction of autophagy by Imatinib sequesters Bcr-Abl in autophagosomes and down-regulates Bcr-Abl protein.

    LENUS (Irish Health Repository)

    Elzinga, Baukje M

    2013-06-01

    Chronic Myeloid Leukemia (CML) is a disease of hematopoietic stem cells which harbor the chimeric gene Bcr-Abl. Expression levels of this constitutively active tyrosine kinase are critical for response to tyrosine kinase inhibitor treatment and also disease progression, yet the regulation of protein stability is poorly understood. We have previously demonstrated that imatinib can induce autophagy in Bcr-Abl expressing cells. Autophagy has been associated with the clearance of large macromolecular signaling complexes and abnormal proteins, however, the contribution of autophagy to the turnover of Bcr-Abl protein in imatinib treated cells is unknown. In this study, we show that following imatinib treatment, Bcr-Abl is sequestered into vesicular structures that co-localize with the autophagy marker LC3 or GABARAP. This association is inhibited by siRNA mediated knockdown of autophagy regulators (Beclin 1\\/ATG7). Pharmacological inhibition of autophagy also reduced Bcr-Abl\\/LC3 co-localization in both K562 and CML patient cells. Bcr-Abl protein expression was reduced with imatinib treatment. Inhibition of both autophagy and proteasome activity in imatinib treated cells was required to restore Bcr-Abl protein levels to those of untreated cells. This ability to down-regulate Bcr-Abl protein levels through the induction of autophagy may be an additional and important feature of the activity of imatinib.

  16. Down-regulation of ERK1 and ERK2 activity during differentiation of the intestinal cell line HT-29.

    Science.gov (United States)

    Luongo, Diomira; Mazzarella, Giuseppe; Della, Ragione Fulvio; Maurano, Francesco; Rossi, Mauro

    2002-02-01

    The role and regulation of signal transduction pathways in proliferation and differentiation of intestinal epithelial cells are still poorly understood. However, growing evidences have been recently accumulated demonstrating that mitogen-activated protein kinases (MAPKs) play a pivotal function in the normal development of intestine. We have investigated, in the intestinal cell line HT-29, the regulation (namely activity and phosphorylation degree) of MAP kinases ERK 1 (p44) and ERK 2 (p42) during differentiation. Addition of fetal calf serum to HT-29 undifferentiated resting cells caused a rapid phosphorylation of both ERKs and an increase of their specific kinase activity. Moreover, nuclear translocation of ERK 1 and ERK 2 occurred concurrently to their activation, leading to the conclusion that ERK 1 and ERK 2 are classically regulated when quiescent HT-29 cells are induced to proliferate. Butyrate addition to the intestinal cell line resulted in terminal differentiation and in a selective down-regulation of ERK 2 activity (and phosphorylation degree) without any effect on ERK 1. Conversely, when HT-29 cells were differentiated by repeated passages in a glucose-free medium, we observed a progressive dephosphorylation and inactivation of p42 and p44 kinases along with the failure of serum to activate both the enzymes. Our findings suggest that, during the differentiation of intestinal cells, remarkable changes occur in ERK 1 and ERK 2 control mechanisms leading to an unresponsiveness of MAP kinase pathway.

  17. Topotecan inhibits cancer cell migration by down-regulation of chemokine CC motif receptor 7 and matrix metalloproteinases

    Institute of Scientific and Technical Information of China (English)

    Sen-sen LIN; Li SUN; Yan-kai ZHANG; Ren-ping ZHAO; Wen-lu LIANG; Sheng-tao YUAN; Lu-yong ZHANG

    2009-01-01

    Aim: The aim of this study was to investigate the effect of topotecan (TPT) on cancer cell migration.Methods: Growth inhibition of TPT was analyzed by MTT assay, and cancer cell migration was measured by transwell double chamber assay. To verify the effect of TPT on the chemokine receptors CXCR4 and CCR7, quantitative PCR, semi-quantitative PCR and Western blot analysis were performed. The secretion of MMP-2 and MMP-9 was detected by enzyme-linked immunosorbent assay (ELISA) and gelatin zymography. To evaluate possible contributions of CCR7 to MMP secretion, the overexpression vectors pcDNA3.1+-CCR7 and CCR7 siRNA were transiently transfected into MDA-MB-435 cells.Results: TPT inhibited cancer cell migration in a dose-dependent manner. Additionally, TPT significantly decreased the expression of CCR7 in both MDA-MB-435 and MDA-MB-231 cells and moderately reduced the expression of CXCR4 in MDA-MB-435 cells. The secretion of MMPs (MMP-2, MMP-9) was also inhibited by TPT. Overexpression of CCR7 increased the secretion of MMP-2/9 and cancer cell migration, whereas knockdown of CCR7 reduced active MMP-2/9 production and migration of MDA-MB-435 cells.Conclusion: TPT inhibited cancer cell migration by down-regulation of CCR7 and MMPs (MMP-2 and MMP-9).

  18. Down-Regulation of lncRNA-AK001085 and its Influences on the Diagnosis of Ankylosing Spondylitis.

    Science.gov (United States)

    Li, Xiang; Chai, Wei; Zhang, Guoqiang; Ni, Ming; Chen, Jiying; Dong, Jiyuan; Zhou, Yonggang; Hao, Libo; Bai, Yang; Wang, Yan

    2017-01-02

    BACKGROUND Long non-coding RNAs (lncRNAs) have been confirmed to play an important role in the development and progression of diseases. Ankylosing spondylitis (AS) is a chronic inflammatory systemic disease and it is hard to be found in early time. The purpose of this study was to investigate the role of lncRNA-AK001085 in the diagnosis of AS. MATERIAL AND METHODS The expression of lncRNA-AK001085 was detected by quantitative real-time polymerase chain reaction (qRT-PCR) analysis. The relationship between its expression and clinicopathologic characteristics was also analyzed. Meanwhile the correlation between lncRNA-AK001085 expression and diseases activity indexes was estimated. In addition, the value of it in the diagnosis of AS was explored through establishing receiver operating characteristic (ROC) curve. RESULTS Serum lncRNA-AK001085 expression was decreased in patients with AS compared with healthy individuals. And its expression was proved to be influenced by ever cigarette smoker, exercise level and occupational activity level. Besides, the correlation of the expression of lncRNA-AK001085 and disease activity indexes (BASDI, ASDAS, ESR, CRP) were all negative, which suggested that the lncRNA-AK001085 was significantly lower in patients with a high disease activity score. It might showed that the expression of lncRNA-AK001085 affected the activity of AS. CONCLUSIONS LncRNA-AK001085 was down-regulated in AS patients and it could be an independent diagnostic indicator.

  19. Down-regulation of miR-181a can reduce heat stress damage in PBMCs of Holstein cows.

    Science.gov (United States)

    Chen, Kun-Lin; Fu, Yuan-Yuan; Shi, Min-Yan; Li, Hui-Xia

    2016-09-01

    Heat stress can weaken the immune system and even increase livestock's susceptibility to disease. MicroRNA (miR) is short non-coding RNA that functions in post-transcriptional regulation of gene expression and some phenotypes. Our recent study found that miR-181a is highly expressed in the serum of heat-stressed Holstein cows, but the potential function of miR-181a is still not clarified. In this study, peripheral blood mononuclear cells (PBMCs), isolated from Holstein cows' peripheral blood, were used to investigate the effects of miR-181a inhibitor on heat stress damage. Our results showed that significant apoptosis and oxidative damage were induced by heat stress in PBMCs. However, with apoptosis, the levels of reactive oxygen species (ROS) and content of malondialdehyde (MDA) were reduced, while the content of glutathione (GSH) and the activity of superoxide dismutase (SOD) were increased even under heat stress conditions after transfecting miR-181a inhibitors to PBMCs. Meanwhile, mRNA expression of bax and caspase-3 was significantly decreased, but mRNA expression of bcl-2 was increased in transfected PBMCs. In conclusion, our results demonstrated that down-regulation of miR-181a can reduce heat stress damage in PBMCs of Holstein cows.

  20. Down-regulation of Fusarium oxysporum endogenous genes by Host-Delivered RNA interference enhances disease resistance

    Science.gov (United States)

    Hu, Zongli; Parekh, Urvi; Maruta, Natsumi; Trusov, Yuri; Botella, Jimmy

    2015-01-01

    Fusarium oxysporum is a devastating pathogen causing extensive yield losses in a variety of crops and development of sustainable, environmentally friendly methods to improve crop resistance is crucial. We have used Host-Derived RNA interference (HD-RNAi) technology to partially silence three different genes (FOW2, FRP1 and OPR) in the hemi-biotrophic fungus Fusarium oxysporum f. sp. conglutinans. Expression of double stranded RNA molecules targeting fungal pathogen genes was achieved in a number of transgenic Arabidopsis lines. F. oxysporum infecting the transgenic lines displayed substantially reduced mRNA levels on all three targeted genes, with an average of 75%, 83% and 72% reduction for FOW2, FRP1 and OPR respectively. The silencing of pathogen genes had a clear positive effect on the ability of the transgenic lines to fight infection. All transgenic lines displayed enhanced resistance to F. oxysporum with delayed disease symptom development, especially FRP1 and OPR lines. Survival rates after fungal infection were higher in the transgenic lines compared to control wild type plants which consistently showed survival rates of 10%, with FOW2 lines showing 25% survival; FRP1 lines 30-50% survival and FOW2 between 45-70% survival. The down-regulation effect was specific for the targeted genes without unintended effects in related genes. In addition to producing resistant crops, HD-RNAi can provide a useful tool to rapidly screen candidate fungal pathogenicity genes without the need to produce fungal knockout mutants.

  1. The vitamin C transporter SVCT2 is down-regulated during postnatal development of slow skeletal muscles.

    Science.gov (United States)

    Sandoval, Daniel; Ojeda, Jorge; Low, Marcela; Nualart, Francisco; Marcellini, Sylvain; Osses, Nelson; Henríquez, Juan Pablo

    2013-06-01

    Vitamin C plays key roles in cell homeostasis, acting as a potent antioxidant as well as a positive modulator of cell differentiation. In skeletal muscle, the vitamin C/sodium co-transporter SVCT2 is preferentially expressed in oxidative slow fibers. Besides, SVCT2 is up-regulated upon the early fusion of primary myoblasts. However, our knowledge of the postnatal expression profile of SVCT2 remains scarce. Here we have analyzed the expression of SVCT2 during postnatal development of the chicken slow anterior and fast posterior latissimus dorsi muscles, ranging from day 7 to adulthood. SVCT2 expression is consistently higher in the slow than in the fast muscle at all stages. After hatching, SVCT2 expression is significantly down-regulated in the anterior latissimus dorsi, which nevertheless maintains a robust slow phenotype. Taking advantage of the C2C12 cell line to recapitulate myogenesis, we confirmed that SVCT2 is expressed in a biphasic fashion, reaching maximal levels upon early myoblasts fusion and decreasing during myotube growth. Together, these findings suggest that the dynamic expression levels of SVCT2 could be relevant for different features of skeletal muscle physiology, such as muscle cell formation, growth and activity.

  2. Transcription of SCO-spondin in the subcommissural organ: evidence for down-regulation mediated by serotonin.

    Science.gov (United States)

    Richter, Hans G; Tomé, María M; Yulis, Carlos R; Vío, Karin J; Jiménez, Antonio J; Pérez-Fígares, José M; Rodríguez, Esteban M

    2004-10-22

    The subcommissural organ (SCO) is a brain gland located in the roof of the third ventricle that releases glycoproteins into the cerebrospinal fluid, where they form a structure known as Reissner's fiber (RF). On the basis of SCO-spondin sequence (the major RF glycoprotein) and experimental findings, the SCO has been implicated in central nervous system development; however, its function(s) after birth remain unclear. There is evidence suggesting that SCO activity in adult animals may be regulated by serotonin (5HT). The use of an anti-5HT serum showed that the bovine SCO is heterogeneously innervated with most part being poorly innervated, whereas the rat SCO is richly innervated throughout. Antibodies against serotonin receptor subtype 2A rendered a strong immunoreaction at the ventricular cell pole of the bovine SCO cells and revealed the expected polypeptides in blots of fresh and organ-cultured bovine SCO. Analyses of organ-cultured bovine SCO treated with 5HT revealed a twofold decrease of both SCO-spondin mRNA level and immunoreactive RF glycoproteins, whereas no effect on release of RF glycoproteins into the culture medium was detected. Rats subjected to pharmacological depletion of 5HT exhibited an SCO-spondin mRNA level twofold higher than untreated rats. These results indicate that 5HT down-regulates SCO-spondin biosynthesis but apparently not its release, and suggest that 5HT may exert the effect on the SCO via the cerebrospinal fluid.

  3. Galectin-1 is expressed in early-type neural progenitor cells and down-regulates neurogenesis in the adult hippocampus

    Directory of Open Access Journals (Sweden)

    Imaizumi Yoichi

    2011-01-01

    Full Text Available Abstract Background In the adult mammalian brain, neural stem cells (NSCs proliferate in the dentate gyrus (DG of the hippocampus and generate new neurons throughout life. A multimodal protein, Galectin-1, is expressed in neural progenitor cells (NPCs and implicated in the proliferation of the NPCs in the DG. However, little is known about its detailed expression profile in the NPCs and functions in adult neurogenesis in the DG. Results Our immunohistochemical and morphological analysis showed that Galectin-1 was expressed in the type 1 and 2a cells, which are putative NSCs, in the subgranular zone (SGZ of the adult mouse DG. To study Galectin-1's function in adult hippocampal neurogenesis, we made galectin-1 knock-out mice on the C57BL6 background and characterized the effects on neurogenesis. In the SGZ of the galectin-1 knock-out mice, increased numbers of type 1 cells, DCX-positive immature progenitors, and NeuN-positive newborn neurons were observed. Using triple-labeling immunohistochemistry and morphological analyses, we found that the proliferation of the type-1 cells was increased in the SGZ of the galectin-1 knock-out mice, and we propose that this proliferation is the mechanism for the net increase in the adult neurogenesis in these knock-out mice DG. Conclusions Galectin-1 is expressed in the neural stem cells and down-regulates neurogenesis in the adult hippocampus.

  4. KCNK5 is Functionally Down-Regulated Upon Long-Term Hypotonicity in Ehrlich Ascites Tumor Cells

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    Signe Skyum Kirkegaard

    2013-11-01

    Full Text Available Background/Aims: Regulatory volume decrease (RVD in response to acute cell swelling is well described and KCNK5 (also known as TASK-2 or K2P5.1 has been shown to be the volume sensitive K+ channel in Ehrlich cells. Very little is, on the other hand, known about the effects of long-term hypotonicity on expression and function of KCNK5, thus we have investigated the effect of long-term hypotonicity (24h - 48h on KCNK5 in Ehrlich cells on the mRNA, protein and physiological levels. Methods: Physiological effects of long-term hypotonicity were measured using patch-clamp and Coulter counter techniques. Expression patterns of KCNK5 on mRNA and protein levels were established using real-time qPCR and western blotting respectively. Results: The maximum swelling-activated current through KCNK5 was significantly decreased upon 48h of hypotonicity and likewise the RVD response was significantly impaired after both 24 and 48h of hypotonic stimulation. No significant differences in the KCNK5 mRNA expression patterns between control and stimulated cells were observed, but a significant decrease in the KCNK5 protein level 48h after stimulation was found. Conclusion: The data suggest that the strong physiological impairment of KCNK5 in Ehrlich cells after long-term hypotonic stimulation is predominantly due to down-regulation of the KCNK5 protein synthesis.

  5. Systemic delivery of siRNA down regulates brain prion protein and ameliorates neuropathology in prion disorder.

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    Sylvain Lehmann

    Full Text Available One of the main challenges for neurodegenerative disorders that are principally incurable is the development of new therapeutic strategies, which raises important medical, scientific and societal issues. Creutzfeldt-Jakob diseases are rare neurodegenerative fatal disorders which today remain incurable. The objective of this study was to evaluate the efficacy of the down-regulation of the prion protein (PrP expression using siRNA delivered by, a water-in-oil microemulsion, as a therapeutic candidate in a preclinical study. After 12 days rectal mucosa administration of Aonys/PrP-siRNA in mice, we observed a decrease of about 28% of the brain PrP(C level. The effect of Aonys/PrP-siRNA was then evaluated on prion infected mice. Several mice presented a delay in the incubation and survival time compared to the control groups and a significant impact was observed on astrocyte reaction and neuronal survival in the PrP-siRNA treated groups. These results suggest that a new therapeutic scheme based an innovative delivery system of PrP-siRNA can be envisioned in prion disorders.

  6. Resistin impairs glucose permeability in EA.hy926 cells by down-regulating GLUT1 expression.

    Science.gov (United States)

    Li, Qiang; Cai, Yuxi; Huang, Jing; Yu, Xiaolan; Sun, Jun; Yang, Zaiqing; Zhou, Lei

    2016-10-15

    Type 2 diabetes mellitus (T2DM) is a chronic disease which is now affecting the health of more and more people in the world. Resistin, discovered in 2001, is considered to be closely related to metabolic dysfunction and obesity. Previous study showed that hyperglycemia is always accompanied by a high serum resistin concentration. We therefore investigated whether resistin can mediate glucose transfer across the blood-tissue barrier. Here, we employed a transwell system to analyze glucose permeability in EA.hy926 human endothelial cells treated without or with human resistin. In EA.hy926 cells treated with resistin, the permeability to glucose was heavily impaired. This was due to the down-regulation of GLUT1 expression as a result of the treatment, rather than regulation of tight junctions. In addition, overexpression of GLUT1 in EA.hy926 cells was able to recover the blocking effect of resistin on glucose permeability. We further found that resistin could inhibit the expression of peroxisome proliferator-activated receptor gamma (PPARγ) and consequently impede the transcription of GLUT1. The results of the present study suggested that resistin could cause glucose retention in serum and thus result in hyperglycemia. This provides a novel explanation for hyperglycemia and a potential new way of treating type 2 diabetes mellitus. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  7. Down-regulation of β-catenin Nuclear Localization by Aspirin Correlates with Growth Inhibition of Jurkat Cell Line

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this study, we examined the effects of aspirin on the growth rates, subcellar distribution of β-catenin protein, the expression of β-catenin/TCF signaling pathway target gene cyclinD1 mRNA,and cell cycle of Jurkat cell line (Human T-acute lymphoblastic leukemia). Our results showed that the treatment with aspirin inhibited the growth of Jurkat cell line. Jurkat cells treated with 3 mmol/L of aspirin could significantly decrease nuclear localization of β-catenin, and at 5 mmol/L of aspirin,the nuclear localization of β-catenin was undetectable. QRT-PCR showed that the target gene cyclinD1 mRNA expression was gradually decreased with the dosage of aspirin. Aspirin induced G0/G1cell cycle arrest in Jurkat cells. We are led to conclude that aspirin acts through β-catenin-independent mechanisms. The effects of aspirin include down-regulation of β-catenin nuclear localization and G0/G1 cell cycle arrest, which might serve as a means of growth inhibition in aspirin-treated human Jurkat cell line.

  8. Preclinical efficacy of sepantronium bromide (YM155) in multiple myeloma is conferred by down regulation of Mcl-1.

    Science.gov (United States)

    Wagner, Verena; Hose, Dirk; Seckinger, Anja; Weiz, Ludmila; Meißner, Tobias; Rème, Thiery; Breitkreutz, Iris; Podar, Klaus; Ho, Anthony D; Goldschmidt, Hartmut; Krämer, Alwin; Klein, Bernard; Raab, Marc S

    2014-11-15

    The inhibitor-of-apoptosis family member survivin has been reported to inhibit apoptosis and regulate mitosis and cytokinesis. In multiple myeloma, survivin has been described to be involved in downstream sequelae of various therapeutic agents. We assessed 1093 samples from previously untreated patients, including two independent cohorts of 392 and 701 patients, respectively. Survivin expression was associated with cell proliferation, adverse prognostic markers, and inferior event-free and overall survival, supporting the evaluation of survivin as a therapeutic target in myeloma. The small molecule suppressant of survivin--YM155--is in clinical development for the treatment of solid tumors. YM155 potently inhibited proliferation and induced apoptosis in primary myeloma cells and cell lines. Gene expression and protein profiling revealed the critical roles of IL6/STAT3-signaling and the unfolded protein response in the efficacy of YM155. Both pathways converged to down regulate anti-apoptotic Mcl-1 in myeloma cells. Conversely, growth inhibition and apoptotic cell death by YM155 was rescued by ectopic expression of Mcl-1 but not survivin, identifying Mcl-1 as the pivotal downstream target of YM155 in multiple myeloma. Mcl-1 expression was likewise associated with adverse prognostic markers, and inferior survival. Our results strongly support the clinical evaluation of YM155 in patients with multiple myeloma.

  9. The association of down-regulated toll-like receptor 4 expression with airflow limitation and emphysema in smokers

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    Lee Sei Won

    2012-11-01

    Full Text Available Abstract Background An association between innate immunity including Toll-like receptors (TLRs and COPD is reported recently; TLR4 deficiency in lung can cause emphysema in animals, which is not evident in humans. We analyzed the association of TLR4 expression, airflow limitation and emphysema in smokers. Methods We enrolled patients of ≥40years old with smoking histories of ≥10 pack-years and who had undergone lung resection. We measured TLR4 expression in lung lysates. The severity of emphysema was evaluated on computed tomography. TLR4 expression was also evaluated immunohistochemically. Results In total, 53 patients were enrolled. Forced expiratory volume in one second per forced vital capacity (FEV1/FVC increased (P=0.03 and emphysema score decreased (P=0.01 as TLR4 expression increased. These were still significant, in multiple regression analysis including sex, age, tuberculosis history, smoking history and inhaled corticosteroid (ICS usage. We also classified patients as high, intermediate, and low expressers according to TLR4 expression. Although no differences in age, gender, tuberculosis, or smoking history were observed among the groups, emphysema severity increased significantly (P = 0.02 and FEV1/FVC decreased significantly (P = 0.006 in TLR4 low expresser. The difference in TLR4 expression based on immunohistochemistry was most prominent in bronchial and alveolar epithelial cells. Conclusion Down-regulated TLR4 expression in lung was associated with emphysema and airflow limitation in smokers.

  10. Atorvastatin protected from paraquat-induced cytotoxicity in alveolar macrophages via down-regulation of TLR-4.

    Science.gov (United States)

    Alizadeh-Tabrizi, Nazli; Malekinejad, Hassan; Varasteh, Soheil; Cheraghi, Hadi

    2017-01-01

    The current study designed to clarify the mechanism of paraquat-induced cytotoxicity and protective effects of Atorvastatin on freshly isolated alveolar macrophages (AMs). AMs were collected via bronchoalveolar lavage and exposed to various concentrations of paraquat in the presence and absence of atorvastatin for 24h. Cell viability, myeloperoxidase activity; nitric oxide generation and total antioxidant capacity were assessed. Expression of TLR-4 at mRNA and protein levels were studied by using PCR and western blot methods Atorvastatin enhanced the paraquat-reduced cell viability and reduced the paraquat-induced myeloperoxidase activity and nitric oxide production. Moreover, atorvastatin down-regulated by 60% the paraquat up-regulated expression of TLR-4 at protein and mRNA level. Our results suggest that, AMs in vitro model could be a novel cytological tool for studies on paraquat poisoning and therapy regimens. Additionally, atorvastatin cytoprotective effects on paraquat-induced cytotoxicity partly attribute to its anti-myeloperoxidase, antioxidant properties, which might be regulated via TLR-4 expression.

  11. Asiaticoside attenuates lipopolysaccharide-induced acute lung injury via down-regulation of NF-κB signaling pathway.

    Science.gov (United States)

    Qiu, Jiaming; Yu, Lijun; Zhang, Xingxing; Wu, Qianchao; Wang, Di; Wang, Xiuzhi; Xia, Cheng; Feng, Haihua

    2015-05-01

    Asiaticoside (AS), a triterpene glycoside isolated from Centella asiatica, has been shown to possess potent anti-inflammatory activity. However, the detailed molecular mechanisms of AS on lipopolysaccharide (LPS)-induced acute lung injury (ALI) model in mice are scanty. The purpose of this study was to evaluate the effect of AS on LPS-induced mouse ALI via down-regulation of NF-κB signaling pathway. We investigated the efficacy of AS on cytokine levels induced by LPS in bronchoalveolar lavage fluid (BALF) and RAW 264.7 cells. The production of cytokine (TNF-α and IL-6) was measured by enzyme-linked immunosorbent assay (ELISA). The lung wet-to-dry weight ratios were measured in LPS-challenged mice, and lung histopathologic changes observed via paraffin section were assessed. To further study the mechanism of AS protective effects on ALI, the activation of NF-κB p65 subunit and the degradation of IκBα were tested by western blot assay. We found that AS treatment at 15, 30 or 45mg/kg dose-dependently attenuated LPS-induced pulmonary inflammation by reducing inflammatory infiltration, histopathological changes, descended cytokine production, and pulmonary edema initiated by LPS. Furthermore, our results suggested that AS suppressed inflammatory responses in LPS-induced ALI through inhibition of the phosphorylation of NF-κB p65 subunit and the degradation of its inhibitor IκBα, and might be a new preventive agent of ALI in the clinical setting.

  12. Lupeol, a dietary triterpene, inhibited growth, and induced apoptosis through down-regulation of DR3 in SMMC7721 cells.

    Science.gov (United States)

    Zhang, Lin; Zhang, Youcheng; Zhang, Lingyi; Yang, Xiaojun; Lv, Zhicheng

    2009-02-01

    Lupeol (Lup-20(29)-en-3H-ol), a novel dietary triterpene, was found in fruits, vegetables, and several medicinal plants. Here, we investigated its growth-inhibitory effect and associated mechanisms in hepatocellular carcinoma SMMC7721 cells. Lupeol treatment resulted in significant inhibition of cell viability in a dose-dependent manner and caused apoptotic death of this cell line with activation of caspase3 expression. Caspase8 inhibitor pretreatment was found to partially block the apoptosis induced by Lupeol. Moreover, Lupeol specifically caused a significant decrease in the expression of Death receptor 3 (DR3) mRNA and protein and a significant elevated expression of FADD mRNA whereas Fas mRNA and protein expression was not detectable. Further more, knockdown of DR3 by small interfering RNA inhibited the growth and induced apoptosis of hepatocellular carcinoma cell. These results suggested that Lupeol treatment induced growth inhibition and apoptosis in SMMC7721 cells, the mechanism is due to down-regulation of DR3 expression. We demonstrated that Lupeol appears to be a promising chemopreventive agent for treating hepatocellular carcinoma, and DR3 may be an important target for liver cancer therapy.

  13. The Structure, Expression, and Function Prediction of DAZAP2, A Down-Regulated Gene in Multiple Myeloma

    Institute of Scientific and Technical Information of China (English)

    Yiwu Shi; Saiqun Luo; Jianbin Peng; Chenghan Huang; Daren Tan; Weixin Hu

    2004-01-01

    In our previous studies, DAZAP2 gene expression was down-regulated in untreated patients of multiple myeloma (MM). For better studying the structure and function of DAZAP2, a full-length Cdna was isolated from mononuclear cells of a normal human bone marrow, sequenced and deposited to Genbank (AY430097). This sequence has an identical ORF (open reading frame) as the NM_014764 from human testis and the D31767 from human cell line KG-1. Phylogenetic analysis and structure prediction reveal that DAZAP2 homologues are highly conserved throughout evolution and share a polyproline region and several potential SH2/SH3 binding sites. DAZAP2 occurs as a single-copy gene with a four-exon organization. We further noticed that the functional DAZAP2 gene is located on Chromosome 12 and its pseudogene gene is on Chromosome 2 with electronic location of human chromosome in Genbank, though no genetic abnormalities of MM have been reported on Chromosome 12. The ORF of human DAZAP2 encodes a 17-kDa protein, which is highly similar to mouse Prtb. The DAZAP2 protein is mainly localized in cytoplasm with a discrete pattern of punctuated distribution. DAZAP2 may associate with carcinogenesis of MM and participate in yet-to-be identified signaling pathways to regulate proliferation and differentiation of plasma cells.

  14. E3B1/ABI-1 Isoforms Are Down-Regulated in Cancers of Human Gastrointestinal Tract

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    Rafia A. Baba

    2012-01-01

    Full Text Available The expression of E3B1/ABI-1 protein and its role in cancer progression and prognosis are largely unknown in the majority of solid tumors. In this study, we examined the expression pattern of E3B1/ABI-1 protein in histologically confirmed cases of esophageal (squamous cell carcinoma and adenocarcinoma, gastro-esophageal junction, colorectal cancers and corresponding normal tissues freshly resected from a cohort of 135 patients, by Western Blotting and Immunofluorescence Staining. The protein is present in its phosphorylated form in cells and tissues. Depending on the extent of phosphorylation it is either present in hyper-phosphorylated (M. Wt. 72 kDa form or in hypo-phosphorylated form (M. Wt. 68 kDa and 65 kDa. A thorough analysis revealed that expression of E3B1/ABI-1 protein is significantly decreased in esophageal, gastro-esophageal junction and colorectal carcinomas irrespective of age, gender, dietary and smoking habits of the patients. The decrease in expression of E3B1/ABI-1 was consistently observed for all the three isoforms. However, the decrease in the expression of isoforms varied with different forms of cancers. Down-regulation of E3B1/ABI-1 expression in human carcinomas may play a critical role in tumor progression and in determining disease prognosis.

  15. Curcumin improves hypoxia induced dysfunctions in 3T3-L1 adipocytes by protecting mitochondria and down regulating inflammation.

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    Priyanka, Ariyapalli; Anusree, Sasidharan Suseela; Nisha, Vijayakumar Marykutty; Raghu, Kozhiparambil Gopalan

    2014-01-01

    Obesity induced metabolic syndrome is increasing worldwide at an alarming rate. It is characterized by excessive expansion of white adipose tissue which leads to hypoxia and impairs normal metabolism. Recent studies reveal that hypoxia could be one of the factors for inflammation, insulin resistance and other obesity related complications. There is a high demand for anti-obese phytoceuticals to control and manage the complications resulting from obesity. In this study, we investigated how hypoxia affect the physiological functions of 3T3-L1 adipocytes emphasizing on oxidative stress, inflammation, and mitochondrial functions. We also evaluated the protective role of various doses of curcumin, a well-known dietary antioxidant, on hypoxia induced alterations. The results revealed that hypoxia significantly altered the vital parameters of adipocyte biology like HIF 1α expression (103.47% ↑), lactate, and glycerol release (184.34% and 69.1% ↑, respectively), reactive oxygen species production (432.53% ↑), lipid and protein oxidation (376.6% and 566.6% ↑, respectively), reduction in antioxidant enzymes (superoxide dismutase and catalase) status, secretion of inflammatory markers (TNF α, IL 6, IL 1β, and IFN γ), and mitochondrial functions (mitochondrial mass, membrane potential, permeability transition pore integrity, and superoxide generation). Curcumin substantially protected adipocytes from toxic effects of hypoxia in a dose dependent manner by protecting mitochondria and down regulating inflammation. Acriflavine is used as a positive control. A detailed investigation is required for the development of curcumin as an effective nutraceutical against obesity.

  16. Altered Lignin Biosynthesis Improves Cellulosic Bioethanol Production in Transgenic Maize Plants Down-Regulated for Cinnamyl Alcohol Dehydrogenase

    Institute of Scientific and Technical Information of China (English)

    Silvia Fornalé; Pere Puigdomènech; Joan Rigau; David Caparrós-Ruiz; Montserrat Capellades; Antonio Encina; Kan Wang; Sami Irar; Catherine Lapierre; Katia Ruel; Jean-Paul Joseleau; Jordi Berenguer

    2012-01-01

    Cinnamyl alcohol dehydrogenase(CAD)is a key enzyme involved in the last step of monolignol biosynthesis.The effect of CAD down-regulation on lignin production was investigated through a transgenic approach in maize.Transgenic CAD-RNAi plants show a different degree of enzymatic reduction depending on the analyzed tissue and show alterations in cell wall composition.Cell walls of CAD-RNAi stems contain a lignin polymer with a slight reduction in the S-to-G ratio without affecting the total lignin content.In addition,these cell walls accumulate higher levels of cellulose and arabinoxylans.In contrast,cell walls of CAD-RNAi midribs present a reduction in the total lignin content and of cell wall polysaccharides.In vitro degradability assays showed that,although to a different extent,the changes induced by the repression of CAD activity produced midribs and stems more degradable than wild-type plants.CAD-RNAi plants grown in the field presented a wild-type phenotype and produced higher amounts of dry biomass.Cellulosic bioethanol assays revealed that CAD-RNAi biomass produced higher levels of ethanol compared to wild-type,making CAD a good target to improve both the nutritional and energetic values of maize lignocellulosic biomass.

  17. Natural product ginsenoside 25-OCH3-PPD inhibits breast cancer growth and metastasis through down-regulating MDM2.

    Directory of Open Access Journals (Sweden)

    Wei Wang

    Full Text Available Although ginseng and related herbs have a long history of utility for various health benefits, their application in cancer therapy and underlying mechanisms of action are not fully understood. Our recent work has shown that 20(S-25-methoxyl-dammarane-3β, 12β, 20-triol (25-OCH(3-PPD, a newly identified ginsenoside from Panax notoginseng, exerts activities against a variety of cancer cells in vitro and in vivo. This study was designed to investigate its anti-breast cancer activity and the underlying mechanisms of action. We observed that 25-OCH(3-PPD decreased the survival of breast cancer cells by induction of apoptosis and G1 phase arrest and inhibited the growth of breast cancer xenografts in vivo. We further demonstrated that, in a dose- and time-dependent manner, 25-OCH(3-PPD inhibited MDM2 expression at both transcriptional and post-translational levels in human breast cancer cells with various p53 statuses (wild type and mutant. Moreover, 25-OCH(3-PPD inhibited in vitro cell migration, reduced the expression of epithelial-to-mesenchymal transition (EMT markers, and prevented in vivo metastasis of breast cancer. In summary, 25-OCH(3-PPD is a potential therapeutic and anti-metastatic agent for human breast cancer through down-regulating MDM2. Further preclinical and clinical development of this agent is warranted.

  18. Down regulation of cyclooxygenase-2 is involved in delayed neuroprotec-tion by ischemic preconditioning in rats

    Institute of Scientific and Technical Information of China (English)

    Liang XIAO; Fei-li ZHAO; Xing-zu ZHU

    2005-01-01

    Aim: To examine whether the prostaglandins (PGs) pathway is involved in triggering delayed neuroprotection by ischemic preconditioning (IPC) and evaluate the effects of IPC on cyclooxygenase-2 (COX-2) expression following focal cerebral ischemia and reperfusion in rats. Methods: IPC was induced by 10 min of saline infusion into the left internal carotid artery with the right common carotid artery clamped at the same time. Middle cerebral artery occlusion (MCAO) and reperfusion model was produced using intraluminal filament method. Results: IPC 48 h prior to MCAO significantly reduced infarct area as compared with MCAO alone. A nonselective inhibitor of COX indomethacin (3 mg/kg ip) applied 1 h prior to or 1 h after IPC failed to affect its protective effects. IPC had no direct effect on the cortex COX-2 mRNA and protein expression 72 h later, but decreased the expres sion of COX-2 mRNA and protein following ischemia and reperfusion insult. Conclusion: PGs pathways was not involved in triggering delayed neuroprotection by IPC, and IPC induced down-regulation of COX-2 following focal cerebral ischemia and reperfusion in rats in vivo.

  19. Cis-mediated down-regulation of a trypsin gene associated with Bt resistance in cotton bollworm.

    Science.gov (United States)

    Liu, Chenxi; Xiao, Yutao; Li, Xianchun; Oppert, Brenda; Tabashnik, Bruce E; Wu, Kongming

    2014-11-27

    Transgenic plants producing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) are useful for pest control, but their efficacy is reduced when pests evolve resistance. Here we examined the mechanism of resistance to Bt toxin Cry1Ac in the laboratory-selected LF5 strain of the cotton bollworm, Helicoverpa armigera. This strain had 110-fold resistance to Cry1Ac protoxin and 39-fold resistance to Cry1Ac activated toxin. Evaluation of five trypsin genes revealed 99% reduced transcription of one trypsin gene (HaTryR) was associated with resistance. Silencing of this gene with RNA interference in susceptible larvae increased their survival on diets containing Cry1Ac. Bioassays of progeny from crosses revealed that resistance to Cry1Ac was genetically linked with HaTryR. We identified mutations in the promoter region of HaTryR in the resistant strain. In transfected insect cell lines, transcription was lower when driven by the resistant promoter compared with the susceptible promoter, implicating cis-mediated down-regulation of HaTryR transcription as a mechanism of resistance. The results suggest that H. armigera can adapt to Bt toxin Cry1Ac by decreased expression of trypsin. Because trypsin activation of protoxin is a critical step in toxicity, transgenic plants with activated toxins rather than protoxins might increase the durability of Bt crops.

  20. Down-regulation of transcription elogation factor A (SII like 4 (TCEAL4 in anaplastic thyroid cancer

    Directory of Open Access Journals (Sweden)

    Miyamoto Shizuyo

    2006-11-01

    Full Text Available Abstract Background Anaplastic thyroid cancer (ATC is one of the most aggressive human malignancies and appears to arise mainly from transformation of pre-existing differentiated thyroid cancer (DTC. However, the carcinogenic mechanism of anaplastic transformation remains unclear. Previously, we investigated specific genes related to ATC based on gene expression profiling using cDNA microarray analysis. One of these genes, transcription elongation factor A (SII-like 4 (TCEAL4, encodes a member of the transcription elongation factor A (SII-like gene family. The detailed function of TCEAL4 has not been described nor has any association between this gene and human cancers been reported previously. Methods To investigate the role of TCEAL4 in ATC carcinogenesis, we examined expression levels of TCEAL4 in ACLs as well as in other types of thyroid cancers and normal human tissue. Results Expression of TCEAL4 was down-regulated in all 11 ACLs as compared to either normal thyroid tissues or papillary and follicular thyroid cancerous tissues. TCEAL4 was expressed ubiquitously in all normal human tissues tested. Conclusion To our knowledge, this is the first report of altered TCEAL4 expression in human cancers. We suggest that loss of TCEAL4 expression might be associated with development of ATC from DTC. Further functional studies are required.

  1. SIRT1 ameliorates oxidative stress induced neural cell death and is down-regulated in Parkinson's disease.

    Science.gov (United States)

    Singh, Preeti; Hanson, Peter S; Morris, Christopher M

    2017-06-02

    Sirtuins (SIRTs) are NAD(+) dependent lysine deacetylases which are conserved from bacteria to humans and have been associated with longevity and lifespan extension. SIRT1, the best studied mammalian SIRT is involved in many physiological and pathological processes and changes in SIRT1 have been implicated in neurodegenerative disorders, with SIRT1 having a suggested protective role in Parkinson's disease. In this study, we determined the effect of SIRT1 on cell survival and α-synuclein aggregate formation in SH-SY5Y cells following oxidative stress. Over-expression of SIRT1 protected SH-SY5Y cells from toxin induced cell death and the protection conferred by SIRT1 was partially independent of its deacetylase activity, which was associated with the repression of NF-кB and cPARP expression. SIRT1 reduced the formation of α-synuclein aggregates but showed minimal co-localisation with α-synuclein. In post-mortem brain tissue obtained from patients with Parkinson's disease, Parkinson's disease with dementia, dementia with Lewy bodies and Alzheimer's disease, the activity of SIRT1 was observed to be down-regulated. These findings suggests a negative effect of oxidative stress in neurodegenerative disorders and possibly explain the reduced activity of SIRT1 in neurodegenerative disorders. Our study shows that SIRT1 is a pro-survival protein that is downregulated under cellular stress.

  2. Bmi1 is down-regulated in the aging brain and displays antioxidant and protective activities in neurons.

    Directory of Open Access Journals (Sweden)

    Mohamed Abdouh

    Full Text Available Aging increases the risk to develop several neurodegenerative diseases, although the underlying mechanisms are poorly understood. Inactivation of the Polycomb group gene Bmi1 in mice results in growth retardation, cerebellar degeneration, and development of a premature aging-like phenotype. This progeroid phenotype is characterized by formation of lens cataracts, apoptosis of cortical neurons, and increase of reactive oxygen species (ROS concentrations, owing to p53-mediated repression of antioxidant response (AOR genes. Herein we report that Bmi1 expression progressively declines in the neurons of aging mouse and human brains. In old brains, p53 accumulates at the promoter of AOR genes, correlating with a repressed chromatin state, down-regulation of AOR genes, and increased oxidative damages to lipids and DNA. Comparative gene expression analysis further revealed that aging brains display an up-regulation of the senescence-associated genes IL-6, p19(Arf and p16(Ink4a, along with the pro-apoptotic gene Noxa, as seen in Bmi1-null mice. Increasing Bmi1 expression in cortical neurons conferred robust protection against DNA damage-induced cell death or mitochondrial poisoning, and resulted in suppression of ROS through activation of AOR genes. These observations unveil that Bmi1 genetic deficiency recapitulates aspects of physiological brain aging and that Bmi1 over-expression is a potential therapeutic modality against neurodegeneration.

  3. miR-214 down-regulates ARL2 and suppresses growth and invasion of cervical cancer cells.

    Science.gov (United States)

    Peng, Ruiqing; Men, Jianlong; Ma, Rui; Wang, Qian; Wang, Yang; Sun, Ying; Ren, Jing

    2017-03-11

    Increasing evidence has shown that miRNAs are implicated in carcinogenesis and can function as oncogenes or tumor suppressor genes in human cancers. In this study, we confirmed that miR-214 is frequently down-regulated in cervical cancer compared with normal cervical tissues. Ectopic expression of miR-214 suppressed proliferation, migration and invasion of HeLa and C33A cervical cancer cells. Bioinformatics analysis revealed that ADP ribosylation factor like 2 (ARL2) was a potential target of miR-214 and was remarkably up-regulated in cervical cancer. Knockdown of ARL2 markedly inhibited cervical cancer cell proliferation, migration and invasion, similarly to over-expression of miR-214, indicating that ARL2 may function as an oncogene in cervical cancer. In conclusion, our study revealed that miR-214 acts as a tumor suppressor via inhibiting proliferation, migration and invasion of cervical cancer cells through targeting ARL2, and that both miR-214 and ARL2 may serve as prognostic or therapeutic targets for cervical cancer.

  4. Down-regulating causes of fibrosis with tamoxifen: a possible cellular/molecular approach to treat rhinophyma.

    Science.gov (United States)

    Payne, Wyatt G; Ko, Francis; Anspaugh, Stephanie; Wheeler, Chad K; Wright, Terry E; Robson, Martin C

    2006-03-01

    Fibrosis and proliferative scarring are prominent features of the severe forms of rhinophyma. Up-regulation of growth and fibroblast kinetics are hallmarks of fibrosis. Persistent overexpression or dysregulated activation of the fibrogenic isoforms of transforming growth factor beta (TGF-beta) is associated with the increased fibroblast function leading to fibrotic conditions such as rhinophyma. Tamoxifen, a synthetic nonsteroidal antiestrogen, can neutralize or down-regulate TGF-beta. Fibroblast-populated collagen lattices (FPCLs) were constructed from fibroblasts cultured from rhinophyma or normal nasal skin. One-half of each set of FPCLs was treated with Tamoxifen. Lattice contraction was serially measured over 5 days, and the supernatants of the cultures were analyzed for TGF-beta-2 by immunoassay. Tamoxifen significantly decreased fibroblast activity by decreasing contraction of the treated lattices (P < 0.05) and significantly decreased the production/secretion of TGF-beta-2 by rhinophyma fibroblasts (P < 0.001). These results suggest a possible new cellular/molecular approach to the treatment of the fibrotic varieties of rhinophyma.

  5. Propranolol inhibits angiogenesis via down-regulating the expression of vascular endothelial growth factor in hemangioma derived stem cell

    Science.gov (United States)

    Zhang, Ling; Mai, Hua-Ming; Zheng, Jing; Zheng, Jia-Wei; Wang, Yan-An; Qin, Zhong-Ping; Li, Ke-Lei

    2014-01-01

    Background: Oral propranolol (PRN) has recently been shown to be highly effective for infantile hemangiomas (IHs), and is currently recommended as the first-line treatment of complicated IHs. However, the therapeutic mechanism(s) still remain unclear. Methods: In this study, we tested hemangioma-derived stem cells for expression of vascular endothelial growth factor (VEGF) in vitro and studied the inhibition of VEGF expression. We used PCR, Elisa, Western blotting and immunohistochemistry in vivo and in vitro trial. Results: The study demonstrated that application of PRN at a “normal” concentration equivalent to plasma concentration did not inhibit proliferation or promote apoptosis of hemangioma derived stem cells (HemSCs) isolated from IH patients. PRN suppressed expression of vascular endothelial growth factor (VEGF) and basic Fibroblast Growth Factor (bFGF) in HemSCs in vitro. Morphological, histological and immunohistological improvement were observed in vivo using murine IH model in which HemSCs pre-treated with PRN were implanted into BALB/c-nu mice. In the pre-treated HemSC grafts, mean micro-vessel density (MVD) significantly decreased and protein levels of VEGF markedly decreased, while bFGF was still detectable. Conclusions: The results suggested PRN inhibited angiogenesis via down-regulating the expression of vascular endothelial growth factor in hemangioma derived stem cell. These findings provide critical insight into the potential mechanisms of PRN action on IH. PMID:24427325

  6. The reported clinical utility of taurine in ischemic disorders may reflect a down-regulation of neutrophil activation and adhesion.

    Science.gov (United States)

    McCarty, M F

    1999-10-01

    The first publications regarding clinical use of taurine were Italian reports claiming therapeutic efficacy in angina, intermittent claudication and symptomatic cerebral arteriosclerosis. A down-regulation of neutrophil activation and endothelial adhesion might plausibly account for these observations. Endothelial platelet-activating factor (PAF) is a crucial stimulus to neutrophil adhesion and activation, whereas endothelial nitric oxide (NO) suppresses PAF production and acts in various other ways to antagonize binding and activation of neutrophils. Hypochlorous acid (HOCl), a neutrophil product which avidly oxidizes many sulfhydryl-dependent proteins, can be expected to inhibit NO synthase while up-regulating PAF generation; thus, a vicious circle can be postulated whereby HOCl released by marginating neutrophils acts on capillary or venular endothelium to promote further neutrophil adhesion and activation. Taurine is the natural detoxicant of HOCl, and thus has the potential to intervene in this vicious circle, promoting a less adhesive endothelium and restraining excessive neutrophil activation. Agents which inhibit the action of PAF on neutrophils, such as ginkgolides and pentoxifylline, have documented utility in ischemic disorders and presumably would complement the efficacy of taurine in this regard. Fish oil, which inhibits endothelial expression of various adhesion factors and probably PAF as well, and which suppresses neutrophil leukotriene production, may likewise be useful in ischemia. These agents may additionally constitute a non-toxic strategy for treating inflammatory disorders in which activated neutrophils play a prominent pathogenic role. Double-blind studies to confirm the efficacy of taurine in symptomatic chronic ischemia are needed.

  7. An anti-inflammatory oligopeptide produced by Entamoeba histolytica down-regulates the expression of pro-inflammatory chemokines.

    Science.gov (United States)

    Utrera-Barillas, Dolores; Velazquez, Juan R; Enciso, Antonio; Cruz, Samira Muñoz; Rico, Guadalupe; Curiel-Quesada, Everardo; Teran, Luis M; Kretschmer, Roberto R

    2003-10-01

    Axenically grown Entamoeba histolytica produces a pentapeptide (Met-Gln-Cys-Asn-Ser) with anti-inflammatory properties that, among others, inhibits the in vitro and in vivo locomotion of human monocytes, sparing polymorphonuclear leucocytes from this effect [hence the name originally given. Monocyte Locomotion Inhibitory Factor (MLIF)]. A synthetic construct of this peptide displays the same effects as the native material. We now added MLIF to resting and PMA-stimulated cells of a human monocyte cell line and measured the effect upon mRNA and protein expression of pro-inflammatory chemokines (RANTES, IP-10, MIP-1alpha, MIP-1beta, MCP-1, IL-8, I-309 and lymphotactin) and the shared CC receptor repertoire. The constitutive expression of these chemokines and the CC receptors was unaffected, whereas induced expression of MIP-1alpha, MIP-1beta, and I-309, and that of the CCR1 receptor--all involved in monocyte chemotaxis--was significantly inhibited by MLIF. This suggests that the inhibition of monocyte functions by MLIF may not only be exerted directly on these cells, but also--and perhaps foremost--through a conglomerate down-regulation of endogenous pro-inflammatory chemokines.

  8. Down-regulation of NF-κB signaling by Gordonia bronchialis prevents the activation of gut epithelial cells.

    Science.gov (United States)

    Smaldini, Paola L; Stanford, John; Romanin, David E; Fossati, Carlos A; Docena, Guillermo H

    2014-08-01

    The immunomodulatory power of heat-killed Gordonia bronchialis was studied on gut epithelial cells activated with pro-inflammatory stimuli (flagellin, TNF-α or IL-1β). Light emission of luciferase-transfected epithelial cells and mRNA expression of IL-1β, TNF-α, IL-6, CCL20, IL-8 and MCP-1 were measured. NF-κB activation was assessed by immunofluorescence and immunoblotting, and induction of reactive oxygen species (ROS) was evaluated. In vivo inhibitory properties of G. bronchialis were studied with ligated intestinal loop assay and in a mouse model of food allergy. G. bronchialis promoted the down-regulation of the expression of CCL20 and IL-1β on activated epithelial cells in a dose-dependent manner. A concomitant blocking of nuclear p65 translocation with increased production of ROS was found. In vivo experiments confirmed the inhibition of CCL20 expression and the suppression of IgE sensitization and hypersensitivity symptoms in the food allergy mouse model. In conclusion, heat-killed G. bronchialis inhibited the activation of NF-κB pathway in human epithelial cells, and suppressed the expression of CCL20. These results indicate that G. bronchialis may be used to modulate the initial steps of innate immune activation, which further suppress the allergic sensitization. This approach may be exploited as a therapy for intestinal inflammation.

  9. A molecular toolbox for rapid generation of viral vectors to up- or down-regulate in vivo neuronal gene expression

    Directory of Open Access Journals (Sweden)

    Melanie D. White

    2011-07-01

    Full Text Available We introduce a molecular toolbox for manipulation of neuronal gene expression in vivo. The toolbox includes promoters, ion channels, optogenetic tools, fluorescent proteins and intronic artificial microRNAs. The components are easily assembled into adeno-associated virus (AAV or lentivirus vectors using recombination cloning. We demonstrate assembly of toolbox components into lentivirus and AAV vectors and use these vectors for in vivo expression of inwardly rectifying potassium channels (Kir2.1, Kir3.1 and Kir3.2 and an artificial microRNA targeted against the ion channel HCN1 (HCN1 miR. We show that AAV assembled to express HCN1 miR produces efficacious and specific in vivo knockdown of HCN1 channels. Comparison of in vivo viral transduction using HCN1 miR with mice containing a germ line deletion of HCN1 reveals similar physiological phenotypes in cerebellar Purkinje cells. The easy assembly and re-usability of the toolbox components, together with the ability to up- or down-regulate neuronal gene expression in vivo, may be useful for applications in many areas of neuroscience.

  10. The down-regulation of the genes encoding Isoamylase 1 alters the starch composition of the durum wheat grain.

    Science.gov (United States)

    Sestili, Francesco; Sparla, Francesca; Botticella, Ermelinda; Janni, Michela; D'Ovidio, Renato; Falini, Giuseppe; Marri, Lucia; Cuesta-Seijo, Jose A; Moscatello, Stefano; Battistelli, Alberto; Trost, Paolo; Lafiandra, Domenico

    2016-11-01

    In rice, maize and barley, the lack of Isoamylase 1 activity materially affects the composition of endosperm starch. Here, the effect of this deficiency in durum wheat has been characterized, using transgenic lines in which Isa1 was knocked down via RNAi. Transcriptional profiling confirmed the partial down-regulation of Isa1 and revealed a pleiotropic effect on the level of transcription of genes encoding other isoamylases, pullulanase and sucrose synthase. The polysaccharide content of the transgenic endosperms was different from that of the wild type in a number of ways, including a reduction in the content of starch and a moderate enhancement of both phytoglycogen and β-glucan. Some alterations were also induced in the distribution of amylopectin chain length and amylopectin fine structure. The amylopectin present in the transgenic endosperms was more readily hydrolyzable after a treatment with hydrochloric acid, which disrupted its semi-crystalline structure. The conclusion was that in durum wheat, Isoamylase 1 is important for both the synthesis of amylopectin and for determining its internal structure. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  11. Perception adapts via top-down regulation to task repetition: A Lotka-Volterra-Haken modeling analysis of experimental data.

    Science.gov (United States)

    Frank, T D

    2016-03-01

    Two experiments are reported in which participants perceived different physical quantities: size and speed. The perceptual tasks were performed in the context of motor performance problems. Participants perceived the size of objects in order to grasp the objects single handed or with both hands. Likewise, participants perceived the speed of a moving treadmill in order to control walking or running at that speed. In both experiments, the perceptual tasks were repeatedly performed by the participants while the to-be-perceived quantity was gradually varied from small to large objects (Experiment 1) and from low to high speeds (Experiment 2). Hysteresis with negative sign was found when participants were not allowed to execute the motor component, that is, when the execution stage was decoupled from the planning stage. No such effect was found in the control condition, when participants were allowed to execute the motor action. Using a Lotka-Volterra-Haken model for two competing neural populations, it is argued that the observations are consistent with the notion that the repetitions induce an adaptation effect of the perceptual system via top-down regulation. Moreover, the amount of synaptic modulation involved in the adaptation is estimated from participant data.

  12. Silibinin induced the apoptosis of Hep-2 cells via oxidative stress and down-regulating survivin expression.

    Science.gov (United States)

    Yang, Xinxin; Li, Xiaoyu; An, Liangxiang; Bai, Bo; Chen, Jing

    2013-08-01

    Silibinin is an anticancer and chemopreventive natural compound, which is extracted from milk thistle (Silybum marianum). It is reported that silibinin has anticancer efficacy in many malignant tumors. Laryngeal carcinoma is the second most common head and neck squamous carcinoma. In the present work, we investigated the effects of silibinin on laryngeal squamous cell carcinoma (LSCC) cell line Hep-2 cells. We found that silibinin induced the decrease of cell viability in Hep-2 cells with a concentration- and time-dependent manner. Moreover, silibinin resulted in the apoptosis of Hep-2 cells and had synergy effects with arsenic trioxide. Intracellular reactive oxygen species (ROS) accumulation increased because of silibinin exposure. ROS scavenger NAC alleviated the cytotoxicity of silibinin to Hep-2 cells. The mitochondrial membrane potential (MMP) was lost in Hep-2 cells treated with silibinin. Subsequently, silibinin induced the activation of caspase-3 in Hep-2 cells and caspase inhibitor Z-VAD-FMK inhibited the cytotoxicity of silibinin in Hep-2 cells. The survivin expression decreased after Hep-2 cells were treated with silibinin. In conclusion, silibinin induced the apoptosis of Hep-2 cells via oxidative stress and down-regulating survivin expression. Therefore, silibinin is a potential therapeutical agent against LSCC in future.

  13. Down-regulation of miR-133a as a poor prognosticator in non-small cell lung cancer.

    Science.gov (United States)

    Wang, Yuzhou; Li, Jinmei; Chen, Hongming; Mo, Yanli; Ye, Haiyin; Luo, Yiping; Guo, Kangwen; Mai, Zongjiong; Zhang, Ying; Chen, Baoying; Zhou, Yijin; Yang, Zhixiong

    2016-10-15

    miR-133a has been demonstrated to play an important role in tumor progression. The aim of present study was to analyze the correlation between miR-133a expression level and clinicopathologic features and its prognostic significance in non-small cell lung cancer (NSCLC). The expression of miR-133a in 104 pairs of human lung cancer tissues and adjacent normal lung tissues were analyzed by qRT-PCR. Here we show that miR-133a was down-regulated in NSCLC. The levels of miR-133a were negatively correlated with the status of N classification (N0-N1 vs. N2-N3, P=0.000), clinical stage (I-II vs. III-IV, P=0.010) and MMP-14 expression (High vs. Low, P=0.012). The patients with low miR-133a expression had shorter survival time than those with high miR-133a expression. Multivariate analysis indicated that the level of miR-133a expression was an independent prognostic indicator (P=0.012) for the survival of patients with NSCLC. In conclusion, decreased expression of miR-133a might be a potential unfavorable prognostic factor for patients with NSCLC, and further studies would be needed to prove our findings.

  14. Kefir inhibits 3T3-L1 adipocyte differentiation through down-regulation of adipogenic transcription factor expression.

    Science.gov (United States)

    Ho, Jin-Nyoung; Choi, Jae-Woo; Lim, Won-Chul; Kim, Mi-Kyoung; Lee, In-Young; Cho, Hong-Yon

    2013-02-01

    Kefir, a traditional fermented milk composed of microbial symbionts, is reported to have various health benefits such as anti-tumour, anti-inflammatory, anti-neoplastic and pro-digestive effects. In this study, to elucidate the effects of kefir on adipocyte differentiation and lipid accumulation, three fractions were prepared from kefir culture broth. The inhibitory effects of kefir liquid culture broth fraction (Fr-1), soluble fraction (Fr-2) and insoluble fraction (Fr-3), prepared by sonication of kefir solid culture broth, on adipocyte differentiation in 3T3-L1 preadipocytes were examined. Fr-3 (0.1 mg mL(-1)) significantly decreased lipid accumulation and glycerol-3-phosphate dehydrogenase (GPDH) activity by 60 and 68% respectively without affecting cell viability. In addition, Fr-3 treatment down-regulated the mRNA expression of adipogenic transcription factors including C/EBPα (32%), PPARγ (46%) and SREBP-1c (34%) during adipocyte differentiation compared with untreated control cells. The mRNA expression of adipocyte-specific genes (aP2, FAS and ACC) was also clearly decreased. The results suggest that the insoluble fraction of kefir (Fr-3) mediates anti-adipogenic effects through the inhibition of adipocyte differentiation, partly via suppression of the C/EBPα-, SREBP-1c- and PPARγ-dependent pathways. Copyright © 2012 Society of Chemical Industry.

  15. Down-regulation of the Caffeic acid O-methyltransferase Gene in Switchgrass Reveals a Novel Monolignol Analog

    Energy Technology Data Exchange (ETDEWEB)

    Tschaplinski, Timothy J [ORNL; Standaert, Robert F [ORNL; Engle, Nancy L [ORNL; Martin, Madhavi Z [ORNL; Sangha, Amandeep K [ORNL; Parks, Jerry M [ORNL; Smith, Jeremy C [ORNL; Samuel, Reichel [ORNL; Pu, Yunqiao [ORNL; Ragauskas, A J [Georgia Institute of Technology; Hamilton, Choo Yieng [ORNL; Fu, Chunxiang [Noble Foundation; Wang, Zeng-Yu [Noble Foundation; Davison, Brian H [ORNL; Dixon, Richard A [Noble Foundation; Mielenz, Jonathan R [ORNL

    2012-01-01

    Down-regulation of the caffeic acid 3-O-methyltransferase (COMT) gene in the lignin biosynthetic pathway of switchgrass (Panicum virgatum) resulted in cell walls of transgenic plants releasing more constituent sugars after pretreatment by dilute acid and treatment with glycosyl hydrolases from an added enzyme preparation and from Clostridium thermocellum. Fermentation of both wild-type and transgenic switchgrass after milder hot water pretreatment with no water washing showed that only the transgenic switchgrass inhibited C. thermocellum. Gas chromatography-mass spectrometry-based metabolomics were undertaken on cell wall aqueous extracts to determine the nature of the microbial inhibitors, confirming the increased concentration of a number of phenolic acids and aldehydes that are known inhibitors of fermentation. Metabolomic analyses of the transgenic biomass additionally revealed the presence of a novel monolignol-like metabolite, identified as trans-3, 4-dimethoxy-5-hydroxycinnamyl alcohol (iso-sinapyl alcohol) in both non-pretreated, as well as hot water pretreated samples. Although there was no indication that iso-sinapyl alcohol was integrated into the cell wall, diversion of substrates from sinapyl alcohol to free iso-sinapyl alcohol, its glucoside, and associated upstream lignin pathway changes, including increased phenolic aldehydes and acids, are associated with more facile cell wall deconstruction, and to the observed inhibitory effect on microbial growth.

  16. Moderate Hypoxia Down-Regulates Interleukin-6 Secretion and TLR4 Expression in Human Sw.71 Placental Cells

    Directory of Open Access Journals (Sweden)

    Koumei Shirasuna

    2015-07-01

    Full Text Available Background/Aims: The placenta is a vital organ for pregnancy. Many in vitro placental experiments are conducted under 21% O2; however, O2 tension could influence cellular functions, including cytokine secretion. We investigated the effects of oxygen tension between moderate hypoxia (5% O2 and normoxia (21% O2 by testing the hypothesis that moderate hypoxia regulates cellular phenotypes differently from normoxia in human trophoblast cells. Methods and Results: Sw.71 trophoblast cells were incubated under normoxic or moderately hypoxic conditions. Cells were also treated with lipopolysaccharide (LPS as a Toll-like receptor 4 (TLR4 ligand inducing inflammation. Interleukin-6 (IL-6 as an inflammatory cytokine was determined, and TLR4, hypoxia-induced factor-1α (HIF1α, and reactive oxygen species (ROS production were detected. Moderate hypoxia increased HIF1α expression and cell proliferation and acted by two different mechanisms to decrease IL-6 secretion compared with normoxia: it limits the TLR4 expression and ROS production. Treatment with cobalt chloride as an HIF1 activator inhibited IL-6 secretion and TLR4 expression; this effect was reversed on treatment with PX-12 as an HIF1 suppressor. Conclusion: IL-6 secretion, TLR4 expression, and ROS production, classical markers of inflammation, are down-regulated by moderate hypoxia, and HIF1α and ROS have a potential to regulate these responses in human trophoblast cells.

  17. Blocking transforming growth factor- receptor signaling down-regulates transforming growth factor-β1 autoproduction in keloid fibroblasts

    Institute of Scientific and Technical Information of China (English)

    刘伟; 蔡泽浩; 王丹茹; 武小莉; 崔磊; 商庆新; 钱云良; 曹谊林

    2002-01-01

    Objective: To study transforming growth factor-β1(TGF-β1) autoproduction in keloid fibroblasts and theregulation effect of blocking TGF-β intracellular signalingon rhTGF-β1 autoproduction.Methods: Keloid fibroblasts cultured in vitro weretreated with either rhTGF-β1 (5 ng/ml ) or recombinantadenovirus containing a truncated type II TGF-β receptorgene (50 pfu/cell ). Their effects of regulating geneexpression of TGF-β1 and its receptor I and II wereobserved with Northern blot.Results: rhTGF-β1 up-regulated the gene expressionof TGF-β1 and receptor I, but not receptor II. Over-expression of the truncated receptor II down-regulated thegene expression of TGF-β1 and its receptor I, but notreceptor II.Conclusions: TGF-β1 autoproduction was observed inkeloid fibroblasts. Over-expression of the truncated TGF-βreceptor H decreased TGF-β1 autoproduction via blockingTGF-β receptor signaling.

  18. VEGFR3 Inhibition Chemosensitizes Ovarian Cancer Stemlike Cells through Down-Regulation of BRCA1 and BRCA2

    Directory of Open Access Journals (Sweden)

    Jaeyoung Lim

    2014-04-01

    Full Text Available In ovarian cancer, loss of BRCA gene expression in tumors is associated with improved response to chemotherapy and increased survival. A means to pharmacologically downregulate BRCA gene expression could improve the outcomes of patients with BRCA wild-type tumors. We report that vascular endothelial growth factor receptor 3 (VEGFR3 inhibition in ovarian cancer cells is associated with decreased levels of both BRCA1 and BRCA2. Inhibition of VEGFR3 in ovarian tumor cells was associated with growth arrest. CD133+ ovarian cancer stemlike cells were preferentially susceptible to VEGFR3-mediated growth inhibition. VEGFR3 inhibition–mediated down-regulation of BRCA gene expression reversed chemotherapy resistance and restored chemosensitivity in resistant cell lines in which a BRCA2 mutation had reverted to wild type. Finally, we demonstrate that tumor-associated macrophages are a primary source of VEGF-C in the tumor microenvironment. Our studies suggest that VEGFR3 inhibition may be a pharmacologic means to downregulate BRCA genes and improve the outcomes of patients with BRCA wild-type tumors.

  19. Cryptococcus neoformans activates bone marrow-derived conventional dendritic cells rather than plasmacytoid dendritic cells and down-regulates macrophages.

    Science.gov (United States)

    Siegemund, Sabine; Alber, Gottfried

    2008-04-01

    Induction of IL-12 and IL-23 is essential for protective immunity against Cryptococcusneoformans. The contribution of dendritic cells vs. macrophages to IL-12/23 production in response to C. neoformans infection is unclear. Activation of conventional bone marrow-derived dendritic cells (BMDC), plasmacytoid BMDC, and bone marrow-derived macrophages (BMMPhi) was assessed by analyzing cytokine responses and the expression of MHC-II, CD86, and CD80 in each cell type. Cryptococcus neoformans induced the release of IL-12/23p40 by BMDC, but not by BMMPhi, in a TLR2- and TLR4-independent but MyD88-dependent manner. Conventional BMDC rather than plasmacytoid BMDC up-regulated MHC-II and CD86, while BMMPhi down-regulated MHC-II and CD86 in response to C. neoformans. The up-regulation of MHC-II and CD86 on BMDC required MyD88. Our data point to conventional DC as critical IL-12/23-producing antigen-presenting cells during cryptococcosis.

  20. Down regulation of TRAIL and FasL on NK cells by Cyclosporin A in renal transplantation patients.

    Science.gov (United States)

    Zhang, Yun; Cheng, Guang; Xu, Zhu-Wei; Li, Zhou-Li; Song, Chao-Jun; Li, Qi; Chen, Li-Hua; Yang, Kun; Yang, An-Gang; Jin, Bo-Quan

    2013-04-01

    TNF-related apoptosis-inducing ligand (TRAIL) and FasL can participate in cell mediated cytotoxicity via their death domain-mediated apoptotic signaling in the host-versus-graft disease occurred after renal transplantation. However, the effect of Cyclosporin A (CsA) commonly used as a drug to prevent and to treat renal transplant rejection, on these molecules have not been fully determined. In the present study, we found that with CsA administration, the expression of TRAIL and FasL predominantly on NK cells from renal transplantation patients was increased at day 5 after operation and went down to normal level on day 13. While, the levels of soluble TRAIL (sTRAIL) and sFasL in the serum increased within 25 days and went down to normal level three month later. In addition, we showed that a remarkable increase of TRAIL and FasL expression both on the surface of activated lymphocytes especially on NK cells and in the supernatants generated from mixed lymphocytes culture (MLC). Furthermore, the enhancement of these two molecules was greatly decreased by adding 500 ng/mL CsA at the beginning of MLC. We conclude that CsA may inhibit the transplant rejection partially by down-regulating the expression of TRAIL and FasL on NK cells. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. KCNK5 is Functionally Down-Regulated Upon Long-Term Hypotonicity in Ehrlich Ascites Tumor Cells

    DEFF Research Database (Denmark)

    Kirkegaard, S. S.; Wulff, Tune; Gammeltoft, S.;

    2013-01-01

    Background/Aims: Regulatory volume decrease (RVD) in response to acute cell swelling is well described and KCNK5 (also known as TASK-2 or K2P5.1) has been shown to be the volume sensitive K+ channel in Ehrlich cells. Very little is, on the other hand, known about the effects of long-term hypotoni......Background/Aims: Regulatory volume decrease (RVD) in response to acute cell swelling is well described and KCNK5 (also known as TASK-2 or K2P5.1) has been shown to be the volume sensitive K+ channel in Ehrlich cells. Very little is, on the other hand, known about the effects of long......-term hypotonicity on expression and function of KCNK5, thus we have investigated the effect of long-term hypotonicity (24h - 48h) on KCNK5 in Ehrlich cells on the mRNA, protein and physiological levels. Methods: Physiological effects of long-term hypotonicity were measured using patch-clamp and Coulter counter...... physiological impairment of KCNK5 in Ehrlich cells after long-term hypotonic stimulation is predominantly due to down-regulation of the KCNK5 protein synthesis.© 2013 S. Karger AG, Basel...

  2. Down-regulation of Fusarium oxysporum endogenous genes by Host-Delivered RNA interference enhances disease resistance

    Directory of Open Access Journals (Sweden)

    Zongli eHu

    2015-01-01

    Full Text Available Fusarium oxysporum is a devastating pathogen causing extensive yield losses in a variety of crops and development of sustainable, environmentally friendly methods to improve crop resistance is crucial. We have used Host-Derived RNA interference (HD-RNAi technology to partially silence three different genes (FOW2, FRP1 and OPR in the hemi-biotrophic fungus Fusarium oxysporum f. sp. conglutinans. Expression of double stranded RNA molecules targeting fungal pathogen genes was achieved in a number of transgenic Arabidopsis lines. F. oxysporum infecting the transgenic lines displayed substantially reduced mRNA levels on all three targeted genes, with an average of 75%, 83% and 72% reduction for FOW2, FRP1 and OPR respectively. The silencing of pathogen genes had a clear positive effect on the ability of the transgenic lines to fight infection. All transgenic lines displayed enhanced resistance to F. oxysporum with delayed disease symptom development, especially FRP1 and OPR lines. Survival rates after fungal infection were higher in the transgenic lines compared to control wild type plants which consistently showed survival rates of 10%, with FOW2 lines showing 25% survival; FRP1 lines 30-50% survival and FOW2 between 45-70% survival. The down-regulation effect was specific for the targeted genes without unintended effects in related genes. In addition to producing resistant crops, HD-RNAi can provide a useful tool to rapidly screen candidate fungal pathogenicity genes without the need to produce fungal knockout mutants.

  3. eEF-2 Phosphorylation Down-Regulates P-Glycoprotein Over-Expression in Rat Brain Microvessel Endothelial Cells.

    Directory of Open Access Journals (Sweden)

    Xing Hua Tang

    Full Text Available We investigated whether glutamate, NMDA receptors, and eukaryote elongation factor-2 kinase (eEF-2K/eEF-2 regulate P-glycoprotein expression, and the effects of the eEF-2K inhibitor NH125 on the expression of P-glycoprotein in rat brain microvessel endothelial cells (RBMECs.Cortex was obtained from newborn Wistar rat brains. After surface vessels and meninges were removed, the pellet containing microvessels was resuspended and incubated at 37°C in culture medium. Cell viability was assessed by the MTT assay. RBMECs were identified by immunohistochemistry with anti-vWF. P-glycoprotein, phospho-eEF-2, and eEF-2 expression were determined by western blot analysis. Mdr1a gene expression was analyzed by RT-PCR.Mdr1a mRNA, P-glycoprotein and phospho-eEF-2 expression increased in L-glutamate stimulated RBMECs. P-glycoprotein and phospho-eEF-2 expression were down-regulated after NH125 treatment in L-glutamate stimulated RBMECs.eEF-2K/eEF-2 should have played an important role in the regulation of P-glycoprotein expression in RBMECs. eEF-2K inhibitor NH125 could serve as an efficacious anti-multidrug resistant agent.

  4. Overexpressed ubiquitin ligase Cullin7 in breast cancer promotes cell proliferation and invasion via down-regulating p53

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Hongsheng [Department of Histology and Embryology, Guangdong Medical College, Dongguan 523808, Guangdong (China); Wu, Fenping [The 7th People’s Hospital of Chengdu, Chengdu 610041, Sichuan (China); Wang, Yan [The Second School of Clinical Medicine, Guangdong Medical College, Dongguan 523808, Guangdong (China); Yan, Chong [School of Pharmacy, Guangdong Medical College, Dongguan 523808, Guangdong (China); Su, Wenmei, E-mail: wenmeisutg@126.com [Oncology of Affiliated Hospital Guangdong Medical College, Zhanjiang 524000, Guangdong (China)

    2014-08-08

    Highlights: • Cullin7 is overexpressed in human breast cancer samples. • Cullin7 stimulated proliferation and invasion of breast cancer cells. • Inhibition of p53 contributes to Cullin7-induced proliferation and invasion. - Abstract: Ubiquitin ligase Cullin7 has been identified as an oncogene in some malignant diseases such as choriocarcinoma and neuroblastoma. However, the role of Cullin7 in breast cancer carcinogenesis remains unclear. In this study, we compared Cullin7 protein levels in breast cancer tissues with normal breast tissues and identified significantly higher expression of Cullin7 protein in breast cancer specimens. By overexpressing Cullin7 in breast cancer cells HCC1937, we found that Cullin7 could promote cell growth and invasion in vitro. In contrast, the cell growth and invasion was inhibited by silencing Cullin7 in breast cancer cell BT474. Moreover, we demonstrated that Cullin7 promoted breast cancer cell proliferation and invasion via down-regulating p53 expression. Thus, our study provided evidence that Cullin7 functions as a novel oncogene in breast cancer and may be a potential therapeutic target for breast cancer management.

  5. Cisplatin and ultra-violet-C synergistically down-regulate receptor tyrosine kinases in human colorectal cancer cells

    Directory of Open Access Journals (Sweden)

    Kawaguchi Junji

    2012-07-01

    Full Text Available Abstract Background Platinum-containing anti-cancer drugs such as cisplatin are widely used for patients with various types of cancers, however, resistance to cisplatin is observed in some cases. Whereas we have recently reported that high dose UV-C (200 J/m² induces colorectal cancer cell proliferation by desensitization of EGFR, which leads oncogenic signaling in these cells, in this study we investigated the combination effect of low dose cisplatin (10 μM and low dose UV-C (10 J/m² on cell growth and apoptosis in several human colorectal cancer cells, SW480, DLD-1, HT29 and HCT116. Results The combination inhibited cell cycle and colony formation, while either cisplatin or UV-C alone had little effect. The combination also induced apoptosis in these cells. In addition, the combination caused the downregulation of EGFR and HER2. Moreover, UV-C alone caused the transient internalization of the EGFR, but with time EGFR recycled back to the cell surface, while cisplatin did not affect its localization. Surprisingly, the combination caused persistent internalization of the EGFR, which results in the lasting downregulation of the EGFR. Conclusions The combination of low dose cisplatin and low dose UV-C synergistically exerted anti-cancer effect by down-regulating RTK, such as EGFR and HER2. These findings may provide a novel strategy for the treatment of patients with colorectal cancer.

  6. Andrographolide could inhibit human colorectal carcinoma Lovo cells migration and invasion via down-regulation of MMP-7 expression.

    Science.gov (United States)

    Shi, Ming-Der; Lin, Hui-Hsuan; Chiang, Tai-An; Tsai, Li-Yu; Tsai, Shu-Mei; Lee, Yi-Chieh; Chen, Jing-Hsien

    2009-08-14

    Andrographolide (Andro), a diterpenoid lactone isolated from a traditional herbal medicine Andrographis paniculata, is known to possess multiple pharmacological activities. In our previous study, Andro had been shown to have potent anti-cancer activity against human colorectal carcinoma Lovo cells by inhibiting cell-cycle progression. To further investigate the mechanism for the anti-cancer properties of Andro, it was used to examine the effect on migration and invasion of Lovo cells. The results of wound-healing assay and in vitro transwell assay revealed that Andro inhibited dose-dependently the migration and invasion of Lovo cells under non-cytotoxic concentrations. Using zymographic assay and RT-PCR, the results revealed that Andro diminished the activity and the mRNA and protein levels of MMP-7, but not MMP-2 or MMP-9. The down-regulation of MMP-7 appeared to be via the inactivation of activator protein-1 (AP-1) since the treatment with Andro suppressed the nuclear protein level of AP-1, which was accompanied by a decrease in DNA-binding level of the factor. Taken together, these results indicated that Andro reduces the MMP-7-mediated cellular events in Lovo cells, and provided a new mechanism for its anti-cancer activity.

  7. Down-regulation of MHC Class I by the Marek's Disease Virus (MDV) UL49.5 Gene Product Mildly Affects Virulence in a Haplotype-specific Fashion

    Science.gov (United States)

    Marek’s disease is a devastating neoplastic disease of chickens caused by gallid herpesvirus 2 or Marek’s disease virus (MDV), which is characterized by massive visceral tumors, immune suppression, neurologic syndromes, and peracute deaths. It has been reported that MDV down-regulates surface expre...

  8. Expression of Fragaria vesca PIP aquaporins in response to drought stress: PIP down-regulation correlates with the decline in substrate moisture content.

    Science.gov (United States)

    Šurbanovski, Nada; Sargent, Daniel J; Else, Mark A; Simpson, David W; Zhang, Hanma; Grant, Olga M

    2013-01-01

    PIP aquaporin responses to drought stress can vary considerably depending on the isoform, tissue, species or level of stress; however, a general down-regulation of these genes is thought to help reduce water loss and prevent backflow of water to the drying soil. It has been suggested therefore, that it may be necessary for the plant to limit aquaporin production during drought stress, but it is unknown whether aquaporin down-regulation is gradual or triggered by a particular intensity of the stress. In this study, ten Fragaria PIP genes were identified from the woodland strawberry (Fragaria vesca L.) genome sequence and characterised at the sequence level. The water relations of F. vesca were investigated and the effect of different intensities of drought stress on the expression of four PIP genes, as well as how drought stress influences their diurnal transcription was determined. PIP down-regulation in the root corresponded to the level of drought stress. Moreover, transcript abundance of two genes highly expressed in the root (FvPIP1;1 and FvPIP2;1) was strongly correlated to the decline in substrate moisture content. The amplitude of diurnal aquaporin expression in the leaves was down-regulated by drought without altering the pattern, but showing an intensity-dependent effect. The results show that transcription of PIP aquaporins can be fine-tuned with the environment in response to declining water availability.

  9. Expression of Fragaria vesca PIP aquaporins in response to drought stress: PIP down-regulation correlates with the decline in substrate moisture content.

    Directory of Open Access Journals (Sweden)

    Nada Šurbanovski

    Full Text Available PIP aquaporin responses to drought stress can vary considerably depending on the isoform, tissue, species or level of stress; however, a general down-regulation of these genes is thought to help reduce water loss and prevent backflow of water to the drying soil. It has been suggested therefore, that it may be necessary for the plant to limit aquaporin production during drought stress, but it is unknown whether aquaporin down-regulation is gradual or triggered by a particular intensity of the stress. In this study, ten Fragaria PIP genes were identified from the woodland strawberry (Fragaria vesca L. genome sequence and characterised at the sequence level. The water relations of F. vesca were investigated and the effect of different intensities of drought stress on the expression of four PIP genes, as well as how drought stress influences their diurnal transcription was determined. PIP down-regulation in the root corresponded to the level of drought stress. Moreover, transcript abundance of two genes highly expressed in the root (FvPIP1;1 and FvPIP2;1 was strongly correlated to the decline in substrate moisture content. The amplitude of diurnal aquaporin expression in the leaves was down-regulated by drought without altering the pattern, but showing an intensity-dependent effect. The results show that transcription of PIP aquaporins can be fine-tuned with the environment in response to declining water availability.

  10. The CD3 gamma leucine-based receptor-sorting motif is required for efficient ligand-mediated TCR down-regulation

    DEFF Research Database (Denmark)

    von Essen, Marina; Menné, Charlotte; Nielsen, Bodil L

    2002-01-01

    that ligand- and PKC-induced TCR down-regulations are not interrelated. By analyses of a newly developed CD3 gamma-negative T cell variant, freshly isolated and PHA-activated PBMC, and a mouse T cell line, we challenged this dogma and demonstrate in this work that PKC activation and the CD3 gamma di...

  11. CD4+ NKG2D+ T cells induce NKG2D down-regulation in natural killer cells in CD86-RAE-1ε transgenic mice

    Science.gov (United States)

    Lin, Zhijie; Wang, Changrong; Xia, Haizui; Liu, Weiguang; Xiao, Weiming; Qian, Li; Jia, Xiaoqin; Ding, Yanbing; Ji, Mingchun; Gong, Weijuan

    2014-01-01

    The binding of NKG2D to its ligands strengthens the cross-talk between natural killer (NK) cells and dendritic cells, particularly at early stages, before the initiation of the adaptive immune response. We found that retinoic acid early transcript-1ε (RAE-1ε), one of the ligands of NKG2D, was persistently expressed on antigen-presenting cells in a transgenic mouse model (pCD86-RAE-1ε). By contrast, NKG2D expression on NK cells, NKG2D-dependent cytotoxicity and tumour rejection, and dextran sodium sulphate-induced colitis were all down-regulated in this mouse model. The down-regulation of NKG2D on NK cells was reversed by stimulation with poly (I:C). The ectopic expression of RAE-1ε on dendritic cells maintained NKG2D expression levels and stimulated the activity of NK cells ex vivo, but the higher frequency of CD4+ NKG2D+ T cells in transgenic mice led to the down-regulation of NKG2D on NK cells in vivo. Hence, high levels of RAE-1ε expression on antigen-presenting cells would be expected to induce the down-regulation of NK cell activation by a regulatory T-cell subset. PMID:24708417

  12. CD4(+) NKG2D(+) T cells induce NKG2D down-regulation in natural killer cells in CD86-RAE-1ε transgenic mice.

    Science.gov (United States)

    Lin, Zhijie; Wang, Changrong; Xia, Haizui; Liu, Weiguang; Xiao, Weiming; Qian, Li; Jia, Xiaoqin; Ding, Yanbing; Ji, Mingchun; Gong, Weijuan

    2014-03-01

    The binding of NKG2D to its ligands strengthens the cross-talk between natural killer (NK) cells and dendritic cells, particularly at early stages, before the initiation of the adaptive immune response. We found that retinoic acid early transcript-1ε (RAE-1ε), one of the ligands of NKG2D, was persistently expressed on antigen-presenting cells in a transgenic mouse model (pCD86-RAE-1ε). By contrast, NKG2D expression on NK cells, NKG2D-dependent cytotoxicity and tumour rejection, and dextran sodium sulphate-induced colitis were all down-regulated in this mouse model. The down-regulation of NKG2D on NK cells was reversed by stimulation with poly (I:C). The ectopic expression of RAE-1ε on dendritic cells maintained NKG2D expression levels and stimulated the activity of NK cells ex vivo, but the higher frequency of CD4(+) NKG2D(+) T cells in transgenic mice led to the down-regulation of NKG2D on NK cells in vivo. Hence, high levels of RAE-1ε expression on antigen-presenting cells would be expected to induce the down-regulation of NK cell activation by a regulatory T-cell subset. © 2013 John Wiley & Sons Ltd.

  13. Down-regulation of the strawberry Bet v 1-homologous allergen in concert with the flavonoid biosynthesis pathway in colorless strawberry mutant

    DEFF Research Database (Denmark)

    Hjernø, Karin; Alm, Rikard; Canbäck, Björn

    2006-01-01

    strawberries, known to be tolerated by individuals affected by allergy, were found to be virtually free from the strawberry allergen. Also several enzymes in the pathway for biosynthesis of flavonoids, to which the red color pelargonidin belongs, were down-regulated. This approach to assess differential...

  14. DOWN-REGULATION OF THE HYPOTHALAMO-PITUITARY-ADRENAL AXIS REDUCES BRAIN-DAMAGE AND NUMBER OF SEIZURES FOLLOWING HYPOXIA/ISCHAEMIA IN RATS

    NARCIS (Netherlands)

    KRUGERS, HJ; KNOLLEMA, S; KEMPER, RHA; TERHORST, GJ; KORF, J

    1995-01-01

    Several reports suggest that the activity of the hypothalamo-pituitary-adrenal axis (HPA-axis) is increased following hypoxia/ischaemia and that this might be associated with increased neuronal vulnerability. The main goal of this study was to examine the effects of down-regulation of the HPA-axis

  15. Combined down-regulation by aromatase inhibitor and GnRH-agonist in IVF patients with endometriomas-A pilot study

    DEFF Research Database (Denmark)

    Løssl, Kristine; Loft, Anne; Freiesleben, Nina L C

    2009-01-01

    . The aim of this study was to test the concept of combined down-regulation prior to IVF in patients with endometriomas. STUDY DESIGN: Prospective pilot study in a university-based tertiary fertility clinic including 20 infertile patients with endometriomas undergoing IVF/ICSI. The patients received...

  16. AKAP150 participates in calcineurin/NFAT activation during the down-regulation of voltage-gated K(+) currents in ventricular myocytes following myocardial infarction.

    Science.gov (United States)

    Nieves-Cintrón, Madeline; Hirenallur-Shanthappa, Dinesh; Nygren, Patrick J; Hinke, Simon A; Dell'Acqua, Mark L; Langeberg, Lorene K; Navedo, Manuel; Santana, Luis F; Scott, John D

    2016-07-01

    The Ca(2+)-responsive phosphatase calcineurin/protein phosphatase 2B dephosphorylates the transcription factor NFATc3. In the myocardium activation of NFATc3 down-regulates the expression of voltage-gated K(+) (Kv) channels after myocardial infarction (MI). This prolongs action potential duration and increases the probability of arrhythmias. Although recent studies infer that calcineurin is activated by local and transient Ca(2+) signals the molecular mechanism that underlies the process is unclear in ventricular myocytes. Here we test the hypothesis that sequestering of calcineurin to the sarcolemma of ventricular myocytes by the anchoring protein AKAP150 is required for acute activation of NFATc3 and the concomitant down-regulation of Kv channels following MI. Biochemical and cell based measurements resolve that approximately 0.2% of the total calcineurin activity in cardiomyocytes is associated with AKAP150. Electrophysiological analyses establish that formation of this AKAP150-calcineurin signaling dyad is essential for the activation of the phosphatase and the subsequent down-regulation of Kv channel currents following MI. Thus AKAP150-mediated targeting of calcineurin to sarcolemmal micro-domains in ventricular myocytes contributes to the local and acute gene remodeling events that lead to the down-regulation of Kv currents.

  17. Metformin suppresses CYP1A1 and CYP1B1 expression in breast cancer cells by down-regulating aryl hydrocarbon receptor expression

    Energy Technology Data Exchange (ETDEWEB)

    Do, Minh Truong; Kim, Hyung Gyun; Tran, Thi Thu Phuong; Khanal, Tilak; Choi, Jae Ho [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon (Korea, Republic of); Chung, Young Chul [Department of Food Science and Culinary, International University of Korea, Jinju (Korea, Republic of); Jeong, Tae Cheon, E-mail: taecheon@ynu.ac.kr [College of Pharmacy, Yeungnam University, Gyeongsan (Korea, Republic of); Jeong, Hye Gwang, E-mail: hgjeong@cnu.ac.kr [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon (Korea, Republic of)

    2014-10-01

    Induction of cytochrome P450 (CYP) 1A1 and CYP1B1 by environmental xenobiotic chemicals or endogenous ligands through the activation of the aryl hydrocarbon receptor (AhR) has been implicated in a variety of cellular processes related to cancer, such as transformation and tumorigenesis. Here, we investigated the effects of the anti-diabetes drug metformin on expression of CYP1A1 and CYP1B1 in breast cancer cells under constitutive and inducible conditions. Our results indicated that metformin down-regulated the expression of CYP1A1 and CYP1B1 in breast cancer cells under constitutive and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced conditions. Down-regulation of AhR expression was required for metformin-mediated decreases in CYP1A1 and CYP1B1 expression, and the metformin-mediated CYP1A1 and CYP1B1 reduction is irrelevant to estrogen receptor α (ERα) signaling. Furthermore, we found that metformin markedly down-regulated Sp1 protein levels in breast cancer cells. The use of genetic and pharmacological tools revealed that metformin-mediated down-regulation of AhR expression was mediated through the reduction of Sp1 protein. Metformin inhibited endogenous AhR ligand-induced CYP1A1 and CYP1B1 expression by suppressing tryptophan-2,3-dioxygenase (TDO) expression in MCF-7 cells. Finally, metformin inhibits TDO expression through a down-regulation of Sp1 and glucocorticoid receptor (GR) protein levels. Our findings demonstrate that metformin reduces CYP1A1 and CYP1B1 expression in breast cancer cells by down-regulating AhR signaling. Metformin would be able to act as a potential chemopreventive agent against CYP1A1 and CYP1B1-mediated carcinogenesis and development of cancer. - Graphical abstract: Schematic of the CYP1A1 and CYP1B1 gene regulation by metformin. - Highlights: • Metformin inhibits CYP1A1 and CYP1B1 expression. • Metformin down-regulates the AhR signaling. • Metformin reduces Sp1 protein expression. • Metformin suppresses TDO expression.

  18. Myelin down-regulates myelin phagocytosis by microglia and macrophages through interactions between CD47 on myelin and SIRPα (signal regulatory protein-α on phagocytes

    Directory of Open Access Journals (Sweden)

    Reichert Fanny

    2011-03-01

    Full Text Available Abstract Background Traumatic injury to axons produces breakdown of axons and myelin at the site of the lesion and then further distal to this where Wallerian degeneration develops. The rapid removal of degenerated myelin by phagocytosis is advantageous for repair since molecules in myelin impede regeneration of severed axons. Thus, revealing mechanisms that regulate myelin phagocytosis by macrophages and microglia is important. We hypothesize that myelin regulates its own phagocytosis by simultaneous activation and down-regulation of microglial and macrophage responses. Activation follows myelin binding to receptors that mediate its phagocytosis (e.g. complement receptor-3, which has been previously studied. Down-regulation, which we test here, follows binding of myelin CD47 to the immune inhibitory receptor SIRPα (signal regulatory protein-α on macrophages and microglia. Methods CD47 and SIRPα expression was studied by confocal immunofluorescence microscopy, and myelin phagocytosis by ELISA. Results We first document that myelin, oligodendrocytes and Schwann cells express CD47 without SIRPα and further confirm that microglia and macrophages express both CD47 and SIRPα. Thus, CD47 on myelin can bind to and subsequently activate SIRPα on phagocytes, a prerequisite for CD47/SIRPα-dependent down-regulation of CD47+/+ myelin phagocytosis by itself. We then demonstrate that phagocytosis of CD47+/+ myelin is augmented when binding between myelin CD47 and SIRPα on phagocytes is blocked by mAbs against CD47 and SIRPα, indicating that down-regulation of phagocytosis indeed depends on CD47-SIRPα binding. Further, phagocytosis in serum-free medium of CD47+/+ myelin is augmented after knocking down SIRPα levels (SIRPα-KD in phagocytes by lentiviral infection with SIRPα-shRNA, whereas phagocytosis of myelin that lacks CD47 (CD47-/- is not. Thus, myelin CD47 produces SIRPα-dependent down-regulation of CD47+/+ myelin phagocytosis in phagocytes

  19. Internalization and down-regulation of human muscarinic acetylcholine receptor m2 subtypes. Role of third intracellular m2 loop and G protein-coupled receptor kinase 2.

    Science.gov (United States)

    Tsuga, H; Kameyama, K; Haga, T; Honma, T; Lameh, J; Sadée, W

    1998-02-27

    Internalization and down-regulation of human muscarinic acetylcholine m2 receptors (hm2 receptors) and a hm2 receptor mutant lacking a central part of the third intracellular loop (I3-del m2 receptor) were examined in Chinese hamster ovary (CHO-K1) cells stably expressing these receptors and G protein-coupled receptor kinase 2 (GRK2). Agonist-induced internalization of up to 80-90% of hm2 receptors was demonstrated by measuring loss of [3H]N-methylscopolamine binding sites from the cell surface, and transfer of [3H]quinuclidinyl benzilate binding sites from the plasma membrane into the light-vesicle fractions separated by sucrose density gradient centrifugation. Additionally, translocation of hm2 receptors with endocytic vesicles were visualized by immunofluorescence confocal microscopy. Agonist-induced down-regulation of up to 60-70% of hm2 receptors was demonstrated by determining the loss of [3H]quinuclidinyl benzilate binding sites in the cells. The half-time (t1/2) of internalization and down-regulation in the presence of 10(-4) M carbamylcholine was estimated to be 9.5 min and 2.3 h, respectively. The rates of both internalization and down-regulation of hm2 receptors in the presence of 10(-6) M or lower concentrations of carbamylcholine were markedly increased by coexpression of GRK2. Agonist-induced internalization of I3-del m2 receptors was barely detectable upon incubation of cells for 1 h, but agonist-induced down-regulation of up to 40-50% of I3-del m2 receptors occurred upon incubation with 10(-4) M carbamylcholine for 16 h. However, the rate of down-regulation was lower compared with wild type receptors (t1/2 = 9.9 versus 2.3 h). These results indicate that rapid internalization of hm2 receptors is facilitated by their phosphorylation with GRK2 and does not occur in the absence of the third intracellular loop, but down-regulation of hm2 receptors may occur through both GRK2-facilitating pathway and third intracellular loop-independent pathways.

  20. Down-regulated peroxisome proliferator-activated receptor γ (PPARγ) in lung epithelial cells promotes a PPARγ agonist-reversible proinflammatory phenotype in chronic obstructive pulmonary disease (COPD).

    Science.gov (United States)

    Lakshmi, Sowmya P; Reddy, Aravind T; Zhang, Yingze; Sciurba, Frank C; Mallampalli, Rama K; Duncan, Steven R; Reddy, Raju C

    2014-03-07

    Chronic obstructive pulmonary disease (COPD) is a progressive inflammatory condition and a leading cause of death, with no available cure. We assessed the actions in pulmonary epithelial cells of peroxisome proliferator-activated receptor γ (PPARγ), a nuclear hormone receptor with anti-inflammatory effects, whose role in COPD is largely unknown. We found that PPARγ was down-regulated in lung tissue and epithelial cells of COPD patients, via both reduced expression and phosphorylation-mediated inhibition, whereas pro-inflammatory nuclear factor-κB (NF-κB) activity was increased. Cigarette smoking is the main risk factor for COPD, and exposing airway epithelial cells to cigarette smoke extract (CSE) likewise down-regulated PPARγ and activated NF-κB. CSE also down-regulated and post-translationally inhibited the glucocorticoid receptor (GR-α) and histone deacetylase 2 (HDAC2), a corepressor important for glucocorticoid action and whose down-regulation is thought to cause glucocorticoid insensitivity in COPD. Treating epithelial cells with synthetic (rosiglitazone) or endogenous (10-nitro-oleic acid) PPARγ agonists strongly up-regulated PPARγ expression and activity, suppressed CSE-induced production and secretion of inflammatory cytokines, and reversed its activation of NF-κB by inhibiting the IκB kinase pathway and by promoting direct inhibitory binding of PPARγ to NF-κB. In contrast, PPARγ knockdown via siRNA augmented CSE-induced chemokine release and decreases in HDAC activity, suggesting a potential anti-inflammatory role of endogenous PPARγ. The results imply that down-regulation of pulmonary epithelial PPARγ by cigarette smoke promotes inflammatory pathways and diminishes glucocorticoid responsiveness, thereby contributing to COPD pathogenesis, and further suggest that PPARγ agonists may be useful for COPD treatment.

  1. Internalization and down-regulation of mu opioid receptors by endomorphins and morphine in SH-SY5Y human neuroblastoma cells.

    Science.gov (United States)

    Horner, Kristen A; Zadina, James E

    2004-12-03

    The human neuroblastoma cell line, SH-SY5Y, was used to examine the effects of morphine and the endogenous opioid peptides, endomorphin-1 (EM-1) and endomorphin-2 (EM-2), on mu opioid receptor (MOR) internalization and down-regulation. Treatment for 24 h with EM-1, EM-2 or morphine at 100 nM, 1 microM and 10 microM resulted in a dose-dependent down-regulation of mu receptors. Exposure of cells to 10 microM EM-1 for 2.5, 5 and 24 h resulted in a time-dependent down-regulation of mu receptors. Down-regulation of mu receptors by morphine and EM-1 was blocked by treatment with hypertonic sucrose, consistent with an endocytosis-dependent mechanism. Sensitive cell-surface binding studies with a radiolabeled mu antagonist revealed that morphine was able to induce internalization of mu receptors naturally expressed in SH-SY5Y cells. EM-1 produced a more rapid internalization of mu receptors than morphine, but hypertonic sucrose blocked the internalization induced by each of these agonists. This study demonstrates that, like morphine, the endomorphins down-regulate mu opioid receptors in a dose- and time-dependent manner. This study also demonstrates that morphine, as well as EM-1, can induce rapid, endocytosis-dependent internalization of mu opioid receptors in SH-SY5Y cells. These results may help elucidate the ability of mu agonists to regulate the number and responsiveness of their receptors.

  2. Apigenin suppresses migration and invasion of transformed cells through down-regulation of C-X-C chemokine receptor 4 expression

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lei; Kuang, Lisha; Hitron, John Andrew; Son, Young-Ok; Wang, Xin; Budhraja, Amit [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Lee, Jeong-Chae [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Institute of Oral Biosciences and BK21 Program, Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Pratheeshkumar, Poyil [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Chen, Gang [Department of Internal Medicine, University of Kentucky College of Medicine, Lexington, KY 40536 (United States); Zhang, Zhuo [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Luo, Jia [Department of Internal Medicine, University of Kentucky College of Medicine, Lexington, KY 40536 (United States); Shi, Xianglin, E-mail: xshi5@email.uky.edu [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States)

    2013-10-01

    Environmental exposure to arsenic is known to cause various cancers. There are some potential relationships between cell malignant transformation and C-X-C chemokine receptor type 4 (CXCR4) expressions. Metastasis, one of the major characteristics of malignantly transformed cells, contributes to the high mortality of cells. CXCR4 and its natural chemokine ligand C-X-C motif ligand 12 (CXCL12) play a critical role in metastasis. Therefore, identification of nutritional factors which are able to inhibit CXCR4 is important for protection from environmental arsenic-induced carcinogenesis and for abolishing metastasis of malignantly transformed cells. The present study demonstrates that apigenin (4′,5,7-trihydroxyflavone), a natural dietary flavonoid, suppressed CXCR4 expression in arsenic-transformed Beas-2B cells (B-AsT) and several other types of transformed/cancer cells in a dose- and time-dependent manner. Neither proteasome nor lysosome inhibitor had any effect in reducing the apigenin-induced down-regulation of CXCR4, indicating that apigenin-induced down-regulation of CXCR4 is not due to proteolytic degradation. The down-regulation of CXCR4 is mainly due to the inhibition of nuclear factor κB (NF-κB) transcriptional activity. Apigenin also abolished migration and invasion of transformed cells induced by CXCL12. In a xenograft mouse model, apigenin down-regulated CXCR4 expression and suppressed tumor growth. Taken together, our results show that apigenin is a novel inhibitor of CXCR4 expression. This dietary flavonoid has the potential to suppress migration and invasion of transformed cells and prevent environmental arsenic-induced carcinogenesis. - Highlights: • Apigenin has a potential in preventing environmental arsenic induced carcinogenesis. • Apigenin suppresses CXCR4 in malignant transformed cells in vitro and in vivo. • The down-regulation of CXCR4 is mainly due to inhibition of NF-κB activity.

  3. Down-regulation of Leucaena leucocephala cinnamoyl CoA reductase (LlCCR) gene induces significant changes in phenotype, soluble phenolic pools and lignin in transgenic tobacco.

    Science.gov (United States)

    Prashant, S; Srilakshmi Sunita, M; Pramod, S; Gupta, Ranadheer K; Anil Kumar, S; Rao Karumanchi, S; Rawal, S K; Kavi Kishor, P B

    2011-12-01

    cDNA and genomic clones of cinnamoyl CoA reductase measuring 1011 and 2992 bp were isolated from a leguminous pulpwood tree Leucaena leucocephala, named as LlCCR. The cDNA exhibited 80-85% homology both at the nucleotide and amino acid levels with other known sequences. The genomic sequence contained five exons and four introns. Sense and antisense constructs of LlCCR were introduced in tobacco plants to up and down-regulate this key enzyme of lignification. The primary transformants showed a good correlation between CCR transcript levels and its activity. Most of the CCR down-regulated lines displayed stunted growth and development, wrinkled leaves and delayed senescence. These lines accumulated unusual phenolics like ferulic and sinapic acids in cell wall. Histochemical staining suggested reduction in aldehyde units and increased syringyl over guaiacyl (S/G) ratio of lignin. Anatomical studies showed thin walled, elongated xylem fibres, collapsed vessels with drastic reduction of secondary xylem. The transmission electron microscopic studies revealed modification of ultrastructure and topochemical distribution of wall polysaccharides and lignin in the xylem fibres. CCR down-regulated lines showed increased thickness of secondary wall layers and poor lignification of S2 and S3 wall layers. The severely down-regulated line AS17 exhibited 24.7% reduction of Klason lignin with an increase of 15% holocellulose content. Contrarily, the CCR up-regulated lines exhibited robust growth, development and significant increase in lignin content. The altered lignin profiles observed in transgenic tobacco lines support a role for CCR down-regulation in improving wood properties of L. leucocephala exclusively used in the pulp and paper industry of India.

  4. Down-regulation of miR-302b, an ESC-specific microRNA, in Gastric Adenocarcinoma

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    Seyed Javad Mowla

    2012-01-01

    -tumorgastric tissue samples. The data further revealed a down-regulation of miR-302b in gastrictumor samples (p=0.001, particularly in high-grade adenocarcinoma (p=0.009. However,ROC analysis data demonstrated a low sensitivity and specificity of miR-302b expressionto discriminate between the tumor and non-tumor state of the samples (AUC=0.63.Conclusion: Despite the upregulation of some hESC-specific genes in tumors, our datarevealed a down-regulation of miR-302b in high-grade tumors. This data suggested a potentialtumor-suppressor role for miR-302b in tumorigenesis of gastric tissue.

  5. Pituitary down-regulation and follicular synchronization%降调节与卵泡发育同步化

    Institute of Scientific and Technical Information of China (English)

    叶虹

    2011-01-01

    The key aim of pituitary down-regulation in controlled ovarian stimulation (COS) is to prevent premature endogenous luteinizing hormone (LH) surge. The down-regulation protocols include long and short GnRH agonist protocols, as well as GnRH antagonist protocol. The long GnRH agonist protocol starting in the midluteal phase of the preceding cycle give the best IVF results with regard to oocyte yield and pregnancy rates. This long protocol induces profound suppression of endogenous release of gonadotrophins during the early follicular phase, allowing the antral follicles to grow coordinately in response to exogenous gonadotrophins to accomplish simultaneous maturation. The short and GnRH antagonist protocols can abridge the duration and complexity of COS and improve patient compliance as compared with the reference long protocol for IVF. Nevertheless, the explanation for the poor IVF-ET outcome achieved with these two protocols compared with long protocol could be, at least in part, related to pre-existing asychronization of early antral follicles before the start of gonadotrophin administration. The steroid (oral contraceptive pill (OCP), synthetic progestogen and natural estrogen) pre-treatment and GnRH-antagonist pre-treatment may be useful to suppress luteal FSH and reduce size differences among FSH-sensitive follicles during the early follicular phase. These approaches represent potential alternatives to synchronize multi-follicular development and improve ovarian stimulation results. However, larger studies are needed to confirm whether follicular growth coordination induced by steroids and premenstrual GnRH antagonist pre-treatment improve IVF-ET pregnancy rates with GnRH antagonist or short agonist protocols.%控制性卵巢刺激(COS)中垂体降调节的主要作用是预防早发内源性黄体生成素(LH)峰.降调节方案包括有促性腺激素释放激素激动剂(GnRH-a)长、短方案,以及GnRH拮抗剂(GnRH-ant)方案等.于前一周期黄体中

  6. Down-regulation of Decapping Protein 2 mediates chronic nicotine exposure-induced locomotor hyperactivity in Drosophila.

    Science.gov (United States)

    Ren, Jing; Sun, Jinghan; Zhang, Yunpeng; Liu, Tong; Ren, Qingzhong; Li, Yan; Guo, Aike

    2012-01-01

    Long-term tobacco use causes nicotine dependence via the regulation of a wide range of genes and is accompanied by various health problems. Studies in mammalian systems have revealed some key factors involved in the effects of nicotine, including nicotinic acetylcholine receptors (nAChRs), dopamine and other neurotransmitters. Nevertheless, the signaling pathways that link nicotine-induced molecular and behavioral modifications remain elusive. Utilizing a chronic nicotine administration paradigm, we found that adult male fruit flies exhibited locomotor hyperactivity after three consecutive days of nicotine exposure, while nicotine-naive flies did not. Strikingly, this chronic nicotine-induced locomotor hyperactivity (cNILH) was abolished in Decapping Protein 2 or 1 (Dcp2 or Dcp1) -deficient flies, while only Dcp2-deficient flies exhibited higher basal levels of locomotor activity than controls. These results indicate that Dcp2 plays a critical role in the response to chronic nicotine exposure. Moreover, the messenger RNA (mRNA) level of Dcp2 in the fly head was suppressed by chronic nicotine treatment, and up-regulation of Dcp2 expression in the nervous system blocked cNILH. These results indicate that down-regulation of Dcp2 mediates chronic nicotine-exposure-induced locomotor hyperactivity in Drosophila. The decapping proteins play a major role in mRNA degradation; however, their function in the nervous system has rarely been investigated. Our findings reveal a significant role for the mRNA decapping pathway in developing locomotor hyperactivity in response to chronic nicotine exposure and identify Dcp2 as a potential candidate for future research on nicotine dependence.

  7. Low Light Stress Down-Regulated Rubisco Gene Expression and Photosynthetic Capacity During Cucumber (Cucumis sativus L.) Leaf Development

    Institute of Scientific and Technical Information of China (English)

    SUN Jian-lei; SUI Xiao-lei; HUANG Hong-yu; WANG Shao-hui; WEI Yu-xia; ZHANG Zhen-xian

    2014-01-01

    Low light stress is one of the most important factors affecting photosynthesis and growth in winter production of cucumber (Cucumis sativus L.) in solar greenhouses in northern China. Here, two genotypes of cucumber (Deltastar and Jinyan 2) are used to determine the effect of low light stress on Rubisco expression and photosynthesis of leaves from emergence to senescence. During leaf development, the net photosynthetic rate (PN), stomatal conductance (gs), Rubisco initial activity and activation state, transcript levels of rbcL and rbcS, and the abundance of rbcL and rbcS DNA in these two genotypes increase rapidly to reach maximum in 10-20 d, and then decrease gradually. Meanwhile, the actual photosystem II efifciency (ФPSI ) of cucumber leaves slowly increased in the early leaf developing stages, but it declined quickly in leaf senescent stages, accompanied by an increased non-photochemical quenching (NPQ). Moreover, PN, gs, initial Rubisco activity, and abundance of protein, mRNA and DNA of Rubisco subunits of leaves grown under 100μmol m-2 s-1 are lower, and require more time to reach their maxima than those grown under 600μmol m-2 s-1 during leaf development. All these results suggest that lower photosynthetic capacity of cucumber leaves from emergence to senescence under low light stress is probably due to down-regulated Rubisco gene expression in transcript and protein levels, and decreased initial and total activity as well as activation state of Rubisco. Deltastar performs better than Jinyan 2 under low light stress.

  8. Down-regulation of Mcl-1 by small interference RNA induces apoptosis and sensitizes HL-60 leukemia cells to etoposide.

    Science.gov (United States)

    Karami, Hadi; Baradaran, Behzad; Esfehani, Ali; Sakhinia, Masoud; Sakhinia, Ebrahim

    2014-01-01

    Acute myeloid leukemia (AML) is a fatal hematological malignancy which is resistant to a variety of chemotherapy drugs. Myeloid cell leukemia-1 (Mcl-1), a death-inhibiting protein that regulates apoptosis, has been shown to be overexpressed in numerous malignancies. In addition, it has been demonstrated that the expression level of the Mcl-1 gene increases at the time of leukemic relapse following chemotherapy. The aim of this study was to target Mcl-1 by small interference RNA (siRNA) and analyze its effects on survival and chemosensitivity of acute myeloid leukemia cell line HL-60. siRNA transfection was performed with a liposome approach. The expression levels of mRNA and protein were measured by real-time quantitative PCR and Western blot analysis, respectively. Trypan blue assays were performed to evaluate tumor cell growth after siRNA transfection. The cytotoxic effects of Mcl-1 siRNA (siMcl-1) and etoposide were determined using MTT assay on their own and in combination. Apoptosis was quantified using a DNA-histone ELISA assay. Transfection with siMcl-1 significantly suppressed the expression of Mcl-1 mRNA and protein in a time- dependent manner, resulting in strong growth inhibition and spontaneous apoptosis. Surprisingly, pretreatment with siMcl-1 synergistically enhanced the cytotoxic effect of etoposide. Furthermore, Mcl-1 down-regulation significantly increased apoptosis sensitivity to etoposide. No significant biological effects were observed with negative control siRNA treatment. Our results suggest that specific suppression of Mcl-1 by siRNA can effectively induce apoptosis and overcome chemoresistance of leukemic cells. Therefore, siMcl-1 may be a potent adjuvant in leukemia chemotherapy.

  9. MRP1 knockdown down-regulates the deposition of collagen and leads to a reduced hypertrophic scar fibrosis.

    Science.gov (United States)

    Li, Yan; Yang, Longlong; Zheng, Zhao; Shi, Jihong; Wu, Xue; Guan, Hao; Jia, Yanhui; Tao, Ke; Wang, Hongtao; Han, Shichao; Gao, Jianxin; Zhao, Bin; Su, Linlin; Hu, Dahai

    2015-10-01

    Multidrug resistance-associated protein 1 (MRP1) belongs to ATP-binding cassette transporters family. The overexpression of MRP1 is predominantly related with the failure of chemo-radiotherapy in various tumors. However, its possible role in hypertrophic scar (HS) is hardly investigated. Here we showed that the mRNA level and protein expression of MRP1 were higher in HS and HS derived fibroblasts (HSFs) than that in normal skin (NS) and NS derived fibroblasts (NSFs). Immunohistochemistry and immunofluorescence showed that the percentage of positive cells was higher in HS and HSFs. Meanwhile, the co-localization of MRP1 and α-SMA was stronger in HS. MRP1 knockdown in HSFs provoked a significant reduction in the protein expressions of collagen 3 and α-SMA in vitro. Moreover, MRP1 siRNA transfection could decrease the deposition of collagen in cultured tissues ex vivo and inhibit the scar formation in rabbit ear scar model in vivo. H&E staining and Masson trichrome staining revealed thinner and more orderly arranged collagen fiber in the MRP1 siRNA transfection group. The appearance of scar was improved as well. All these results indicate that MRP1 plays an important role in the formation of HS, MRP1 knockdown could be a potential method to reduce the accumulation of collagen and to improve the abnormal deposition of extracellular matrix in HS, which indicates that down-regulation of MRP1 has the potential therapeutic effect in the treatment and prophylaxis of HS.

  10. Intermedin 1-53 Inhibits Myocardial Fibrosis in Rats by Down-Regulating Transforming Growth Factor-β

    Science.gov (United States)

    Fang, Jian; Luan, Jiangwei; Zhu, Gaohong; Qi, Chang; Yang, Zhiyong; Zhao, Sheng; Li, Bin; Zhang, Xinzhong; Guo, Naipeng; Li, Xiaodong; Wang, Dandan

    2017-01-01

    Background Myocardial fibrosis is the result of persistent anoxia and ischemic myocardial fibers caused by coronary atherosclerotic stenosis, which lead to heart failure, threatening the patient’s life. This study aimed to explore the regulatory role of intermedin 1-53 (IMD1-53) in cardiac fibrosis using neonatal rat cardiac fibroblasts and a myocardial infarction (MI) rat model both in vitro and in vivo. Material/Methods The Western blot method was used to detect the protein expression of collagen I and collagen III in myocardial fibroblasts. The SYBR Green I real-time quantitative polymerase chain reaction (PCR) assay was used to detect the mRNA expression of collagen type I and III, IMD1-53 calcitonin receptor-like receptor (CRLR), transforming growth factor-β (TGF-β), and matrix metalloproteinase-2 (MMP-2). Masson staining was used to detect the area changes of myocardial fibrosis in MI rats. Results Results in vivo showed that IMD1-53 reduced the scar area on the heart of MI rats and inhibited the expression of collagen type I and III both in mRNA and protein. Results of an in vitro study showed that IMD1-53 inhibited the transformation of cardiomyocytes into myofibroblasts caused by angiotensin II (Ang II). The further mechanism study showed that IMD1-53 inhibited the expression of TGF-β and the phosphorylation of smad3, which further up-regulated the expression of MMP-2. Conclusions IMD1-53 is an effective anti-fibrosis hormone that inhibits cardiac fibrosis formation after MI by down-regulating the expression of TGF-β and the phosphorylation of smad3, blocking fibrous signal pathways, and up-regulating the expression of MMP-2, thereby demonstrating its role in regression of myocardial fibrosis. PMID:28065931

  11. Foxa1 reduces lipid accumulation in human hepatocytes and is down-regulated in nonalcoholic fatty liver.

    Directory of Open Access Journals (Sweden)

    Marta Moya

    Full Text Available Triglyceride accumulation in nonalcoholic fatty liver (NAFL results from unbalanced lipid metabolism which, in the liver, is controlled by several transcription factors. The Foxa subfamily of winged helix/forkhead box (Fox transcription factors comprises three members which play important roles in controlling both metabolism and homeostasis through the regulation of multiple target genes in the liver, pancreas and adipose tissue. In the mouse liver, Foxa2 is repressed by insulin and mediates fasting responses. Unlike Foxa2 however, the role of Foxa1 in the liver has not yet been investigated in detail. In this study, we evaluate the role of Foxa1 in two human liver cell models, primary cultured hepatocytes and HepG2 cells, by adenoviral infection. Moreover, human and rat livers were analyzed to determine Foxa1 regulation in NAFL. Results demonstrate that Foxa1 is a potent inhibitor of hepatic triglyceride synthesis, accumulation and secretion by repressing the expression of multiple target genes of these pathways (e.g., GPAM, DGAT2, MTP, APOB. Moreover, Foxa1 represses the fatty acid transporter protein FATP2 and lowers fatty acid uptake. Foxa1 also increases the breakdown of fatty acids by inducing peroxisomal fatty acid β-oxidation and ketone body synthesis. Finally, Foxa1 is able to largely up-regulate UCP1, thereby dissipating energy and consistently decreasing the mitochondria membrane potential. We also report that human and rat NAFL have a reduced Foxa1 expression, possibly through a protein kinase C-dependent pathway. We conclude that Foxa1 is an antisteatotic factor that coordinately tunes several lipid metabolic pathways to block triglyceride accumulation in hepatocytes. However, Foxa1 is down-regulated in human and rat NAFL and, therefore, increasing Foxa1 levels could protect from steatosis. Altogether, we suggest that Foxa1 could be a novel therapeutic target for NAFL disease and insulin resistance.

  12. Mxi1 inhibits the proliferation of U87 glioma cells through down-regulation of cyclin B1 gene expression

    Science.gov (United States)

    Manni, I; Tunici, P; Cirenei, N; Albarosa, R; Colombo, B M; Roz, L; Sacchi, A; Piaggio, G; Finocchiaro, G

    2002-01-01

    Mxi1 is a Mad family member that plays a role in cell proliferation and differentiation. To test the role of Mxi1 on tumorigenesis of glioma cells we transfected a CMV-driven MXI1 cDNA in U87 human glioblastoma cells. Two clones were isolated expressing MXI1 levels 18- and 3.5-fold higher than wild-type U87 cells (clone U87.Mxi1.14 and U87.Mxi1.22, respectively). In vivo, U87.Mxi1.14 cells were not tumorigenic in nude mice and delayed development of tumours was observed with U87.Mxi1.22 cells. In vitro, the proliferation rate was partially and strongly inhibited in U87.Mxi1.22 and U87.Mxi1.14 cells respectively. The cell cycle analysis revealed a relevant accumulation of U87.Mxi1.14 cells in the G2/M phase. Interestingly, the expression of cyclin B1 was inhibited to about 60% in U87.Mxi1.14 cells. This inhibition occurs at the transcriptional level and depends, at least in part, on the E-box present on the cyclin B1 promoter. Consistent with this, the endogenous Mxi1 binds this E-box in vitro. Thus, our findings indicate that Mxi1 can act as a tumour suppressor in human glioblastomas through a molecular mechanism involving the transcriptional down-regulation of cyclin B1 gene expression. British Journal of Cancer (2002) 86, 477–484. DOI: 10.1038/sj/bjc/6600065 www.bjcancer.com © 2002 The Cancer Research Campaign PMID:11875718

  13. Metformin reduces the endotoxin-induced down-regulation of apolipoprotein E gene expression in macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Stavri, Simona; Trusca, Violeta G.; Simionescu, Maya; Gafencu, Anca V., E-mail: anca.gafencu@icbp.ro

    2015-05-29

    The atheroprotective role of macrophage-derived apolipoprotein E (apoE) is well known. Our previous reports demonstrated that inflammatory stress down-regulates apoE expression in macrophages, aggravating atherogenesis. Metformin, extensively used as an anti-diabetic drug, has also anti-inflammatory properties, and thus confers vascular protection. In this study, we questioned whether metformin could have an effect on apoE expression in macrophages in normal conditions or under lipopolysaccharide (LPS)-induced stress. The results showed that metformin slightly increases the apoE expression only at high doses (5–10 mM). Low doses of metformin (1–3 mM) significantly reduce the LPS down-regulatory effect on apoE expression in macrophages. Our experiments demonstrated that LPS-induced NF-κB binds to the macrophage-specific distal regulatory element of apoE gene, namely to the multienhancer 2 (ME.2) and its 5′-deletion fragments. The NF-κB binding on ME.2 and apoE promoter has a down-regulatory effect. In addition, data revealed that metformin impairs NF-κB nuclear translocation, and thus, improves the apoE levels in macrophages under inflammatory stress. The positive effect of metformin in the inflammatory states, its clinical safety and low cost, make this drug a potential adjuvant in the therapeutic strategies for atherosclerosis. - Highlights: • High doses of metformin slightly increase apoE expression in macrophages. • Low doses of metformin up-regulate apoE gene in endotoxin-stressed macrophages. • Metformin reduces the negative effect of LPS on apoE expression by NF-κB inhibition.

  14. Down-regulation of POLYGALACTURONASE1 alters firmness, tensile strength and water loss in apple (Malus x domestica fruit

    Directory of Open Access Journals (Sweden)

    Atkinson Ross G

    2012-08-01

    Full Text Available Abstract Background While there is now a significant body of research correlating apple (Malus x domestica fruit softening with the cell wall hydrolase ENDO-POLYGALACTURONASE1 (PG1, there is currently little knowledge of its physiological effects in planta. This study examined the effect of down regulation of PG1 expression in ‘Royal Gala’ apples, a cultivar that typically has high levels of PG1, and softens during fruit ripening. Results PG1-suppressed ‘Royal Gala’ apples harvested from multiple seasons were firmer than controls after ripening, and intercellular adhesion was higher. Cell wall analyses indicated changes in yield and composition of pectin, and a higher molecular weight distribution of CDTA-soluble pectin. Structural analyses revealed more ruptured cells and free juice in pulled apart sections, suggesting improved integrity of intercellular connections and consequent cell rupture due to failure of the primary cell walls under stress. PG1-suppressed lines also had reduced expansion of cells in the hypodermis of ripe apples, resulting in more densely packed cells in this layer. This change in morphology appears to be linked with reduced transpirational water loss in the fruit. Conclusions These findings confirm PG1’s role in apple fruit softening and suggests that this is achieved in part by reducing cellular adhesion. This is consistent with previous studies carried out in strawberry but not with those performed in tomato. In apple PG1 also appears to influence other fruit texture characters such as juiciness and water loss.

  15. Down-regulated expression of atypical PKC-binding domain deleted asip isoforms in human hepatocellular carcinomas

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Asip is a mammalian homologue of polarity protein Par-3 of Caenorhabditis elegans and Bazooka of Drosophila melanogaster. Asip/Par-3/Bazooka are PDZ-motif containing proteins that localize asymmetrically to the cell periphery and play a pivotal role in cell polarity and asymmetric cell division. In the present study, we have cloned human asip cDNA and its splicing variants by 5'-RACE and RT-PCR using candidate human EST clones which have a high homology to rat asip cDNA. The full-length cDNA of human asip encodes a 1,353 aa protein exhibiting 88% similarity to the rat one. Human asip is a single copy gene consisting of at least 26 exons and localizing in human chromosome 10, band p11.2, with some extraordinarily long introns. All exon/intron boundary nucleotides conform to the “gt-ag” rule. Three main transcripts were detected by Northern blot analysis, and at least five variants, from alternative splicing and polyadenylation, have been identified by RT-PCR and liver cDNA library screening. Exon 17b deleted asip mRNAs expressed ubiquitously in normal human tissues, including liver, on RT-PCR analysis. However, they were absent from most human liver cancer cell lines examined. More interestingly, the expression of exon 17b deleted variants was down regulated in 52.6% (10/19) clinic specimens of human hepatocellular carcinomas (HCCs), compared with the surrounding nontumorous liver tissues from the same patients. The presence of various splicing transcripts, the variation of their distribution among different tissues and cells, and their differential expressions in human HCCs suggest that human Asip isoforms may function in different context.

  16. Nutrient/serum starvation derived TRIP-Br3 down-regulation accelerates apoptosis by destabilizing XIAP

    Science.gov (United States)

    Lee, Soonduck; Jeong, Dongjun; Yang, Young; Kim, Keun-Il; Lim, Jong-Seok; Cheon, Chung-Il; Kim, Changjin; Kang, Young-Sook; Lee, Myeong-Sok

    2015-01-01

    TRIP-Br3 and TRIP-Br1 have shown to have important biological functions. However, the function of TRIP-Br3 in tumorigenesis is not well characterized compared to oncogenic TRIP-Br1. Here, we investigated the function of TRIP-Br3 in tumorigenesis by comparing with that of TRIP-Br1. Under nutrient/serum starvation, TRIP-Br3 expression was down-regulated slightly in cancer cells and significantly in normal cells. Unexpectedly, TRIP-Br1 expression was greatly up-regulated in cancer cells but not in normal cells. Moreover, TRIP-Br3 activated autophagy while TRIP-Br1 inactivated it under serum starvation. In spite of different expression and roles of TRIP-Br3 and TRIP-Br1, both of them alleviate cell death by directly binding to and stabilizing XIAP, a potent apoptosis inhibitor, through blocking its ubiquitination. Taken together, we propose that TRIP-Br3 primarily activates the autophagy and suppresses apoptosis in nutrient sufficient condition. However, the prolonged extreme stressful condition of nutrient starvation causes a dramatic decrease of TRIP-Br3, which in turn induces apoptosis by destabilizing XIAP. Up-regulated TRIP-Br1 in cancer cells compensates this effect and delays apoptosis. This can be explained by the competitive alternative binding of TRIP-Br3 and TRIP-Br1 to the BIR2 domain of XIAP. In an extended study, our immunohistochemical analysis revealed a markedly lower level of TRIP-Br3 protein in human carcinoma tissues compared to normal epithelial tissues, implying the role of TRIP-Br3 as a tumor suppressor rather than onco-protein. PMID:25691055

  17. Apigenin ameliorates hypertension-induced cardiac hypertrophy and down-regulates cardiac hypoxia inducible factor-lα in rats.

    Science.gov (United States)

    Zhu, Zeng-Yan; Gao, Tian; Huang, Yan; Xue, Jie; Xie, Mei-Lin

    2016-04-01

    Apigenin is a natural flavonoid compound that can inhibit hypoxia-inducible factor (HIF)-1α expression in cultured tumor cells under hypoxic conditions. Hypertension-induced cardiac hypertrophy is always accompanied by abnormal myocardial glucolipid metabolism due to an increase of HIF-1α. However, whether or not apigenin may ameliorate the cardiac hypertrophy and abnormal myocardial glucolipid metabolism remains unknown. This study aimed to examine the effects of apigenin. Rats with cardiac hypertrophy induced by renovascular hypertension were treated with apigenin 50-100 mg kg(-1) (the doses can be achieved by pharmacological or dietary supplementation for an adult person) by gavage for 4 weeks. The results showed that after treatment with apigenin, the blood pressure, heart weight, heart weight index, cardiomyocyte cross-sectional area, serum angiotensin II, and serum and myocardial free fatty acids were reduced. It is important to note that apigenin decreased the expression level of myocardial HIF-1α protein. Moreover, apigenin simultaneously increased the expression levels of myocardial peroxisome proliferator-activated receptor (PPAR) α, carnitine palmitoyltransferase (CPT)-1, and pyruvate dehydrogenase kinase (PDK)-4 proteins and decreased the expression levels of myocardial PPARγ, glycerol-3-phosphate acyltransferase genes (GPAT), and glucose transporter (GLUT)-4 proteins. These findings demonstrated that apigenin could improve hypertensive cardiac hypertrophy and abnormal myocardial glucolipid metabolism in rats, and its mechanisms might be associated with the down-regulation of myocardial HIF-1α expression and, subsequently increasing the expressions of myocardial PPARα and its target genes CPT-1 and PDK-4, and decreasing the expressions of myocardial PPARγ and its target genes GPAT and GLUT-4.

  18. MicroRNA-224 inhibits proliferation and migration of breast cancer cells by down-regulating Fizzled 5 expression.

    Science.gov (United States)

    Liu, Feng; Liu, Yang; Shen, Jingling; Zhang, Guoqiang; Han, Jiguang

    2016-08-02

    The Wnt/β-catenin signaling is crucial for the proliferation and migration of breast cancer cells. However, the expression of microRNA-224 (miR-224) in the different types of breast cancers and its role in the Wnt/β-catenin signaling and the proliferation and migration of breast cancer cells are poorly understood. In this study, the levels of miR-224 in different types of breast cancer tissues and cell lines were examined by quantitative RT-PCR and the potential targets of miR-224 in the Wnt/β-catenin signaling were investigated. The effects of altered miR-224 expression on the frequency of CD44+CD24- cancer stem-like cells (CSC), proliferation and migration of MCF-7 and MDA-MB-231 cells were examined by flow cytometry, MTT and transwell migration. We found that the levels of miR-224 expression in different types of breast cancer tissues and cell lines were associated inversely with aggressiveness of breast cancers. Enhanced miR-224 expression significantly reduced the fizzled 5-regulated luciferase activity in 293T cells, fizzled 5 expression in MCF-7 and MDA-MB-231 cells, the β-dependent luciferase activity in MCF-7 cells, and the nuclear translocation of β-catenin in MDA-MB-231 cells. miR-224 inhibition significantly increased the percentages of CSC in MCF-7 cells and enhanced proliferation and migration of MCF-7 cells. Enhanced miR-224 expression inhibited proliferation and migration of MDA-MB-231 cells, and the growth of implanted breast cancers in vivo. Induction of Frizzled 5 over-expression mitigated the miR-224-mediated inhibition of breast cancer cell proliferation. Collectively, these data indicated that miR-224 down-regulated the Wnt/β-catenin signaling possibly by binding to Frizzled 5 and inhibited proliferation and migration of breast cancer cells.

  19. Acute physiological stress down-regulates mRNA expressions of growth-related genes in coho salmon.

    Directory of Open Access Journals (Sweden)

    Toshiki Nakano

    Full Text Available Growth and development in fish are regulated to a major extent by growth-related factors, such as liver-derived insulin-like growth factor (IGF -1 in response to pituitary-secreted growth hormone (GH binding to the GH receptor (GHR. Here, we report on the changes in the expressions of gh, ghr, and igf1 genes and the circulating levels of GH and IGF-1 proteins in juvenile coho salmon (Oncorhynchus kisutch in response to handling as an acute physiological stressor. Plasma GH levels were not significantly different between stressed fish and prestressed control. Plasma IGF-1 concentrations in stressed fish 1.5 h post-stress were the same as in control fish, but levels in stressed fish decreased significantly 16 h post-stress. Real-time quantitative PCR (qPCR analysis showed that ghr mRNA levels in pituitary, liver, and muscle decreased gradually in response to the stressor. After exposure to stress, hepatic igf1 expression transiently increased, whereas levels decreased 16 h post-stress. On the other hand, the pituitary gh mRNA level did not change in response to the stressor. These observations indicate that expression of gh, ghr, and igf1 responded differently to stress. Our results show that acute physiological stress can mainly down-regulate the expressions of growth-related genes in coho salmon in vivo. This study also suggests that a relationship between the neuroendocrine stress response and growth-related factors exists in fish.

  20. Cetuximab in combination with anti-human IgG antibodies efficiently down-regulates the EGF receptor by macropinocytosis

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    Berger, Christian [Department of Pathology, Oslo University Hospital, Rikshospitalet, Post box 4950 Nydalen, 0424 Oslo (Norway); Madshus, Inger Helene [Institute of Pathology, University of Oslo, Rikshospitalet, 0027 Oslo (Norway); Department of Pathology, Oslo University Hospital, Rikshospitalet, Post box 4950 Nydalen, 0424 Oslo (Norway); Stang, Espen, E-mail: espsta@rr-research.no [Department of Pathology, Oslo University Hospital, Rikshospitalet, Post box 4950 Nydalen, 0424 Oslo (Norway)

    2012-12-10

    The monoclonal antibody C225 (Cetuximab) blocks binding of ligand to the epidermal growth factor receptor (EGFR). In addition, it is known that incubation with C225 induces endocytosis of the EGFR. This endocytosis has previously been shown to be increased when C225 is combined with an additional monoclonal anti-EGFR antibody. However, the effects of antibody combinations on EGFR activation, endocytosis, trafficking and degradation have been unclear. By binding a secondary antibody to the C225-EGFR complex, we here demonstrate that a combination of antibodies can efficiently internalize and degrade the EGFR. Although the combination of antibodies activated the EGFR kinase and induced ubiquitination of the EGFR, the kinase activity was not required for internalization of the EGFR. In contrast to EGF-induced EGFR down-regulation, the antibody combination efficiently degraded the EGFR without initiating downstream proliferative signaling. The antibody-induced internalization of EGFR was found not to depend on clathrin and/or dynamin, but depended on actin polymerization, suggesting induction of macropinocytosis. Macropinocytosis may cause internalization of large membrane areas, and this could explain the highly efficient internalization of the EGFR induced by combination of antibodies. -- Highlight: Black-Right-Pointing-Pointer Cetuximab induced endocytosis of EGFR increases upon combination with anti-human IgG. Black-Right-Pointing-Pointer Antibody combination causes internalization of EGFR by macropinocytosis. Black-Right-Pointing-Pointer Antibody-induced internalization of EGFR is independent of EGFR kinase activity. Black-Right-Pointing-Pointer Antibody combination may have a zipper effect and cross-link EGFRs on neighboring cells.

  1. Interactions with the young down-regulate adult olfactory neurogenesis and enhance the maturation of olfactory neuroblasts in sheep mothers.

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    Maïna eBRUS

    2014-02-01

    Full Text Available New neurons are continuously added in the dentate gyrus and the olfactory bulb of mammalian brain. While numerous environmental factors controlling survival of newborn neurons have been extensively studied, regulation by social interactions is less documented. We addressed this question by investigating the influence of parturition and interactions with the young on neurogenesis in sheep mothers. Using Bromodeoxyuridine, a marker of cell division, in combination with markers of neuronal maturation, the percentage of neuroblasts and new mature neurons in the olfactory bulb and the dentate gyrus was compared between groups of parturient ewes which could interact or not with their lamb, and virgins. In addition, a morphological analysis was performed by measuring the dendritic arbor of neuroblasts in both structures. We showed that the post-partum period was associated with a decrease in olfactory and hippocampal adult neurogenesis. In the olfactory bulb, the suppressive effect on neuroblasts was dependent on interactions with the young whereas in the dentate gyrus the decrease in new mature neurons was associated with parturition. In addition, dendritic length and number of nodes of neuroblasts were significantly enhanced by interactions with the lamb in the olfactory bulb but not in the dentate gyrus. Because interactions with the young involved learning of the olfactory signature of the lamb, we hypothesize that this learning is associated with a down-regulation in olfactory neurogenesis and an enhancement of olfactory neuroblast maturation. Our assumption is that fewer new neurons decrease cell competition in the olfactory bulb and enhance maturation of those new neurons selected to participate in the learning of the young odor.

  2. Hemoglobin A1c induced down-regulation of CD36 of Plasmodium Falciparum parasitized red cell

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    Hassan Hijazi, Atif Alagib, Hisham Waggiallah

    2014-03-01

    Full Text Available Objective: High values of glycosylated hemoglobin have been found to correlate with decreased deformability of erythrocyte. CD36 (Cluster of Differentiation 36 is an integral membrane protein found on the surface of many cell types of class B scavenger receptor family. Plasmodium falciparum and diabetes mellitus is associated many complications. Aim of this study to investigate the down-regulation of HbA1c to CD36 on P. falciparum parasitized red blood cells Diabetes mellitus patients. Methods: This is cross section study conducted among diabetic patients attending in Jabir Abo Eleiz diabetic center in Khartoum state. Venous blood samples were collected in heparin containers for Plasmodium falciparum culture, and random blood sugar. For HbA1c in 0.04 mg EDTA anticoagulant, 2-5 ml of blood was collected. Sample size was 45 samples and was collected from known diabetic patients with HbA1c more than 8%. All data were analyzed by using Statistical Package for Social Science (SPSS. Results: show the mean difference between CD36 negative control and CD36 positive control was found to be statistically significant increasing of CD36 presence at P. value =0.001 (P ≤0.001. The mean difference between CD36 positive control and diabetic patients with HbA1C more 8% was found to be statistically significant reduction of CD36 expression at p=0.001. Conclusion: Hyperglycemia (HbA1c leads to decrease of CD36 expression and interfere with innate and active immunity. In this study HbA1c participates in increasing of P. falciparum malaria complications.

  3. JNK phosphorylation promotes degeneration of cervical endplate chondrocytes through down-regulation of the expression of ANK in humans

    Institute of Scientific and Technical Information of China (English)

    XU Hong-guang; SONG Jun-xing; CHENG Jia-feng; ZHANG Ping-Zhi; WANG Hong; LIU Ping; L(U) Kun

    2013-01-01

    Background C-Jun N-terminal kinase (JNK) signaling pathway and ankylosis gene (ANK) play a critical role in endplate chondrocytes degeneration.The purpose of this study was to investigate whether the expression levels of ANK was associated with the activation of JNK.Methods Cartilage endplates of 49 patients were divided into the control group (n=19) and the experimental group (n=30).The patients in the control group were graded 0 and those in the experimental group were graded Ⅰ-Ⅲ according to Miller's classification.Endplate chondrocytes were isolated by enzyme digestion and cultured in vitro.The inverted phase contrast microscope,teluidine blue staining,HE staining,real time RT-PCR,and MTT were used to observe morphological appearances,biological characteristics,and growth curve of endplate chondrocytes from the cartilage endplate of the two groups.Real time RT-PCR and Western blotting were used to analyze the mRNA and protein expression levels of associated factors in the degeneration process in the cultured endplate chondrocytes with or without subjected SP600125.Results The expression levels of type Ⅱ collagen,aggrecan,and ANK in endplate chondrocytes of experimental group were lower than that of control group and phosphorylation level of JNK in the experimental group which was higher than that in the control group.Application of JNK phosphorylation inhibitor to degeneration chondrocytes resulted in a marked decrease in the phosphorylation level of JNK and a significant increase in the expression levels of type Ⅱ collagen,aggrecan,and ANK.Conclusion The degeneration of the human cervical endplate chondrocytes might be promoted by JNK phosphorylation by down-regulating the expression of ANK

  4. siRNA against presenilin 1 (PS1 down regulates amyloid β42 production in IMR-32 cells

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    Kandimalla Ramesh JL

    2012-01-01

    Full Text Available Abstract Background One of the pathological hallmarks of Alzheimer's disease (AD is the deposition of the ~4 kDa amyloid β protein (Aβ within lesions known as senile plaques. Aβ is also deposited in the walls of cerebral blood vessels in many cases of AD. A substantial proportion of the Aβ that accumulates in the AD brain is deposited as Amyloid, which is highly insoluble, proteinaceous material with a β-pleated-sheet conformation and deposited extracellularly in the form of 5-10 nm wide straight fibrils. As γ-secretase catalyzes the final cleavage that releases the Aβ42 or 40 from amyloid β -protein precursor (APP, therefore, it is a potential therapeutic target for the treatment of AD. γ-Secretase cleavage is performed by a high molecular weight protein complex containing presenilins (PSs, nicastrin, Aph-1 and Pen-2. Previous studies have demonstrated that the presenilins (PS1 and PS2 are critical components of a large enzyme complex that performs γ-secretase cleavage. Methods In this study we used RNA interference (RNAi technology to examine the effects of small-interfering RNA (siRNA against PS1 on expression levels of PS1 and Aβ42 in IMR-32 Cells using RTPCR, western blotting and immunofluorescence techniques. Results The results of the present study showed down regulation of PS1 and Aβ42 in IMR32 cells transfected with siRNA against PS1. Conclusion Our results substantiate the concept that PS1 is involved in γ-secretase activity and provides the rationale for therapeutic strategies aimed at influencing Aβ42 production.

  5. Interleukin-10 receptor expression and signalling were down-regulated in CD4+ T cells of lupus nephritis patients

    Science.gov (United States)

    Cui, H D; Qi, Z M; Yang, L L; Qi, L; Zhang, N; Zhang, X L; Du, S Y; Jiang, Y

    2011-01-01

    Studies have indicated that interleukin (IL)-10 has a pathogenic role in systemic lupus erythematosus (SLE); however, a protective effect of IL-10 in SLE was also observed. Because the exact mechanism of IL-10 signalling in the pathogenesis of SLE is unclear, this study sought to assess the expression and signalling of interleukin-10 receptor (IL-10R) in peripheral leucocytes from patients with SLE. We used flow cytometry to examine the expression of IL-10R1 on different peripheral leucocytes from 28 SLE patients, of whom 14 had lupus nephritis (LN) and 14 were healthy controls. We also examined the effects of IL-10 on phosphorylation of signal transducer and activator of transcription (STAT)-3 and STAT-1 in peripheral blood mononuclear cells (PBMCs) obtained from 13 SLE patients and seven healthy controls. Plasma cytokines were detected by flow cytometric bead array (CBA) techniques. Although IL-10R1 expression levels on each peripheral leucocyte subset from 28 SLE patients and 14 healthy controls were similar, the expression levels on CD4+ T cells from LN patients were significantly lower than on CD4+ T cells from controls and SLE patients without nephritis (P < 0·01). IL-10R1 expression levels on CD4+ and CD8+ T cells were correlated negatively with the SLE disease activity index (P < 0·01). Additionally, the phosphorylation of STAT-3 was delayed and reduced in PBMCs from LN patients and active SLE patients. Plasma IL-10 levels were significantly higher in LN patients than controls. IL-10R1 expression on CD4+ T cells and signalling in PBMCs were down-regulated in LN patients, indicating that IL-10 and its receptor may have a special role in LN pathogenesis. PMID:21635228

  6. Down-regulation of photosynthesis following girdling, but contrasting effects on fruit set and retention, in two sweet cherry cultivars.

    Science.gov (United States)

    Quentin, A G; Close, D C; Hennen, L M H P; Pinkard, E A

    2013-12-01

    Sweet cherry (Prunus avium) trees were manipulated to analyse the contribution of soluble sugars to sink feedback down-regulation of leaf net CO2 assimilation rate (Anet) and fruit set and quality attributes. Total soluble sugar concentration and Anet were measured in the morning on fully expanded leaves of girdled branches in two sweet cherry cultivars, 'Kordia' and 'Sylvia' characterised typically by low and high crop load, respectively. Leaves on girdled trees had higher soluble sugar concentrations and reduced Anet than leaves on non-girdled trees. Moreover, RuBP carboxylation capacity of Rubisco (Vcmax) and triose-phosphate utilisation (TPU) were repressed in the girdled treatments, despite Jmax remaining unchanged; suggesting an impairment of photosynthetic capacity in response to the girdling treatment. Leaf Anet was negatively correlated to soluble sugars, suggesting a sink feedback regulatory control of photosynthesis. Although there were significantly less fruit set and retained in 'Kordia' than 'Sylvia'; girdling had contrasting effects in each cultivar. Girdling significantly increased fruit set and fruitlet retention in 'Sylvia' cultivar, but had no effect in 'Kordia' cultivar. We propose that low inherent sink demand for photoassimilates of 'Kordia' fruit could have contributed to the low fruit retention rate, since both non-girdled and girdled trees exhibited similar retention rate and that increases in foliar carbohydrates was observed above the girdle. In 'Sylvia' cultivar, the carbohydrate status may be a limiting factor for 'Sylvia' fruit, since girdling improved both fruit set and retention, and leaf soluble solids accumulation. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  7. Foxa1 Reduces Lipid Accumulation in Human Hepatocytes and Is Down-Regulated in Nonalcoholic Fatty Liver

    Science.gov (United States)

    Moya, Marta; Benet, Marta; Guzmán, Carla; Tolosa, Laia; García-Monzón, Carmelo; Pareja, Eugenia; Castell, José Vicente; Jover, Ramiro

    2012-01-01

    Triglyceride accumulation in nonalcoholic fatty liver (NAFL) results from unbalanced lipid metabolism which, in the liver, is controlled by several transcription factors. The Foxa subfamily of winged helix/forkhead box (Fox) transcription factors comprises three members which play important roles in controlling both metabolism and homeostasis through the regulation of multiple target genes in the liver, pancreas and adipose tissue. In the mouse liver, Foxa2 is repressed by insulin and mediates fasting responses. Unlike Foxa2 however, the role of Foxa1 in the liver has not yet been investigated in detail. In this study, we evaluate the role of Foxa1 in two human liver cell models, primary cultured hepatocytes and HepG2 cells, by adenoviral infection. Moreover, human and rat livers were analyzed to determine Foxa1 regulation in NAFL. Results demonstrate that Foxa1 is a potent inhibitor of hepatic triglyceride synthesis, accumulation and secretion by repressing the expression of multiple target genes of these pathways (e.g., GPAM, DGAT2, MTP, APOB). Moreover, Foxa1 represses the fatty acid transporter protein FATP2 and lowers fatty acid uptake. Foxa1 also increases the breakdown of fatty acids by inducing peroxisomal fatty acid β-oxidation and ketone body synthesis. Finally, Foxa1 is able to largely up-regulate UCP1, thereby dissipating energy and consistently decreasing the mitochondria membrane potential. We also report that human and rat NAFL have a reduced Foxa1 expression, possibly through a protein kinase C-dependent pathway. We conclude that Foxa1 is an antisteatotic factor that coordinately tunes several lipid metabolic pathways to block triglyceride accumulation in hepatocytes. However, Foxa1 is down-regulated in human and rat NAFL and, therefore, increasing Foxa1 levels could protect from steatosis. Altogether, we suggest that Foxa1 could be a novel therapeutic target for NAFL disease and insulin resistance. PMID:22238690

  8. Valsartan attenuates cardiac and renal hypertrophy in rats with experimental cardiorenal syndrome possibly through down-regulating galectin-3 signaling.

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    Zhang, M-J; Gu, Y; Wang, H; Zhu, P-F; Liu, X-Y; Wu, J

    2016-01-01

    Aortocaval fistula (AV) induced chronic volume overload in rats with preexisting mild renal dysfunction (right kidney remove: UNX) could mimic the type 4 cardiorenal syndrome (CRS): chronic renocardiac syndrome. Galectin-3, a β-galactoside binding lectin, is an emerging biomarker in cardiovascular as well as renal diseases. We observed the impact of valsartan on cardiac and renal hypertrophy and galectin-3 changes in this model. Adult male Sprague-Dawley (SD) rats (200-250 g) were divided into S (Sham, n = 7), M (UNX+AV, n = 7) and M+V (UNX+AV+valsartan, n = 7) groups. Eight weeks later, cardiac function was measured by echocardiography. Renal outcome was measured by glomerular filtration rate, effective renal plasma flow, renal blood flow and 24 hours albuminuria. Immunohistochemistry and real-time PCR were used to evaluate the expressions of galectin-3 in heart and renal. Cardiac hypertrophy and renal hypertrophy as well as cardiac enlargement were evidenced in this AV shunt induced chronic volume overload rat model with preexisting mild renal dysfunction. Cardiac and renal hypertrophy were significantly attenuated but cardiac enlargement was unaffected by valsartan independent of its blood pressure lowering effect. 24 hours urine albumin was significantly increased, which was significantly reduced by valsartan in this model. Immunohistochemistry and real-time PCR evidenced significantly up-regulated galectin-3 expression in heart and kidney and borderline increased myocardial collagen I expression, which tended to be lower post valsartan treatment. Up-regulated galectin-3 signaling might also be involved in the pathogenesis in this CRS model. The beneficial effects of valsartan in terms of attenuating cardiac and renal hypertrophy and reducing 24 hours albumin in this model might partly be mediated through down-regulating galectin-3 signal pathway.

  9. Resveratrol down-regulates survivin and induces apoptosis in human multidrug-resistant SPC-A-1/CDDP cells.

    Science.gov (United States)

    Zhao, Weiguo; Bao, Pengtao; Qi, Haowen; You, Houcheng

    2010-01-01

    We studied the effect of resveratrol treatment on multidrug-resistant human non-small cell lung cancer cells. Human multidrug-resistant SPC-A-1/CDDP cells were treated with resveratrol at a concentration of 25, 50, or 100 microM in in vitro studies and nude mice were implanted with multidrug-resistant SPC-A-1/and fed a special diet that included resveratrol at a dose of either 1 g/kg/day or 3 g/kg/day in in vivo studies. No adverse toxicological effects of resveratrol treatment were observed. The rate of cell proliferation, apoptosis ratio, cell cycle phase distribution, IC50 values of cisplatin, gefitinib, and paclitaxel, implanted tumour volume, and expression of survivin in resveratrol-treated and control mice were then determined. Resveratrol significantly inhibited the proliferation of SPC-A-1/CDDP cells, induced apoptosis, arrested the cell cycle phase between G0-G1 and S phase or at the G2/M phase, decreased the IC50 values of multiple chemotherapeutic drugs, and showed anti-tumour effects in nude mice that had been implanted with SPC-A-1/CDDP cells. In additional, resveratrol affected the proliferation of SPC-A-1/CDDP cells in a dose- and time-dependent manner. Expression of survivin in SPC-A-1/CDDP cells decreased after they were treated with all concentrations of resveratrol and resveratrol was also found to have a dose-dependent effect on survivin expression. Resveratrol can induce apoptosis in multidrug-resistant human NSCLC SPC-A-1/CDDP cells by down-regulating the expression of survivin.

  10. Maternal obesity down-regulates microRNA (miRNA) let-7g expression, a possible mechanism for enhanced adipogenesis during ovine fetal skeletal muscle development

    Science.gov (United States)

    Yan, Xu; Huang, Yan; Zhao, Jun-Xing; Rogers, Carl J.; Zhu, Mei-Jun; Ford, Stephen P.; Nathanielsz, Peter W.; Du, Min

    2014-01-01

    Background Obesity in women of childbearing age is increasing at an alarming rate. Growing evidence shows that maternal obesity induces detrimental effects on offspring health including pre-disposition to obesity. We have shown that maternal obesity increases fetal intramuscular adipogenesis at mid-gestation. However, the mechanisms are poorly understood. MicroRNAs (miRNAs) regulate mRNA stability. We hypothesized that maternal obesity alters fetal muscle miRNA expression, thereby influencing intramuscular adipogenesis. Methods Non-pregnant ewes received a control diet (Con, fed 100% of NRC recommendations, n = 6) or obesogenic diet (OB; 150% NRC recommendations, n = 6) from 60 days before to 75 days after conception when the fetal longissimus dorsi (LD) muscle was sampled and miRNA expression analyzed by miRNA microarray. One of miRNAs with differential expression between Con and OB fetal muscle, let-7g, was further tested for its role in adipogenesis and cell proliferation in C3H10T1/2 cells. Results A total of 155 miRNAs were found with a signal above 500, among which, 3 miRNAs, hsa-miR-381, hsa-let-7g and bta-miR-376d, were differentially expressed between Con and OB fetuses, and confirmed by QRT-PCR analyses. Reduced expression of miRNA let-7g, an abundantly expressed miRNA, in OB fetal muscle was correlated with higher expression of its target genes. Over-expression of let-7g in C3H10T1/2 cells reduced their proliferation rate. Expression of adipogenic markers decreased in cells over-expressing let-7g, and the formation of adipocytes was also reduced. Over-expression of let-7g decreased expression of inflammatory cytokines. Conclusion Fetal muscle miRNA expression was altered due to maternal obesity, and let-7g down-regulation may enhance intramuscular adipogenesis during fetal muscle development in the setting of maternal obesity. PMID:22614057

  11. Down-regulated βIII-tubulin Expression Can Reverse Paclitaxel Resistance in A549/Taxol Cells Lines

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    Yinling ZHUO

    2014-08-01

    Full Text Available Background and objective Chemotherapy drug resistance is the primary causes of death in patients with pulmonary carcinoma which make tumor recurrence or metastasis. β-tubulin is the main cell targets of anti-microtubule drug. Increased expression of βIII-tubulin has been implicated in non-small cell lung cancer (NSCLC cell lines. To explore the relationship among the expression level of βIII-tubulin and the sensitivity of A549/Taxolcell lines to Taxol and cell cycles and cell apoptosis by RNA interference-mediated inhibition of βIII-tubulin in A549/Taxol cells. Methods Three pairs of siRNA targetd βIII-tubulin were designed and prepared, which were transfected into A549/Taxol cells using LipofectamineTM 2000. We detected the expression of βIII-tubulin mRNA using Real-time fluorescence qRT-PCR. Tedhen we selected the most efficient siRNA by the expression of βIII-tubulin mRNA in transfected group. βIII-tubulin protein level were mesured by Western blot. The taxol sensitivity in transfected group were evaluated by MTT assay. And the cell apoptosis and cell cycles were determined by flow cytometry. Results βIII-tubulin mRNA levels in A549/Taxol cells were significantly decreased in transfected grop by Real-time qRT-PCR than control groups. And βIII-tubulin siRNA-1 sequence showed the highest transfection efficiency, which was (87.73±4.87% (P<0.01; Western blot results showed that the expressional level of BIII tublin protein was significantly down-reulated in the transfectant cells than thant in the control cells. By MTT assay, we showed that the inhibition ratio of Taxol to A549/Taxol cells transfeced was higher than that of control group (51.77±4.60% (P<0.01. The early apoptosis rate of A549/Taxol cells in transfected group were significantly higher than that of control group (P<0.01; G2-M content in taxol group obviously increased than untreated samples by the cell cycle (P<0.05. Conclusion βIII-tubulin down-regulated significantly

  12. Transcriptional down regulation of hTERT and senescence induction in HepG2 cells by chelidonine

    Science.gov (United States)

    Kazemi Noureini, Sakineh; Wink, Michael

    2009-01-01

    aged with large volume and dark staining in the β-galactosidase assay. CONCLUSION: Chelidonine reduces telomerase activity through down-regulation of hTERT expression. Senescence induction might not be directly caused by reducing telomerase activity as it occurs after a few population doublings. PMID:19653337

  13. Resveratrol Induced Premature Senescence Is Associated with DNA Damage Mediated SIRT1 and SIRT2 Down-Regulation.

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    Mehtap Kilic Eren

    agent doxorubicin also induced senescence in BJ fibroblasts associated with decreased SIRT1/2 levels. In conclusion our data reveal that resveratrol induced premature senescence is associated with SIRT1 and SIRT2 down regulation in human dermal fibroblasts. Here we suggest that the concomitant decline in SIRT1/2 expression in response to resveratrol treatment may be a cause for induction of senescence, which is most likely mediated by a regulatory mechanism activated by DNA damage response.

  14. Down-regulation of neogenin accelerated glioma progression through promoter Methylation and its overexpression in SHG-44 Induced Apoptosis.

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    Xinmin Wu

    Full Text Available BACKGROUND: Dependence receptors have been proved to act as tumor suppressors in tumorigenesis. Neogenin, a DCC homologue, well known for its fundamental role in axon guidance and cellular differentiation, is also a dependence receptor functioning to control apoptosis. However, loss of neogenin has been reported in several kinds of cancers, but its role in glioma remains to be further investigated. METHODOLOGY/PRINCIPAL FINDINGS: Western blot analysis showed that neogenin level was lower in glioma tissues than in their matching surrounding non-neoplastic tissues (n = 13, p<0.01. By immunohistochemical analysis of 69 primary and 16 paired initial and recurrent glioma sections, we found that the loss of neogenin did not only correlate negatively with glioma malignancy (n = 69, p<0.01, but also glioma recurrence (n = 16, p<0.05. Kaplan-Meier plot and Cox proportional hazards modelling showed that over-expressive neogenin could prolong the tumor latency (n = 69, p<0.001, 1187.6 ± 162.6 days versus 687.4 ± 254.2 days and restrain high-grade glioma development (n = 69, p<0.01, HR: 0.264, 95% CI: 0.102 to 0.687. By Methylation specific polymerase chain reaction (MSP, we reported that neogenin promoter was methylated in 31.0% (9/29 gliomas, but absent in 3 kinds of glioma cell lines. Interestingly, the prevalence of methylation in high-grade gliomas was higher than low-grade gliomas and non-neoplastic brain tissues (n = 33, p<0.05 and overall methylation rate increased as glioma malignancy advanced. Furthermore, when cells were over-expressed by neogenin, the apoptotic rate in SHG-44 was increased to 39.7% compared with 8.1% in the blank control (p<0.01 and 9.3% in the negative control (p<0.01. CONCLUSIONS/SIGNIFICANCE: These observations recapitulated the proposed role of neogenin as a tumor suppressor in gliomas and we suggest its down-regulation owing to promoter methylation is a selective advantage for glioma genesis, progression and recurrence

  15. Transcriptional down regulation of hTERT and senescence induction in HepG2 cells by chelidonine

    Institute of Scientific and Technical Information of China (English)

    Sakineh Kazemi Noureini; Michael Wink

    2009-01-01

    aged with large volume and dark staining in the β-galactosidase assay. CONCLUSION: Chelidonine reduces telomerase activity through down-regulation of hTERT expression. Senescence induction might not be directly caused by reducing telomerase activity as it occurs after a few population doublings.

  16. Low-dose paclitaxel ameliorates fibrosis in the remnant kidney model by down-regulating miR-192.

    Science.gov (United States)

    Sun, Lin; Zhang, Dongshan; Liu, Fuyou; Xiang, Xudong; Ling, Guanghui; Xiao, Li; Liu, Yinghong; Zhu, Xuejing; Zhan, Ming; Yang, Yeyi; Kondeti, Vinay K; Kanwar, Yashpal S

    2011-11-01

    Transforming growth factor (TGF)-β has been shown to play a central role in the development of tubulointerstitial fibrosis, which can be corrected via treatment with paclitaxel. The biology of microRNA (miR) can be modulated by paclitaxel. We hypothesized that paclitaxel may attenuate renal fibrosis in a rat model of remnant kidney disease by inhibiting TGF-β induced-miRs. Rats in groups of 12 were subjected to 5/6 nephrectomy and received low-dose intraperitoneal injection of paclitaxel. Renal functions were assessed at 8 weeks. The TGF-β signalling cascade and ECM proteins were evaluated by real-time polymerase chain reaction (TRT-PCR) and immunofluorescence microscopy. Animals with remnant kidneys developed hypertension, which was not relieved with paclitaxel treatment. However, paclitaxel treatment resulted in dampening the proteinuric response, reduction in serum BUN, creatinine levels and urine protein : creatinine ratio and normalization of creatinine clearance. These effects were accompanied by the inhibition of Smad2/3 activation, attenuation of renal fibrosis and normalization of integrin-linked kinase (ILK), COL(I)A1, COL(IV)A2 and α-SMA expression. Also, paclitaxel down-regulated the expression of miR-192, miR-217 and miR -377, while miR-15 was up-regulated in the remnant kidney. In vitro, in tubular epithelial cells (NRK-52E), paclitaxel also inhibited TGF-β1-induced Smad2/3 activation and normalized ILK, COL(I)A1, COL(IV)A2 and α-SMA expression. Furthermore, ChIP analyses indicated that Taxol suppressed Smad3-mediated miR-192 transcriptional activity. Over-expression of miR-192 in NRK-52E mimicked the changes seen in the remnant kidney, while inclusion of miR-192 inhibitor in the culture medium blocked TGF-β1-induced COL(I)A1 and COL(IV)A2 expression, while ILK and α-SMA were unaffected. These data suggest that low-dose paclitaxel ameliorates renal fibrosis via modulating miR-192 pathobiology and TGF-β/Smad signalling. Copyright © 2011

  17. Atherosclerosis-Associated Endothelial Cell Apoptosis by MiR-429-Mediated Down Regulation of Bcl-2

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    Tao Zhang

    2015-10-01

    -associated endothelial cell apoptosis may result from down regulation of Bcl-2, through increased miR-429 that binds and suppresses translation of Bcl-2 mRNA.

  18. The rapid antidepressant effect of ketamine in rats is associated with down-regulation of pro-inflammatory cytokines in the hippocampus

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    Wang, Nan; Yu, Hai-Ying; Shen, Xiao-Feng; Gao, Zhi-Qin; Yang, Chun; Yang, Jian-Jun; Zhang, Guang-Fen

    2015-01-01

    Objectives. Active inflammatory responses play an important role in the pathogenesis of depression. We hypothesized that the rapid antidepressant effect of ketamine is associated with the down-regulation of pro-inflammatory mediators. Methods. Forty-eight rats were equally randomized into six groups (a control and five chronic unpredictable mild stress (CUMS) groups) and given either saline or 10 mg/kg ketamine, respectively. The forced swimming test was performed, and the hippocampus was sub...

  19. Francisella tularensis elicits IL-10 via a PGE₂-inducible factor, to drive macrophage MARCH1 expression and class II down-regulation.

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    Danielle Hunt

    Full Text Available Francisella tularensis is a bacterial pathogen that uses host-derived PGE₂ to subvert the host's adaptive immune responses in multiple ways. Francisella-induced PGE₂ acts directly on CD4 T cells to blunt production of IFN-γ. Francisella-induced PGE₂ can also elicit production of a >10 kDa soluble host factor termed FTMØSN (F. tularensismacrophage supernatant, which acts on IFN-γ pre-activated MØ to down-regulate MHC class II expression via a ubiquitin-dependent mechanism, blocking antigen presentation to CD4 T cells. Here, we report that FTMØSN-induced down-regulation of MØ class II is the result of the induction of MARCH1, and that MØ expressing MARCH1 "resistant" class II molecules are resistant to FTMØSN-induced class II down-regulation. Since PGE₂ can induce IL-10 production and IL-10 is the only reported cytokine able to induce MARCH1 expression in monocytes and dendritic cells, these findings suggested that IL-10 is the active factor in FTMØSN. However, use of IL-10 knockout MØ established that IL-10 is not the active factor in FTMØSN, but rather that Francisella-elicited PGE₂ drives production of a >10 kDa host factor distinct from IL-10. This factor then drives MØ IL-10 production to induce MARCH1 expression and the resultant class II down-regulation. Since many human pathogens such as Salmonella typhi, Mycobacterium tuberculosis and Legionella pneumophila also induce production of host PGE₂, these results suggest that a yet-to-be-identified PGE₂-inducible host factor capable of inducing IL-10 is central to the immune evasion mechanisms of multiple important human pathogens.

  20. Sulindac sulfide induces autophagic death in gastric epithelial cells via survivin down-regulation: a mechanism of NSAIDs-induced gastric injury.

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    Chiou, Shiun-Kwei; Hoa, Neil; Hodges, Amy

    2011-06-01

    Sulindac sulfide, a nonsteroidal anti-inflammatory drug (NSAID), has anti-tumorigenic and anti-inflammatory activities, but causes gastric mucosal damage. NSAIDs cause gastric injury in part by down-regulation of Survivin, an apoptosis inhibitor, resulting in apoptosis induction. Autophagy is a process that promotes cellular health by destroying unwanted cellular materials. Excessive autophagy induction could lead to a non-apoptotic cell death (autophagic cell death). The present study showed that sulindac sulfide at a physiological concentration also induces autophagic death in human gastric epithelial AGS and rat gastric epithelial RGM-1 cells, and that Survivin down-regulation is a mechanism involved: Sulindac sulfide treatment increased LC3b-II and APG7 levels and cytosolic vacuole formation, indications of autophagy induction, in AGS and RGM-1 cells. Sulindac sulfide treatment induced AGS and RGM-1 cell death, which was significantly reduced by pretreatment with the autophagy inhibitors 3-methyladenine and chloroquine, indicating that sulindac sulfide induced autophagic cell death. Stable overexpression of Survivin in RGM-1 cells did not inhibit the induction of LC3b-II levels or vacuole formation by sulindac sulfide, but significantly reduced the resulting cell death, suggesting that Survivin may inhibit autophagic cell death downstream of LC3b-II induction and vacuole formation. Indeed, siRNA depletion of LC3b in AGS cells inhibited the down-regulation of Survivin levels and the induction of cell death by sulindac sulfide, confirming that down-regulation of Survivin occurs in the autophagy pathway downstream of LC3b-II induction by sulindac sulfide. Induction of Survivin-dependent autophagic cell death is a novel mechanism by which sulindac sulfide induces gastric mucosal injury.

  1. Lower Expression of SLC27A1 Enhances Intramuscular Fat Deposition in Chicken via Down-Regulated Fatty Acid Oxidation Mediated by CPT1A

    Science.gov (United States)

    Qiu, Fengfang; Xie, Liang; Ma, Jing-e; Luo, Wen; Zhang, Li; Chao, Zhe; Chen, Shaohao; Nie, Qinghua; Lin, Zhemin; Zhang, Xiquan

    2017-01-01

    Intramuscular fat (IMF) is recognized as the predominant factor affecting meat quality due to its positive correlation with tenderness, juiciness, and flavor. Chicken IMF deposition depends on the balance among lipid synthesis, transport, uptake, and subsequent metabolism, involving a lot of genes and pathways, however, its precise molecular mechanisms remain poorly understood. In the present study, the breast muscle tissue of female Wenchang chickens (WC) (higher IMF content, 1.24 in D120 and 1.62 in D180) and female White Recessive Rock chickens (WRR; lower IMF content, 0.53 in D120 and 0.90 in D180) were subjected to RNA-sequencing (RNA-seq) analysis. Results showed that many genes related to lipid catabolism, such as SLC27A1, LPL, ABCA1, and CPT1A were down-regulated in WC chickens, and these genes were involved in the PPAR signaling pathway and formed an IPA® network related to lipid metabolism. Furthermore, SLC27A1 was more down-regulated in WRR.D180.B than in WRR.D120.B. Decreased cellular triglyceride (TG) and up-regulated CPT1A were observed in the SLC27A1 overexpression QM-7 cells, and increased cellular triglyceride (TG) and down-regulated CPT1A were observed in the SLC27A1 knockdown QM-7 cells. These results suggest that lower lipid catabolism exists in WC chickens but not in WRR chickens, and lower expression of SLC27A1 facilitate IMF deposition in chicken via down-regulated fatty acid oxidation mediated by CPT1A. These findings indicate that reduced lipid catabolism, rather than increased lipid anabolism, contributes to chicken IMF deposition. PMID:28706492

  2. MiR-155 induction by F. novicida but not the virulent F. tularensis results in SHIP down-regulation and enhanced pro-inflammatory cytokine response.

    Directory of Open Access Journals (Sweden)

    Thomas J Cremer

    Full Text Available The intracellular gram-negative bacterium Francisella tularensis causes the disease tularemia and is known for its ability to subvert host immune responses. Previous work from our laboratory identified the PI3K/Akt pathway and SHIP as critical modulators of host resistance to Francisella. Here, we show that SHIP expression is strongly down-regulated in monocytes and macrophages following infection with F. tularensis novicida (F.n.. To account for this negative regulation we explored the possibility that microRNAs (miRs that target SHIP may be induced during infection. There is one miR that is predicted to target SHIP, miR-155. We tested for induction and found that F.n. induced miR-155 both in primary monocytes/macrophages and in vivo. Using luciferase reporter assays we confirmed that miR-155 led to down-regulation of SHIP, showing that it specifically targets the SHIP 3'UTR. Further experiments showed that miR-155 and BIC, the gene that encodes miR-155, were induced as early as four hours post-infection in primary human monocytes. This expression was dependent on TLR2/MyD88 and did not require inflammasome activation. Importantly, miR-155 positively regulated pro-inflammatory cytokine release in human monocytes infected with Francisella. In sharp contrast, we found that the highly virulent type A SCHU S4 strain of Francisella tularensis (F.t. led to a significantly lower miR-155 response than the less virulent F.n. Hence, F.n. induces miR-155 expression and leads to down-regulation of SHIP, resulting in enhanced pro-inflammatory responses. However, impaired miR-155 induction by SCHU S4 may help explain the lack of both SHIP down-regulation and pro-inflammatory response and may account for the virulence of Type A Francisella.

  3. DNA methylation-mediated down-regulation of DNA methyltransferase-1 (DNMT1) is coincident with, but not essential for, global hypomethylation in human placenta.

    Science.gov (United States)

    Novakovic, Boris; Wong, Nick C; Sibson, Mandy; Ng, Hong-Kiat; Morley, Ruth; Manuelpillai, Ursula; Down, Thomas; Rakyan, Vardhman K; Beck, Stephan; Hiendleder, Stefan; Roberts, Claire T; Craig, Jeffrey M; Saffery, Richard

    2010-03-26

    The genome of extraembryonic tissue, such as the placenta, is hypomethylated relative to that in somatic tissues. However, the origin and role of this hypomethylation remains unclear. The DNA methyltransferases DNMT1, -3A, and -3B are the primary mediators of the establishment and maintenance of DNA methylation in mammals. In this study, we investigated promoter methylation-mediated epigenetic down-regulation of DNMT genes as a potential regulator of global methylation levels in placental tissue. Although DNMT3A and -3B promoters lack methylation in all somatic and extraembryonic tissues tested, we found specific hypermethylation of the maintenance DNA methyltransferase (DNMT1) gene and found hypomethylation of the DNMT3L gene in full term and first trimester placental tissues. Bisulfite DNA sequencing revealed monoallelic methylation of DNMT1, with no evidence of imprinting (parent of origin effect). In vitro reporter experiments confirmed that DNMT1 promoter methylation attenuates transcriptional activity in trophoblast cells. However, global hypomethylation in the absence of DNMT1 down-regulation is apparent in non-primate placentas and in vitro derived human cytotrophoblast stem cells, suggesting that DNMT1 down-regulation is not an absolute requirement for genomic hypomethylation in all instances. These data represent the first demonstration of methylation-mediated regulation of the DNMT1 gene in any system and demonstrate that the unique epigenome of the human placenta includes down-regulation of DNMT1 with concomitant hypomethylation of the DNMT3L gene. This strongly implicates epigenetic regulation of the DNMT gene family in the establishment of the unique epigenetic profile of extraembryonic tissue in humans.

  4. Src family kinase inhibitor PP2 efficiently inhibits cervical cancer cell proliferation through down-regulating phospho-Src-Y416 and phospho-EGFR-Y1173.

    Science.gov (United States)

    Kong, Lu; Deng, Zhihong; Shen, Haiying; Zhang, Yuxiang

    2011-02-01

    Tyrosine (Y) kinases inhibitors have been approved for targeted treatment of cancer. However, their clinical use is limited to some cancers and the mechanism of their action remains unclear. Previous study has indicated that PP2, a selective inhibitor of the Src family of non-receptor tyrosine kinases (nRTK), efficiently repressed cervical cancer growth in vitro and in vivo. In this regard, our aims are to explore the mechanism of PP2 on cervical cancer cell growth inhibition by investigating the suppressive divergence among PP1, PP2, and a negative control compound PP3. MTT results showed that three compounds had different inhibitory effects on proliferation of two cervical cancer cells, HeLa and SiHa, and PP2 was most efficient in a time- and dose-dependent manner. Moreover, we found 10 μM PP2 down-regulated pSrc-Y416 (P < 0.05), pEGFR-Y845 (P < 0.05), and -Y1173 (P < 0.05) expression levels, while 10 μM PP1 down-regulated pSrc-Y416 (P < 0.05) and pEGFR-Y845 (P < 0.05), but not pEGFR-Y1173; 10 μM PP3 down-regulated only pEGFR-Y1173 (P < 0.05). PP2 could modulate cell cycle arrest by up-regulating p21(Cip1) and p27(Kip1) in both HeLa and SiHa cells and down-regulating expression of cyclin A, and cyclin dependent kinase-2, -4 (Cdk-2, -4) in HeLa and of cyclin B and Cdk-2 in SiHa. Our results indicate that Src pathway and EGFR pathway play different roles in the proliferation of cervical cancer cells and PP2 efficiently reduces cervical cancer cell proliferation by reduction of both Src and EGFR activity.

  5. Down-regulation of paramyxovirus hemagglutinin-neuraminidase glycoprotein surface expression by a mutant fusion protein containing a retention signal for the endoplasmic reticulum.

    Science.gov (United States)

    Tanaka, Y; Heminway, B R; Galinski, M S

    1996-08-01

    The human parainfluenza virus type 3 (HPIV3) fusion (F) and hemagglutinin-neuraminidase (HN) glycoproteins are the principal components involved in virion receptor binding, membrane penetration, and ultimately, syncytium formation. While the requirement for both F and HN in this process has been determined from recombinant expression studies, stable physical association of these proteins in coimmunoprecipitation studies has not been observed. In addition, coexpression of other heterologous paramyxovirus F or HN glycoproteins with either HPIV3 F or HN does not result in the formation of syncytia, suggesting serotype-specific protein differences. In this study, we report that simian virus 5 and Sendai virus heterologous HN proteins and measles virus hemagglutinin (H) were found to be down-regulated when coexpressed with HPIV3 F. As an alternative to detecting physical associations of these proteins by coimmunoprecipitation, further studies were performed with a mutant HPIV3 F protein (F-KDEL) lacking a transmembrane anchor and cytoplasmic tail and containing a carboxyl-terminal retention signal for the endoplasmic reticulum (ER). F-KDEL was defective for transport to the cell surface and could down-regulate surface expression of HPIV3 HN and heterologous HN/H proteins from simian virus 5, Sendai virus, and measles virus in coexpression experiments. HN/H down-regulation appeared to result, in part, from an early block to HPIV3 HN synthesis, as well as an instability of the heterologous HN/H proteins within the ER. In contrast, coexpression of F-KDEL with HPIV3 wild-type F or the heterologous receptor-binding proteins, respiratory syncytial virus glycoprotein (G) and vesicular stomatitis virus glycoprotein (G), were not affected in transport to the cell surface. Together, these results support the notion that the reported serotype-specific restriction of syncytium formation may involve, in part, down-regulation of heterologous HN expression.

  6. Down-Regulation of KORRIGAN-Like Endo-β-1,4-Glucanase Genes Impacts Carbon Partitioning, Mycorrhizal Colonization and Biomass Production in Populus

    OpenAIRE

    2016-01-01

    A greater understanding of the genetic regulation of plant cell wall remodeling and the impact of modified cell walls on plant performance is important for the development of sustainable biofuel crops. Here, we studied the impact of down-regulating KORRIGAN-like cell wall biosynthesis genes, belonging to the endo-β-1,4-glucanase gene family, on Populus growth, metabolism and the ability to interact with symbiotic microbes. The reductions in cellulose content and lignin syringyl-to-guaiacyl un...

  7. Down-regulation of KORRIGAN-like endo-β-1,4-glucanase genes impacts carbon partitioning, mycorrhizal colonization and biomass production in Populus

    OpenAIRE

    2016-01-01

    A greater understanding of the genetic regulation of plant cell wall remodeling and the impact of modified cell walls on plant performance is important for the development of sustainable biofuel crops. Here, we studied the impact of down-regulating KORRIGAN-like cell wall biosynthesis genes, belonging to the endo-β-1,4-glucanase gene family, on Populus growth, metabolism and the ability to interact with symbiotic microbes. The reductions in cellulose content and lignin syringyl-to-guaiacyl un...

  8. Real-time neurofeedback using functional MRI could improve down-regulation of amygdala activity during emotional stimulation: a proof-of-concept study.

    Science.gov (United States)

    Brühl, Annette Beatrix; Scherpiet, Sigrid; Sulzer, James; Stämpfli, Philipp; Seifritz, Erich; Herwig, Uwe

    2014-01-01

    The amygdala is a central target of emotion regulation. It is overactive and dysregulated in affective and anxiety disorders and amygdala activity normalizes with successful therapy of the symptoms. However, a considerable percentage of patients do not reach remission within acceptable duration of treatment. The amygdala could therefore represent a promising target for real-time functional magnetic resonance imaging (rtfMRI) neurofeedback. rtfMRI neurofeedback directly improves the voluntary regulation of localized brain activity. At present, most rtfMRI neurofeedback studies have trained participants to increase activity of a target, i.e. up-regulation. However, in the case of the amygdala, down-regulation is supposedly more clinically relevant. Therefore, we developed a task that trained participants to down-regulate activity of the right amygdala while being confronted with amygdala stimulation, i.e. negative emotional faces. The activity in the functionally-defined region was used as online visual feedback in six healthy subjects instructed to minimize this signal using reality checking as emotion regulation strategy. Over a period of four training sessions, participants significantly increased down-regulation of the right amygdala compared to a passive viewing condition to control for habilitation effects. This result supports the concept of using rtfMRI neurofeedback training to control brain activity during relevant stimulation, specifically in the case of emotion, and has implications towards clinical treatment of emotional disorders.

  9. Hypoxia-Mediated Down-Regulation of Bid and Bax in Tumors Occurs via Hypoxia-Inducible Factor 1-Dependent and -Independent Mechanisms and Contributes to Drug Resistance

    Science.gov (United States)

    Erler, Janine T.; Cawthorne, Christopher J.; Williams, Kaye J.; Koritzinsky, Marianne; Wouters, Bradley G.; Wilson, Clare; Miller, Crispin; Demonacos, Costas; Stratford, Ian J.; Dive, Caroline

    2004-01-01

    Solid tumors with disorganized, insufficient blood supply contain hypoxic cells that are resistant to radiotherapy and chemotherapy. Drug resistance, an obstacle to curative treatment of solid tumors, can occur via suppression of apoptosis, a process controlled by pro- and antiapoptotic members of the Bcl-2 protein family. Oxygen deprivation of human colon cancer cells in vitro provoked decreased mRNA and protein levels of proapoptotic Bid and Bad. Hypoxia-inducible factor 1 (HIF-1) was dispensable for the down-regulation of Bad but required for that of Bid, consistent with the binding of HIF-1α to a hypoxia-responsive element (positions −8484 to −8475) in the bid promoter. Oxygen deprivation resulted in proteosome-independent decreased expression of Bax in vitro, consistent with a reduction in global translation efficiency. The physiological relevance of Bid and Bax down-regulation was confirmed in tumors in vivo. Oxygen deprivation resulted in decreased drug-induced apoptosis and clonogenic resistance to agents with different mechanisms of action. The contribution of Bid and/or Bax down-regulation to drug responsiveness was demonstrated by the relative resistance of normoxic cells that had no or reduced expression of Bid and/or Bax and by the finding that forced expression of Bid in hypoxic cells resulted in increased sensitivity to the topoisomerase II inhibitor etoposide. PMID:15024076

  10. Cellular transcriptional profiling in human lung epithelial cells infected by different subtypes of influenza A viruses reveals an overall down-regulation of the host p53 pathway

    Directory of Open Access Journals (Sweden)

    Lina Bruno

    2011-06-01

    Full Text Available Abstract Background Influenza viruses can modulate and hijack several cellular signalling pathways to efficiently support their replication. We recently investigated and compared the cellular gene expression profiles of human lung A549 cells infected by five different subtypes of human and avian influenza viruses (Josset et al. Plos One 2010. Using these transcriptomic data, we have focused our analysis on the modulation of the p53 pathway in response to influenza infection. Results Our results were supported by both RT-qPCR and western blot analyses and reveal multiple alterations of the p53 pathway during infection. A down-regulation of mRNA expression was observed for the main regulators of p53 protein stability during infection by the complete set of viruses tested, and a significant decrease in p53 mRNA expression was also observed in H5N1 infected cells. In addition, several p53 target genes were also down-regulated by these influenza viruses and the expression of their product reduced. Conclusions Our data reveal that influenza viruses cause an overall down-regulation of the host p53 pathway and highlight this pathway and p53 protein itself as important viral targets in the altering of apoptotic processes and in cell-cycle regulation.

  11. Region-specific down-regulation of Crhr1 gene expression in alcohol-preferring msP rats following ad lib access to alcohol.

    Science.gov (United States)

    Hansson, Anita C; Cippitelli, Andrea; Sommer, Wolfgang H; Ciccocioppo, Roberto; Heilig, Markus

    2007-03-01

    Corticotropin-releasing hormone 1 receptors (CRH-R1) mediate increased behavioral sensitivity to stress and excessive alcohol self-administration following a history of dependence. It was recently demonstrated that the genetically selected alcohol-preferring msP rat line replicates many characteristics of the post-dependent state, due to an innate up-regulation of the Crhr1 transcript in several limbic areas related to alcohol drinking motivation. Here, we examined whether voluntary alcohol consumption might be able to down-regulate Crhr1 transcript levels in msP rats in brain areas where elevated expression previously has been shown. Within central and medial amygdala (CeA, MeA), as well as the Nc. Accumbens, 2 weeks'ad lib access to alcohol led to a highly significant down-regulation of the Crhr1 transcript. Alcohol-induced Crhr1 down-regulation was not seen in cingulate cortex. These data support that recruitment of CRH-R1 signaling within components of the extended amygdala drives excessive alcohol intake, and that alcohol is voluntarily consumed in part for its ability to reduce CRH-R1 activity in this region.

  12. Down-regulation of heat shock protein HSP90ab1 in radiation-damaged lung cells other than mast cells.

    Science.gov (United States)

    Haase, Michael G; Geyer, Peter; Fitze, Guido; Baretton, Gustavo B

    2014-05-01

    Ionizing radiation (IR) leads to fibrosing alveolitis (FA) after a lag period of several weeks to months. In a rat model, FA starts at 8 weeks after IR. Before that, at 5.5 weeks after IR, the transcription factors Sp1 (stimulating protein 1) and AP-1 (activator protein 1) are inactivated. To find genes/proteins that were down-regulated at that time, differentially expressed genes were identified in a subtractive cDNA library and verified by quantitative RT-PCR (reverse transcriptase polymerase chain reaction), western blotting and immunohistochemistry (IH). The mRNA of the molecular chaperone HSP90AB1 (heat shock protein 90 kDa alpha, class B member 1) was down-regulated 5.5 weeks after IR. Later, when FA manifested, HSP90ab1 protein was down-regulated by more than 90% in lung cells with the exception of mast cells. In most mast cells of the normal lung, both HSP90ab1 and HSP70, another major HSP, show a very low level of expression. HSP70 was massively up-regulated in all mast cells three months after irradiation whereas HSP90AB1 was up-regulated only in a portion of mast cells. The strong changes in the expression of central molecular chaperones may contribute to the well-known disturbance of cellular functions in radiation-damaged lung tissue.

  13. Aspirin down Regulates Hepcidin by Inhibiting NF-κB and IL6/JAK2/STAT3 Pathways in BV-2 Microglial Cells Treated with Lipopolysaccharide

    Directory of Open Access Journals (Sweden)

    Wan-Ying Li

    2016-12-01

    Full Text Available Aspirin down regulates transferrin receptor 1 (TfR1 and up regulates ferroportin 1 (Fpn1 and ferritin expression in BV-2 microglial cells treated without lipopolysaccharides (LPS, as well as down regulates hepcidin and interleukin 6 (IL-6 in cells treated with LPS. However, the relevant mechanisms are unknown. Here, we investigate the effects of aspirin on expression of hepcidin and iron regulatory protein 1 (IRP1, phosphorylation of Janus kinase 2 (JAK2, signal transducer and activator of transcription 3 (STAT3 and P65 (nuclear factor-κB, and the production of nitric oxide (NO in BV-2 microglial cells treated with and without LPS. We demonstrated that aspirin inhibited hepcidin mRNA as well as NO production in cells treated with LPS, but not in cells without LPS, suppresses IL-6, JAK2, STAT3, and P65 (nuclear factor-κB phosphorylation and has no effect on IRP1 in cells treated with or without LPS. These findings provide evidence that aspirin down regulates hepcidin by inhibiting IL6/JAK2/STAT3 and P65 (nuclear factor-κB pathways in the cells under inflammatory conditions, and imply that an aspirin-induced reduction in TfR1 and an increase in ferritin are not associated with IRP1 and NO.

  14. Down-regulation of the P-glycoprotein relevant for multidrug resistance by intracellular acidification through the crosstalk of MAPK signaling pathways.

    Science.gov (United States)

    Jin, Weina; Lu, Ying; Li, Qinghua; Wang, Jian; Zhang, Hongju; Chang, Guoqiang; Lin, Yani; Pang, Tianxiang

    2014-09-01

    In our previous study, we have found that the tumor multidrug resistance mediated by P-glycoprotein could be reversed by sustained intracellular acidification through down-regulating the multidrug resistance gene 1 mRNA and P-glycoprotein expression. However, the molecular events linking the intracellular acidification and the regulation of P-glycoprotein remain unclear. In the present study, the molecular pathways involved in the regulation of P-glycoprotein expression by the intracellular acidification were investigated. We found that the P-glycoprotein expression was down-regulated by the intracellular acidification through inhibition of p38 mitogen-activated protein kinase (MAPK) and the activation of c-Jun N-terminal kinase (JNK) in the resisitant K562/DOX cells. In the sensitive K562 and HL60 cell lines, the changes of the p38 MAPK expression after the acidification are not as obvious as that of K562/DOX cells, but the activation of extracellular signal-regulated kinase (ERK) is also observed, which indicates that the down-regulation of p38 MAPK by the intracellular acidification might be the resistant cell line specific. Blockade of ERK and JNK signaling by the inhibitors or RNA interference increased p38MAPK activities suggesting that cross-talk within MAPKs is also important for this response. Our study provides the first direct evidence that the reversal of P-glycoprotein-mediated multidrug resistance by intracellular acidification is mediated by the crosstalk of MAPK signaling pathways.

  15. Meta-analysis reveals up-regulation of cholesterol processes in non-alcoholic and down-regulation in alcoholic fatty liver disease

    Science.gov (United States)

    Wruck, Wasco; Adjaye, James

    2017-01-01

    AIM To compare transcriptomes of non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) in a meta-analysis of liver biopsies. METHODS Employing transcriptome data from patient liver biopsies retrieved from several public repositories we performed a meta-analysis comparing ALD and NAFLD. RESULTS We observed predominating commonalities at the transcriptome level between ALD and NAFLD, most prominently numerous down-regulated metabolic pathways and cytochrome-related pathways and a few up-regulated pathways which include ECM-receptor interaction, phagosome and lysosome. However some pathways were regulated in opposite directions in ALD and NAFLD, for example, glycolysis was down-regulated in ALD and up-regulated in NAFLD. Interestingly, we found rate-limiting genes such as HMGCR, SQLE and CYP7A1 which are associated with cholesterol processes adversely regulated between ALD (down-regulated) and NAFLD (up-regulated). We propose that similar phenotypes in both diseases may be due to a lower level of the enzyme CYP7A1 compared to the cholesterol synthesis enzymes HMGCR and SQLE. Additionally, we provide a compendium of comparative KEGG pathways regulation in ALD and NAFLD. CONCLUSION Our finding of adversely regulated cholesterol processes in ALD and NAFLD draws the focus to regulation of cholesterol secretion into bile. Thus, it will be interesting to further investigate CYP7A1-mediated cholesterol secretion into bile - also as possible drug targets. The list of potential novel biomarkers may assist differential diagnosis of ALD and NAFLD. PMID:28357032

  16. Warfarin and coumarin-like Murraya paniculata extract down-regulate EpCAM-mediated cell adhesion: individual components versus mixture for studying botanical metastatic chemopreventives.

    Science.gov (United States)

    Shao, Jingwei; Zhou, Suxia; Jiang, Zhou; Chi, Ting; Ma, Ji; Kuo, Minliang; Lee, Alan Yueh-Luen; Jia, Lee

    2016-08-02

    We recently defined cancer metastatic chemoprevention as utilizing safe and effective molecules to comprehensively prevent the spark of activation-adhesion-extravasation-proliferation metastatic cascade caused by circulating tumor cells (CTCs). The strategy focuses on preventing the most important starting point of the cascade. We identified an extract from a well-known medical plant Murraya paniculata, which inhibited both embryonic implantation to human endometrium as traditionally-used for abortion and CTC adhesion to human endothelium. Here, we separated and characterized five coumarin-containing components (Z1-Z5) from the botanic extract. Flow cytometry revealed that within 1-100 μg/mL, Z3 and Z5 down-regulated EpCAM expression in human colon HCT116, whereas, Z1 and Z2 did oppositely. Warfarin and Z1-Z5 component mixture (CM) also down-regulated EpCAM expression. The down-regulation of EpCAM by Z3, Z5, CM and warfarin was confirmed by western blotting, and caused inhibition on adhesion of cancer cells to human endothelial cells. Rat coagulation study showed that warfarin prolonged prothrombin time, whereas, Z3 did not. The present studies revealed that, for the first time, warfarin and coumarin-like components Z3, Z5 and CM from Murraya paniculata could directly inhibit EpCAM-mediated cell-cell adhesion.

  17. Involvement of SIRT1 in hypoxic down-regulation of c-Myc and β-catenin and hypoxic preconditioning effect of polyphenols

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Kyung-Soo [Department of Biochemistry, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Research Center for Ischemic Tissue regeneration, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Park, Jun-Ik [Department of Biochemistry, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Kim, Mi-Ju; Kim, Hak-Bong; Lee, Jae-Won [Department of Biochemistry, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Research Center for Ischemic Tissue regeneration, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Dao, Trong Tuan; Oh, Won Keun [BK21 Project Team, College of Pharmacy, Chosun University, Gwangju (Korea, Republic of); Kang, Chi-Dug, E-mail: kcdshbw@pusan.ac.kr [Department of Biochemistry, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Kim, Sun-Hee, E-mail: ksh7738@pusan.ac.kr [Department of Biochemistry, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Research Center for Ischemic Tissue regeneration, Pusan National University School of Medicine, Yangsan (Korea, Republic of)

    2012-03-01

    SIRT1 has been found to function as a Class III deacetylase that affects the acetylation status of histones and other important cellular nonhistone proteins involved in various cellular pathways including stress responses and apoptosis. In this study, we investigated the role of SIRT1 signaling in the hypoxic down-regulations of c-Myc and β-catenin and hypoxic preconditioning effect of the red wine polyphenols such as piceatannol, myricetin, quercetin and resveratrol. We found that the expression of SIRT1 was significantly increased in hypoxia-exposed or hypoxic preconditioned HepG2 cells, which was closely associated with the up-regulation of HIF-1α and down-regulation of c-Myc and β-catenin expression via deacetylation of these proteins. In addition, blockade of SIRT1 activation using siRNA or amurensin G, a new potent SIRT1 inhibitor, abolished hypoxia-induced HIF-1α expression but increased c-Myc and β-catenin expression. SIRT1 was also found to stabilize HIF-1α protein and destabilize c-Myc, β-catenin and PHD2 under hypoxia. We also found that myricetin, quercetin, piceatannol and resveratrol up-regulated HIF-1α and down-regulated c-Myc, PHD2 and β-catenin expressions via SIRT1 activation, in a manner that mimics hypoxic preconditioning. This study provides new insights of the molecular mechanisms of hypoxic preconditioning and suggests that polyphenolic SIRT1 activators could be used to mimic hypoxic/ischemic preconditioning. -- Graphical abstract: Polyphenols mimicked hypoxic preconditioning by up-regulating HIF-1α and SIRT1 and down-regulating c-Myc, PHD2, and β-catenin. HepG2 cells were pretreated with the indicated doses of myricetin (MYR; A), quercetin (QUR; B), or piceatannol (PIC; C) for 4 h and then exposed to hypoxia for 4 h. Levels of HIF-1α, SIRT1, c-Myc, β-catenin, and PHD2 were determined by western blot analysis. The data are representative of three individual experiments. Highlights: ► SIRT1 expression is increased in hypoxia

  18. Pioglitazone ameliorates nonalcoholic steatohepatitis by down-regulating hepatic nuclear factor-kappa B and cyclooxygenases-2 expression in rats

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jia-sheng; ZHU Feng-shang; LIU Su; YANG Chang-qing; CHEN Xi-mei

    2012-01-01

    was decreased in the NASHgroup.Real-time PCR and Western blotting revealed mRNA and protein expression of COX-2 were increased in theNASH group compared with the control group (0.57±0.08 vs.2.83±0.24; 0.38±0.03 vs.1.00±0.03,P<0.001 and,P=0.004,respectively).After pioglitazone intervention,all of those parameters markedly improved (P <0.05 or P <0.01 ).Conclusion Down-regulating hepatic NF-κB and COX-2 expression,at least in part,is one of the possible therapeutic mechanisms of pioglitazone in NASH rats.

  19. Activation of Cdk5/p25 and tau phosphorylation following chronic brain hypoperfusion in rats involves microRNA-195 down-regulation.

    Science.gov (United States)

    Sun, Li-Hua; Ban, Tao; Liu, Cheng-Di; Chen, Qing-Xin; Wang, Xu; Yan, Mei-Ling; Hu, Xue-Ling; Su, Xiao-Lin; Bao, Ya-Nan; Sun, Lin-Lin; Zhao, Lin-Jing; Pei, Shuang-Chao; Jiang, Xue-Mei; Zong, De-Kang; Ai, Jing

    2015-09-01

    Chronic brain hypoperfusion (CBH) is a common clinical feature of Alzheimer's disease and vascular dementia, but the underlying molecular mechanism is unclear. Our previous study reported that the down-regulation of microRNA-195 (miR-195) promotes amyloidogenesis via regulation of amyloid precursor protein and β-site amyloid precursor protein cleaving enzyme 1 (BACE1) expression at the post-transcriptional level in CBH rats with bilateral common carotid artery occlusion (2VO). CBH owing to unilateral common carotid artery occlusion (UCCAO) increases tau phosphorylation levels at multiple phosphorylation sites in the brain, but the molecular mechanism is poorly understood. The purpose of this study was to investigate whether miR-195 could both deregulate amyloid metabolism and indirectly deregulate tau phosphorylation in CBH. We observed that 2VO leads to tau hyperphosphorylation at Ser202/Thr205, Ser262, Thr231, and Ser422 and to the conversion from cyclin-dependent kinase 5 (Cdk5)/p35 to Cdk5/p25 in rat hippocampi. Endogenous miR-195 was knocked down using over-expression of its antisense molecule (pre-AMO-miR-195) via a lentivirus (lenti-pre-AMO-miR-195); this knockdown increased the tau phosphorylation at Ser202/Thr205, Ser262, Thr231, Ser422, and the Cdk5/p25 activation, but over-expression of miR-195 using lenti-pre-miR-195 decreased the tau phosphorylation and Cdk5/p25 activation. Further in vitro studies demonstrated that miR-195 over-expression prevented tau hyperphosphorylation and Cdk5/p35 activity, which were increased by miR-195 inhibition. A dual luciferase reporter assay showed that miR-195 bound to the Cdk5r1 gene, which encodes p35 protein, in the 3'UTR and inhibited p35 expression. We concluded that tau hyperphosphorylation involves the down-regulation of miR-195, which is mediated by Cdk5/p25 activation in 2VO rats. Our findings demonstrated that down-regulation of miR-195 led to increased vulnerability via the regulation of multiple targets

  20. Cell-based Fluorescence Complementation Reveals a Role for HIV-1 Nef Protein Dimerization in AP-2 Adaptor Recruitment and CD4 Co-receptor Down-regulation.

    Science.gov (United States)

    Shu, Sherry T; Emert-Sedlak, Lori A; Smithgall, Thomas E

    2017-02-17

    The HIV-1 Nef accessory factor enhances viral infectivity, immune evasion, and AIDS progression. Nef triggers rapid down-regulation of CD4 via the endocytic adaptor protein 2 (AP-2) complex, a process linked to enhanced viral infectivity and immune escape. Here, we describe a bimolecular fluorescence complementation (BiFC) assay to visualize the interaction of Nef with AP-2 and CD4 in living cells. Interacting protein pairs were fused to complementary non-fluorescent fragments of YFP and co-expressed in 293T cells. Nef interactions with both CD4 and AP-2 resulted in complementation of YFP and a bright fluorescent signal by confocal microcopy that localized to the cell periphery. Co-expression of the AP-2 α subunit enhanced the Nef·AP-2 σ2 subunit BiFC signal and vice versa, suggesting that the AP-2 α-σ2 hemicomplex interacts cooperatively with Nef. Mutagenesis of Nef amino acids Arg-134, Glu-174, and Asp-175, which stabilize Nef for AP-2 α-σ2 binding in a recent co-crystal structure, substantially reduced AP-2 interaction without affecting CD4 binding. A dimerization-defective mutant of Nef failed to interact with either CD4 or AP-2 in the BiFC assay, indicating that Nef quaternary structure is required for CD4 and AP-2 recruitment as well as CD4 down-regulation. A small molecule previously shown to bind the Nef dimerization interface also reduced Nef interactions with AP-2 and CD4 and restored CD4 expression to the surface of HIV-infected cells. Our findings provide a mechanistic explanation for previous observations that dimerization-defective Nef mutants fail to down-regulate CD4 and validate the Nef dimerization interface as a target site for antiretroviral drug development. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  1. Nicotine-induced retardation of chondrogenesis through down-regulation of IGF-1 signaling pathway to inhibit matrix synthesis of growth plate chondrocytes in fetal rats

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Yu; Cao, Hong; Cu, Fenglong [Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); Xu, Dan [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Research Center of Food and Drug Evaluation, Wuhan University, Wuhan 430071 (China); Lei, Youying [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Tan, Yang [Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); Magdalou, Jacques [UMR 7561 CNRS-Nancy Université, Faculté de Médicine, Vandoeuvre-lès-Nancy (France); Wang, Hui [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Research Center of Food and Drug Evaluation, Wuhan University, Wuhan 430071 (China); Chen, Liaobin, E-mail: lbchen@whu.edu.cn [Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China)

    2013-05-15

    Previous studies have confirmed that maternal tobacco smoking causes intrauterine growth retardation (IUGR) and skeletal growth retardation. Among a multitude of chemicals associated with cigarette smoking, nicotine is one of the leading candidates for causing low birth weights. However, the possible mechanism of delayed chondrogenesis by prenatal nicotine exposure remains unclear. We investigated the effects of nicotine on fetal growth plate chondrocytes in vivo and in vitro. Rats were given 2.0 mg/kg·d of nicotine subcutaneously from gestational days 11 to 20. Prenatal nicotine exposure increased the levels of fetal blood corticosterone and resulted in fetal skeletal growth retardation. Moreover, nicotine exposure induced the inhibition of matrix synthesis and down-regulation of insulin-like growth factor 1 (IGF-1) signaling in fetal growth plates. The effects of nicotine on growth plates were studied in vitro by exposing fetal growth plate chondrocytes to 0, 1, 10, or 100 μM of nicotine for 10 days. Nicotine inhibited matrix synthesis and down-regulated IGF-1 signaling in chondrocytes in a concentration-dependent manner. These results suggest that prenatal nicotine exposure induces delayed chondrogenesis and that the mechanism may involve the down-regulation of IGF-1 signaling and the inhibition of matrix synthesis by growth plate chondrocytes. The present study aids in the characterization of delayed chondrogenesis caused by prenatal nicotine exposure, which might suggest a candidate mechanism for intrauterine origins of osteoporosis and osteoarthritis. - Highlights: ► Prenatal nicotine-exposure could induce delayed chondrogenesis in fetal rats. ► Nicotine inhibits matrix synthesis of fetal growth plate chondrocytes. ► Nicotine inhibits IGF-1 signaling pathway in fetal growth plate chondrocytes.

  2. Steroidogenesis and early response gene expression in MA-10 Leydig tumor cells following heterologous receptor down-regulation and cellular desensitization

    Directory of Open Access Journals (Sweden)

    Tsuey-Ming Chen

    2016-03-01

    Full Text Available The Leydig tumor cell line, MA-10, expresses the luteinizing hormone receptor, a G protein-coupled receptor that, when activated with luteinizing hormone or chorionic gonadotropin (CG, stimulates cAMP production and subsequent steroidogenesis, notably progesterone. These cells also respond to epidermal growth factor (EGF and phorbol esters with increased steroid biosynthesis. In order to probe the intracellular pathways along with heterologous receptor down-regulation and cellular desensitization, cells were preincubated with EGF or phorbol esters and then challenged with CG, EGF, dibutryl-cyclic AMP, and a phorbol ester. Relative receptor numbers, steroid biosynthesis, and expression of the early response genes, JUNB and c-FOS, were measured. It was found that in all cases but one receptor down-regulation and decreased progesterone production were closely coupled under the conditions used; the exception involved preincubation of the cells with EGF followed by addition of CG where the CG-mediated stimulation of steroidogenesis was considerably lower than the level of receptor down-regulation. In a number of instances JUNB and c-FOS expression paralleled the decreases in receptor number and progesterone production, while in some cases these early response genes were affected little if at all by the changes in receptor number. This finding may indicate that even low levels of activated signaling kinases, e.g. protein kinase A, protein kinase C, or receptor tyrosine kinase, may suffice to yield good expression of JUNB and c-FOS, or it may suggest alternative pathways for regulating expression of these two early response genes.

  3. Nerve growth factor blocks the glucose-induced down-regulation of caveolin-1 expression in Schwann cells via p75 neurotrophin receptor signaling.

    Science.gov (United States)

    Tan, Wenbin; Rouen, Shefali; Barkus, Kristin M; Dremina, Yelena S; Hui, Dongwei; Christianson, Julie A; Wright, Douglas E; Yoon, Sung Ok; Dobrowsky, Rick T

    2003-06-20

    Altered neurotrophism in diabetic peripheral neuropathy (DPN) is associated in part with substantial degenerative changes in Schwann cells (SCs) and an increased expression of the p75 neurotrophin receptor (p75NTR). Caveolin-1 (Cav-1) is highly expressed in adult SCs, and changes in its expression can regulate signaling through Erb B2, a co-receptor that mediates the effects of neuregulins in promoting SC growth and differentiation. We examined the hypothesis that hyperglycemia-induced changes in Cav-1 expression and p75NTR signaling may contribute to altered neurotrophism in DPN by modulating SC responses to neuregulins. In an animal model of type 1 diabetes, hyperglycemia induced a progressive decrease of Cav-1 in SCs of sciatic nerve that was reversed by insulin therapy. Treatment of primary neonatal SCs with 20-30 mm d-glucose, but not l-glucose, was sufficient to inhibit transcription from the Cav-1 promoter and decrease Cav-1 mRNA and protein expression. Hyperglycemia prolonged the kinetics of Erb B2 phosphorylation and significantly enhanced the mitogenic response of SCs to neuregulin1-beta1, and this effect was mimicked by the forced down-regulation of Cav-1. Intriguingly, nerve growth factor antagonized the enhanced mitogenic response of SCs to neuregulin1-beta1 and inhibited the glucose-induced down-regulation of Cav-1 transcription, mRNA, and protein expression through p75NTR-dependent activation of JNK. Our data suggest that Cav-1 down-regulation may contribute to altered neurotrophism in DPN by enhancing the response of SCs to neuregulins and that p75NTR-mediated JNK activation may provide a mechanism for the neurotrophic modulation of hyperglycemic stress.

  4. Ovarian down Regulation by GnRF Vaccination Decreases Reproductive Tract Tumour Size in Female White and Greater One-Horned Rhinoceroses.

    Directory of Open Access Journals (Sweden)

    Robert Hermes

    Full Text Available Reproductive tract tumours, specifically leiomyoma, are commonly found in female rhinoceroses. Similar to humans, tumour growth in rhinoceroses is thought to be sex hormone dependent. Tumours can form and expand from the onset of ovarian activity at puberty until the cessation of sex-steroid influences at senescence. Extensive tumour growth results in infertility. The aim of this study was to down regulate reproductive function of tumour-diseased and infertile females to stop further tumour growth using a Gonadotropin releasing factor (GnRF vaccine. Four infertile southern white (Ceratotherium simum simum and three Greater one-horned rhinoceroses (rhinoceros unicornis with active ovaries and 2.7 ± 0.9 and 14.0 ± 1.5 reproductive tract tumours respectively were vaccinated against GnRF (Improvac®, Zoetis, Germany at 0, 4 and 16 weeks and re-boostered every 6-8 months thereafter. After GnRF vaccination ovarian and luteal activity was suppressed in all treated females. Three months after vaccination the size of the ovaries, the number of follicles and the size of the largest follicle were significantly reduced (P<0.03. Reproductive tract tumours decreased significantly in diameter (Greater-one horned rhino: P<0.0001; white rhino: P<0.01, presumably as a result of reduced sex-steroid influence. The calculated tumour volumes were reduced by 50.8 ± 10.9% in Greater one-horned and 48.6 ± 12.9% in white rhinoceroses. In conclusion, GnRF vaccine effectively down regulated reproductive function and decreased the size of reproductive tract tumours in female rhinoceros. Our work is the first to use down regulation of reproductive function as a symptomatic treatment against benign reproductive tumour disease in a wildlife species. Nonetheless, full reversibility and rhinoceros fertility following GnRF vaccination warrants further evaluation.

  5. In vitro mechanism for down-regulation of ERalpha expression by epigallocatechin gallate in ER+/PR+ human breast cancer cells

    Science.gov (United States)

    De Amicis, Francesca; Russo, Alessandra; Avena, Paola; Santoro, Marta; Vivacqua, Adele; Bonofiglio, Daniela; Mauro, Loredana; Aquila, Saveria; Tramontano, Donatella; Fuqua, Suzanne AW; Andò, Sebastiano

    2015-01-01

    Scope Exposure of the breast to estrogens and other sex hormones is an important cancer risk factor and estrogen receptor down-regulators are attracting significant clinical interest. Epigallocatechin gallate (EGCG), a polyphenolic compound found in green tea, has gained considerable attention for its antitumor properties. Here we aimed to investigate the molecular mechanisms through which EGCG regulates ERα expression in ER+ PR+ breast cancer cells. Material and Methods Western blotting analysis, real time PCR and transient transfections of deletion fragments of the ERα gene promoter show that EGCG down-regulates ERα protein, mRNA and gene promoter activity with a concomitant reduction of ERα genomic and non genomic signal. These events occur through p38MAPK/CK2 activation, causing the release from Hsp90 of PR-B and its consequent nuclear translocation as evidenced by immunofluorescence studies. EMSA and ChIP assay reveal that, upon EGCG treatment, PR-B is recruited at the half PRE site on ERα promoter. This is concomitant with the formation of a corepressor complex containing NCoR and HDAC1 while RNA polymerase II is displaced. The events are crucially mediated by PR-B isoform, since they are abrogated with PR-B siRNA. Conclusions Our data provide evidence for a mechanism by which EGCG down-regulates ERα and explain the inhibitory action of EGCG on the proliferation of ER+ PR+ cancer cells tested. We suggest that the EGCG/PR-B signaling should be further exploited for clinical approach. PMID:23322423

  6. Specific down-regulation of spermatogenesis genes targeted by 22G RNAs in hybrid sterile males associated with an X-Chromosome introgression.

    Science.gov (United States)

    Li, Runsheng; Ren, Xiaoliang; Bi, Yu; Ho, Vincy Wing Sze; Hsieh, Chia-Ling; Young, Amanda; Zhang, Zhihong; Lin, Tingting; Zhao, Yanmei; Miao, Long; Sarkies, Peter; Zhao, Zhongying

    2016-09-01

    Hybrid incompatibility (HI) prevents gene flow between species, thus lying at the heart of speciation genetics. One of the most common HIs is male sterility. Two superficially contradictory observations exist for hybrid male sterility. First, an introgression on the X Chromosome is more likely to produce male sterility than on autosome (so-called large-X theory); second, spermatogenesis genes are enriched on the autosomes but depleted on the X Chromosome (demasculinization of X Chromosome). Analysis of gene expression in Drosophila hybrids suggests a genetic interaction between the X Chromosome and autosomes that is essential for male fertility. However, the prevalence of such an interaction and its underlying mechanism remain largely unknown. Here we examine the interaction in nematode species by contrasting the expression of both coding genes and transposable elements (TEs) between hybrid sterile males and its parental nematode males. We use two lines of hybrid sterile males, each carrying an independent introgression fragment from Caenorhabditis briggsae X Chromosome in an otherwise Caenorhabditis nigoni background, which demonstrate similar defects in spermatogenesis. We observe a similar pattern of down-regulated genes that are specific for spermatogenesis between the two hybrids. Importantly, the down-regulated genes caused by the X Chromosome introgressions show a significant enrichment on the autosomes, supporting an epistatic interaction between the X Chromosome and autosomes. We investigate the underlying mechanism of the interaction by measuring small RNAs and find that a subset of 22G RNAs specifically targeting the down-regulated spermatogenesis genes is significantly up-regulated in hybrids, suggesting that perturbation of small RNA-mediated regulation may contribute to the X-autosome interaction.

  7. Expression of the IL-7 receptor alpha-chain is down regulated on the surface of CD4 T-cells by the HIV-1 Tat protein.

    Directory of Open Access Journals (Sweden)

    Denny McLaughlin

    Full Text Available HIV infection elicits defects in CD4 T-cell homeostasis in both a quantitative and qualitative manner. Interleukin-7 (IL-7 is essential to T-cell homeostasis and several groups have shown reduced levels of the IL-7 receptor alpha-chain (CD127 on both CD4 and CD8 T-cells in viremic HIV+ patients. We have shown previously that soluble HIV Tat protein specifically down regulates cell surface expression of CD127 on human CD8 T-cells in a paracrine fashion. The effects of Tat on CD127 expression in CD4 T-cells has yet to be described. To explore this effect, CD4 T-cells were isolated from healthy individuals and expression levels of CD127 were examined on cells incubated in media alone or treated with Tat protein. We show here that, similar to CD8 T-cells, the HIV-1 Tat protein specifically down regulates CD127 on primary human CD4 T-cells and directs the receptor to the proteasome for degradation. Down regulation of CD127 in response to Tat was seen on both memory and naive CD4 T-cell subsets and was blocked using either heparin or anti-Tat antibodies. Tat did not induce apoptosis in cultured primary CD4 T-cells over 72 hours as determined by Annexin V and PI staining. Pre-incubation of CD4 T-cells with HIV-1 Tat protein did however reduce the ability of IL-7 to up regulate Bcl-2 expression. Similar to exogenous Tat, endogenously expressed HIV Tat protein also suppressed CD127 expression on primary CD4 T-cells. In view of the important role IL-7 plays in lymphocyte proliferation, homeostasis and survival, down regulation of CD127 by Tat likely plays a central role in immune dysregulation and CD4 T-cell decline. Understanding this effect could lead to new approaches to mitigate the CD4 T-cell loss evident in HIV infection.

  8. Growth promotion in pigs by oxytetracycline coincides with down regulation of serum inflammatory parameters and of hibernation-associated protein HP-27

    DEFF Research Database (Denmark)

    Soler, Laura; Miller, Ingrid; Hummel, Karin

    2016-01-01

    The growth promoting effect of supplementing animal feed with antibiotics like tetracycline has traditionally been attributed to their antibiotic character. However, more evidence has been accumulated on their direct anti-inflammatory effect during the last two decades. Here we used a pig model...... and lipid metabolism, confirming the anti-inflammatory mechanism of OTC. Interestingly, apart from the classic acute phase reactants also down regulation was seen of a hibernation associated plasma protein (HP-27), which is to our knowledge the first description in pigs. Although the exact function in non-hibernators...

  9. Silencing of microRNA-155 in mice during acute inflammatory response leads to derepression of c/ebp Beta and down-regulation of G-CSF

    DEFF Research Database (Denmark)

    Worm, Jesper; Stenvang, Jan; Petri, Andreas;

    2009-01-01

    microRNA-155 (miR-155) has been implicated as a central regulator of the immune system, but its function during acute inflammatory responses is still poorly understood. Here we show that exposure of cultured macrophages and mice to lipopolysaccharide (LPS) leads to up-regulation of miR-155......-stimulating factor (G-CSF), a central regulator of granulopoiesis during inflammatory responses. Consistent with these data, we show that silencing of miR-155 in LPS-treated mice by systemically administered LNA-antimiR results in derepression of the c/ebp Beta isoforms and down-regulation of G-CSF expression...

  10. Hypoxia-mediated down-regulation of Bid and Bax in tumors occurs via hypoxia-inducible factor 1-dependent and -independent mechanisms and contributes to drug resistance

    DEFF Research Database (Denmark)

    Erler, Janine Terra; Cawthorne, Christopher J; Williams, Kaye J;

    2004-01-01

    of the Bcl-2 protein family. Oxygen deprivation of human colon cancer cells in vitro provoked decreased mRNA and protein levels of proapoptotic Bid and Bad. Hypoxia-inducible factor 1 (HIF-1) was dispensable for the down-regulation of Bad but required for that of Bid, consistent with the binding of HIF-1......alpha to a hypoxia-responsive element (positions -8484 to -8475) in the bid promoter. Oxygen deprivation resulted in proteosome-independent decreased expression of Bax in vitro, consistent with a reduction in global translation efficiency. The physiological relevance of Bid and Bax down...

  11. AS1411-Induced Growth Inhibition of Glioma Cells by Up-Regulation of p53 and Down-Regulation of Bcl-2 and Akt1 via Nucleolin

    OpenAIRE

    Cheng, Ye; Zhao, Gang; Zhang, Siwen; Nigim, Fares; Zhou, Guangtong; Yu, Zhiyun; Song, Yang; Chen, Yong; Li, Yunqian

    2016-01-01

    AS1411 binds nucleolin (NCL) and is the first oligodeoxynucleotide aptamer to reach phase I and II clinical trials for the treatment of several cancers. However, the mechanisms by which AS1411 targets and kills glioma cells and tissues remain unclear. Here we report that AS1411 induces cell apoptosis and cycle arrest, and inhibits cell viability by up-regulation of p53 and down-regulation of Bcl-2 and Akt1 in human glioma cells. NCL was overexpressed in both nucleus and cytoplasm in human gli...

  12. SKP2 siRNA inhibits the degradation of P27kip1 and down-regulates the expression of MRP in HL-60/A cells.

    Science.gov (United States)

    Xiao, Jie; Yin, Songmei; Li, Yiqing; Xie, Shuangfeng; Nie, Danian; Ma, Liping; Wang, Xiuju; Wu, Yudan; Feng, Jianhong

    2009-08-01

    S-phase kinase-associated protein 2 (SKP2) gene is a tumor suppressor gene, and is involved in the ubiquitin-mediated degradation of P27kip1. SKP2 and P27kip1 affect the proceeding and prognosis of leukemia through regulating the proliferation, apoptosis and differentiation of leukemia cells. In this study, we explored the mechanism of reversing of HL-60/A drug resistance through SKP2 down-regulation. HL-60/A cells were nucleofected by Amaxa Nucleofector System with SKP2 siRNA. The gene and protein expression levels of Skp2, P27kip1, and multi-drug resistance associated protein (MRP) were determined by reverse transcription-polymerase chain reaction and western blot analysis, respectively. The cell cycle was analyzed by flow cytometry. The 50% inhibitory concentration value was calculated using cytotoxic analysis according to the death rate of these two kinds of cells under different concentrations of chemotherapeutics to compare the sensitivity of the cells. HL-60/A cells showed multi-drug resistance phenotype characteristic by cross-resistance to adriamycin, daunorubicin, and arabinosylcytosine, due to the expression of MRP. We found that the expression of SKP2 was higher in HL-60/A cells than in HL-60 cells, but the expression of P27kip1 was lower. The expression of SKP2 in HL-60/A cells nucleofected by SKP2 siRNA was down-regulated whereas the protein level of P27kip1 was up-regulated. Compared with the MRP expression level in the control group (nucleofected by control siRNA), the mRNA and protein expression levels of MRP in HL-60/A cells nucleofected by SKP2 siRNA were lower, and the latter cells were more sensitive to adriamycin, daunorubicin, and arabinosylcytosine. Down-regulating the SKP2 expression and arresting cells in the G0/G1 phase improve drug sensitivity of leukemia cells with down-regulated MRP expression.

  13. Glucagon-like peptide 2 prevents down-regulation of intestinal multidrug resistance-associated protein 2 and P-glycoprotein in endotoxemic rats.

    Science.gov (United States)

    Arana, Maite Rocío; Tocchetti, Guillermo Nicolás; Zecchinati, Felipe; Londero, Ana Sofía; Dominguez, Camila; Perdomo, Virginia; Rigalli, Juan Pablo; Villanueva, Silvina Stella Maris; Mottino, Aldo Domingo

    2017-08-23

    Multidrug resistance-associated protein 2 (Mrp2, ABCC2) and P-glycoprotein (P-gp, ABCB1) constitute essential components of the intestinal biochemical barrier that prevent incorporation of food contaminants, drugs or toxic metabolites into the blood stream. Endotoxemia induced in rats by administration of bacterial lipopolysaccharide (LPS) results in elevated intestinal permeability and toxicity of xenobiotics in part associated with down-regulation of expression and activity of Mrp2 and P-gp. We evaluated the protective effect of glucagon-like peptide 2 (GLP-2), a peptide hormone with enterotrophic properties, on Mrp2 and P-gp alterations induced by single i.p. injection of LPS (5mg/kg b.wt.) to rats. Two different protocols of GLP-2 administration, namely prevention and reversion, were examined. The prevention protocol consisted of 7s.c. injections of GLP-2 (125μg/kg b.wt.) administered every 12h, starting 60h before LPS administration. The reversion protocol consisted of 2 doses of GLP-2, starting 3h after LPS injection. Intestinal samples were collected 24h after LPS administration and expression (protein and mRNA) and activity of Mrp2 were evaluated in proximal jejunum whereas those of P-gp were studied in ileum. GLP-2 completely neutralized down-regulation of expression of Mrp2 and P-gp and loss of their respective activities induced by LPS under prevention protocol. GLP-2 was also able to prevent internalization of both transporters from the apical membrane of the enterocyte to intracellular compartments, as detected by confocal microscopy. LPS induced an increase in IL-1β and oxidized glutathione tissue levels, which were also counterbalanced by GLP-2 administration. In contrast, the reversion protocol failed to attenuate Mrp2 and P-gp down-regulation induced by LPS. We conclude that GLP-2 can prevent down-regulation of intestinal expression and activity of Mrp2 and P-gp in endotoxemic rats and that IL-1β and oxidative stress constitute potential targets

  14. The dietary bioflavonoid, quercetin, selectively induces apoptosis of prostate cancer cells by down-regulating the expression of heat shock protein 90.

    Science.gov (United States)

    Aalinkeel, Ravikumar; Bindukumar, B; Reynolds, Jessica L; Sykes, Donald E; Mahajan, Supriya D; Chadha, Kailash C; Schwartz, Stanley A

    2008-12-01

    Human and animal studies have suggested that diet-derived flavonoids, in particular quercetin may play a beneficial role by preventing or inhibiting oncogenesis, but the underlying mechanism remains unclear. The aim of this study is to evaluate the effect(s) of quercetin on normal and malignant prostate cells and to identify the target(s) of quercetin's action. We addressed this question using cells in culture and investigated whether quercetin affects key biological processes responsible for tumor cell properties such as cell proliferation and apoptosis and also studied the effect of quercetin on the proteome of prostate cancer cells using difference gel electrophoresis (DIGE) to assess changes in the expression of relevant proteins. Our findings demonstrate that quercetin treatment of prostate cancer cells results in decreased cell proliferation and viability. Furthermore, we demonstrate that quercetin promotes cancer cell apoptosis by down-regulating the levels of heat shock protein (Hsp) 90. Depletion of Hsp90 by quercetin results in decreased cell viability, levels of surrogate markers of Hsp90 inhibition (intracellular and secreted), induced apoptosis and activation of caspases in cancer cells but not in normal prostate epithelial cells. Knockdown of Hsp90 by short interfering RNA also resulted in induction apoptosis similar to quercetin in cancer cells as indicated by annexin V staining. Our results demonstrate that quercetin down-regulates the expression of Hsp90 which, in turn, induces inhibition of growth and cell death in prostate cancer cells while exerting no quantifiable effect on normal prostate epithelial cells.

  15. Long Non-Coding RNA HOTAIR Promotes Cell Migration and Invasion via Down-Regulation of RNA Binding Motif Protein 38 in Hepatocellular Carcinoma Cells

    Directory of Open Access Journals (Sweden)

    Chaofeng Ding

    2014-03-01

    Full Text Available Long non-coding RNA HOTAIR exerts regulatory functions in various biological processes in cancer cells, such as proliferation, apoptosis, mobility, and invasion. We previously found that HOX transcript antisense RNA (HOTAIR is a negative prognostic factor and exhibits oncogenic activity in hepatocellular carcinoma (HCC. In this study, we aimed to investigate the role and molecular mechanism of HOTAIR in promoting HCC cell migration and invasion. Firstly, we profiled its gene expression pattern by microarray analysis of HOTAIR loss in Bel-7402 HCC cell line. The results showed that 129 genes were significantly down-regulated, while 167 genes were significantly up-regulated (fold change >2, p < 0.05. Bioinformatics analysis indicated that RNA binding proteins were involved in this biological process. HOTAIR suppression using RNAi strategy with HepG2 and Bel-7402 cells increased the mRNA and protein expression levels of RNA binding motif protein 38 (RBM38. Moreover, the expression levels of RBM38 in HCC specimens were significantly lower than paired adjacent noncancerous tissues. In addition, knockdown of HOTAIR resulted in a decrease of cell migration and invasion, which could be specifically rescued by down-regulation of RBM38. Taken together, HOTAIR could promote migration and invasion of HCC cells by inhibiting RBM38, which indicated critical roles of HOTAIR and RBM38 in HCC progression.

  16. Human Leukocyte Antigen (HLA Class I Down-Regulation by Human Immunodeficiency Virus Type 1 Negative Factor (HIV-1 Nef: What Might We Learn From Natural Sequence Variants?

    Directory of Open Access Journals (Sweden)

    Philip Mwimanzi

    2012-09-01

    Full Text Available HIV-1 causes a chronic infection in humans that is characterized by high plasma viremia, progressive loss of CD4+ T lymphocytes, and severe immunodeficiency resulting in opportunistic disease and AIDS. Viral persistence is mediated in part by the ability of the Nef protein to down-regulate HLA molecules on the infected cell surface, thereby allowing HIV-1 to evade recognition by antiviral CD8+ T lymphocytes. Extensive research has been conducted on Nef to determine protein domains that are required for its immune evasion activities and to identify critical cellular co-factors, and our mechanistic understanding of this process is becoming more complete. This review highlights our current knowledge of Nef-mediated HLA class I down-regulation and places this work in the context of naturally occurring sequence variation in this protein. We argue that efforts to fully understand the critical role of Nef for HIV-1 pathogenesis will require greater analysis of patient-derived sequences to elucidate subtle differences in immune evasion activity that may alter clinical outcome.

  17. Standardized bioactive fraction of Phaleria macrocarpa(Proliverenol) prevents ethanol-induced hepatotoxicity via down-regulation of NF-kB-TNFα-caspase-8 pathway

    Institute of Scientific and Technical Information of China (English)

    Guntur Berlian; Olivia Mayasari Tandrasasmita; Raymond Rubianto Tjandrawinata

    2016-01-01

    Objective: To verify that Proliverenol has a potential ability in protecting cells from ethanol-induced hepatotoxicity.Methods: Activity of Proliverenol against ethanol-induced apoptosis was evaluated at m RNA and protein levels in Hep G2 cell exposed to Proliverenol for 1 and 3 h.Results: Proliverenol conferred hepatoprotective activity through increasing cell survival up to 53%–69% via up-regulation of APEX1 DNA repair enzyme for 3.0–4.7 fold and down-regulating of nuclear factor-kB, tumor necrosis factora and caspase-8 expression,allowing them to prevent 4.5–6.9 fold of alanine aminotransferase(ALT) leakage in Hep G2 cells. Our finding revealed that Proliverenol repressed expression of ALT, which is significantly important as possible alternative mechanism for increased blood transaminase activities. In addition, the result also showed that caspase-8 pathway seemed to be involved in the molecular pathway rather than directly inducing mitochondrial damage.Conclusions: The data support our hypothesis that Proliverenol has a potential ability in protecting cells from ethanol-induced hepatotoxicity. We propose that Proliverenol provides hepatoprotective activity through up-regulating expression of APEX1 that repress DNA fragmentation, and down-regulating expression of nuclear factor-kB, tumor necrosis factora and caspase-8, which therefore repress ALT leakage and its expression.

  18. Bone marrow mesenchymal stromal cells affect the cell cycle arrest effect of genotoxic agents on acute lymphocytic leukemia cells via p21 down-regulation.

    Science.gov (United States)

    Zhang, Yiran; Hu, Kaimin; Hu, Yongxian; Liu, Lizhen; Wang, Binsheng; Huang, He

    2014-09-01

    The effect of bone marrow microenvironment on the cell cycle of acute lymphocytic leukemia (ALL) and the underlying mechanism has not been elucidated. In this study, we found that in normal condition, bone marrow mesenchymal stromal cells (BM-MSCs) had no significant effect on the cell cycle and apoptosis of ALL; in the condition when the cell cycle of ALL was blocked by genotoxic agents, BM-MSCs could increase the S-phase cell ratio and decrease the G2/M phase ratio of ALL. Besides, BM-MSCs could protect ALL cells from drug-induced apoptosis. Then, we proved that BM-MSCs affect the cell cycle arrest effect of genotoxic agents on ALL cells via p21 down-regulation. Moreover, our results indicated that activation of Wnt/β-catenin and Erk pathways might be involved in the BM-MSC-induced down-regulation of p21 in ALL cells. Targeting microenvironment-related signaling pathway may therefore be a potential novel approach for ALL therapy.

  19. CIL-102 induces matrix metalloproteinase-2 (MMP-2)/MMP-9 down-regulation via simultaneous suppression of genetic transcription and mRNA stability.

    Science.gov (United States)

    Liu, Wen-Hsin; Chen, Yeh-Long; Chang, Long-Sen

    2012-12-01

    This study explores the CIL-102 suppression mechanism on matrix metalloproteinase-2 (MMP-2) and MMP-9 expression in human leukemia K562 cells. CIL-102 attenuated K562 cell invasion with decreased MMP-2/MMP-9 protein expression and mRNA levels. Moreover, CIL-102 reduced luciferase activity of MMP-2/MMP-9 promoter constructs and MMP-2/MMP-9 mRNA stability. CIL-102 treatment induced JNK and p38 MAPK activation but reduced the phospho-ERK level. Transfection of constitutively active MEK1 restored MMP-2 and MMP-9 promoter activity in CIL-102-treated cells, while suppression of p38 MAPK/JNK activation abolished CIL-102-induced MMP-2/MMP-9 mRNA decay. CIL-102-induced p38 MAPK/JNK activation led to protein phosphatase 2A-mediated tristetraprolin (TTP) down-regulation. The reduction in TTP-KH-type splicing regulatory protein (KSRP) complexes formation promoted KSRP-mediated MMP-2/MMP-9 mRNA decay in CIL-102-treated K562 cells. Moreover, CIL-102 reduced invasion and MMP-2/MMP-9 expression in breast and liver cancer cells. Taken together, our data indicate that CIL-102 induces MMP-2/MMP-2 down-regulation via simultaneous suppression of genetic transcription and mRNA stability, and suggest a potential utility for CIL-102 in reducing MMP-2/MMP-9-mediated cancer progression.

  20. Down-regulation of membrana granulosa cell gap junctions is correlated with irreversible commitment to resume meiosis in golden Syrian hamster oocytes.

    Science.gov (United States)

    Racowsky, C; Baldwin, K V; Larabell, C A; DeMarais, A A; Kazilek, C J

    1989-08-01

    One of the currently popular hypotheses for the regulation of meiotic resumption in mammalian oocytes proposes that the preovulatory surge of luteinizing hormone causes down-regulation of follicular gap junctions, which in turn disrupts transfer of a meiotic arrester from the somatic cells into the oocyte. The present study has investigated this hypothesis by examining the integrity of membrana granulosa cell gap junctions during the period of irreversible commitment to maturation of golden Syrian hamster oocytes in vivo. Our results have revealed a significant progressive decrease in the fractional area of cell surface occupied by gap junction membrane with increasing percentage of oocytes irreversibly committed to mature (1.946% and 0.921% fractional gap junction area at 0% and 100% oocytes irreversibly committed to mature, respectively, P less than 0.05). This net loss of membrana granulosa cell gap junctions from the cell surface was accompanied by a significant decrease in density of gap junction particles, whether they were arranged in rectilinear or non-rectilinear packing patterns. Furthermore, the number of gap junction particles per unit area of surface membrane scanned also underwent a significant progressive decrease with increasing percentage of oocytes irreversibly committed to mature. These data with the hamster are consistent with the hypothesis that down-regulation of membrana granulosa cell gap junctions may be of central importance in the regulation of gonadotropic stimulation of meiotic resumption in mammalian oocytes.

  1. Curcumin ameliorates neuropathic pain by down-regulating spinal IL-1β via suppressing astroglial NALP1 inflammasome and JAK2-STAT3 signalling

    Science.gov (United States)

    Liu, Shenbin; Li, Qian; Zhang, Meng-Ting; Mao-Ying, Qi-Liang; Hu, Lang-Yue; Wu, Gen-Cheng; Mi, Wen-Li; Wang, Yan-Qing

    2016-01-01

    Curcumin has been shown to possess strong anti-inflammatory activity in many diseases. It has been demonstrated that the janus kinase 2 (JAK2)-signal transducer and activator of transcription 3 (STAT3) cascade and the NAcht leucine-rich-repeat protein 1 (NALP1) inflammasome are important for the synthesis of Pro-Interleukin (IL)-1β and the processing of the inactive protein to its mature form, which plays an active role in the pathogenesis of neuropathic pain. The present study showed that repeated intraperitoneal injection of curcumin ameliorated SNI-induced mechanical and cold allodynia in a dose-dependent manner and inhibited the elevation of spinal mature IL-1β protein levels. Additionally, repeated curcumin treatment significantly inhibited the aggregation of the NALP1 inflammasome and the activation of the JAK2-STAT3 cascade in spinal astrocytes. Furthermore, the genetic down-regulation of NALP1 inflammasome activation by NALP1 siRNA and the pharmacological inhibition of the JAK2-STAT3 cascade by AG490 markedly inhibited IL-1β maturation and Pro-IL-1β synthesis, respectively, and reduced SNI-induced pain hypersensitivity. Our results suggest that curcumin attenuated neuropathic pain and down-regulated the production of spinal mature IL-1β by inhibiting the aggregation of NALP1 inflammasome and the activation of the JAK2-STAT3 cascade in astrocytes. PMID:27381056

  2. Escin Ia suppresses the metastasis of triple-negative breast cancer by inhibiting epithelial-mesenchymal transition via down-regulating LOXL2 expression.

    Science.gov (United States)

    Wang, Yuhui; Xu, Xiaotian; Zhao, Peng; Tong, Bei; Wei, Zhifeng; Dai, Yue

    2016-04-26

    The saponin fraction of Aesculus chinensis Bunge fruits (SFAC) could inhibit the invasion and migration of MDA-MB-231 cells. Among which, escin Ia showed more potent inhibition of the invasion than other five main saponin constituents. It selectively reduced the expression of LOXL2 mRNA and promoted the expression of E-cadherin mRNA, and prevented the EMT process of MDA-MB-231 cells and TNF-α/TGF-β-stimulated MCF-7 cells. Moreover, it reduced the LOXL2 level in MDA-MB-231 cells but not in MCF-7 cells. When MCF-7 cells were stimulated with TNF-α/TGF-β, transfected with LOXL2 or treated with hypoxia, escin Ia down-regulated the level of LOXL2 in MCF-7 cells. Meanwhile, escin Ia suppressed the EMT process in LOXL2-transfected or hypoxia-treated MCF-7 cells. Of interest, escin Ia did not alter the level of HIF-1α in hypoxia-induced MCF-7 cells. In TNBC xenograft mice, the metastasis and EMT of MDA-MB-231 cells were suppressed by escin Ia. In conclusion, escin Ia was the main active ingredient of SFAC for the anti-TNBC metastasis activity, and its action mechanisms involved inhibition of EMT process by down-regulating LOXL2 expression.

  3. Down-regulation of IKKβ expression in glioma-infiltrating microglia/macrophages is associated with defective inflammatory/immune gene responses in glioblastoma.

    Science.gov (United States)

    Mieczkowski, Jakub; Kocyk, Marta; Nauman, Pawel; Gabrusiewicz, Konrad; Sielska, Małgorzata; Przanowski, Piotr; Maleszewska, Marta; Rajan, Wenson D; Pszczolkowska, Dominika; Tykocki, Tomasz; Grajkowska, Wieslawa; Kotulska, Katarzyna; Roszkowski, Marcin; Kostkiewicz, Boguslaw; Kaminska, Bozena

    2015-10-20

    Glioblastoma (GBM) is an aggressive malignancy associated with profound host immunosuppression. Microglia and macrophages infiltrating GBM acquire the pro-tumorigenic, M2 phenotype and support tumor invasion, proliferation, survival, angiogenesis and block immune responses both locally and systematically. Mechanisms responsible for immunological deficits in GBM patients are poorly understood. We analyzed immune/inflammatory gene expression in five datasets of low and high grade gliomas, and performed Gene Ontology and signaling pathway analyses to identify defective transcriptional responses. The expression of many immune/inflammatory response and TLR signaling pathway genes was reduced in high grade gliomas compared to low grade gliomas. In particular, we found the reduced expression of the IKBKB, a gene coding for IKKβ, which phosphorylates IκB proteins and represents a convergence point for most signal transduction pathways leading to NFκB activation. The reduced IKBKB expression and IKKβ levels in GBM tissues were demonstrated by qPCR, Western blotting and immunohistochemistry. The IKKβ expression was down-regulated in microglia/macrophages infiltrating glioblastoma. NFκB activation, prominent in microglia/macrophages infiltrating low grade gliomas, was reduced in microglia/macrophages in glioblastoma tissues. Down-regulation of IKBKB expression and NFκB signaling in microglia/macrophages infiltrating glioblastoma correlates with defective expression of immune/inflammatory genes and M2 polarization that may result in the global impairment of anti-tumor immune responses in glioblastoma.

  4. Nitric oxide affects ERK signaling through down-regulation of MAP kinase phosphatase levels during larval development of the ascidian Ciona intestinalis.

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    Immacolata Castellano

    Full Text Available In the ascidian Ciona intestinalis larval development and metamorphosis require a complex interplay of events, including nitric oxide (NO production, MAP kinases (ERK, JNK and caspase-3 activation. We have previously shown that NO levels affect the rate of metamorphosis, regulate caspase activity and promote an oxidative stress pathway, resulting in protein nitration. Here, we report that NO down-regulates MAP kinase phosphatases (mkps expression affecting positively ERK signaling. By pharmacological approach, we observed that the reduction of endogenous NO levels caused a decrease of ERK phosphorylation, whereas increasing levels of NO induced ERK activation. We have also identified the ERK gene network affected by NO, including mpk1, mpk3 and some key developmental genes by quantitative gene expression analysis. We demonstrate that NO induces an ERK-independent down-regulation of mkp1 and mkp3, responsible for maintaining the ERK phosphorylation levels necessary for transcription of key metamorphic genes, such as the hormone receptor rev-erb and the van willebrand protein vwa1c. These results add new insights into the role played by NO during larval development and metamorphosis in Ciona, highlighting the cross-talk between different signaling pathways.

  5. pH-responsive artemisinin derivatives and lipid nanoparticle formulations inhibit growth of breast cancer cells in vitro and induce down-regulation of HER family members.

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    Yitong J Zhang

    Full Text Available Artemisinin (ART dimers show potent anti-proliferative activities against breast cancer cells. To facilitate their clinical development, novel pH-responsive artemisinin dimers were synthesized for liposomal nanoparticle formulations. A new ART dimer was designed to become increasingly water-soluble as pH declines. The new artemisinin dimer piperazine derivatives (ADPs remained tightly associated with liposomal nanoparticles (NPs at neutral pH but were efficiently released at acidic pH's that are known to exist within solid tumors and organelles such as endosomes and lysosomes. ADPs incorporated into nanoparticles down regulated the anti-apoptotic protein, survivin, and cyclin D1 when incubated at low concentrations with breast cancer cell lines. We demonstrate for the first time, for any ART derivative, that ADP NPs can down regulate the oncogenic protein HER2, and its counterpart, HER3 in a HER2+ cell line. We also show that the wild type epidermal growth factor receptor (EGFR or HER1 declines in a triple negative breast cancer (TNBC cell line in response to ADP NPs. The declines in these proteins are achieved at concentrations of NP109 at or below 1 µM. Furthermore, the new artemisinin derivatives showed improved cell-proliferation inhibition effects compared to known dimer derivatives.

  6. HACE1 is a putative tumor suppressor gene in B-cell lymphomagenesis and is down-regulated by both deletion and epigenetic alterations.

    Science.gov (United States)

    Bouzelfen, Abdelilah; Alcantara, Marion; Kora, Hafid; Picquenot, Jean-Michel; Bertrand, Philippe; Cornic, Marie; Mareschal, Sylvain; Bohers, Elodie; Maingonnat, Catherine; Ruminy, Philippe; Adriouch, Sahil; Boyer, Olivier; Dubois, Sydney; Bastard, Christian; Tilly, Hervé; Latouche, Jean-Baptiste; Jardin, Fabrice

    2016-06-01

    HECT domain and ankyrin repeat containing E3 ubiquitin protein ligase 1, HACE1, located on chromosome 6q, encodes an E3 ubiquitin ligase and is downregulated in many human tumors. Here, we report HACE1 as a candidate tumor suppressor gene down-regulated by a combination of deletion and epigenetic mechanisms. HACE1 deletions were observed in 40% of B-cell lymphoma tumors. Hypermethylation of the HACE1 promoter CpG177 island was found in 60% (68/111) of cases and in all tested B-cell lymphoma lines. Using HDAC inhibitors, we observed predominantly inactive chromatin conformation (methylated H3 histones H3K9me2) in HACE1 gene promoter region. We demonstrated in Ramos and Raji cells that down-regulation of HACE1 expression was associated with a significant decrease in apoptosis and an accumulation of cells in the S and G2/M phases. Our experiments indicate that HACE1 can act as a haploinsufficient tumor suppressor gene in most B-cell lymphomas and can be downregulated by deacetylation of its promoter region chromatin, which makes HACE1 a potential target for HDAC inhibitors.

  7. Transient down-regulation of sound-induced c-Fos protein expression in the inferior colliculus after ablation of the auditory cortex

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    Cheryl Clarkson

    2010-10-01

    Full Text Available We tested whether lesions of the excitatory glutamatergic projection from the auditory cortex to the inferior colliculus induce plastic changes in neurons of this nucleus. Changes in neuronal activation in the inferior colliculus deprived unilaterally of the cortico-collicular projection were assessed by quantitative c-Fos immunocytochemistry. Densitometry and stereology measures of sound-induced c-Fos immunoreactivity in the inferior colliculus showed diminished labeling at 1, 15, 90 and 180 days after lesions to the auditory cortex suggesting protein down-regulation, at least up to 15 days post-lesion. Between 15 and 90 days after the lesion, c-Fos labeling recovers, approaching control values at 180 days. Thus, glutamatergic excitation from the cortex maintains sound-induced activity in neurons of the inferior colliculus. Subdivisions of this nucleus receiving a higher density of cortical innervation such as the dorsal cortex showed greater changes in c-Fos immunoreactivity, suggesting that the anatomical strength of the projection correlates with effect strength. Therefore, after damage of the corticofugal projection, neurons of the inferior colliculus down-regulate and further recover sound-induced c-Fos protein expression. This may be part of cellular mechanisms aimed at balancing or adapting neuronal responses to altered synaptic inputs.

  8. Collagen I-induced dendritic cells activation is regulated by TNF-alpha production through down-regulation of IRF4.

    Science.gov (United States)

    Poudel, Barun; Ki, Hyeon-Hui; Lee, Young-Mi; Kim, Dae-Ki

    2015-03-01

    Previously we have shown that collagen I enhances the maturation and function of dendritic cells (DCs). Inflammatory mediators such as tumour necrosis factor (TNF)- alpha, interleukin (IL)-1 beta and lipopolysaccharide (LPS) are also known to activate DCs. Here we investigated the involvement of TNF-alpha on the collagen I-induced DCs activation. TNF-a neutralization inhibited collagen I-induced IL-12 secretions by DCs. Additionally, we observed suppression of collagen I-induced costimulatory molecules expression along with down-regulation of genes involved in DCs activation pathway. Furthermore, TNF- alpha inhibition upon collagen Istimulation up-regulated the expression of interferon regulatory transcription factor IRF4, when compared to collagen I only treated cells. Collectively, our data demonstrate that collagen I induce TNF- alpha production, which is crucial for the activation and function of DCs, through down-regulation of IRF4, and implicates the importance in development of anti- TNF-alpha therapeutics for several inflammatory diseases.

  9. Down regulation of pRb in cultures of avian neuroretina cells promotes proliferation of reactive Müller-like cells and emergence of retinal stem/progenitors.

    Science.gov (United States)

    Marx, Maria; Lebuhotel, Céline; Laugier, Danielle; Chapelle, Audrey; Calothy, Georges; Saule, Simon

    2010-06-01

    The aim of this work was to define the role of pRb depletion in the proliferation and differentiation of avian retinoblasts in vitro. For this purpose vectors expressing pRb short hairpin RNA were used to deplete pRb in cultures of avian neuroretinal cells. Down regulation of pRb was observed by Western blot and quantification of nuclear pRb. Cell proliferation and differentiation were studied following BrdU labeling and immunostaining. Transfection significantly down-regulated pRb in neuroretinal cells. Long-term effect of pRb depletion mainly induced proliferation of epithelial-like cells that expressed markers of reactive Müller glial cells. A minority of these cells that survived passaging could be maintained as neurosphere-like aggregates with low pRb, not observed in control cultures. BrdU labeling followed by a two week chase showed the presence of cells still remained labelled, indicating low cell cycling. Under appropriate conditions, these aggregates differentiate in precursors of amacrine interneurons shown by the expression of AP2, in absence of the photoreceptors marker visinin and the late neuronal marker MAP2. Taken together these data show that decrease pRb level in cultures of avian neuroretinal cells promotes the emergence and proliferation of stem cell/progenitors from reactive-like Muller cells.

  10. Allopregnanolone suppresses diabetes-induced neuropathic pain and motor deficit through inhibition of GABAA receptor down-regulation in the spinal cord of diabetic rats

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    Samira Afrazi

    2014-05-01

    Full Text Available Objective(s:Painful diabetic neuropathy is associated with hyperexcitability and hyperactivity of spinal cord neurons. However, its underlying pathophysiological mechanisms have not been fully clarified. Induction of excitatory/inhibitory neurotransmission imbalance at the spinal cord seems to account for the abnormal neuronal activity in diabetes. Protective properties of neurosteroids have been demonstrated in numerous cellular and animal models of neurodegeneration. Materials and Methods: Here, the protective effects of allopregnanolone, a neurosteroid were investigated in an in vivo model of diabetic neuropathy. The tail-flick test was used to assess the nociceptive threshold. Diabetes was induced by injection of 50 mg/kg (IP streptozotocin. Seven weeks after the induction of diabetes, the dorsal half of the lumbar spinal cord was assayed for the expression of γ2 subunit of GABAA receptor using semiquantitative RT-PCR. Results: The data shows that allopregnanolone (5 and 20 mg/kg markedly ameliorated diabetes-induced thermal hyperalgesia and motor deficit. The weights of diabetic rats that received 5 and 20 mg/kg allopregnanolone did not significantly reduce during the time course of study. Furthermore, this neurosteroid could inhibit GABAA receptor down-regulation induced by diabetes in the rat spinal cord. Conclusion: The data revealed that allopregnanolone has preventive effects against hyperglycemic-induced neuropathic pain and motor deficit which are related to the inhibition of GABAA receptor down-regulation.

  11. Effects of stereochemistry, saturation, and hydrocarbon chain length on the ability of synthetic constrained azacyclic sphingolipids to trigger nutrient transporter down-regulation, vacuolation, and cell death.

    Science.gov (United States)

    Perryman, Michael S; Tessier, Jérémie; Wiher, Timothy; O'Donoghue, Heather; McCracken, Alison N; Kim, Seong M; Nguyen, Dean G; Simitian, Grigor S; Viana, Matheus; Rafelski, Susanne; Edinger, Aimee L; Hanessian, Stephen

    2016-09-15

    Constrained analogs containing a 2-hydroxymethylpyrrolidine core of the natural sphingolipids sphingosine, sphinganine, N,N-dimethylsphingosine and N-acetyl variants of sphingosine and sphinganine (C2-ceramide and dihydro-C2-ceramide) were synthesized and evaluated for their ability to down-regulate nutrient transporter proteins and trigger cytoplasmic vacuolation in mammalian cells. In cancer cells, the disruptions in intracellular trafficking produced by these sphingolipids lead to cancer cell death by starvation. Structure activity studies were conducted by varying the length of the hydrocarbon chain, the degree of unsaturation and the presence or absence of an aryl moiety on the appended chains, and stereochemistry at two stereogenic centers. In general, cytotoxicity was positively correlated with nutrient transporter down-regulation and vacuolation. This study was intended to identify structural and functional features in lead compounds that best contribute to potency, and to develop chemical biology tools that could be used to isolate the different protein targets responsible for nutrient transporter loss and cytoplasmic vacuolation. A molecule that produces maximal vacuolation and transporter loss is expected to have the maximal anti-cancer activity and would be a lead compound.

  12. Interleukin-22 restored mitochondrial damage and impaired glucose-stimulated insulin secretion through down-regulation of uncoupling protein-2 in INS-1 cells.

    Science.gov (United States)

    Hu, Minling; Lin, Hanxiao; Yang, Li; Cheng, Yanzhen; Zhang, Hua

    2017-01-07

    Defective glucose-stimulated insulin secretion (GSIS) induced by chronic exposure to fatty acids is a hallmark of type 2 diabetes (T2D). Interleukin-22 (IL-22) has been shown to exert beneficial effects on insulin secretion and to protect pancreatic β-cells from stress. Moreover, uncoupling protein-2 (UCP-2) plays a central role in the regulation of GSIS and β-cell dysfunction, whereas the role of UCP-2 in IL-22-enhanced glycemic control under conditions of lipotoxicity remains unclear. In this present study, we investigated the effects of IL-22 on rat insulin-secreting cells (INS-1 cells) and the mechanisms that underlie IL-22 and lipotoxicity-impaired GSIS in vitro. Chronic palmitate (PA) treatment impaired insulin secretion and activated UCP-2 expression in INS-1 cells. Furthermore, in INS-1 cells, both reduced mitochondrial membrane potential (ΔΨm) and impaired GSIS induced by PA treatment were effectively reversed by an inhibitor of UCP-2 (genipin). Additionally, compared with the PA-treated group, INS-1 cells treated with IL-22 down-regulated UCP-2 expression, increased mitochondrial membrane potential, and restored GSIS. Together, our findings indicate that chronic exposure to PA could activate UCP-2, resulting in mitochondrial damage and impaired GSIS in INS-1 cells. We also suggest that IL-22 plays a protective role in this process via the down-regulation of UCP-2.

  13. AS1411-Induced Growth Inhibition of Glioma Cells by Up-Regulation of p53 and Down-Regulation of Bcl-2 and Akt1 via Nucleolin.

    Science.gov (United States)

    Cheng, Ye; Zhao, Gang; Zhang, Siwen; Nigim, Fares; Zhou, Guangtong; Yu, Zhiyun; Song, Yang; Chen, Yong; Li, Yunqian

    2016-01-01

    AS1411 binds nucleolin (NCL) and is the first oligodeoxynucleotide aptamer to reach phase I and II clinical trials for the treatment of several cancers. However, the mechanisms by which AS1411 targets and kills glioma cells and tissues remain unclear. Here we report that AS1411 induces cell apoptosis and cycle arrest, and inhibits cell viability by up-regulation of p53 and down-regulation of Bcl-2 and Akt1 in human glioma cells. NCL was overexpressed in both nucleus and cytoplasm in human glioma U87, U251 and SHG44 cells compared to normal human astrocytes (NHA). AS1411 bound NCL and inhibited the proliferation of glioma cells but not NHA, which was accompanied with up-regulation of p53 and down-regulation of Bcl-2 and Akt1. Moreover, AS1411 treatment resulted in the G2/M cell cycle arrest in glioma cells, which was however abolished by overexpression of NCL. Further, AS1411 induced cell apoptosis, which was prevented by silencing of p53 and overexpression of Bcl-2. In addition, AS1411 inhibited the migration and invasion of glioma cells in an Akt1-dependent manner. Importantly, AS1411 inhibited the growth of glioma xenograft and prolonged the survival time of glioma tumor-bearing mice. These results revealed a promising treatment of glioma by oligodeoxynucleotide aptamer.

  14. HIV infection enhances TRAIL-induced cell death in macrophage by down-regulating decoy receptor expression and generation of reactive oxygen species.

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    Dan-Ming Zhu

    Full Text Available BACKGROUND: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL could induce apoptosis of HIV-1-infected monocyte-derived macrophage (MDM, but the molecular mechanisms are not well understood. METHODOLOGY/PRINCIPAL FINDINGS: By using an HIV-1 Env-pseudotyped virus (HIV-1 PV-infected MDM cell model we demonstrate that HIV-1 PV infection down-regulates the expression of TRAIL decoy receptor 1 (DcR1 and 2 (DcR2, and cellular FLICE-inhibitory protein (c-FLIP, but dose not affect the expression of death receptor 4 and 5 (DR4, DR5, and Bcl-2 family members in MDM cells. Furthermore, recombinant soluble TRAIL and an agonistic anti-DR5 antibody, AD5-10, treatment stimulates reactive oxygen species (ROS generation and JNK phosphorylation. CONCLUSIONS/SIGNIFICANCE: HIV infection facilitates TRIAL-induced cell death in MDM by down-regulating the expression of TRAIL decoy receptors and intracellular c-FLIP. Meanwhile, the agonistic anti-DR5 antibody, AD5-10, induces apoptosis synergistically with TRAIL in HIV-1-infected cells. ROS generation and JNK phosphorylation are involved in this process. These findings potentiate clinical usage of the combination of TRAIL and AD5-10 in eradication of HIV-infected macrophage and AIDS.

  15. Down-regulation of pancreatic and duodenal homeobox-1 by somatostatin receptor subtype 5: a novel mechanism for inhibition of cellular proliferation and insulin secretion by somatostatin

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    Charles eBrunicardi

    2014-06-01

    Full Text Available Somatostatin is a regulatory peptide and acts as an endogenous inhibitory regulator of the secretory and proliferative responses of target cells. Somatostatin’s actions are mediated by a family of seven transmembrane domain G protein-coupled receptors that comprise five distinct subtypes (SSTR1-5. SSTR5 is one of the major SSTRs in the islets of Langerhans. Homeodomain-containing transcription factor pancreatic and duodenal homeobox-1 (PDX-1 is essential for pancreatic development, β cell differentiation, maintenance of normal β cell functions in adults and tumorigenesis. Recent studies show that SSTR5 acts as a negative regulator for PDX-1 expression and that SSTR5 mediates somatostatin’s inhibitory effect on cell proliferation and insulin expression/excretion through down-regulating PDX-1 expression. SSTR5 exerts its inhibitory effect on PDX-1 expression at both the transcriptional level by down-regulating PDX-1 mRNA and the post-translational level by enhancing PDX-1 ubiquitination. Identification of PDX-1 as a transcriptional target for SSTR5 may help in guiding the choice of therapeutic cancer treatments.

  16. Lack of clinical manifestations in asymptomatic dengue infection is attributed to broad down-regulation and selective up-regulation of host defence response genes.

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    Adeline S L Yeo

    Full Text Available OBJECTIVES: Dengue represents one of the most serious life-threatening vector-borne infectious diseases that afflicts approximately 50 million people across the globe annually. Whilst symptomatic infections are frequently reported, asymptomatic dengue remains largely unnoticed. Therefore, we sought to investigate the immune correlates conferring protection to individuals that remain clinically asymptomatic. METHODS: We determined the levels of neutralizing antibodies (nAbs and gene expression profiles of host immune factors in individuals with asymptomatic infections, and whose cognate household members showed symptoms consistent to clinical dengue infection. RESULTS: We observed broad down-regulation of host defense response (innate, adaptive and matrix metalloprotease genes in asymptomatic individuals as against symptomatic patients, with selective up-regulation of distinct genes that have been associated with protection. Selected down-regulated genes include: TNF α (TNF, IL8, C1S, factor B (CFB, IL2, IL3, IL4, IL5, IL8, IL9, IL10 and IL13, CD80, CD28, and IL18, MMP8, MMP10, MMP12, MMP15, MMP16, and MMP24. Selected up-regulated genes include: RANTES (CCL5, MIP-1α (CCL3L1/CCL3L3, MIP-1β (CCL4L1, TGFβ (TGFB, and TIMP1. CONCLUSION: Our findings highlight the potential association of certain host genes conferring protection against clinical dengue. These data are valuable to better explore the mysteries behind the hitherto poorly understood immunopathogenesis of subclinical dengue infection.

  17. Selective oral ROCK2 inhibitor down-regulates IL-21 and IL-17 secretion in human T cells via STAT3-dependent mechanism.

    Science.gov (United States)

    Zanin-Zhorov, Alexandra; Weiss, Jonathan M; Nyuydzefe, Melanie S; Chen, Wei; Scher, Jose U; Mo, Rigen; Depoil, David; Rao, Nishta; Liu, Ben; Wei, Jianlu; Lucas, Sarah; Koslow, Matthew; Roche, Maria; Schueller, Olivier; Weiss, Sara; Poyurovsky, Masha V; Tonra, James; Hippen, Keli L; Dustin, Michael L; Blazar, Bruce R; Liu, Chuan-ju; Waksal, Samuel D

    2014-11-25

    Rho-associated kinase 2 (ROCK2) regulates the secretion of proinflammatory cytokines and the development of autoimmunity in mice. Data from a phase 1 clinical trial demonstrate that oral administration of KD025, a selective ROCK2 inhibitor, to healthy human subjects down-regulates the ability of T cells to secrete IL-21 and IL-17 by 90% and 60%, respectively, but not IFN-γ in response to T-cell receptor stimulation in vitro. Pharmacological inhibition with KD025 or siRNA-mediated inhibition of ROCK2, but not ROCK1, significantly diminished STAT3 phosphorylation and binding to IL-17 and IL-21 promoters and reduced IFN regulatory factor 4 and nuclear hormone RAR-related orphan receptor γt protein levels in T cells derived from healthy subjects or rheumatoid arthritis patients. Simultaneously, treatment with KD025 also promotes the suppressive function of regulatory T cells through up-regulation of STAT5 phosphorylation and positive regulation of forkhead box p3 expression. The administration of KD025 in vivo down-regulates the progression of collagen-induced arthritis in mice via targeting of the Th17-mediated pathway. Thus, ROCK2 signaling appears to be instrumental in regulating the balance between proinflammatory and regulatory T-cell subsets. Targeting of ROCK2 in man may therefore restore disrupted immune homeostasis and have a role in the treatment of autoimmunity.

  18. Asclepiasterol, a novel C21 steroidal glycoside derived from Asclepias curassavica, reverses tumor multidrug resistance by down-regulating P-glycoprotein expression.

    Science.gov (United States)

    Yuan, Wei-Qi; Zhang, Rong-Rong; Wang, Jun; Ma, Yan; Li, Wen-Xue; Jiang, Ren-Wang; Cai, Shao-Hui

    2016-05-24

    Multidrug resistance (MDR) mediated by P-glycoprotein (P-gp) is a major cause of cancer therapy failure. In this study, we identified a novel C21 steroidal glycoside, asclepiasterol, capable of reversing P-gp-mediated MDR. Asclepiasterol (2.5 and 5.0μM) enhanced the cytotoxity of P-gp substrate anticancer drugs in MCF-7/ADR and HepG-2/ADM cells. MDR cells were more responsive to paclitaxel in the presence of asclepiasterol, and colony formation of MDR cells was only reduced upon treatment with a combination of asclepiasterol and doxorubicin. Consistent with these findings, asclepiasterol treatment increased the intracellular accumulation of doxorubicin and rhodamine 123 (Rh123) in MDR cells. Asclepiasterol decreased expression of P-gp protein without stimulating or suppressing MDR1 mRNA levels. Asclepiasterol-mediated P-gp suppression caused inhibition of ERK1/2 phosphorylation in two MDR cell types, and EGF, an activator of the MAPK/ERK pathway, reversed the P-gp down-regulation, implicating the MAPK/ERK pathway in asclepiasterol-mediated P-gp down-regulation. These results suggest that asclepiasterol could be developed as a modulator for reversing P-gp-mediated MDR in P-gp-overexpressing cancer variants.

  19. Down-regulation of cytoplasmic PLZF correlates with high tumor grade and tumor aggression in non-small cell lung carcinoma.

    Science.gov (United States)

    Xiao, Guang-Qian; Li, Faqian; Findeis-Hosey, Jennifer; Hyrien, Ollivier; Unger, Pamela D; Xiao, Lu; Dunne, Richard; Kim, Eric S; Yang, Qi; McMahon, Loralee; Burstein, David E

    2015-11-01

    There are currently no effective prognostic biomarkers for lung cancer. Promyelocytic leukemia zinc finger (PLZF), a transcriptional repressor, has a role in cell cycle progression and tumorigenicity in various cancers. The expression and value of PLZF in lung carcinoma, particularly in the subclass of non-small cell lung carcinoma (NSCLC), has not been studied. Our aim was to study the immunohistochemical expression of PLZF in lung adenocarcinoma and squamous cell carcinoma and correlate the alteration of PLZF expression with tumor differentiation, lymph node metastasis, tumor stage, and overall survival. A total of 296 NSCLCs being mounted on tissue microarray (181 adenocarcinomas and 91 squamous cell carcinomas) were investigated. Moderate to strong expression of PLZF was found in the cytoplasm of all the nonneoplastic respiratory epithelium and most (89.9%) well-differentiated adenocarcinoma. The proportions of moderately differentiated, poorly differentiated adenocarcinoma, and paired lymph node adenocarcinoma metastases that demonstrated negative or only weak PLZF reactivity were 75.6%, 97.2%, and 89.9%, respectively. The expression of PLZF in squamous cell carcinoma was mostly weak or absent and significantly lower than that in adenocarcinoma of the same grade (P carcinoma and adenocarcinoma (P < .0001). Down-regulation of PLZF also correlated with higher tumor stage and shorter overall survival (P < .05). These results support a prognostic value for loss of cytoplasmic PLZF expression in the stratification of NSCLC and a possible role of cytoplasmic shift and down-regulation of PLZF in the pathogenesis of NSCLC.

  20. Localized Down-regulation of P-glycoprotein by Focused Ultrasound and Microbubbles induced Blood-Brain Barrier Disruption in Rat Brain

    Science.gov (United States)

    Cho, Hongseok; Lee, Hwa-Youn; Han, Mun; Choi, Jong-Ryul; Ahn, Sanghyun; Lee, Taekwan; Chang, Yongmin; Park, Juyoung

    2016-08-01

    Multi-drug resistant efflux transporters found in Blood-Brain Barrier (BBB) acts as a functional barrier, by pumping out most of the drugs into the blood. Previous studies showed focused ultrasound (FUS) induced microbubble oscillation can disrupt the BBB by loosening the tight junctions in the brain endothelial cells; however, no study was performed to investigate its impact on the functional barrier of the BBB. In this study, the BBB in rat brains were disrupted using the MRI guided FUS and microbubbles. The immunofluorescence study evaluated the expression of the P-glycoprotein (P-gp), the most dominant multi-drug resistant protein found in the BBB. Intensity of the P-gp expression at the BBB disruption (BBBD) regions was significantly reduced (63.2 ± 18.4%) compared to the control area. The magnitude of the BBBD and the level of the P-gp down-regulation were significantly correlated. Both the immunofluorescence and histologic analysis at the BBBD regions revealed no apparent damage in the brain endothelial cells. The results demonstrate that the FUS and microbubbles can induce a localized down-regulation of P-gp expression in rat brain. The study suggests a clinically translation of this method to treat neural diseases through targeted delivery of the wide ranges of brain disorder related drugs.

  1. The down-regulation of the mitogenic fibrinogen receptor (MFR) in serum-containing medium does not occur in defined medium.

    Science.gov (United States)

    Levesque, J P; Hatzfeld, A; Domart, I; Hatzfeld, J

    1990-02-01

    Normal human hemopoietic cells such as early bone marrow progenitors, or lymphoma-derived cell lines such as Raji or JM cells, possess a low-affinity receptor specific for fibrinogen. This receptor triggers a mitogenic effect. It differs from the glycoprotein IIb-IIIa which is involved in fibrinogen-induced platelet aggregation. We demonstrate here that this mitogenic fibrinogen receptor (MFR) can be internalized or reexpressed, depending on culture conditions. Internalization was temperature-dependent. At 37 degrees C in the presence of cycloheximide or actinomycin D, the half-life of cell surface MFRs was 2 h, independent of receptor occupancy. Binding of fibrinogen to the MFR resulted in a down-regulation which was fibrinogen dose-dependent. This occurred in serum-supplemented medium but not in defined medium supplemented with fatty acids. Reexpression of MFRs could be induced in 28 to 42 h by serum removal. The down-regulation of mitogenic receptors in plasma or serum could explain why normal cells do not proliferate in the peripheral blood.

  2. Elevated progesterone in GnRH agonist down regulated in vitro fertilisation (IVFICSI) cycles reduces live birth rates but not embryo quality.

    Science.gov (United States)

    Lahoud, Robert; Kwik, Michele; Ryan, John; Al-Jefout, Moamar; Foley, Jane; Illingworth, Peter

    2012-02-01

    To assess the impact of pre-hCG elevated progesterone on live birth outcomes during GnRH agonist long down regulated protocol assisted reproduction cycles. Retrospective cohort study. Single Centre Private IVF Clinic. A total of 582 consecutive cycles of IVF/ICSI in 2003. All patients underwent a long down-regulation protocol, controlled ovarian stimulation and IVF/ICSI. Serum progesterone concentrations were measured just prior to HCG administration. 253 patients were followed to 2009 for outcomes of their frozen embryo cycles. Live birth rate in fresh and frozen cycles. Patients in the upper quartile pre-hCG progesterone concentration (≥ 5.4 pmol/L) had a higher final estradiol level, more oocytes collected and more usable embryos, when compared to those with lower quartiles. They also had lower live birth rates per cycle started (21.9% vs. 15%, P live birth rates from frozen embryo cycles were not significantly different between the groups. Pre-hCG progesterone elevation leads to lower live birth rates in stimulated IVF cycles. Live birth rates achieved with frozen embryos in the high progesterone cycles suggest, that pre-hCG progesterone elevation negatively affects endometrial receptivity without adversely affecting embryo quality.

  3. Enhanced disease resistance to Botrytis cinerea in myb46 Arabidopsis plants is associated to an early down-regulation of CesA genes.

    Science.gov (United States)

    Ramírez, Vicente; García-Andrade, Javier; Vera, Pablo

    2011-06-01

    The cell wall is a protective barrier of paramount importance for the survival of plant cells. Monitoring the integrity of cell wall allows plants to quickly activate defence pathways to minimize pathogen entry and reduce the spread of disease. Counterintuitively, however, pharmacological effects as well as genetic lesions that affect cellulose biosynthesis and content confer plants with enhanced resistance against necrotrophic fungi. This kind of pathogens target cellulose for degradation to facilitate penetration and to generate glucose units as a food source. Our results points towards the existence of a transcriptional reprogramming mechanism in genes encoding cellulose synthases (CesAs) that occurs very soon after Botrytis cinerea attack and that results in a temporarily shut down of some CesA genes. Interestingly, the observed coordinated down-regulation of CesA genes is more pronounced, and occurs earlier, in myb46 mutant plants. In the resistant myb46 plants, pathogen infection induces transient down-regulation of CesA genes that concurs with a selective transcriptional reprogramming in a set of genes encoding structural cell wall proteins and extracellular remodelling enzymes. Together with previous indications, our results favour the hypothesis that CesAs are part of a surveillance system of the cell wall integrity that senses the presence of a pathogen and transduces that signal into a rapid transcriptional reprogramming of the affected cell.

  4. Localized Down-regulation of P-glycoprotein by Focused Ultrasound and Microbubbles induced Blood-Brain Barrier Disruption in Rat Brain

    Science.gov (United States)

    Cho, HongSeok; Lee, Hwa-Youn; Han, Mun; Choi, Jong-ryul; Ahn, Sanghyun; Lee, Taekwan; Chang, Yongmin; Park, Juyoung

    2016-01-01

    Multi-drug resistant efflux transporters found in Blood-Brain Barrier (BBB) acts as a functional barrier, by pumping out most of the drugs into the blood. Previous studies showed focused ultrasound (FUS) induced microbubble oscillation can disrupt the BBB by loosening the tight junctions in the brain endothelial cells; however, no study was performed to investigate its impact on the functional barrier of the BBB. In this study, the BBB in rat brains were disrupted using the MRI guided FUS and microbubbles. The immunofluorescence study evaluated the expression of the P-glycoprotein (P-gp), the most dominant multi-drug resistant protein found in the BBB. Intensity of the P-gp expression at the BBB disruption (BBBD) regions was significantly reduced (63.2 ± 18.4%) compared to the control area. The magnitude of the BBBD and the level of the P-gp down-regulation were significantly correlated. Both the immunofluorescence and histologic analysis at the BBBD regions revealed no apparent damage in the brain endothelial cells. The results demonstrate that the FUS and microbubbles can induce a localized down-regulation of P-gp expression in rat brain. The study suggests a clinically translation of this method to treat neural diseases through targeted delivery of the wide ranges of brain disorder related drugs. PMID:27510760

  5. Uteroplacental insufficiency down regulates insulin receptor and affects expression of key enzymes of long-chain fatty acid (LCFA metabolism in skeletal muscle at birth

    Directory of Open Access Journals (Sweden)

    Puglianiello Antonella

    2008-05-01

    Full Text Available Abstract Background Epidemiological studies have revealed a relationship between early growth restriction and the subsequent development of insulin resistance and type 2 diabetes. Ligation of the uterine arteries in rats mimics uteroplacental insufficiency and serves as a model of intrauterine growth restriction (IUGR and subsequent developmental programming of impaired glucose tolerance, hyperinsulinemia and adiposity in the offspring. The objective of this study was to investigate the effects of uterine artery ligation on the skeletal muscle expression of insulin receptor and key enzymes of LCFA metabolism. Methods Bilateral uterine artery ligation was performed on day 19 of gestation in Sprague-Dawley pregnant rats. Muscle of the posterior limb was dissected at birth and processed by real-time RT-PCR to analyze the expression of insulin receptor, ACCα, ACCβ (acetyl-CoA carboxylase alpha and beta subunits, ACS (acyl-CoA synthase, AMPK (AMP-activated protein kinase, alpha2 catalytic subunit, CPT1B (carnitine palmitoyltransferase-1 beta subunit, MCD (malonyl-CoA decarboxylase in 14 sham and 8 IUGR pups. Muscle tissue was treated with lysis buffer and Western immunoblotting was performed to assay the protein content of insulin receptor and ACC. Results A significant down regulation of insulin receptor protein (p Conclusion Our data suggest that uteroplacental insufficiency may affect skeletal muscle metabolism down regulating insulin receptor and reducing the expression of key enzymes involved in LCFA formation and oxidation.

  6. Down-regulation of wt1 expression in leukemia cell lines as part of apoptotic effect in arsenic treatment using two compounds.

    Science.gov (United States)

    Glienke, Wolfgang; Chow, Kai U; Bauer, Nina; Bergmann, Lothar

    2006-08-01

    Arsenic trioxide (As2O3) induces remission in patients with acute promyelocytic leukemia (APL). To better understand molecular mechanisms of arsenic actions, this study investigated the effect of two different arsenic compounds on gene expression of apoptosis and cellular proliferation related genes. The Wilms' tumor gene (wt1) is up-regulated in acute myeloid leukemia (AML) and a variety of leukemia cell lines. The expression of wt1 in these cells is proposed to have an anti-apoptotic effect. HL-60 and K562 were treated with arsenic trioxide (As2O3) and sodium arsenite (NaAsO2) at concentrations between 0 - 10 microM for up to 48 h. The induction of apoptosis was accompanied by down-regulation of hTERT and wt1 mRNA and protein expression but up-regulation of par-4. Low concentrations of 0.1 microM arsenic induced expression of the anti-apoptotic bcl-2 gene in both cell lines HL-60 and K562. There were no major differences encountered between compounds. After arsenic treatment of the leukemia cell lines HL-60 and K562 the up-regulation of par-4 may contribute to the induction of apoptosis rather than down-regulation of bcl-2. The therapeutic effect of arsenic is the induction of apoptosis by modulating the gene expression profile of pro- and anti-apoptotic genes including the wt1 gene.

  7. Salinomycin enhances cisplatin-induced cytotoxicity in human lung cancer cells via down-regulation of AKT-dependent thymidylate synthase expression.

    Science.gov (United States)

    Ko, Jen-Chung; Zheng, Hao-Yu; Chen, Wen-Ching; Peng, Yi-Shuan; Wu, Chia-Hung; Wei, Chia-Li; Chen, Jyh-Cheng; Lin, Yun-Wei

    2016-12-15

    Salinomycin, a polyether antibiotic, acts as a highly selective potassium ionophore and has anticancer activity on various cancer cell lines. Cisplatin has been proved as chemotherapy drug for advanced human non-small cell lung cancer (NSCLC). Thymidylate synthase (TS) is a key enzyme in the pyrimidine salvage pathway, and increased expression of TS is thought to be associated with resistance to cisplatin. In this study, we showed that salinomycin (0.5-2μg/mL) treatment down-regulating of TS expression in an AKT inactivation manner in two NSCLC cell lines, human lung adenocarcinoma A549 and squamous cell carcinoma H1703 cells. Knockdown of TS using small interfering RNA (siRNA) or inhibiting AKT activity with PI3K inhibitor LY294002 enhanced the cytotoxicity and cell growth inhibition of salinomycin. A combination of cisplatin and salinomycin resulted in synergistic enhancement of cytotoxicity and cell growth inhibition in NSCLC cells, accompanied with reduced activation of phospho-AKT, and TS expression. Overexpression of a constitutive active AKT (AKT-CA) expression vector reversed the salinomycin and cisplatin-induced synergistic cytotoxicity. In contrast, pretreatment with LY294002 further decreased the cell viability in salinomycin and cisplatin cotreated cells. Our findings suggested that the down-regulation of AKT-mediated TS expression by salinomycin enhanced the cisplatin-induced cytotoxicity in NSCLC cells. These results may provide a rationale to combine salinomycin with cisplatin for lung cancer treatment.

  8. Suppression of c-Myc is involved in multi-walled carbon nanotubes' down-regulation of ATP-binding cassette transporters in human colon adenocarcinoma cells.

    Science.gov (United States)

    Wang, Zhaojing; Xu, Yonghong; Meng, Xiangning; Watari, Fumio; Liu, Hudan; Chen, Xiao

    2015-01-01

    Over-expression of ATP-binding cassette (ABC) transporters, a large family of integral membrane proteins that decrease cellular drug uptake and accumulation by active extrusion, is one of the major causes of cancer multi-drug resistance (MDR) that frequently leads to failure of chemotherapy. Carbon nanotubes (CNTs)-based drug delivery devices hold great promise in enhancing the efficacy of cancer chemotherapy. However, CNTs' effects on the ABC transporters remain under-investigated. In this study, we found that multiwalled carbon nanotubes (MWCNTs) reduced transport activity and expression of ABC transporters including ABCB1/Pgp and ABCC4/MRP4 in human colon adenocarcinoma Caco-2 cells. Proto-oncogene c-Myc, which directly regulates ABC gene expression, was concurrently decreased in MWCNT-treated cells and forced over-expression of c-Myc reversed MWCNTs' inhibitory effects on ABCB1 and ABCC4 expression. MWCNT-cell membrane interaction and cell membrane oxidative damage were observed. However, antioxidants such as vitamin C, β-mecaptoethanol and dimethylthiourea failed to antagonize MWCNTs' down-regulation of ABC transporters. These data suggest that MWCNTs may act on c-Myc, but not through oxidative stress, to down-regulate ABC transporter expression. Our findings thus shed light on CNTs' novel cellular effects that may be utilized to develop CNTs-based drug delivery devices to overcome ABC transporter-mediated cancer chemoresistance.

  9. Both gene deletion and promoter hyper-methylation contribute to the down-regulation of ZAC/PLAGL1 gene in gastric adenocarcinomas: a case control study.

    Science.gov (United States)

    Li, Zhi; Ding, Yi; Zhu, Yunliang; Yin, Mingxing; Le, Xiaoping; Wang, Luo; Yang, Yang; Zhang, Qinxian

    2014-12-01

    Pleiomorphic adenoma gene-like 1 (PLAGL1, also known as LOT1 and ZAC) is a zinc-finger nuclear transcription factor, which possesses antiproliferative effects and is frequently epigenetically silenced during tumorigenesis. PLAGL1 gene is located on 6q24-25, a chromosomal region that is frequently deleted in various kinds of cancers. Both promoter hyper-methylation and loss of heterozygosity may lead to the down-regulation of PLAGL1 in human somatic cancers. Here we aimed to investigate the abnormalities of PLAGL1 in gastric cancers. We collected 153 case-matched gastric adenocarcinoma (GAC) cases. Quantitative real-time PCR method was applied to evaluate the expression levels as well as gene copy numbers of PLAGL1 in the collected samples. Methylation-specific PCR (MSP) assay was performed to analyze the methylation status of PLAGL1 P1 promoter. Decreased expression of PLAGL1 mRNA was observed in GAC tissues, especially in advanced GACs. Copy number decrease of PLAGL1 gene in GACs was observed in 9.15% (19 out of 153) of the GAC samples and was closely correlated with gene expression. Methylation status of PLAGL1 promoter in GAC tissues was higher than in normal controls, which was inversely correlated with the expression levels of PLAGL1 mRNA. DNA deletion and promoter hyper-methylation both contribute to the down-regulation of PLAGL1 in GACs. Copyright © 2013. Published by Elsevier Masson SAS.

  10. Genome-wide mRNA-seq profiling reveals predominant down-regulation of lipid metabolic processes in adipose tissues of Small Tail Han than Dorset sheep.

    Science.gov (United States)

    Miao, Xiangyang; Luo, Qingmiao; Qin, Xiaoyu; Guo, Yuntao; Zhao, Huijing

    2015-11-13

    Small Tail Han and Dorset sheep are two different sheep with distinguished morphologies in fat depositions. In order to characterize their gene expression profiles, our present study took the advantages of RNA sequencing technology with the aims to identify important genes regulating the metabolisms in adipose tissues of two different sheep. In obtained high quality sequencing reads, 85.9 (Han) and 86.1% (Dorset) were uniquely aligned to Oar v3.1 sheep reference genome, and over 76% of bases in mapped reads corresponded to mRNA. Using R package EBSeq, we identified 602 differentially expressed genes. Using the 602 genes, GO analysis showed that 30 out of 56 significantly enriched biological processes were metabolism related, of which the most significant one was triglyceride biosynthetic process. The KEGG pathway analysis indicated the down-regulation of several fat metabolic pathways. The predominant down-regulation of massive metabolic processes, particularly the lipid metabolism, in adipose tissues of Han sheep could explain, at least in part, the distinguished fat deposition between two different sheep, and our data constitute a basic picture of transcriptomes in these sheep for better understanding of underline biological mechanism in their lipid metabolisms.

  11. The Cln3 cyclin is down-regulated by translational repression and degradation during the G1 arrest caused by nitrogen deprivation in budding yeast.

    Science.gov (United States)

    Gallego, C; Garí, E; Colomina, N; Herrero, E; Aldea, M

    1997-12-01

    Nutrients are among the most important trophic factors in all organisms. When deprived of essential nutrients, yeast cells use accumulated reserves to complete the current cycle and arrest in the following G1 phase. We show here that the Cln3 cyclin, which has a key role in the timely activation of SBF (Swi4-Swi6)- and MBF (Mbp1-Swi6)-dependent promoters in late G1, is down-regulated rapidly at a post-transcriptional level in cells deprived of the nitrogen source. In addition to the fact that Cln3 is degraded faster by ubiquitin-dependent mechanisms, we have found that translation of the CLN3 mRNA is repressed approximately 8-fold under nitrogen deprivation conditions. As a consequence, both SBF- and MBF-dependent expression is strongly down-regulated. Mainly because of their transcriptional dependence on SBF, and perhaps with the contribution of similar post-transcriptional mechanisms to those found for Cln3, the G1 cyclins Cln1 and 2 become undetectable in starved cells. The complete loss of Cln cyclins and the sustained presence of the Clb-cyclin kinase inhibitor Sic1 in starved cells may provide the molecular basis for the G1 arrest caused by nitrogen deprivation.

  12. Down-regulation of EBV-LMP1 radio-sensitizes nasal pharyngeal carcinoma cells via NF-κB regulated ATM expression.

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    Xiaoqian Ma

    Full Text Available BACKGROUND: The latent membrane protein 1 (LMP1 encoded by EBV is expressed in the majority of EBV-associated human malignancies and has been suggested to be one of the major oncogenic factors in EBV-mediated carcinogenesis. In previous studies we experimentally demonstrated that down-regulation of LMP1 expression by DNAzymes could increase radiosensitivity both in cells and in a xenograft NPC model in mice. RESULTS: In this study we explored the molecular mechanisms underlying the radiosensitization caused by the down-regulation of LMP1 in nasopharyngeal carcinoma. It was confirmed that LMP1 could up-regulate ATM expression in NPCs. Bioinformatic analysis of the ATM ptomoter region revealed three tentative binding sites for NF-κB. By using a specific inhibitor of NF-κB signaling and the dominant negative mutant of IkappaB, it was shown that the ATM expression in CNE1-LMP1 cells could be efficiently suppressed. Inhibition of LMP1 expression by the DNAzyme led to attenuation of the NF-κB DNA binding activity. We further showed that the silence of ATM expression by ATM-targeted siRNA could enhance the radiosensitivity in LMP1 positive NPC cells. CONCLUSIONS: Together, our results indicate that ATM expression can be regulated by LMP1 via the NF-κB pathways through direct promoter binding, which resulted in the change of radiosensitivity in NPCs.

  13. Down-regulation of lactate dehydrogenase-A by siRNAs for reduced lactic acid formation of Chinese hamster ovary cells producing thrombopoietin.

    Science.gov (United States)

    Kim, Sung Hyun; Lee, Gyun Min

    2007-02-01

    Lactate, one of the major waste products in mammalian cell culture, can inhibit cell growth and affect cellular metabolism at high concentrations. To reduce lactate formation, lactate dehydrogenase-A (LDH-A), an enzyme catalyzing the conversion of glucose-derived pyruvate to lactate, was down-regulated by an expression vector of small interfering RNAs (siRNA) in recombinant Chinese hamster ovary (rCHO) cells producing human thrombopoietin (hTPO). Three clones expressing low levels of LDH-A, determined by reverse transcription-PCR and an enzyme activity test, were established in addition to a negative control cell line. LDH-A activities in the three clones were decreased by 75-89%, compared with that of the control CHO cell line, demonstrating that the effect of siRNA is more significant than that of other traditional methods such as homologous recombination (30%) and antisense mRNA (29%). The specific glucose consumption rates of the three clones were reduced to 54-87% when compared to the control cell line. Similarly, the specific lactate production rates were reduced to 45-79% of the control cell line level. In addition, reduction of LDH-A did not impair either cell proliferation or hTPO productivity. Taken together, these results show that the lactate formation rate in rCHO cell culture can be efficiently reduced through the down-regulation of LDH via siRNA.

  14. Harmine combined with paclitaxel inhibits tumor proliferation and induces apoptosis through down-regulation of cyclooxygenase-2 expression in gastric cancer

    Science.gov (United States)

    Yu, Xiao-Juan; Sun, Kun; Tang, Xiao-He; Zhou, Cun-Jin; Sun, Hui; Yan, Zhe; Fang, Ling; Wu, Hong-Wen; Xie, Yi-Kui; Gu, Bin

    2016-01-01

    Cyclooxygenase-2 (COX-2) serves an important role in the carcinogenesis and progression of gastric cancer. Harmine (HM) and paclitaxel (PTX) are reported as promising drug candidates for cancer therapy, but whether a synergistic anti-tumor effect of HM combined with PTX exists in human gastric cancer remains unknown. The present study evaluated the effects of HM and/or PTX on cell proliferation and apoptosis in a gastric cancer cell line, SGC-7901. HM and PTX inhibited cell proliferation in a dose-dependent manner. Both HM and PTX alone induced apoptosis in gastric cancer cells. The combination of HM and PTX exerted synergistic effects on proliferation inhibition and apoptosis induction in SGC-7901 cells, with down-regulation of COX-2, PCNA and Bcl-2 and up-regulation of Bax expression. The results indicated that combination chemotherapy using HM with PTX exerts an anti-tumor effect for treating gastric cancer. The combination of the two drugs inhibits gastric cancer development more effectively than each drug alone through down-regulation of COX-2 expression. PMID:27446381

  15. MiR-29b inhibits collagen maturation in hepatic stellate cells through down-regulating the expression of HSP47 and lysyl oxidase

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yifei; Ghazwani, Mohammed; Li, Jiang [Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Sun, Ming; Stolz, Donna B. [Department of Cell Biology and Physiology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261 (United States); He, Fengtian [Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Third Military Medical University, Chongqing 400038 (China); Fan, Jie [Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Xie, Wen [Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Li, Song, E-mail: sol4@pitt.edu [Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261 (United States)

    2014-04-18

    Highlights: • Enhanced HSP47 and LOX expression is associated with decreased miR-29b level in liver fibrosis. • miR-29b down-regulates HSP47 and LOX expression. • The suppression of HSP47 and LOX by miR-29b is mediated by putative sites at their 3′-UTRs. • miR-29b inhibits extracellular LOX activity and collagen maturation. - Abstract: Altered expression of miR-29b is implicated in the pathogenesis and progression of liver fibrosis. We and others previously demonstrated that miR-29b down-regulates the expression of several extracellular-matrix (ECM) genes including Col 1A1, Col 3A1 and Elastin via directly targeting their 3′-UTRs. However, whether or not miR-29b plays a role in the post-translational regulation of ECM biosynthesis has not been reported. Heat shock protein 47 (HSP47) and lysyl oxidase (LOX) are known to be essential for ECM maturation. In this study we have demonstrated that expression of HSP47 and LOX was significantly up-regulated in culture-activated primary rat hepatic stellate cells (HSCs), TGF-β stimulated LX-2 cells and liver tissue of CCl{sub 4}-treated mice, which was accompanied by a decrease of miR-29b level. In addition, over-expression of miR-29b in LX-2 cells resulted in significant inhibition on HSP47 and LOX expression. Mechanistically, miR-29b inhibited the expression of a reporter gene that contains the respective full-length 3′-UTR from HSP47 and LOX gene, and this inhibitory effect was abolished by the deletion of a putative miR-29b targeting sequence from the 3′-UTRs. Transfection of LX-2 cells with miR-29b led to abnormal collagen structure as shown by electron-microscopy, presumably through down-regulation of the expression of molecules involved in ECM maturation including HSP47 and LOX. These results demonstrated that miR-29b is involved in regulating the post-translational processing of ECM and fibril formation.

  16. Effect of Aqueous Extract of Aegle marmelos Fruit on Adherence and β-Lactam Resistance of Enteropathogenic Escherichia coli by Down Regulating Outer Membrane Protein C

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    Subramaniya Bharathi Raja

    2009-01-01

    Full Text Available Problem statement: Enteropathogenic Escherichia Coli (EPEC continue to be a major health problem, leading to death due to diarrhea, predominantly in children below the age of five. Due to evolution of multi drug resistance in EPEC and side effects caused to host by antibiotics necessitated a search for alternative medicines from medicinal plants. One such medicinal plant used since ancient times to cure diarrhea is Aegle marmelos. This study was done to investigate the effect of aqueous extract of Aegle marmelos fruit (AEAM on outer membrane protein C (OmpC of EPEC, which plays a key role in adherence and antibiotic resistance. Approach: Fixation of minimum inhibitory concentration. In presence and absence of AEAM antibiotic susceptibility test was performed. Expression analysis of OmpC and OmpF was carried out by RT-PCR of EPEC in presence and absence of AEAM. Morphological changes of EPEC in presence and absence of AEAM were analyzed by TEM. In infant mouse ileal loop model, histological analysis, adherence of bacteria to ileal loops and Western blotting for caspase-3 and Hsp70 were done. Results: OmpC (~42kDa a porin, played an important role in selective transport of nutrients and also acted as an adhesin, whereas OmpF (~38kDa is also a porin which is non selective. Susceptibility of EPEC to β-lactam antibiotics in presence of AEAM can be attributed to down regulation of OmpC and upregulation of OmpF. The changes in Omp expression also triggered morphological changes in EPEC. Histology and western blot of Hsp70 and Caspase-3 in rat ileal loop confirmed the effect of AEAM on attenuating the virulence of EPEC by preventing its infection due to loss of adherence. Loss of adherence was due to morphological changes and down regulation of OmpC in EPEC. Conclusion: From this study, we concluded that the protection offered by AEAM against EPEC was due to down regulation of OmpC, leading to loss of adherence and up regulation of OmpF, which

  17. Mycobacterium tuberculosis-infected human monocytes down-regulate microglial MMP-2 secretion in CNS tuberculosis via TNFα, NFκB, p38 and caspase 8 dependent pathways

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    Elkington Paul T

    2011-05-01

    Full Text Available Abstract Tuberculosis (TB of the central nervous system (CNS is a deadly disease characterized by extensive tissue destruction, driven by molecules such as Matrix Metalloproteinase-2 (MMP-2 which targets CNS-specific substrates. In a simplified cellular model of CNS TB, we demonstrated that conditioned medium from Mycobacterium tuberculosis-infected primary human monocytes (CoMTb, but not direct infection, unexpectedly down-regulates constitutive microglial MMP-2 gene expression and secretion by 72.8% at 24 hours, sustained up to 96 hours (P M.tb-infected monocyte-dependent networks paradoxically involves the pro-inflammatory mediators TNF-α, p38 MAP kinase and NFκB in addition to a novel caspase 8-dependent pathway.

  18. Antioxidant compounds and their bioaccessibility in tomato fruit and puree obtained from a DETIOLATED-1 (DET-1) down-regulated genetically modified genotype.

    Science.gov (United States)

    Talens, P; Mora, L; Bramley, Peter M; Fraser, Paul D

    2016-12-15

    The economic value, the ease of cultivation and processing, and the well-known health-promoting properties of tomato fruit, make the tomato an important target for genetic manipulation to increase its nutritional content. A transgenic variety, down-regulated in the DETIOLATED-1 (DET-1) gene, has been studied in comparison with the parental line, for antioxidant levels in fresh and hot break fruit, as well as the bioaccessibility of antioxidants from puree. Differences in the concentrations of antioxidants between the wild-type and the genetically modified raw tomatoes were confirmed, but antioxidant levels were maintained to a greater extent in the GM puree than in the parent. The bioaccessibility of the compounds, tested using an in vitro digestion model, showed an increase in the genetically modified samples.

  19. The brain 5-HT4 receptor binding is down-regulated in the Flinders Sensitive Line depression model and in response to paroxetine administration

    DEFF Research Database (Denmark)

    Licht, Cecilie Löe; Marcussen, Anders Bue; Wegener, Gregers

    2009-01-01

    The 5-hydroxytryptamine (5-HT(4)) receptor may be implicated in depression and is a new potential target for antidepressant treatment. We have investigated the brain 5-HT(4) receptor [(3)H]SB207145 binding in the Flinders Sensitive Line rat depression model by quantitative receptor autoradiography......, and related this to 5-HT transporter (S)-[N-methyl-(3)H]citalopram binding. We also determined the regulation of 5-HT(4) receptor binding by 1, 14, and 21 days of paroxetine administration and subchronic 5-HT depletion, and compared this with changes in 5-HT(2A) receptor [(3)H]MDL100907 binding....... In the Flinders Sensitive Line, the 5-HT(4) receptor and 5-HT transporter binding were decreased in the dorsal and ventral hippocampus, and the changes in binding were directly correlated within the dorsal hippocampus. Chronic but not acute paroxetine administration caused a 16-47% down-regulation of 5-HT(4...

  20. Transmembrane neural cell-adhesion molecule (NCAM), but not glycosyl-phosphatidylinositol-anchored NCAM, down-regulates secretion of matrix metalloproteinases

    DEFF Research Database (Denmark)

    Edvardsen, K; Chen, W; Rucklidge, G

    1993-01-01

    proteinases, and proteinase inhibitors all participate in the construction, maintenance, and remodeling of extracellular matrix by cells. The neural cell-adhesion molecule (NCAM)-negative rat glioma cell line BT4Cn secretes substantial amounts of metalloproteinases, as compared with its NCAM-positive mother...... cell line BT4C. We have transfected the BT4Cn cell line with cDNAs encoding the human NCAM-B and -C isoforms. We report here that the expression of transmembrane NCAM-B, but not of glycosyl-phosphatidylinositol-linked NCAM-C, induces a down-regulation of 92-kDa gelatinase (matrix metalloproteinase 9......) and interstitial collagenase (matrix metalloproteinase 1), indicating that cellular expression of the recognition molecule NCAM regulates the metabolism of the surrounding matrix....

  1. Ginsenoside Rc Promotes Anti-Adipogenic Activity on 3T3-L1 Adipocytes by Down-Regulating C/EBPα and PPARγ

    Directory of Open Access Journals (Sweden)

    Ji-Won Yang

    2015-01-01

    Full Text Available Panax ginseng and its major components, the ginsenosides, are widely used in oriental medicine for the prevention of various disorders. In the present study, the inhibitory activity of ginsenoside Rc on adipogenesis was investigated using the 3T3-L1 cell line. The results obtained showed that Rc reduced the proliferation and viability of 3T3-L1 preadipocytes in a dose-dependent manner. Treatment with Rc decreased the number of adipocytes and reduced lipid accumulation in maturing 3T3-L1 preadipocytes, demonstrating an inhibitory effect on lipogenesis. Moreover, it was found that Rc directly induced lipolysis in adipocytes and down-regulated the expression of major transcription factors of the adipogenesis pathway, such as PPARγ and C/EBPα. These findings indicate that Rc is capable of suppressing adipogenesis and therefore they seem to be natural bioactive factors effective in adipose tissue mass modulation.

  2. Whole blood transcriptional profiling reveals significant down-regulation of human leukocyte antigen class I and II genes in essential thrombocythemia, polycythemia vera and myelofibrosis

    DEFF Research Database (Denmark)

    Skov, Vibe; Riley, Caroline Hasselbalch; Thomassen, Mads

    2013-01-01

    Gene expression profiling studies in the Philadelphia-negative chronic myeloproliferative neoplasms have revealed significant deregulation of several immune and inflammation genes that might be of importance for clonal evolution due to defective tumor immune surveillance. Other mechanisms might...... be down-regulation of major histocompatibility (MHC) class I and II genes, which are used by tumor cells to escape antitumor T-cell-mediated immune responses. We have performed whole blood transcriptional profiling of genes encoding human leukocyte antigen (HLA) class I and II molecules, β2-microglobulin...... treatment with epigenome modulating agents (DNA-hypomethylators and DNA-hyperacetylators [histone deacetylase inhibitors]) and interferon-α2, our findings call for prospective transcriptional studies of HLA genes during treatment with these agents....

  3. Melatonin down-regulates hTERT expression induced by either natural estrogens (17beta-estradiol) or metalloestrogens (cadmium) in MCF-7 human breast cancer cells.

    Science.gov (United States)

    Martínez-Campa, Carlos M; Alonso-González, Carolina; Mediavilla, Maria D; Cos, Samuel; González, Alicia; Sanchez-Barcelo, Emilio J

    2008-09-18

    The goal was to evaluate whether melatonin (Mel) down-regulates hTERT expression induced by 17beta-estradiol (E(2)) or cadmium (Cd) in breast cancer cells. We found that: (a) Mel inhibits E(2) or Cd-induced hTERT transcription in hTERT-Luc transfected MCF-7 cells, (b) Mel significantly reduces E(2)- and Cd-mediated hTERT transactivation triggered by ERalpha in transfected HeLa cells, (c) Mel inhibits hTERT expression induced by E(2) or Cd in MCF-7 cells. Melatonin inhibition of telomerase activity supports a possible role in treatment of estrogen-dependent tumors or carcinogenesis by environmental or occupational exposure to xenoestrogens.

  4. Down-regulation of Slit-Robo pathway mediating neuronal cytoskeletal remodeling processes facilitates the antidepressive-like activity of Gastrodia elata Blume.

    Science.gov (United States)

    Lin, Shih-Hang; Chen, Wei-Cheng; Lu, Kuan-Hung; Chen, Pei-Ju; Hsieh, Shu-Chen; Pan, Tzu-Ming; Chen, Shui-Tein; Sheen, Lee-Yan

    2014-10-29

    Nowadays, depression is a serious psychological disorder that causes extreme economic loss and social problems. Previously, we discovered that the water extract of Gastrodia elata Blume (WGE) improved depressive-like behavior by influencing neurotransmitters in rats subjected to the forced swimming test. To elucidate possible mechanisms, in the present study, we performed a proteomics and bioinformatics analysis to identify the related pathways. Western blot-validated results indicated that the core protein network modulated by WGE administration was closely associated with down-regulation of the Slit-Robo pathway, which modulates neuronal cytoskeletal remodeling processes. Although Slit-Robo signaling has been well investigated in neuronal development, its relationship with depression is not fully understood. We provide a potential hint on the mechanism responsible for the antidepressive-like activity of WGE. In conclusion, we suggest that the Slit-Robo pathway and neuronal cytoskeleton remodeling are possibly one of the pathways associated with the antidepressive-like effects of WGE.

  5. Virus-Induced Gene Silencing in the Culinary Ginger (Zingiber officinale): An Effective Mechanism for Down-Regulating Gene Expression in Tropical Monocots

    Institute of Scientific and Technical Information of China (English)

    Tanya Renner; Jennifer Bragga; Heather E. Driscoll; Juliana Cho; Andrew O. Jackson; Chelsea D. Specht

    2009-01-01

    Virus-induced gene silencing (VIGS) has been shown to be effective for transient knockdown of gene expres-sion in plants to analyze the effects of specific genes in development and stress-related responses. VlGS is well established for studies of model systems and crops within the Solanaceae, Brassicaceae, Leguminaceae, and Poaceae, but only recently has been applied to plants residing outside these families. Here, we have demonstrated that barley stripe mosaic virus (BSMV) can infect two species within the Zingiberaceae, and that BSMV-VlGS can be applied to specifically down-regulate phytoene desaturase in the culinary ginger Zingiber officinale. These results suggest that extension of BSMV-VIGS to monocots other than cereals has the potential for directed genetic analyses of many important temperate and tropical crop species.

  6. Posttranscriptional down-regulation of small ribosomal subunit proteins correlates with reduction of 18S rRNA in RPS19 deficiency.

    Science.gov (United States)

    Badhai, Jitendra; Fröjmark, Anne-Sophie; Razzaghian, Hamid Reza; Davey, Edward; Schuster, Jens; Dahl, Niklas

    2009-06-18

    Ribosomal protein S19 (RPS19) is mutated in patients with Diamond-Blackfan anemia (DBA). We hypothesized that decreased levels of RPS19 lead to a coordinated down-regulation of other ribosomal (r-)proteins at the subunit level. We show that small interfering RNA (siRNA) knock-down of RPS19 results in a relative decrease of small subunit (SSU) r-proteins (S20, S21 and S24) when compared to large subunit (LSU) r-proteins (L3, L9, L30 and L38). This correlates with a relative decrease in 18S rRNA with respect to 28S rRNA. The r-protein mRNA levels remain relatively unchanged indicating a post transcriptional regulation of r-proteins at the level of subunit formation.

  7. Down-regulation of transcobalamin receptor TCblR/CD320 by siRNA inhibits cobalamin uptake and proliferation of cells in culture

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Shao-Chiang [School of Graduate Studies, SUNY-Downstate Medical Center, Brooklyn, NY 11203 (United States); Nakayama, Yasumi; Sequeira, Jeffrey M. [Department of Medicine, Cell Biology, SUNY-Downstate Medical Center, Brooklyn, NY 11203 (United States); Quadros, Edward V., E-mail: Edward.Quadros@downstate.edu [Department of Medicine, Cell Biology, SUNY-Downstate Medical Center, Brooklyn, NY 11203 (United States); School of Graduate Studies, SUNY-Downstate Medical Center, Brooklyn, NY 11203 (United States)

    2011-07-01

    The clinical phenotype of cobalamin (Cbl) deficiency is dictated by the essential role of this vitamin in two key enzymatic reactions. Multiple proteins and receptors participate in the absorption, transport and delivery of this vitamin to tissue cells. Cellular uptake of Cbl is mediated by transcobalamin (TC), a plasma protein and a transmembrane receptor (TCblR) with high affinity for TC saturated with Cbl. Knockdown of TCblR with siRNA results in decreased TC-Cbl uptake. The ensuing Cbl deficiency leads to an increase in doubling time and decreased proliferation of these cells. The study confirms the seminal role of this receptor in the cellular uptake of Cbl and its down-regulation as a potential strategy to inhibit proliferation of cancer cells.

  8. p38 MAPK-Mediated Bmi-1 down-regulation and defective proliferation in ATM-deficient neural stem cells can be restored by Akt activation.

    Directory of Open Access Journals (Sweden)

    Jeesun Kim

    Full Text Available A-T (ataxia telangiectasia is a genetic disease caused by a mutation in the Atm (A-T mutated gene that leads to neurodegeneration. Despite an increase in the numbers of studies in this area in recent years, the mechanisms underlying neurodegeneration in human A-T are still poorly understood. Previous studies demonstrated that neural stem cells (NSCs isolated from the subventricular zone (SVZ of Atm(-/- mouse brains show defective self-renewal and proliferation, which is accompanied by activation of chronic p38 mitogen-activated protein kinase (MAPK and a lower level of the polycomb protein Bmi-1. However, the mechanism underlying Bmi-1 down-regulation and its relevance to defective proliferation in Atm(-/- NSCs remained unclear. Here, we show that over-expression of Bmi-1 increases self-renewal and proliferation of Atm(-/- NSCs to normal, indicating that defective proliferation in Atm(-/- NSCs is a consequence of down-regulation of Bmi-1. We also demonstrate that epidermal growth factor (EGF-induced Akt phosphorylation renders Bmi-1 resistant to the proteasomal degradation, leading to its stabilization and accumulation in the nucleus. However, inhibition of the Akt-dependent Bmi-1 stabilizing process by p38 MAPK signaling reduces the levels of Bmi-1. Treatment of the Atm(-/- NSCs with a specific p38 MAPK inhibitor SB203580 extended Bmi-1 posttranscriptional turnover and H2A ubiquitination in Atm(-/- NSCs. Our observations demonstrate the molecular basis underlying the impairment of self-renewal and proliferation in Atm(-/- NSCs through the p38 MAPK-Akt-Bmi-1-p21 signaling pathway.

  9. Budesonide suppresses pulmonary antibacterial host defense by down-regulating cathelicidin-related antimicrobial peptide in allergic inflammation mice and in lung epithelial cells

    Directory of Open Access Journals (Sweden)

    Wang Peng

    2013-02-01

    Full Text Available Abstract Background Glucocorticoids are widely regarded as the most effective treatment for asthma. However, the direct impact of glucocorticoids on the innate immune system and antibacterial host defense during asthma remain unclear. Understanding the mechanisms underlying this process is critical to the clinical application of glucocorticoids for asthma therapy. After sensitization and challenge with ovalbumin (OVA, BALB/c mice were treated with inhaled budesonide and infected with Pseudomonas aeruginosa (P. aeruginosa. The number of viable bacteria in enflamed lungs was evaluated, and levels of interleukin-4 (IL-4 and interferon-γ (IFN-γ in serum were measured. A lung epithelial cell line was pretreated with budesonide. Levels of cathelicidin-related antimicrobial peptide (CRAMP were measured by immunohistochemistry and western blot analysis. Intracellular bacteria were observed in lung epithelial cells. Results Inhaled budesonide enhanced lung infection in allergic mice exposed to P. aeruginosa and increased the number of viable bacteria in lung tissue. Higher levels of IL-4 and lower levels of IFN-γ were observed in the serum. Budesonide decreased the expression of CRAMP, increased the number of internalized P. aeruginosa in OVA-challenged mice and in lung epithelial cell lines. These data indicate that inhaled budesonide can suppress pulmonary antibacterial host defense by down-regulating CRAMP in allergic inflammation mice and in cells in vitro. Conclusions Inhaled budesonide suppressed pulmonary antibacterial host defense in an asthmatic mouse model and in lung epithelium cells in vitro. This effect was dependent on the down-regulation of CRAMP.

  10. Enterococcus faecalis Infection and Reactive Oxygen Species Down-Regulates the miR-17-92 Cluster in Gastric Adenocarcinoma Cell Culture

    Directory of Open Access Journals (Sweden)

    Jesper A. B. Strickertsson

    2014-08-01

    Full Text Available Chronic inflammation due to bacterial overgrowth of the stomach predisposes to the development of gastric cancer and is also associated with high levels of reactive oxygen species (ROS. In recent years increasing attention has been drawn to microRNAs (miRNAs due to their role in the pathogenesis of many human diseases including gastric cancer. Here we studied the impact of infection by the gram-positive bacteria Enterococcus faecalis (E. faecalis on global miRNA expression as well as the effect of ROS on selected miRNAs. Human gastric adenocarcinoma cell line MKN74 was infected with living E. faecalis for 24 h or for 5 days or with E. faecalis lysate for 5 days. The miRNA expression was examined by microarray analysis using Affymetrix GeneChip miRNA Arrays. To test the effect of ROS, MKN74 cells were treated with 100 mM tert-Butyl hydroperoxide (TBHP. Following 5 days of E. faecalis infection we found 91 differentially expressed miRNAs in response to living bacteria and 2 miRNAs responded to E. faecalis lysate. We verified the down-regulation of the miR-17-92 and miR-106-363 clusters and of other miRNAs involved in the oxidative stress-response by qRT-PCR. We conclude that only infection by living E. faecalis bacteria caused a significant global response in miRNA expression in the MKN74 cell culture. E. faecalis infection as well as ROS stimulation down-regulated the expression of the miR-17-92 cluster. We believe that these changes could reflect a general response of gastric epithelial cells to bacterial infections.

  11. Moraxella catarrhalis decreases antiviral innate immune responses by down-regulation of TLR3 via inhibition of p53 in human bronchial epithelial cells.

    Science.gov (United States)

    Heinrich, Annina; Haarmann, Helge; Zahradnik, Sabrina; Frenzel, Katrin; Schreiber, Frauke; Klassert, Tilman E; Heyl, Kerstin A; Endres, Anne-Sophie; Schmidtke, Michaela; Hofmann, Jörg; Slevogt, Hortense

    2016-06-01

    Chronic obstructive pulmonary disease (COPD) is complicated by infectious exacerbations with acute worsening of respiratory symptoms. Coinfections of bacterial and viral pathogens are associated with more severe exacerbations. Moraxella catarrhalis is one of the most frequent lower respiratory tract pathogens detected in COPD. We therefore studied the impact of M. catarrhalis on the antiviral innate immune response that is mediated via TLR3 and p53. Molecular interactions between M. catarrhalis and normal human bronchial epithelial (NHBE) cells as well as Beas-2B cells were studied using flow cytometry, quantitative PCR analysis, chromatin immunoprecipitation, RNA interference, and ELISA. M. catarrhalis induces a significant down-regulation of TLR3 in human bronchial epithelial cells. In M. catarrhalis-infected cells, expression of p53 was decreased. We detected a reduced binding of p53 to the tlr3 promoter, resulting in reduced TLR3 gene transcription. M. catarrhalis diminished the TLR3-dependent secretion of IFN-β, IFN-λ, and chemokine (C-X-C motif) ligand 8. In addition in M. catarrhalis infected cells, expression of rhinovirus type 1A RNA was increased compared with uninfected cells. M. catarrhalis reduces antiviral defense functions of bronchial epithelial cells, which may increase susceptibility to viral infections.-Heinrich, A., Haarmann, H., Zahradnik, S., Frenzel, K., Schreiber, F., Klassert, T. E., Heyl, K. A., Endres, A.-S., Schmidtke, M., Hofmann, J., Slevogt, H. Moraxella catarrhalis decreases antiviral innate immune responses by down-regulation of TLR3 via inhibition of p53 in human bronchial epithelial cells.

  12. DMSO efficiently down regulates pluripotency genes in human embryonic stem cells during definitive endoderm derivation and increases the proficiency of hepatic differentiation.

    Directory of Open Access Journals (Sweden)

    Katherine Czysz

    Full Text Available BACKGROUND: Definitive endoderm (DE is one of the three germ layers which during in vivo vertebrate development gives rise to a variety of organs including liver, lungs, thyroid and pancreas; consequently efficient in vitro initiation of stem cell differentiation to DE cells is a prerequisite for successful cellular specification to subsequent DE-derived cell types [1, 2]. In this study we present a novel approach to rapidly and efficiently down regulate pluripotency genes during initiation of differentiation to DE cells by addition of dimethyl sulfoxide (DMSO to Activin A-based culture medium and report its effects on the downstream differentiation to hepatocyte-like cells. MATERIALS AND METHODS: Human embryonic stem cells (hESC were differentiated to DE using standard methods in medium supplemented with 100ng/ml of Activin A and compared to cultures where DE specification was additionally enhanced with different concentrations of DMSO. DE cells were subsequently primed to generate hepatic-like cells to investigate whether the addition of DMSO during formation of DE improved subsequent expression of hepatic markers. A combination of flow cytometry, real-time quantitative reverse PCR and immunofluorescence was applied throughout the differentiation process to monitor expression of pluripotency (POUF5/OCT4 & NANOG, definitive endoderm (SOX17, CXCR4 & GATA4 and hepatic (AFP & ALB genes to generate differentiation stage-specific signatures. RESULTS: Addition of DMSO to the Activin A-based medium during DE specification resulted in rapid down regulation of the pluripotency genes OCT4 and NANOG, accompanied by an increase expression of the DE genes SOX17, CXCR4 and GATA4. Importantly, the expression level of ALB in DMSO-treated cells was also higher than in cells which were differentiated to the DE stage via standard Activin A treatment.

  13. Association between activation of phase 2 enzymes and down-regulation of dendritic cell maturation by c9,t11-conjugated linoleic acid.

    Science.gov (United States)

    Bergamo, Paolo; Maurano, Francesco; D'Arienzo, Rossana; David, Chella; Rossi, Mauro

    2008-05-15

    Antioxidant and cytoprotective enzymes (phase 2) exert protective activity against reactive oxygen species (ROS)-induced injury. We have recently shown how the beneficial effects of conjugated linoleic acid (CLA) in a mouse model of an autoimmune disease are parallel with the activation of phase 2 enzymes. In the present study we found that c9,t11-CLA isomer activates cytoprotective enzymes and down-regulates LPS- or gliadin-induced maturation in dendritic cells (DCs) obtained from a murine model of celiac disease. As expected, the enhancement of LPS-induced maturation (increased NFkappaB p65 nuclear translocation, CD86 expression and decreased CD11c+ cell number) was exacerbated by specific glutathione (GSH) inhibitor (buthionine sulphoximine; BSO). Conversely, the down-regulation of DC maturation by antioxidant N-acetylcysteine (NAC) was associated with the marked increase of intracellular thiol concentration. c9,t11-CLA activation of phase 2 enzymes in mouse DCs was observed first. Next, we found that the significant reduction of LPS- and gliadin-induced DC maturation in cultures pre-treated with c9,t11-CLA improved cellular redox status (decreased ROS and higher antioxidant defenses). Finally, the process of DC maturation triggered by gliadin, in contrast with that exhibited by LPS, was not associated with enhanced NFkappaB nuclear translocation and pro-inflammatory cytokines synthesis. These results demonstrate that c9,t11-CLA renders DCs more resistant to gliadin- or LPS-induced maturation, thus indicating that a cytoprotective mechanism elicited by c9,t11-CLA may modulate DC responsiveness.

  14. Down-regulation of MicroRNAs 222/221 in Acute Myelogenous Leukemia with Deranged Core-Binding Factor Subunits

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    Matteo Brioschi

    2010-11-01

    Full Text Available Core-binding factor leukemia (CBFL is a subgroup of acutemyeloid leukemia (AML characterized by genetic mutations involving the subunits of the core-binding factor (CBF. The leukemogenesis model for CBFL posits that one, or more, gene mutations inducing increased cell proliferation and/or inhibition of apoptosis cooperate with CBF mutations for leukemia development. One of the most commonmutations associated with CBF mutations involves the KIT receptor. A high expression of KIT is a hallmark of a high proportion of CBFL. Previous studies indicate that microRNA (MIR 222/221 targets the 3′ untranslated region of the KIT messenger RNA and our observation that AML1 can bind the MIR-222/221 promoter, we hypothesized that MIR-222/221 represents the link between CBF and KIT. Here, we show that MIR-222/221 expression is upregulated after myeloid differentiation of normal bone marrow AC133+ stem progenitor cells. CBFL blasts with either t(8;21 or inv(16 CBF rearrangements with high expression levels of KIT (CD117 display a significantly lower level of MIR-222/221 expression than non-CBFL blasts. Consistently, we found that the t(8;21 AML1-MTG8 fusion protein binds the MIR-222/221 promoter and induces transcriptional repression of a MIR-222/221-LUC reporter. Because of the highly conserved sequence homology, we demonstrated concomitant MIR-222/221 down-regulation and KIT up-regulation in the 32D/WT1 mouse cell model carrying the AML1-MTG16 fusion protein. This study provides the first hint that CBFL-associated fusion proteins may lead to up-regulation of the KIT receptor by down-regulating MIR-222/221, thus explaining the concomitant occurrence of CBF genetic rearrangements and overexpression of wild type or mutant KIT in AML.

  15. Down-regulation of Sonic hedgehog signaling pathway activity is involved in 5-fluorouracil-induced apoptosis and motility inhibition in Hep3B cells

    Institute of Scientific and Technical Information of China (English)

    Qiyu Wang; Shuhong Huang; Ling Yang; Ling Zhao; Yuxia Yin; Zhongzhen Liu; Zheyu Chen; Hongwei Zhang

    2008-01-01

    The Sonic hedgehog (SHh) pathway plays a critical role in normal embryogenesis and carcinogenesis, but its function in cancer cells treated with 5-fluorouracil (5-FU) remains unknown. We examined the expression of a subset of SHh signaling pathway genes, including SHh, SMO, PTC1, Su(Fu) and HIP in human hepatocellular carcinoma (HCC) cell lines,Hep3B and HepG2, treated with 5-FU by reverse transcriptionpolymerase chain reaction. Using trypan blue analysis,3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick-end labeling assay, we also detected the apoptosis of Hep3B cells resulting from the transfection of pCS2-Gli1 expression vector combined with 5-FU treatment.The motility of the cells was detected by scratch wound closure assay. The expression and subcellular location of PTC1 protein in Hep3B cells treated by 5-FU were also investigated by Western blot analysis and immunofluorescent microscopy. The results indicated that the expression of SHh pathway target molecules at both messenger RNA and protein levels are evidently down-regulated in Hep3B cells treated with 5-FU. The overexpression of Gli1 restores cell viability and, to some extent, the migration abilities inhibited by 5-FU.Furthermore, 5-FU treatment affects the subcellular localization of PTC1 protein, a key member in SHh signaling pathway. Our data showed that the down-regulation of SHh signaling pathway activity was involved in 5-FU-induced apoptosis and the inhibition of motility in hedgehog-activated HCC cell lines. This implies that the combination of SHh signaling pathway inhibitor and 5-FU-based chemotherapy might represent a more promising strategy against HCC.

  16. Reactive Neurogenesis and Down-Regulation of the Potassium-Chloride Cotransporter KCC2 in the Cochlear Nuclei after Cochlear Deafferentation

    Science.gov (United States)

    Tighilet, Brahim; Dutheil, Sophie; Siponen, Marina I.; Noreña, Arnaud J.

    2016-01-01

    While many studies have been devoted to investigating the homeostatic plasticity triggered by cochlear hearing loss, the cellular and molecular mechanisms involved in these central changes remain elusive. In the present study, we investigated the possibility of reactive neurogenesis after unilateral cochlear nerve section in the cochlear nucleus (CN) of cats. We found a strong cell proliferation in all the CN sub-divisions ipsilateral to the lesion. Most of the newly generated cells survive up to 1 month after cochlear deafferentation in all cochlear nuclei (except the dorsal CN) and give rise to a variety of cell types, i.e., microglial cells, astrocytes, and neurons. Interestingly, many of the newborn neurons had an inhibitory (GABAergic) phenotype. This result is intriguing since sensory deafferentation is usually accompanied by enhanced excitation, consistent with a reduction in central inhibition. The membrane potential effect of GABA depends, however, on the intra-cellular chloride concentration, which is maintained at low levels in adults by the potassium chloride co-transporter KCC2. The KCC2 density on the plasma membrane of neurons was then assessed after cochlear deafferentation in the cochlear nuclei ipsilateral and contralateral to the lesion. Cochlear deafferentation is accompanied by a strong down-regulation of KCC2 ipsilateral to the lesion at 3 and 30 days post-lesion. This study suggests that reactive neurogenesis and down-regulation of KCC2 is part of the vast repertoire involved in homeostatic plasticity triggered by hearing loss. These central changes may also play a role in the generation of tinnitus and hyperacusis. PMID:27630564

  17. Monocytes from cystic fibrosis patients are locked in an LPS tolerance state: down-regulation of TREM-1 as putative underlying mechanism.

    Directory of Open Access Journals (Sweden)

    Carlos del Fresno

    Full Text Available Cystic Fibrosis (CF is an inherited pleiotropic disease that results from abnormalities in the gene that codes for the chloride channel, Cystic Fibrosis Transmembrane Conductance Regulator (CFTR. CF patients are frequently colonized by several pathogens, but the mechanisms that allow colonization in spite of apparently functional immune systems are incompletely understood. In this paper we show that blood peripheral monocytes isolated from CF patients are found in an endotoxin tolerance state, yet this is not due to a deficient TLR activation. On the other hand, levels of the amplifier of inflammatory responses, TREM-1 (Triggering Receptor Expressed on Myeloid cells, are notably down-regulated in monocytes from patients, in comparison to those extracted from healthy volunteers. Furthermore, the soluble form of TREM-1 (sTREM-1 was not detected in the sera of patients. Additionally, and in strict contrast to patients who suffer from Chronic Obstructive Pulmonary Disease (COPD, CF monocytes challenged ex vivo with LPS neither up-regulated membrane-anchored TREM-1 nor sTREM-1. Finally, similar levels of PGE(2 expression and p65 translocation into the nucleus were found in both patients and healthy volunteers, thus suggesting that TREM-1 regulation is neither controlled by PGE(2 levels nor by p65 activation in this case. However, PU.1 translocation into the nucleus was significantly higher in CF monocytes than in controls, suggesting a role for this transcription factor in the control of TREM-1 expression. We conclude that down-regulation of TREM-1 expression in cystic fibrosis patients is at least partly responsible for the endotoxin tolerance state in which their monocytes are locked.

  18. Cholesterol-lowering activity of sesamin is associated with down-regulation on genes of sterol transporters involved in cholesterol absorption.

    Science.gov (United States)

    Liang, Yin Tong; Chen, Jingnan; Jiao, Rui; Peng, Cheng; Zuo, Yuanyuan; Lei, Lin; Liu, Yuwei; Wang, Xiaobo; Ma, Ka Ying; Huang, Yu; Chen, Zhen-Yu

    2015-03-25

    Sesame seed is rich in sesamin. The present study was to (i) investigate the plasma cholesterol-lowering activity of dietary sesamin and (ii) examine the interaction of dietary sesamin with the gene expression of sterol transporters, enzymes, receptors, and proteins involved in cholesterol metabolism. Thirty hamsters were divided into three groups fed the control diet (CON) or one of two experimental diets containing 0.2% (SL) and 0.5% (SH) sesamin, respectively, for 6 weeks. Plasma total cholesterol (TC) levels in hamsters given the CON, SL, and SH diets were 6.62 ± 0.40, 5.32 ± 0.40, and 5.00 ± 0.44 mmol/L, respectively, indicating dietary sesamin could reduce plasma TC in a dose-dependent manner. Similarly, the excretion of total fecal neutral sterols was dose-dependently increased with the amounts of sesamin in diets (CON, 2.65 ± 0.57; SL, 4.30 ± 0.65; and SH, 5.84 ± 1.27 μmol/day). Addition of sesamin into diets was associated with down-regulation of mRNA of intestinal Niemann-Pick C1 like 1 protein (NPC1L1), acyl-CoA:cholesterol acyltransferase 2 (ACAT2), microsomal triacylglycerol transport protein (MTP), and ATP-binding cassette transporters subfamily G members 5 and 8 (ABCG5 and ABCG8). Results also showed that dietary sesamin could up-regulate hepatic cholesterol-7α-hydroxylase (CYP7A1), whereas it down-regulated hepatic 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase and liver X receptor alpha (LXRα). It was concluded that the cholesterol-lowering activity of sesamin was mediated by promoting the fecal excretion of sterols and modulating the genes involved in cholesterol absorption and metabolism.

  19. Insulin-Mediated Down-Regulation of Apolipoprotein A5 Gene Expression through the Phosphatidylinositol 3-Kinase Pathway: Role of Upstream Stimulatory Factor

    Science.gov (United States)

    Nowak, Maxime; Helleboid-Chapman, Audrey; Jakel, Heidelinde; Martin, Geneviève; Duran-Sandoval, Daniel; Staels, Bart; Rubin, Edward M.; Pennacchio, Len A.; Taskinen, Marja-Riitta; Fruchart-Najib, Jamila; Fruchart, Jean-Charles

    2005-01-01

    The apolipoprotein A5 gene (APOA5) has been repeatedly implicated in lowering plasma triglyceride levels. Since several studies have demonstrated that hyperinsulinemia is associated with hypertriglyceridemia, we sought to determine whether APOA5 is regulated by insulin. Here, we show that cell lines and mice treated with insulin down-regulate APOA5 expression in a dose-dependent manner. Furthermore, we found that insulin decreases human APOA5 promoter activity, and subsequent deletion and mutation analyses uncovered a functional E box in the promoter. Electrophoretic mobility shift and chromatin immunoprecipitation assays demonstrated that this APOA5 E box binds upstream stimulatory factors (USFs). Moreover, in transfection studies, USF1 stimulates APOA5 promoter activity, and the treatment with insulin reduced the binding of USF1/USF2 to the APOA5 promoter. The inhibition of the phosphatidylinositol 3-kinase (PI3K) pathway abolished insulin's effect on APOA5 gene expression, while the inhibition of the P70 S6 kinase pathway with rapamycin reversed its effect and increased APOA5 gene expression. Using an oligonucleotide precipitation assay for USF from nuclear extracts, we demonstrate that phosphorylated USF1 fails to bind to the APOA5 promoter. Taken together, these data indicate that insulin-mediated APOA5 gene transrepression could involve a phosphorylation of USFs through the PI3K and P70 S6 kinase pathways that modulate their binding to the APOA5 E box and results in APOA5 down-regulation. The effect of exogenous hyperinsulinemia in men showed a decrease in the plasma ApoAV level. These results suggest a potential contribution of the APOA5 gene in hypertriglyceridemia associated with hyperinsulinemia. PMID:15684402

  20. Low-dose irradiation promotes Rad51 expression by down-regulating miR-193b-3p in hepatocytes

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