WorldWideScience

Sample records for factor gata-4 regulates

  1. PIAS1 is a GATA4 SUMO ligase that regulates GATA4-dependent intestinal promoters independent of SUMO ligase activity and GATA4 sumoylation.

    Directory of Open Access Journals (Sweden)

    Narasimhaswamy S Belaguli

    Full Text Available GATA4 confers cell type-specific gene expression on genes expressed in cardiovascular, gastro-intestinal, endocrine and neuronal tissues by interacting with various ubiquitous and cell-type-restricted transcriptional regulators. By using yeast two-hybrid screening approach, we have identified PIAS1 as an intestine-expressed GATA4 interacting protein. The physical interaction between GATA4 and PIAS1 was confirmed in mammalian cells by coimmunoprecipitation and two-hybrid analysis. The interacting domains were mapped to the second zinc finger and the adjacent C-terminal basic region of GATA4 and the RING finger and the adjoining C-terminal 60 amino acids of PIAS1. PIAS1 and GATA4 synergistically activated IFABP and SI promoters but not LPH promoters suggesting that PIAS1 differentially activates GATA4 targeted promoters. In primary murine enterocytes PIAS1 was recruited to the GATA4-regulated IFABP promoter. PIAS1 promoted SUMO-1 modification of GATA4 on lysine 366. However, sumoylation was not required for the nuclear localization and stability of GATA4. Further, neither GATA4 sumoylation nor the SUMO ligase activity of PIAS1 was required for coactivation of IFABP promoter by GATA4 and PIAS1. Together, our results demonstrate that PIAS1 is a SUMO ligase for GATA4 that differentially regulates GATA4 transcriptional activity independent of SUMO ligase activity and GATA4 sumoylation.

  2. GATA4 and GATA6 regulate intestinal epithelial cytodifferentiation during development.

    Science.gov (United States)

    Walker, Emily M; Thompson, Cayla A; Battle, Michele A

    2014-08-15

    The intestinal epithelium performs vital roles in organ function by absorbing nutrients and providing a protective barrier. The zinc-finger containing transcription factors GATA4 and GATA6 regulate enterocyte gene expression and control regional epithelial cell identity in the adult intestinal epithelium. Although GATA4 and GATA6 are expressed in the developing intestine, loss of either factor alone during the period of epithelial morphogenesis and cytodifferentiation fails to disrupt these processes. Therefore, we tested the hypothesis that GATA4 and GATA6 function redundantly to control these aspects of intestinal development. We used Villin-Cre, which deletes specifically in the intestinal epithelium during the period of villus development and epithelial cytodifferentiation, to generate Gata4Gata6 double conditional knockout embryos. Mice lacking GATA4 and GATA6 in the intestinal epithelium died within 24h of birth. At E18.5, intestinal villus architecture and epithelial cell populations were altered. Enterocytes were lost, and goblet cells were increased. Proliferation was also increased in GATA4-GATA6 deficient intestinal epithelium. Although villus morphology appeared normal at E16.5, the first time at which both Gata4 and Gata6 were efficiently reduced, changes in expression of markers of enterocytes, goblet cells, and proliferative cells were detected. Moreover, goblet cell number was increased at E16.5. Expression of the Notch ligand Dll1 and the Notch target Olfm4 were reduced in mutant tissue indicating decreased Notch signaling. Finally, we found that GATA4 occupies chromatin near the Dll1 transcription start site suggesting direct regulation of Dll1 by GATA4. We demonstrate that GATA4 and GATA6 play an essential role in maintaining proper intestinal epithelial structure and in regulating intestinal epithelial cytodifferentiation. Our data highlight a novel role for GATA factors in fine tuning Notch signaling during intestinal epithelial development to

  3. A GATA4-regulated tumor suppressor network represses formation of malignant human astrocytomas

    Science.gov (United States)

    Agnihotri, Sameer; Wolf, Amparo; Munoz, Diana M.; Smith, Christopher J.; Gajadhar, Aaron; Restrepo, Andres; Clarke, Ian D.; Fuller, Gregory N.; Kesari, Santosh; Dirks, Peter B.; McGlade, C. Jane; Stanford, William L.; Aldape, Kenneth; Mischel, Paul S.; Hawkins, Cynthia

    2011-01-01

    Glioblastoma Multiforme (GBM), the most common and lethal primary human brain tumor, exhibits multiple molecular aberrations. We report that loss of the transcription factor GATA4, a negative regulator of normal astrocyte proliferation, is a driver in glioma formation and fulfills the hallmarks of a tumor suppressor gene (TSG). Although GATA4 was expressed in normal brain, loss of GATA4 was observed in 94/163 GBM operative samples and was a negative survival prognostic marker. GATA4 loss occurred through promoter hypermethylation or novel somatic mutations. Loss of GATA4 in normal human astrocytes promoted high-grade astrocytoma formation, in cooperation with other relevant genetic alterations such as activated Ras or loss of TP53. Loss of GATA4 with activated Ras in normal astrocytes promoted a progenitor-like phenotype, formation of neurospheres, and the ability to differentiate into astrocytes, neurons, and oligodendrocytes. Re-expression of GATA4 in human GBM cell lines, primary cultures, and brain tumor–initiating cells suppressed tumor growth in vitro and in vivo through direct activation of the cell cycle inhibitor P21CIP1, independent of TP53. Re-expression of GATA4 also conferred sensitivity of GBM cells to temozolomide, a DNA alkylating agent currently used in GBM therapy. This sensitivity was independent of MGMT (O-6-methylguanine-DNA-methyltransferase), the DNA repair enzyme which is often implicated in temozolomide resistance. Instead, GATA4 reduced expression of APNG (alkylpurine-DNA-N-glycosylase), a DNA repair enzyme which is poorly characterized in GBM-mediated temozolomide resistance. Identification and validation of GATA4 as a TSG and its downstream targets in GBM may yield promising novel therapeutic strategies. PMID:21464220

  4. GATA4 regulates Fgf16 to promote heart repair after injury.

    Science.gov (United States)

    Yu, Wei; Huang, Xiuzhen; Tian, Xueying; Zhang, Hui; He, Lingjuan; Wang, Yue; Nie, Yu; Hu, Shengshou; Lin, Zhiqiang; Zhou, Bin; Pu, William; Lui, Kathy O; Zhou, Bin

    2016-03-15

    Although the mammalian heart can regenerate during the neonatal stage, this endogenous regenerative capacity is lost with age. Importantly, replication of cardiomyocytes has been found to be the key mechanism responsible for neonatal cardiac regeneration. Unraveling the transcriptional regulatory network for inducing cardiomyocyte replication will, therefore, be crucial for the development of novel therapies to drive cardiac repair after injury. Here, we investigated whether the key cardiac transcription factor GATA4 is required for neonatal mouse heart regeneration. Using the neonatal mouse heart cryoinjury and apical resection models with an inducible loss of GATA4 specifically in cardiomyocytes, we found severely depressed ventricular function in the Gata4-ablated mice (mutant) after injury. This was accompanied by reduced cardiomyocyte replication. In addition, the mutant hearts displayed impaired coronary angiogenesis and increased hypertrophy and fibrosis after injury. Mechanistically, we found that the paracrine factor FGF16 was significantly reduced in the mutant hearts after injury compared with littermate controls and was directly regulated by GATA4. Cardiac-specific overexpression of FGF16 via adeno-associated virus subtype 9 (AAV9) in the mutant hearts partially rescued the cryoinjury-induced cardiac hypertrophy, promoted cardiomyocyte replication and improved heart function after injury. Altogether, our data demonstrate that GATA4 is required for neonatal heart regeneration through regulation of Fgf16, suggesting that paracrine factors could be of potential use in promoting myocardial repair.

  5. SUMOylation regulates the transcriptional repression activity of FOG-2 and its association with GATA-4.

    Directory of Open Access Journals (Sweden)

    José Perdomo

    Full Text Available Friend of GATA 2 (FOG-2, a co-factor of several GATA transcription factors (GATA-4, -5 and 6, is a critical regulator of coronary vessel formation and heart morphogenesis. Here we demonstrate that FOG-2 is SUMOylated and that this modification modulates its transcriptional activity. FOG-2 SUMOylation occurs at four lysine residues (K324, 471, 915, 955 [corrected]. Three of these residues are part of the characteristic SUMO consensus site (ψKXE, while K955 is found in the less frequent TKXE motif. Absence of SUMOylation did not affect FOG-2's nuclear localization. However, mutation of the FOG-2 SUMOylation sites, or de-SUMOylation, with SENP-1 or SENP-8 resulted in stronger transcriptional repression activity in both heterologous cells and cardiomyocytes. Conversely, increased FOG-2 SUMOylation by overexpression of SUMO-1 or expression of a SUMO-1-FOG-2 fusion protein rendered FOG-2 incapable of repressing GATA-4-mediated activation of the B-type natriuretic peptide (BNP promoter. Moreover, we demonstrate both increased interaction between a FOG-2 SUMO mutant and GATA-4 and enhanced SUMOylation of wild-type FOG-2 by co-expression of GATA-4. These data suggest a new dynamics in which GATA-4 may alter the activity of FOG-2 by influencing its SUMOylation status.

  6. Regulation of a vascular plexus by gata4 is mediated in zebrafish through the chemokine sdf1a.

    Directory of Open Access Journals (Sweden)

    Ingrid Torregroza

    Full Text Available Using the zebrafish model we describe a previously unrecognized requirement for the transcription factor gata4 controlling embryonic angiogenesis. The development of a vascular plexus in the embryonic tail, the caudal hematopoietic tissue (CHT, fails in embryos depleted of gata4. Rather than forming a normal vascular plexus, the CHT of gata4 morphants remains fused, and cells in the CHT express high levels of osteogenic markers ssp1 and runx1. Definitive progenitors emerge from the hemogenic aortic endothelium, but fail to colonize the poorly vascularized CHT. We also found abnormal patterns and levels for the chemokine sdf1a in gata4 morphants, which was found to be functionally relevant, since the embryos also show defects in development of the lateral line, a mechano-sensory organ system highly dependent on a gradient of sdf1a levels. Reduction of sdf1a levels was sufficient to rescue lateral line development, circulation, and CHT morphology. The result was surprising since neither gata4 nor sdf1a is obviously expressed in the CHT. Therefore, we generated transgenic fish that conditionally express a dominant-negative gata4 isoform, and determined that gata4 function is required during gastrulation, when it is co-expressed with sdf1a in lateral mesoderm. Our study shows that the gata4 gene regulates sdf1a levels during early embryogenesis, which impacts embryonic patterning and subsequently the development of the caudal vascular plexus.

  7. Serine 105 phosphorylation of transcription factor GATA4 is necessary for stress-induced cardiac hypertrophy in vivo.

    Science.gov (United States)

    van Berlo, Jop H; Elrod, John W; Aronow, Bruce J; Pu, William T; Molkentin, Jeffery D

    2011-07-26

    Cardiac hypertrophy is an adaptive growth process that occurs in response to stress stimulation or injury wherein multiple signal transduction pathways are induced, culminating in transcription factor activation and the reprogramming of gene expression. GATA4 is a critical transcription factor in the heart that is known to induce/regulate the hypertrophic program, in part, by receiving signals from MAPKs. Here we generated knock-in mice in which a known MAPK phosphorylation site at serine 105 (S105) in Gata4 that augments activity was mutated to alanine. Homozygous Gata4-S105A mutant mice were viable as adults, although they showed a compromised stress response of the myocardium. For example, cardiac hypertrophy in response to phenylephrine agonist infusion for 2 wk was largely blunted in Gata4-S105A mice, as was the hypertrophic response to pressure overload at 1 and 2 wk of applied stimulation. Gata4-S105A mice were also more susceptible to heart failure and cardiac dilation after 2 wk of pressure overload. With respect to the upstream pathway, hearts from Gata4-S105A mice did not efficiently hypertrophy following direct ERK1/2 activation using an activated MEK1 transgene in vivo. Mechanistically, GATA4 mutant protein from these hearts failed to show enhanced DNA binding in response to hypertrophic stimulation. Moreover, hearts from Gata4-S105A mice had significant changes in the expression of hypertrophy-inducible, fetal, and remodeling-related genes.

  8. Regulation of Cardiac Gene Expression by GATA-4/5/6.

    Science.gov (United States)

    Evans, T

    1997-04-01

    The identification of nuclear regulatory proteins provides great promise for advancing our understanding of the transcriptional control of cardiac gene expression. Three new members of the GATA family of DNA-binding transcription factors were recently discovered and designated GATA-4/5/6. On the basis of expression patterns, the identification of candidate cardiac target genes and the current understanding of how other GATA factors function in the hematopoietic system, it appears that these genes are important for regulating programs of cardiac development and terminal differentiation. Indeed, a functional role for GATA-4/5/6 in activating the cardiac differentiation program was demonstrated in cell culture and embryonic systems; however, recent results obtained in embryonic stem (ES) cells with a targeted mutation of GATA-4 raise new questions regarding specificity of action among the three genes. The future direction of research in the field is discussed; understanding GATA-4/5/6 function and regulation is likely to provide important insight into the specification and/or differentiation of cardiac progenitors, development and morphogenesis of the heart, and regulation of cardiac-specific gene expression. (Trends Cardiovasc Med 1997;7:75-83). © 1997, Elsevier Science Inc.

  9. DNA methylation restricts lineage-specific functions of transcription factor Gata4 during embryonic stem cell differentiation.

    Directory of Open Access Journals (Sweden)

    Masaaki Oda

    2013-06-01

    Full Text Available DNA methylation changes dynamically during development and is essential for embryogenesis in mammals. However, how DNA methylation affects developmental gene expression and cell differentiation remains elusive. During embryogenesis, many key transcription factors are used repeatedly, triggering different outcomes depending on the cell type and developmental stage. Here, we report that DNA methylation modulates transcription-factor output in the context of cell differentiation. Using a drug-inducible Gata4 system and a mouse embryonic stem (ES cell model of mesoderm differentiation, we examined the cellular response to Gata4 in ES and mesoderm cells. The activation of Gata4 in ES cells is known to drive their differentiation to endoderm. We show that the differentiation of wild-type ES cells into mesoderm blocks their Gata4-induced endoderm differentiation, while mesoderm cells derived from ES cells that are deficient in the DNA methyltransferases Dnmt3a and Dnmt3b can retain their response to Gata4, allowing lineage conversion from mesoderm cells to endoderm. Transcriptome analysis of the cells' response to Gata4 over time revealed groups of endoderm and mesoderm developmental genes whose expression was induced by Gata4 only when DNA methylation was lost, suggesting that DNA methylation restricts the ability of these genes to respond to Gata4, rather than controlling their transcription per se. Gata4-binding-site profiles and DNA methylation analyses suggested that DNA methylation modulates the Gata4 response through diverse mechanisms. Our data indicate that epigenetic regulation by DNA methylation functions as a heritable safeguard to prevent transcription factors from activating inappropriate downstream genes, thereby contributing to the restriction of the differentiation potential of somatic cells.

  10. Transcriptional regulation of the sodium channel gene (SCN5A) by GATA4 in human heart.

    Science.gov (United States)

    Tarradas, Anna; Pinsach-Abuin, Mel Lina; Mackintosh, Carlos; Llorà-Batlle, Oriol; Pérez-Serra, Alexandra; Batlle, Montserrat; Pérez-Villa, Félix; Zimmer, Thomas; Garcia-Bassets, Ivan; Brugada, Ramon; Beltran-Alvarez, Pedro; Pagans, Sara

    2017-01-01

    Aberrant expression of the sodium channel gene (SCN5A) has been proposed to disrupt cardiac action potential and cause human cardiac arrhythmias, but the mechanisms of SCN5A gene regulation and dysregulation still remain largely unexplored. To gain insight into the transcriptional regulatory networks of SCN5A, we surveyed the promoter and first intronic regions of the SCN5A gene, predicting the presence of several binding sites for GATA transcription factors (TFs). Consistent with this prediction, chromatin immunoprecipitation (ChIP) and sequential ChIP (Re-ChIP) assays show co-occupancy of cardiac GATA TFs GATA4 and GATA5 on promoter and intron 1 SCN5A regions in fresh-frozen human left ventricle samples. Gene reporter experiments show GATA4 and GATA5 synergism in the activation of the SCN5A promoter, and its dependence on predicted GATA binding sites. GATA4 and GATA6 mRNAs are robustly expressed in fresh-frozen human left ventricle samples as measured by highly sensitive droplet digital PCR (ddPCR). GATA5 mRNA is marginally but still clearly detected in the same samples. Importantly, GATA4 mRNA levels are strongly and positively correlated with SCN5A transcript levels in the human heart. Together, our findings uncover a novel mechanism of GATA TFs in the regulation of the SCN5A gene in human heart tissue. Our studies suggest that GATA5 but especially GATA4 are main contributors to SCN5A gene expression, thus providing a new paradigm of SCN5A expression regulation that may shed new light into the understanding of cardiac disease. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. GATA4 is a critical regulator of gonadectomy-induced adrenocortical tumorigenesis in mice.

    Science.gov (United States)

    Krachulec, Justyna; Vetter, Melanie; Schrade, Anja; Löbs, Ann-Kathrin; Bielinska, Malgorzata; Cochran, Rebecca; Kyrönlahti, Antti; Pihlajoki, Marjut; Parviainen, Helka; Jay, Patrick Y; Heikinheimo, Markku; Wilson, David B

    2012-06-01

    In response to gonadectomy certain inbred mouse strains develop sex steroidogenic adrenocortical neoplasms. One of the hallmarks of neoplastic transformation is expression of GATA4, a transcription factor normally present in gonadal but not adrenal steroidogenic cells of the adult mouse. To show that GATA4 directly modulates adrenocortical tumorigenesis and is not merely a marker of gonadal-like differentiation in the neoplasms, we studied mice with germline or conditional loss-of-function mutations in the Gata4 gene. Germline Gata4 haploinsufficiency was associated with attenuated tumor growth and reduced expression of sex steroidogenic genes in the adrenal glands of ovariectomized B6D2F1 and B6AF1 mice. At 12 months after ovariectomy, wild-type B6D2F1 mice had biochemical and histological evidence of adrenocortical estrogen production, whereas Gata4(+/-) B6D2F1 mice did not. Germline Gata4 haploinsufficiency exacerbated the secondary phenotype of postovariectomy obesity in B6D2F1 mice, presumably by limiting ectopic estrogen production in the adrenal glands. Amhr2-cre-mediated deletion of floxed Gata4 (Gata4(F)) in nascent adrenocortical neoplasms of ovariectomized B6.129 mice reduced tumor growth and the expression of gonadal-like markers in a Gata4(F) dose-dependent manner. We conclude that GATA4 is a key modifier of gonadectomy-induced adrenocortical neoplasia, postovariectomy obesity, and sex steroidogenic cell differentiation.

  12. Gata4 expression in lateral mesoderm is downstream of BMP4 and isactivated directly by Forkhead and GATA transcription factors through adistal enhancer element

    Energy Technology Data Exchange (ETDEWEB)

    Rojas, Anabel; De Val, Sarah; Heidt, Analeah B.; Xu, Shan-Mei; Bristow, James; Black, Brian L.

    2005-05-20

    The GATA family of zinc-finger transcription factors plays key roles in the specification and differentiation of multiple cell types during development. GATA4 is an early regulator of gene expression during the development of endoderm and mesoderm, and genetic studies in mice have demonstrated that GATA4 is required for embryonic development.Despite the importance of GATA4 in tissue specification and differentiation, the mechanisms by which Gata4 expression is activated and the transcription factor pathways upstream of GATA4 remain largely undefined. To identify transcriptional regulators of Gata4 in the mouse,we screened conserved noncoding sequences from the mouse Gata4 gene for enhancer activity in transgenic embryos. Here, we define the regulation of a distal enhancer element from Gata4 that is sufficient to direct expression throughout the lateral mesoderm, beginning at 7.5 days of mouse embryonic development. The activity of this enhancer is initially broad but eventually becomes restricted to the mesenchyme surrounding the liver. We demonstrate that the function of this enhancer in transgenic embryos is dependent upon highly conserved Forkhead and GATA transcription factor binding sites, which are bound by FOXF1 and GATA4,respectively. Furthermore, the activity of the Gata4 lateral mesoderm enhancer is attenuated by the BMP antagonist Noggin, and the enhancer is not activated in Bmp4-null embryos. Thus, these studies establish that Gata4 is a direct transcriptional target of Forkhead and GATA transcription factors in the lateral mesoderm, and demonstrate that Gata4lateral mesoderm enhancer activation requires BMP4, supporting a model in which GATA4 serves as a downstream effector of BMP signaling in the lateral mesoderm.

  13. Epigenetic regulation of GATA4 expression by histone modification in AFP-producing gastric adenocarcinoma.

    Science.gov (United States)

    Yamamura, Nobuhisa; Kishimoto, Takashi

    2012-08-01

    AFP-producing adenocarcinoma is a variant of adenocarcinoma with high malignancy. Production of AFP suggests enteroblastic or hepatoid differentiation of cancer cells. GATA4 is a key molecule involved in the prenatal development of the stomach and liver. GATA4 is epigenetically silenced by hypermethylation of primer region in many types of cancers including gastric cancer. The aim of this study is to investigate the expression and epigenetic regulation of GATA4 in AFP-producing adenocarcinoma. Immunohistochemical analysis revealed that GATA4 was positive in 3/8 cases of AFP-producing gastric adenocarcinomas and in 28/30 cases of common type adenocarcinomas. Epigenetic modification of GATA4 promoter region was investigated with 3 AFP-producing and 4 common-type gastric cancer cell lines. GATA4 mRNA was detected in 1/3 of AFP-producing and 2/4 of common-type gastric cancer cell lines by RT-PCR. Methylation-specific PCR revealed no GATA4 methylation in any of the AFP-producing gastric cancers, whereas methylation was consistent with GATA4 expression in the common-type gastric cancers. Chromatin immunoprecipitation assay for AFP-producing gastric cancers revealed that histones H3 and H4 were hypoacetylated in the GATA4-negative cells, while they were hyperacetylated in the GATA4-positive cells. Treatment with trichostain A, an inhibitor for histone deacetylase, induced acetylation of histones H3 and H4, and tri-methylation of lysine 4 of histone H3, which was associated with the active transcription of GATA4 in GATA4-negative AFP-producing cells. These results indicated that histone deacetylation is a silencing mechanism for GATA4 expression in AFP-producing gastric cancer cells. Differences between AFP-producing gastric cancer and common-type gastric cancer in terms of the mechanism of GATA4 regulation may be reflected in the phenotypic deviation of AFP-producing gastric cancer from common-type gastric cancer.

  14. Helicase-like transcription factor (Hltf regulates G2/M transition, Wt1/Gata4/Hif-1a cardiac transcription networks, and collagen biogenesis.

    Directory of Open Access Journals (Sweden)

    Rebecca A Helmer

    Full Text Available HLTF/Hltf regulates transcription, remodels chromatin, and coordinates DNA damage repair. Hltf is expressed in mouse brain and heart during embryonic and postnatal development. Silencing Hltf is semilethal. Seventy-four percent of congenic C57BL/6J Hltf knockout mice died, 75% within 12-24 hours of birth. Previous studies in neonatal (6-8 hour postpartum brain revealed silencing Hltf disrupted cell cycle progression, and attenuated DNA damage repair. An RNA-Seq snapshot of neonatal heart transcriptome showed 1,536 of 20,000 total transcripts were altered (p < 0.05 - 10 up- and 1,526 downregulated. Pathway enrichment analysis with MetaCore™ showed Hltf's regulation of the G2/M transition (p=9.726E(-15 of the cell cycle in heart is nearly identical to its role in brain. In addition, Brca1 and 12 members of the Brca1 associated genome surveillance complex are also downregulated. Activation of caspase 3 coincides with transcriptional repression of Bcl-2. Hltf loss caused downregulation of Wt1/Gata4/Hif-1a signaling cascades as well as Myh7b/miR499 transcription. Hltf-specific binding to promoters and/or regulatory regions of these genes was authenticated by ChIP-PCR. Hif-1a targets for prolyl (P4ha1, P4ha2 and lysyl (Plod2 collagen hydroxylation, PPIase enzymes (Ppid, Ppif, Ppil3 for collagen trimerization, and lysyl oxidase (Loxl2 for collagen-elastin crosslinking were downregulated. However, transcription of genes for collagens, fibronectin, Mmps and their inhibitors (Timps was unaffected. The collective downregulation of genes whose protein products control collagen biogenesis caused disorganization of the interstitial and perivascular myocardial collagen fibrillar network as viewed with picrosirius red-staining, and authenticated with spectral imaging. Wavy collagen bundles in control hearts contrasted with collagen fibers that were thin, short and disorganized in Hltf null hearts. Collagen bundles in Hltf null hearts were tangled and

  15. Disease Model of GATA4 Mutation Reveals Transcription Factor Cooperativity in Human Cardiogenesis.

    Science.gov (United States)

    Ang, Yen-Sin; Rivas, Renee N; Ribeiro, Alexandre J S; Srivas, Rohith; Rivera, Janell; Stone, Nicole R; Pratt, Karishma; Mohamed, Tamer M A; Fu, Ji-Dong; Spencer, C Ian; Tippens, Nathaniel D; Li, Molong; Narasimha, Anil; Radzinsky, Ethan; Moon-Grady, Anita J; Yu, Haiyuan; Pruitt, Beth L; Snyder, Michael P; Srivastava, Deepak

    2016-12-15

    Mutation of highly conserved residues in transcription factors may affect protein-protein or protein-DNA interactions, leading to gene network dysregulation and human disease. Human mutations in GATA4, a cardiogenic transcription factor, cause cardiac septal defects and cardiomyopathy. Here, iPS-derived cardiomyocytes from subjects with a heterozygous GATA4-G296S missense mutation showed impaired contractility, calcium handling, and metabolic activity. In human cardiomyocytes, GATA4 broadly co-occupied cardiac enhancers with TBX5, another transcription factor that causes septal defects when mutated. The GATA4-G296S mutation disrupted TBX5 recruitment, particularly to cardiac super-enhancers, concomitant with dysregulation of genes related to the phenotypic abnormalities, including cardiac septation. Conversely, the GATA4-G296S mutation led to failure of GATA4 and TBX5-mediated repression at non-cardiac genes and enhanced open chromatin states at endothelial/endocardial promoters. These results reveal how disease-causing missense mutations can disrupt transcriptional cooperativity, leading to aberrant chromatin states and cellular dysfunction, including those related to morphogenetic defects. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. GATA-4/-6 and HNF-1/-4 families of transcription factors control the transcriptional regulation of the murine Muc5ac mucin during stomach development and in epithelial cancer cells.

    Science.gov (United States)

    Jonckheere, Nicolas; Vincent, Audrey; Franquet-Ansart, Hélène; Witte-Bouma, Janneke; Korteland-van Male, Anita; Leteurtre, Emmanuelle; Renes, Ingrid B; Van Seuningen, Isabelle

    2012-08-01

    During human embryonic and fetal development of the gastrointestinal tract, the gene encoding the MUC5AC mucin has a spatio-temporal pattern of expression restricted to the stomach. In order to better understand the molecular mechanisms responsible for this restricted pattern of expression, we have studied Muc5ac expression in the developing stomach of the mouse and correlated it to that of transcription factors known to be involved in cell differentiation programs during development. Our results indicate that GATA-6 and HNF-4α expression increased concomitantly with the induction of Muc5ac expression in embryonic stomach. We then studied Muc5ac transcriptional regulation by these transcription factors and showed that they all transactivate Muc5ac promoter. We also identified several active GATA-4/-5/-6 and HNF-1/-4 cis-elements using gel shift assays, chromatin immunoprecipitation and site-directed mutagenesis. Among all Muc5ac regulators, only GATA-6 and HNF-4a expression was concomitant to that of Muc5ac in the developing stomach. This is thus in favor of an important role for these two transcription factors as regulators of expression of the Muc5ac mucin during stomach development and in epithelial cancer cells.

  17. Direct transcriptional regulation of Gata4 during early endoderm specification is controlled by FoxA2 binding to an intronic enhancer.

    Science.gov (United States)

    Rojas, Anabel; Schachterle, William; Xu, Shan-Mei; Martín, Franz; Black, Brian L

    2010-10-15

    The embryonic endoderm is a multipotent progenitor cell population that gives rise to the epithelia of the digestive and respiratory tracts, the liver and the pancreas. Among the transcription factors that have been shown to be important for endoderm development and gut morphogenesis is GATA4. Despite the important role of GATA4 in endoderm development, its transcriptional regulation is not well understood. In this study, we identified an intronic enhancer from the mouse Gata4 gene that directs expression to the definitive endoderm in the early embryo. The activity of this enhancer is initially broad in all endodermal progenitors, as demonstrated by fate mapping analysis using the Cre/loxP system, but becomes restricted to the dorsal foregut and midgut, and associated organs such as dorsal pancreas and stomach. The function of the intronic Gata4 enhancer is dependent upon a conserved Forkhead transcription factor-binding site, which is bound by recombinant FoxA2 in vitro. These studies identify Gata4 as a direct transcriptional target of FoxA2 in the hierarchy of the transcriptional regulatory network that controls the development of the definitive endoderm. Copyright © 2010 Elsevier Inc. All rights reserved.

  18. Nuclear Receptor-Like Structure and Interaction of Congenital Heart Disease-Associated Factors GATA4 and NKX2-5.

    Directory of Open Access Journals (Sweden)

    Sini Kinnunen

    Full Text Available Transcription factor GATA4 is a dosage sensitive regulator of heart development and alterations in its level or activity lead to congenital heart disease (CHD. GATA4 has also been implicated in cardiac regeneration and repair. GATA4 action involves combinatorial interaction with other cofactors such as NKX2-5, another critical cardiac regulator whose mutations also cause CHD. Despite its critical importance to the heart and its evolutionary conservation across species, the structural basis of the GATA4-NKX2-5 interaction remains incompletely understood.A homology model was constructed and used to identify surface amino acids important for the interaction of GATA4 and NKX2-5. These residues were subjected to site-directed mutagenesis, and the mutant proteins were characterized for their ability to bind DNA and to physically and functionally interact with NKX2-5. The studies identify 5 highly conserved amino acids in the second zinc finger (N272, R283, Q274, K299 and its C-terminal extension (R319 that are critical for physical and functional interaction with the third alpha helix of NKX2-5 homeodomain. Integration of the experimental data with computational modeling suggests that the structural arrangement of the zinc finger-homeodomain resembles the architecture of the conserved DNA binding domain of nuclear receptors.The results provide novel insight into the structural basis for protein-protein interactions between two important classes of transcription factors. The model proposed will help to elucidate the molecular basis for disease causing mutations in GATA4 and NKX2-5 and may be relevant to other members of the GATA and NK classes of transcription factors.

  19. The regulation of troponins I, C and ANP by GATA4 and Nkx2-5 in heart of hibernating thirteen-lined ground squirrels, Ictidomys tridecemlineatus.

    Directory of Open Access Journals (Sweden)

    Bryan E Luu

    Full Text Available Hibernation is an adaptive strategy used by various mammals to survive the winter under situations of low ambient temperatures and limited or no food availability. The heart of hibernating thirteen-lined ground squirrels (Ictidomys tridecemlineatus has the remarkable ability to descend to low, near 0°C temperatures without falling into cardiac arrest. We hypothesized that the transcription factors GATA4 and Nkx2-5 may play a role in cardioprotection by facilitating the expression of key downstream targets such as troponin I, troponin C, and ANP (atrial natriuretic peptide. This study measured relative changes in transcript levels, protein levels, protein post-translational modifications, and transcription factor binding over six stages: euthermic control (EC, entrance into torpor (EN, early torpor (ET, late torpor (LT, early arousal (EA, and interbout arousal (IA. We found differential regulation of GATA4 whereby transcript/protein expression, post-translational modification (phosphorylation of serine 261, and DNA binding were enhanced during the transitory phases (entrance and arousal of hibernation. Activation of GATA4 was paired with increases in cardiac troponin I, troponin C and ANP protein levels during entrance, while increases in p-GATA4 DNA binding during early arousal was paired with decreases in troponin I and no changes in troponin C and ANP protein levels. Unlike its binding partner, the relative mRNA/protein expression and DNA binding of Nkx2-5 did not change during hibernation. This suggests that either Nkx2-5 does not play a substantial role or other regulatory mechanisms not presently studied (e.g. posttranslational modifications are important during hibernation. The data suggest a significant role for GATA4-mediated gene transcription in the differential regulation of genes which aid cardiac-specific challenges associated with torpor-arousal.

  20. Cardiac expression of ms1/STARS, a novel gene involved in cardiac development and disease, is regulated by GATA4.

    Science.gov (United States)

    Ounzain, Samir; Kobayashi, Satoru; Peterson, Richard E; He, Aibin; Motterle, Anna; Samani, Nilesh J; Menick, Donald R; Pu, William T; Liang, Qiangrong; Chong, Nelson W

    2012-05-01

    Ms1/STARS is a novel muscle-specific actin-binding protein that specifically modulates the myocardin-related transcription factor (MRTF)-serum response factor (SRF) regulatory axis within striated muscle. This ms1/STARS-dependent regulatory axis is of central importance within the cardiac gene regulatory network and has been implicated in cardiac development and postnatal cardiac function/homeostasis. The dysregulation of ms1/STARS is associated with and causative of pathological cardiac phenotypes, including cardiac hypertrophy and cardiomyopathy. In order to gain an understanding of the mechanisms governing ms1/STARS expression in the heart, we have coupled a comparative genomic in silico analysis with reporter, gain-of-function, and loss-of-function approaches. Through this integrated analysis, we have identified three evolutionarily conserved regions (ECRs), α, SINA, and DINA, that act as cis-regulatory modules and confer differential cardiac cell-specific activity. Two of these ECRs, α and DINA, displayed distinct regulatory sensitivity to the core cardiac transcription factor GATA4. Overall, our results demonstrate that within embryonic, neonatal, and adult hearts, GATA4 represses ms1/STARS expression with the pathologically associated depletion of GATA4 (type 1/type 2 diabetic models), resulting in ms1/STARS upregulation. This GATA4-dependent repression of ms1/STARS expression has major implications for MRTF-SRF signaling in the context of cardiac development and disease.

  1. Cx30.2 enhancer analysis identifies Gata4 as a novel regulator of atrioventricular delay

    Science.gov (United States)

    Munshi, Nikhil V.; McAnally, John; Bezprozvannaya, Svetlana; Berry, Jeff M.; Richardson, James A.; Hill, Joseph A.; Olson, Eric N.

    2009-01-01

    Summary The cardiac conduction system comprises a specialized tract of electrically coupled cardiomyocytes responsible for impulse propagation through the heart. Abnormalities in cardiac conduction are responsible for numerous forms of cardiac arrhythmias, but relatively little is known about the gene regulatory mechanisms that control the formation of the conduction system. We demonstrate that a distal enhancer for the connexin 30.2 (Cx30.2, also known as Gjd3) gene, which encodes a gap junction protein required for normal atrioventricular (AV) delay in mice, is necessary and sufficient to direct expression to the developing AV conduction system (AVCS). Moreover, we show that this enhancer requires Tbx5 and Gata4 for proper expression in the conduction system, and Gata4+/- mice have short PR intervals indicative of accelerated AV conduction. Thus, our results implicate Gata4 in conduction system function and provide a clearer understanding of the transcriptional pathways that impact normal AV delay. PMID:19592579

  2. An Ebox element in the proximal Gata4 promoter is required for Gata4 expression in vivo.

    Directory of Open Access Journals (Sweden)

    Alain Boulende Sab

    Full Text Available GATA4 is an essential transcription factor required for the development and function of multiple tissues, including a major role in gonadogenesis. Despite its crucial role, the molecular mechanisms that regulate Gata4 expression in vivo remain poorly understood. We recently found that the Gata4 gene is expressed as multiple transcripts with distinct 5' origins. These co-expressed alternative transcripts are generated by different non-coding first exons with transcripts E1a and E1b being the most prominent. Moreover, we previously showed that an Ebox element, located in Gata4 5' flanking sequences upstream of exon 1a, is important for the promoter activity of these sequences in cell lines. To confirm the importance of this element in vivo, we generated and characterized Gata4 Ebox knockout mice. Quantitative PCR analyses realized on gonads, heart and liver at three developmental stages (embryonic, pre-pubertal and adult revealed that the Ebox mutation leads to a robust and specific decrease (up to 89% of Gata4 E1a transcript expression in all tissues and stages examined. However, a detailed characterization of the gonads revealed normal morphology and GATA4 protein levels in these mutants. Our qPCR data further indicate that this outcome is most likely due to the presence of Gata4 E1b mRNA, whose expression levels were not decreased by the Ebox mutation. In conclusion, our work clearly confirms the importance of the proximal Ebox element and suggests that adequate GATA4 protein expression is likely protected by a compensation mechanism between Gata4 E1a and E1b transcripts operating at the translational level.

  3. Inhibitory effect of melatonin on testosterone synthesis is mediated via GATA-4/SF-1 transcription factors.

    Science.gov (United States)

    Qin, Fenju; Zhang, Jie; Zan, Linsen; Guo, Weiqiang; Wang, Jin; Chen, Lili; Cao, Yi; Shen, Ouxi; Tong, Jian

    2015-11-01

    The aim of the present study was to elucidate whether the GATA-4/SF-1 signalling pathway is involved in the inhibitory effects of melatonin on testosterone production in both the TM3 Leydig cell line and in C57BL/6J mice. In-vitro experiments demonstrated that melatonin treatment significantly reduced testosterone levels in cell culture medium (P SF-1 (NR5A1), StAR, P450SCC (CYP11A1) and 3β-HSD (P SF-1 (P SF-1 expression.

  4. Smad4 mediated BMP2 signal is essential for the regulation of GATA4 and Nkx2.5 by affecting the histone H3 acetylation in H9c2 cells

    Energy Technology Data Exchange (ETDEWEB)

    Si, Lina; Shi, Jin; Gao, Wenqun [Heart Centre, Children’s Hospital of Chongqing Medical University, 136 Zhongshan 2nd Road, Yu Zhong District, Chongqing 400014 (China); Ministry of Education Key Laboratory of Child Development and Disorders, Key Laboratory of Pediatrics in Chongqing, Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, 136 Zhongshan 2nd Road, Yu Zhong District, Chongqing 400014 (China); Zheng, Min [Heart Centre, Children’s Hospital of Chongqing Medical University, 136 Zhongshan 2nd Road, Yu Zhong District, Chongqing 400014 (China); Liu, Lingjuan; Zhu, Jing [Ministry of Education Key Laboratory of Child Development and Disorders, Key Laboratory of Pediatrics in Chongqing, Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, 136 Zhongshan 2nd Road, Yu Zhong District, Chongqing 400014 (China); Tian, Jie, E-mail: jietian@cqmu.edu.cn [Heart Centre, Children’s Hospital of Chongqing Medical University, 136 Zhongshan 2nd Road, Yu Zhong District, Chongqing 400014 (China)

    2014-07-18

    Highlights: • BMP2 can upregulated cardiac related gene GATA4, Nkx2.5, MEF2c and Tbx5. • Inhibition of Smad4 decreased BMP2-induced hyperacetylation of histone H3. • Inhibition of Smad4 diminished BMP2-induced overexpression of GATA4 and Nkx2.5. • Inhibition of Smad4 decreased hyperacetylated H3 in the promoter of GATA4 and Nkx2.5. • Smad4 is essential for BMP2 induced hyperacetylated histone H3. - Abstract: BMP2 signaling pathway plays critical roles during heart development, Smad4 encodes the only common Smad protein in mammals, which is a pivotal nuclear mediator. Our previous studies showed that BMP2 enhanced the expression of cardiac transcription factors in part by increasing histone H3 acetylation. In the present study, we tested the hypothesis that Smad4 mediated BMP2 signaling pathway is essential for the expression of cardiac core transcription factors by affecting the histone H3 acetylation. We successfully constructed a lentivirus-mediated short hairpin RNA interference vector targeting Smad4 (Lv-Smad4) in rat H9c2 embryonic cardiac myocytes (H9c2 cells) and demonstrated that it suppressed the expression of the Smad4 gene. Cultured H9c2 cells were transfected with recombinant adenoviruses expressing human BMP2 (AdBMP2) with or without Lv-Smad4. Quantitative real-time RT-PCR analysis showed that knocking down of Smad4 substantially inhibited both AdBMP2-induced and basal expression levels of cardiac transcription factors GATA4 and Nkx2.5, but not MEF2c and Tbx5. Similarly, chromatin immunoprecipitation (ChIP) analysis showed that knocking down of Smad4 inhibited both AdBMP2-induced and basal histone H3 acetylation levels in the promoter regions of GATA4 and Nkx2.5, but not of Tbx5 and MEF2c. In addition, Lv-Smad4 selectively suppressed AdBMP2-induced expression of HAT p300, but not of HAT GCN5 in H9c2 cells. The data indicated that inhibition of Smad4 diminished both AdBMP2 induced and basal histone acetylation levels in the promoter regions of

  5. Identification of functional mutations in GATA4 in patients with congenital heart disease.

    Directory of Open Access Journals (Sweden)

    Erli Wang

    Full Text Available Congenital heart disease (CHD is one of the most prevalent developmental anomalies and the leading cause of noninfectious morbidity and mortality in newborns. Despite its prevalence and clinical significance, the etiology of CHD remains largely unknown. GATA4 is a highly conserved transcription factor that regulates a variety of physiological processes and has been extensively studied, particularly on its role in heart development. With the combination of TBX5 and MEF2C, GATA4 can reprogram postnatal fibroblasts into functional cardiomyocytes directly. In the past decade, a variety of GATA4 mutations were identified and these findings originally came from familial CHD pedigree studies. Given that familial and sporadic CHD cases allegedly share a basic genetic basis, we explore the GATA4 mutations in different types of CHD. In this study, via direct sequencing of the GATA4 coding region and exon-intron boundaries in 384 sporadic Chinese CHD patients, we identified 12 heterozygous non-synonymous mutations, among which 8 mutations were only found in CHD patients when compared with 957 controls. Six of these non-synonymous mutations have not been previously reported. Subsequent functional analyses revealed that the transcriptional activity, subcellular localization and DNA binding affinity of some mutant GATA4 proteins were significantly altered. Our results expand the spectrum of GATA4 mutations linked to cardiac defects. Together with the newly reported mutations, approximately 110 non-synonymous mutations have currently been identified in GATA4. Our future analysis will explore why the evolutionarily conserved GATA4 appears to be hypermutable.

  6. Transcription factors MYOCD, SRF, Mesp1 and SMARCD3 enhance the cardio-inducing effect of GATA4, TBX5, and MEF2C during direct cellular reprogramming.

    Directory of Open Access Journals (Sweden)

    Nicolas Christoforou

    Full Text Available Transient overexpression of defined combinations of master regulator genes can effectively induce cellular reprogramming: the acquisition of an alternative predicted phenotype from a differentiated cell lineage. This can be of particular importance in cardiac regenerative medicine wherein the heart lacks the capacity to heal itself, but simultaneously contains a large pool of fibroblasts. In this study we determined the cardio-inducing capacity of ten transcription factors to actuate cellular reprogramming of mouse embryonic fibroblasts into cardiomyocyte-like cells. Overexpression of transcription factors MYOCD and SRF alone or in conjunction with Mesp1 and SMARCD3 enhanced the basal but necessary cardio-inducing effect of the previously reported GATA4, TBX5, and MEF2C. In particular, combinations of five or seven transcription factors enhanced the activation of cardiac reporter vectors, and induced an upregulation of cardiac-specific genes. Global gene expression analysis also demonstrated a significantly greater cardio-inducing effect when the transcription factors MYOCD and SRF were used. Detection of cross-striated cells was highly dependent on the cell culture conditions and was enhanced by the addition of valproic acid and JAK inhibitor. Although we detected Ca(2+ transient oscillations in the reprogrammed cells, we did not detect significant changes in resting membrane potential or spontaneously contracting cells. This study further elucidates the cardio-inducing effect of the transcriptional networks involved in cardiac cellular reprogramming, contributing to the ongoing rational design of a robust protocol required for cardiac regenerative therapies.

  7. Smad4 mediated BMP2 signal is essential for the regulation of GATA4 and Nkx2.5 by affecting the histone H3 acetylation in H9c2 cells.

    Science.gov (United States)

    Si, Lina; Shi, Jin; Gao, Wenqun; Zheng, Min; Liu, Lingjuan; Zhu, Jing; Tian, Jie

    2014-07-18

    BMP2 signaling pathway plays critical roles during heart development, Smad4 encodes the only common Smad protein in mammals, which is a pivotal nuclear mediator. Our previous studies showed that BMP2 enhanced the expression of cardiac transcription factors in part by increasing histone H3 acetylation. In the present study, we tested the hypothesis that Smad4 mediated BMP2 signaling pathway is essential for the expression of cardiac core transcription factors by affecting the histone H3 acetylation. We successfully constructed a lentivirus-mediated short hairpin RNA interference vector targeting Smad4 (Lv-Smad4) in rat H9c2 embryonic cardiac myocytes (H9c2 cells) and demonstrated that it suppressed the expression of the Smad4 gene. Cultured H9c2 cells were transfected with recombinant adenoviruses expressing human BMP2 (AdBMP2) with or without Lv-Smad4. Quantitative real-time RT-PCR analysis showed that knocking down of Smad4 substantially inhibited both AdBMP2-induced and basal expression levels of cardiac transcription factors GATA4 and Nkx2.5, but not MEF2c and Tbx5. Similarly, chromatin immunoprecipitation (ChIP) analysis showed that knocking down of Smad4 inhibited both AdBMP2-induced and basal histone H3 acetylation levels in the promoter regions of GATA4 and Nkx2.5, but not of Tbx5 and MEF2c. In addition, Lv-Smad4 selectively suppressed AdBMP2-induced expression of HAT p300, but not of HAT GCN5 in H9c2 cells. The data indicated that inhibition of Smad4 diminished both AdBMP2 induced and basal histone acetylation levels in the promoter regions of GATA4 and Nkx2.5, suggesting that Smad4 mediated BMP2 signaling pathway was essential for the regulation of GATA4 and Nkx2.5 by affecting the histone H3 acetylation in H9c2 cells.

  8. GATA4 and GATA6 control mouse pancreas organogenesis

    Science.gov (United States)

    Carrasco, Manuel; Delgado, Irene; Soria, Bernat; Martín, Francisco; Rojas, Anabel

    2012-01-01

    Recently, heterozygous mutations in GATA6 have been found in neonatal diabetic patients with failed pancreatic organogenesis. To investigate the roles of GATA4 and GATA6 in mouse pancreas organogenesis, we conditionally inactivated these genes within the pancreas. Single inactivation of either gene did not have a major impact on pancreas formation, indicating functional redundancy. However, double Gata4/Gata6 mutant mice failed to develop pancreata, died shortly after birth, and displayed hyperglycemia. Morphological defects in Gata4/Gata6 mutant pancreata were apparent during embryonic development, and the epithelium failed to expand as a result of defects in cell proliferation and differentiation. The number of multipotent pancreatic progenitors, including PDX1+ cells, was reduced in the Gata4/Gata6 mutant pancreatic epithelium. Remarkably, deletion of only 1 Gata6 allele on a Gata4 conditional knockout background severely reduced pancreatic mass. In contrast, a single WT allele of Gata4 in Gata6 conditional knockout mice was sufficient for normal pancreatic development, indicating differential contributions of GATA factors to pancreas formation. Our results place GATA factors at the top of the transcriptional network hierarchy controlling pancreas organogenesis. PMID:23006330

  9. Lrrc10 is a novel cardiac-specific target gene of Nkx2-5 and GATA4

    Science.gov (United States)

    Brody, Matthew J.; Cho, Eunjin; Mysliwiec, Matthew R.; Kim, Tae-gyun; Carlson, Clayton D.; Lee, Kyu-Ho; Lee, Youngsook

    2013-01-01

    Cardiac gene expression is precisely regulated and its perturbation causes developmental defects and heart disease. Leucine-rich repeat containing 10 (Lrrc10) is a cardiac-specific factor that is crucial for proper cardiac development and deletion of Lrrc10 in mice results in dilated cardiomyopathy. However, the mechanisms regulating Lrrc10 expression in cardiomyocytes remain unknown. Therefore, we set out to determine trans-acting factors and cis-elements critical for mediating Lrrc10 expression. We identify Lrrc10 as a transcriptional target of Nkx2-5 and GATA4. The Lrrc10 promoter region contains two highly conserved cardiac regulatory elements, which are functional in cardiomyocytes but not in fibroblasts. In vivo, Nkx2-5 and GATA4 endogenously occupy the proximal and distal cardiac regulatory elements of Lrrc10 in the heart. Moreover, embryonic hearts of Nkx2-5 knockout mice have dramatically reduced expression of Lrrc10. These data demonstrate the importance of Nkx2-5 and GATA4 in regulation of Lrrc10 expression in vivo. The proximal cardiac regulatory element located at around −200 bp is synergistically activated by Nkx2-5 and GATA4 while the distal cardiac regulatory element present around −3 Kb requires SRF in addition to Nkx2-5 and GATA4 for synergistic activation. Mutational analyses identify a pair of adjacent Nkx2-5 and GATA binding sites within the proximal cardiac regulatory element that are necessary to induce expression of Lrrc10. In contrast, only the GATA site is functional in the distal regulatory element. Taken together, our data demonstrate that the transcription factors Nkx2-5 and GATA4 cooperatively regulate cardiac-specific expression of Lrrc10. PMID:23751912

  10. Gata4 potentiates second heart field proliferation and Hedgehog signaling for cardiac septation.

    Science.gov (United States)

    Zhou, Lun; Liu, Jielin; Xiang, Menglan; Olson, Patrick; Guzzetta, Alexander; Zhang, Ke; Moskowitz, Ivan P; Xie, Linglin

    2017-02-21

    GATA4, an essential cardiogenic transcription factor, provides a model for dominant transcription factor mutations in human disease. Dominant GATA4 mutations cause congenital heart disease (CHD), specifically atrial and atrioventricular septal defects (ASDs and AVSDs). We found that second heart field (SHF)-specific Gata4 heterozygote embryos recapitulated the AVSDs observed in germline Gata4 heterozygote embryos. A proliferation defect of SHF atrial septum progenitors and hypoplasia of the dorsal mesenchymal protrusion, rather than anlage of the atrioventricular septum, were observed in this model. Knockdown of the cell-cycle repressor phosphatase and tensin homolog (Pten) restored cell-cycle progression and rescued the AVSDs. Gata4 mutants also demonstrated Hedgehog (Hh) signaling defects. Gata4 acts directly upstream of Hh components: Gata4 activated a cis-regulatory element at Gli1 in vitro and occupied the element in vivo. Remarkably, SHF-specific constitutive Hh signaling activation rescued AVSDs in Gata4 SHF-specific heterozygous knockout embryos. Pten expression was unchanged in Smoothened mutants, and Hh pathway genes were unchanged in Pten mutants, suggesting pathway independence. Thus, both the cell-cycle and Hh-signaling defects caused by dominant Gata4 mutations were required for CHD pathogenesis, suggesting a combinatorial model of disease causation by transcription factor haploinsufficiency.

  11. GATA-4 protects against hypoxia-induced cardiomyocyte injury: effects on mitochondrial membrane potential.

    Science.gov (United States)

    Li, Hong-Xia; Zhou, Ya-Feng; Zhao, Xin; Jiang, Bin; Yang, Xiang-Jun

    2014-08-01

    Our previous studies have suggested that GATA-4 increases the differentiation of bone-marrow-derived mesenchymal stem cells (MSCs) into cardiac phenotypes. This study further investigated whether GATA-4 enhances MSC-mediated cardioprotection following hypoxia. MSCs were harvested from rat bone marrow and transduced with GATA-4 (MSC(GATA-4)). To mimic ischemic injury, cultured cardiomyocytes (CMs) isolated from neonatal rat ventricles were exposed to hypoxia or were pretreated with concentrated conditioned medium (CdM) from MSC(GATA-4) or transduced control MSC (MSC(Null)) for 16 h before exposure to hypoxic culture conditions (low glucose and low oxygen). Myocyte damage was estimated by annexin-V-PE and TUNEL technique and by lactate dehydrogenase (LDH) release. Cell survival was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium (MTT) uptake. Mitochondrial membrane potential was determined using confocal microscopy. ELISA studies indicated that insulin-like growth factor 1 (IGF-1) and vascular endothelial growth factor (VEGF) were significantly increased in MSC(GATA-4) compared with MSC(Null). Hypoxia-induced apoptosis/cell death was significantly reduced when CMs were co-cultured with MSC(GATA-4) in a dual-chamber system. Cell protection mediated by MSC(GATA-4) was mimicked by treating CMs with CdM from MSC(GATA-4) and abrogated with IGF-1- and VEGF-neutralizing antibodies. MSC(GATA-4) protects CMs under hypoxic conditions. The release of IGF-1 and VEGF from MSC(GATA-4) is likely to be responsible for protection of CMs.

  12. Gut microbiota inhibit Asbt-dependent intestinal bile acid reabsorption via Gata4

    Science.gov (United States)

    Out, Carolien; Patankar, Jay V.; Doktorova, Marcela; Boesjes, Marije; Bos, Trijnie; de Boer, Sanna; Havinga, Rick; Wolters, Henk; Boverhof, Renze; van Dijk, Theo H.; Smoczek, Anna; Bleich, André; Sachdev, Vinay; Kratky, Dagmar; Kuipers, Folkert; Verkade, Henkjan J.; Groen, Albert K.

    2017-01-01

    Background & Aims Regulation of bile acid homeostasis in mammals is a complex process regulated via extensive cross-talk between liver, intestine and intestinal microbiota. Here we studied the effects of gut microbiota on bile acid homeostasis in mice. Methods Bile acid homeostasis was assessed in four mouse models. Germfree mice, conventionally-raised mice, Asbt-KO mice and intestinal-specific Gata4-iKO mice were treated with antibiotics (bacitracin, neomycin and vancomycin; 100 mg/kg) for five days and subsequently compared with untreated mice. Results Attenuation of the bacterial flora by antibiotics strongly reduced fecal excretion and synthesis of bile acids, but increased the expression of the bile acid synthesis enzyme CYP7A1. Similar effects were seen in germfree mice. Intestinal bile acid absorption was increased and accompanied by increases in plasma bile acid levels, biliary bile acid secretion and enterohepatic cycling of bile acids. In the absence of microbiota, the expression of the intestinal bile salt transporter Asbt was strongly increased in the ileum and was also expressed in more proximal parts of the small intestine. Most of the effects of antibiotic treatment on bile acid homeostasis could be prevented by genetic inactivation of either Asbt or the transcription factor Gata4. Conclusions Attenuation of gut microbiota alters Gata4-controlled expression of Asbt, increasing absorption and decreasing synthesis of bile acids. Our data support the concept that under physiological conditions microbiota stimulate Gata4, which suppresses Asbt expression, limiting the expression of this transporter to the terminal ileum. Our studies expand current knowledge on the bacterial control of bile acid homeostasis. PMID:26022694

  13. Intestinal Specific Gene Regulation by Transcription Factors Gata4 and Hnfla in Vivo

    OpenAIRE

    Bosse, Tjalling

    2006-01-01

    textabstractThe mammalian small intestine is responsible for the terminal digestion and absorption of nutrients, water homeostasis, and the elimination of waste products, which in turn, are essential processes for life. These processes however, are easily disrupted by infection, inflammatory processes such as Crohn’s disease, cancer, and resection. The small intestine is equipped with specific proteins, such as enzymes to digest nutrients (digestion) and ‘transporters’ to carry the nutrients ...

  14. Intestinal Specific Gene Regulation by Transcription Factors Gata4 and Hnfla in Vivo

    NARCIS (Netherlands)

    T. Bosse (Tjalling)

    2006-01-01

    textabstractThe mammalian small intestine is responsible for the terminal digestion and absorption of nutrients, water homeostasis, and the elimination of waste products, which in turn, are essential processes for life. These processes however, are easily disrupted by infection, inflammatory process

  15. Pancreas-specific deletion of mouse Gata4 and Gata6 causes pancreatic agenesis

    Science.gov (United States)

    Xuan, Shouhong; Borok, Matthew J.; Decker, Kimberly J.; Battle, Michele A.; Duncan, Stephen A.; Hale, Michael A.; Macdonald, Raymond J.; Sussel, Lori

    2012-01-01

    Pancreatic agenesis is a human disorder caused by defects in pancreas development. To date, only a few genes have been linked to pancreatic agenesis in humans, with mutations in pancreatic and duodenal homeobox 1 (PDX1) and pancreas-specific transcription factor 1a (PTF1A) reported in only 5 families with described cases. Recently, mutations in GATA6 have been identified in a large percentage of human cases, and a GATA4 mutant allele has been implicated in a single case. In the mouse, Gata4 and Gata6 are expressed in several endoderm-derived tissues, including the pancreas. To analyze the functions of GATA4 and/or GATA6 during mouse pancreatic development, we generated pancreas-specific deletions of Gata4 and Gata6. Surprisingly, loss of either Gata4 or Gata6 in the pancreas resulted in only mild pancreatic defects, which resolved postnatally. However, simultaneous deletion of both Gata4 and Gata6 in the pancreas caused severe pancreatic agenesis due to disruption of pancreatic progenitor cell proliferation, defects in branching morphogenesis, and a subsequent failure to induce the differentiation of progenitor cells expressing carboxypeptidase A1 (CPA1) and neurogenin 3 (NEUROG3). These studies address the conserved and nonconserved mechanisms underlying GATA4 and GATA6 function during pancreas development and provide a new mouse model to characterize the underlying developmental defects associated with pancreatic agenesis. PMID:23006325

  16. Cardiac gene activation analysis in mammalian non-myoblasic cells by Nkx2-5, Tbx5, Gata4 and Myocd.

    Directory of Open Access Journals (Sweden)

    Lei Zhou

    Full Text Available Cardiac transcription factors are master regulators during heart development. Some were shown to transdifferentiate tail tip and cardiac fibroblasts into cardiomyocytes. However, recent studies have showed that controversies exist. Potential difference in tail tip and cardiac fibroblast isolation may possibly confound the observations. Moreover, due to the use of a cardiac reporter (Myh6 selection strategy for induced cardiomyocyte enrichment, and the lack of tracking signals for each transcription factors, individual roles of each transcription factors in activating cardiac gene expression in mammalian non-myoblastic cells have never been elucidated. Answers to these questions are an important step toward cardiomyocyte regeneration. Because mouse 10T1/2 fibroblasts are non-myoblastic in nature and can be induced to express genes of all three types of muscle cells, they are an ideal model for the analysis of cardiac and non-cardiac gene activation after induction. We constructed bi-cistronic lentiviral vectors, capable of expressing cardiac transcription factors along with different fluorescent tracking signals. By infecting 10T1/2 fibroblasts with Nkx2-5, Tbx5, Gata4 or Myocd cardiac transcription factor lentivirus alone or different combinations, we found that only Tbx5+Myocd and Tbx5+Gata4+Myocd combinations induced Myh6 and Tnnt2 cardiac marker protein expression. Microarray-based gene ontology analysis revealed that Tbx5 alone activated genes involved in the Wnt receptor signaling pathway and inhibited genes involved in a number of cardiac-related processes. Myocd alone activated genes involved in a number of cardiac-related processes and inhibited genes involved in the Wnt receptor signaling pathway and non-cardiac processes. Gata4 alone inhibited genes involved in non-cardiac processes. Tbx5+Gata4+Myocd was the most effective activator of genes associated with cardiac-related processes. Unlike Tbx5, Gata4, Myocd alone or Tbx5+Myocd, Tbx5

  17. Evaluation of the effect of genetic variations in GATA-4 on the phenprocoumon and acenocoumarol maintenance dose

    NARCIS (Netherlands)

    Schie, R.M. van; Wessels, J.A.M.; Verhoef, T.I.; Schalekamp, T.; Cessie, S. le; Meer, F.J. van der; Rosendaal, F.R.; Visser, L.E.; Teichert, M.; Hofman, A.; Buhre, P.N.; Boer, A. de; Maitland-van der Zee, A.H.

    2012-01-01

    Aim: To investigate whether the phenprocoumon and acenocoumarol maintenance doses are influenced by genetic variations in GATA-4, a transcription factor of CYP2C9. Patients & methods: The influence of seven GATA-4 SNPs on the coumarin maintenance dose was investigated by performing an analysis of va

  18. GATA transcription factors in adrenal development and tumors.

    Science.gov (United States)

    Parviainen, Helka; Kiiveri, Sanne; Bielinska, Malgorzata; Rahman, Nafis; Huhtaniemi, Ilpo T; Wilson, David B; Heikinheimo, Markku

    2007-02-01

    Of the six GATA transcription factors, GATA-4 and GATA-6 are expressed in the mouse and human adrenal with distinct developmental profiles. GATA-4 is confined to the fetal cortex, i.e. to the less differentiated proliferating cells, while GATA-6 is expressed both in the fetal and adult adrenal. In vitro, GATA-4 regulates inhibin-alpha and steroidogenic factor-1 implicated in normal adrenal function. GATA-6 probably has roles in the development and differentiation of adrenocortical cells, and in the regulation of steroidogenesis. GATA-4 expression is dramatically upregulated and GATA-6 downregulated in gonadotropin dependent mouse adrenocortical tumors. This is accompanied by the appearance of luteinizing hormone receptor (LHR). In vitro, GATA-4 transactivates LHR promoter, and gonadotropins upregulate GATA-4 levels. Human adrenal tumors occasionally express GATA-4, whereas GATA-6 levels are usually lower than normal.

  19. Retinoid X receptor alpha represses GATA-4-mediated transcription via a retinoid-dependent interaction with the cardiac-enriched repressor FOG-2.

    Science.gov (United States)

    Clabby, Martha L; Robison, Trevor A; Quigley, Heather F; Wilson, David B; Kelly, Daniel P

    2003-02-21

    Dietary vitamin A and its derivatives, retinoids, regulate cardiac growth and development. To delineate mechanisms involved in retinoid-mediated control of cardiac gene expression, the regulatory effects of the retinoid X receptor alpha (RXR alpha) on atrial naturietic factor (ANF) gene transcription was investigated. The transcriptional activity of an ANF promoter-reporter in rat neonatal ventricular myocytes was repressed by RXR alpha in the presence of 9-cis-RA and by the constitutively active mutant RXR alpha F318A indicating that liganded RXR confers the regulatory effect. The RXR alpha-mediated repression mapped to the proximal 147 bp of the rat ANF promoter, a region lacking a consensus retinoid response element but containing several known cardiogenic cis elements including a well characterized GATA response element. Glutathione S-transferase "pull-down" assays revealed that RXR alpha interacts directly with GATA-4, in a ligand-independent manner, via the DNA binding domain of RXR alpha and the second zinc finger of GATA-4. Liganded RXR alpha repressed the activity of a heterologous promoter-reporter construct containing GATA-response element recognition sites in cardiac myocytes but not in several other cell types, suggesting that additional cardiac-enriched factors participate in the repression complex. Co-transfection of liganded RXR alpha and the known cardiac-enriched GATA-4 repressor, FOG-2, resulted in additive repression of GATA-4 activity in ventricular myocytes. In addition, RXR alpha was found to bind FOG-2, in a 9-cis-RA-dependent manner. These data reveal a novel mechanism by which retinoids regulate cardiogenic gene expression through direct interaction with GATA-4 and its co-repressor, FOG-2.

  20. Activation of GATA4 gene expression at the early stage of cardiac specification

    Directory of Open Access Journals (Sweden)

    Ayse eYilbas

    2014-03-01

    Full Text Available Currently, there are no effective treatments to directly repair damaged heart tissue after cardiac injury since existing therapies focus on rescuing or preserving reversibly damaged tissue. Cell-based therapies using cardiomyocytes generated from stem cells present a promising therapeutic approach to directly replace damaged myocardium with new healthy tissue. However, the molecular mechanisms underlying the commitment of stem cells into cardiomyocytes are not fully understood and will be critical to guide this new technology into the clinic. Since GATA4 is a critical regulator of cardiac differentiation, we examined the molecular basis underlying the early activation of GATA4 gene expression during cardiac differentiation of pluripotent stem cells. Our studies demonstrate the direct involvement of histone acetylation and transcriptional coactivator p300 in the regulation of GATA4 gene expression. More importantly, we show that histone acetyltransferase (HAT activity is important for GATA4 gene expression with the use of curcumin, a HAT inhibitor. In addition, the widely used histone deacetylase inhibitor valproic acid enhances both histone acetylation and cardiac specification.

  1. Activation of GATA4 gene expression at the early stage of cardiac specification

    Science.gov (United States)

    Yilbas, Ayse; Hamilton, Alison; Wang, Yingjian; Mach, Hymn; Lacroix, Natascha; Davis, Darryl; Chen, Jihong; LI, Qiao

    2014-03-01

    Currently, there are no effective treatments to directly repair damaged heart tissue after cardiac injury since existing therapies focus on rescuing or preserving reversibly damaged tissue. Cell-based therapies using cardiomyocytes generated from stem cells present a promising therapeutic approach to directly replace damaged myocardium with new healthy tissue. However, the molecular mechanisms underlying the commitment of stem cells into cardiomyocytes are not fully understood and will be critical to guide this new technology into the clinic. Since GATA4 is a critical regulator of cardiac differentiation, we examined the molecular basis underlying the early activation of GATA4 gene expression during cardiac differentiation of pluripotent stem cells. Our studies demonstrate the direct involvement of histone acetylation and transcriptional coactivator p300 in the regulation of GATA4 gene expression. More importantly, we show that histone acetyltransferase (HAT) activity is important for GATA4 gene expression with the use of curcumin, a HAT inhibitor. In addition, the widely used histone deacetylase inhibitor valproic acid enhances both histone acetylation and cardiac specification.

  2. Screening of 99 Danish patients with congenital heart disease for GATA4 mutations

    DEFF Research Database (Denmark)

    Zhang, Litu; Tümer, Zeynep; Jacobsen, Joes Ramsøe;

    2006-01-01

    Congenital heart disease (CHD) affects nearly 1% of the population, but only few genes involved in human CHD are presently known. Germ-line mutations in the zinc finger transcription factor GATA4 have been associated with familial cases of atrial and ventricular septal defects and pulmonary...

  3. Gata4 is required for formation of the genital ridge in mice.

    Directory of Open Access Journals (Sweden)

    Yueh-Chiang Hu

    Full Text Available In mammals, both testis and ovary arise from a sexually undifferentiated precursor, the genital ridge, which first appears during mid-gestation as a thickening of the coelomic epithelium on the ventromedial surface of the mesonephros. At least four genes (Lhx9, Sf1, Wt1, and Emx2 have been demonstrated to be required for subsequent growth and maintenance of the genital ridge. However, no gene has been shown to be required for the initial thickening of the coelomic epithelium during genital ridge formation. We report that the transcription factor GATA4 is expressed in the coelomic epithelium of the genital ridge, progressing in an anterior-to-posterior (A-P direction, immediately preceding an A-P wave of epithelial thickening. Mouse embryos conditionally deficient in Gata4 show no signs of gonadal initiation, as their coelomic epithelium remains a morphologically undifferentiated monolayer. The failure of genital ridge formation in Gata4-deficient embryos is corroborated by the absence of the early gonadal markers LHX9 and SF1. Our data indicate that GATA4 is required to initiate formation of the genital ridge in both XX and XY fetuses, prior to its previously reported role in testicular differentiation of the XY gonad.

  4. GATA4 mediates gene repression in the mature mouse small intestine through interactions with friend of GATA (FOG) cofactors

    NARCIS (Netherlands)

    E. Beuling (Eva); T. Bosse (Tjalling); D.J. Kerk (Daniel); C.M. Piaseckyj (Christina); Y. Fujiwara (Yuko); S.G. Katz (Samuel); S.H. Orkin (Stuart); R.J. Grand (Richard); S.D. Krasinski (Stephen)

    2008-01-01

    textabstractGATA4, a transcription factor expressed in the proximal small intestine but not in the distal ileum, maintains proximal-distal distinctions by multiple processes involving gene repression, gene activation, and cell fate determination. Friend of GATA (FOG) is an evolutionarily conserved f

  5. Isolation, characterization and genetic analysis of canine GATA4 gene in a family of Doberman Pinschers with an atrial septal defect

    Indian Academy of Sciences (India)

    Shin-Aeh Lee; Seung-Gon Lee; Hyeong-Sun Moon; Lopeti Lavulo; Kyoung-Oh Cho; Changbaig Hyun

    2007-12-01

    GATA4 is expressed early in the developing heart where it plays a key role in regulating the expression of genes encoding myocardial contractile proteins. Gene mutations in the human GATA4 have been implicated in various congenital heart defects (CHD), including atrial septal defect (ASD). Although ASD is the third most common CHD in humans, it is generally rare in dogs and cats. There is also no obvious predilection for ASD in dogs and cats, based on sex or breed. However, among dogs, the incidence rate of ASD is relatively high in Samoyeds and Doberman Pinschers, where its inheritance and genetic aetiology are not well understood. In this study, we identified and investigated the genetic aetiology of an ASD affected family in a pure breed dog population. Although the GATA4 gene was screened, we did not find any mutations that would result in the alteration of the coding sequence and hence, the predicted GATA4 structure and function. Although the aetiology of ASD is multifactorial, our findings indicate that GATA4 may not be responsible for the ASD in the dogs used in this study. However, this does not eliminate GATA4 as a candidate for ASD in other dog breeds.

  6. Next-Generation Sequencing Approach in Methylation Analysis of HNF1B and GATA4 Genes: Searching for Biomarkers in Ovarian Cancer

    Directory of Open Access Journals (Sweden)

    Ivana Bubancova

    2017-02-01

    Full Text Available DNA methylation is well-known to be associated with ovarian cancer (OC and has great potential to serve as a biomarker in monitoring response to therapy and for disease screening. The purpose of this study was to investigate methylation of HNF1B and GATA4 and correlate detected methylation with clinicopathological characteristic of OC patients. The study group consisted of 64 patients with OC and 35 control patients. To determine the most important sites of HNF1B and GATA4, we used next-generation sequencing. For further confirmation of detected methylation of selected regions, we used high-resolution melting analysis and methylation-specific real-time polymerase chain reaction (PCR. Selected regions of HNF1B and GATA4 were completely methylation free in all control samples, whereas methylation-positive pattern was observed in 32.8% (HNF1B and 45.3% (GATA4 of OC samples. Evaluating both genes together, we were able to detect methylation in 65.6% of OC patients. We observed a statistically significant difference in HNF1B methylation between samples with different stages of OC. We also detected subtype specific methylation in GATA4 and a decrease of methylation in late stages of OC. The combination of unmethylated HNF1B and methylated GATA4 was associated with longer overall survival. In our study, we employed innovative approach of methylation analysis of HNF1B and GATA4 to search for possible epigenetic biomarkers. We confirmed the significance of the HNF1B and GATA4 hypermethylation with emphasis on the need of selecting the most relevant sites for analysis. We suggest selected CpGs to be further examined as a potential positive prognostic factor.

  7. Next-Generation Sequencing Approach in Methylation Analysis of HNF1B and GATA4 Genes: Searching for Biomarkers in Ovarian Cancer

    Science.gov (United States)

    Bubancova, Ivana; Kovarikova, Helena; Laco, Jan; Ruszova, Ema; Dvorak, Ondrej; Palicka, Vladimir; Chmelarova, Marcela

    2017-01-01

    DNA methylation is well-known to be associated with ovarian cancer (OC) and has great potential to serve as a biomarker in monitoring response to therapy and for disease screening. The purpose of this study was to investigate methylation of HNF1B and GATA4 and correlate detected methylation with clinicopathological characteristic of OC patients. The study group consisted of 64 patients with OC and 35 control patients. To determine the most important sites of HNF1B and GATA4, we used next-generation sequencing. For further confirmation of detected methylation of selected regions, we used high-resolution melting analysis and methylation-specific real-time polymerase chain reaction (PCR). Selected regions of HNF1B and GATA4 were completely methylation free in all control samples, whereas methylation-positive pattern was observed in 32.8% (HNF1B) and 45.3% (GATA4) of OC samples. Evaluating both genes together, we were able to detect methylation in 65.6% of OC patients. We observed a statistically significant difference in HNF1B methylation between samples with different stages of OC. We also detected subtype specific methylation in GATA4 and a decrease of methylation in late stages of OC. The combination of unmethylated HNF1B and methylated GATA4 was associated with longer overall survival. In our study, we employed innovative approach of methylation analysis of HNF1B and GATA4 to search for possible epigenetic biomarkers. We confirmed the significance of the HNF1B and GATA4 hypermethylation with emphasis on the need of selecting the most relevant sites for analysis. We suggest selected CpGs to be further examined as a potential positive prognostic factor. PMID:28241454

  8. The cardiac transcription network modulated by Gata4, Mef2a, Nkx2.5, Srf, histone modifications, and microRNAs.

    Directory of Open Access Journals (Sweden)

    Jenny Schlesinger

    2011-02-01

    Full Text Available The transcriptome, as the pool of all transcribed elements in a given cell, is regulated by the interaction between different molecular levels, involving epigenetic, transcriptional, and post-transcriptional mechanisms. However, many previous studies investigated each of these levels individually, and little is known about their interdependency. We present a systems biology study integrating mRNA profiles with DNA-binding events of key cardiac transcription factors (Gata4, Mef2a, Nkx2.5, and Srf, activating histone modifications (H3ac, H4ac, H3K4me2, and H3K4me3, and microRNA profiles obtained in wild-type and RNAi-mediated knockdown. Finally, we confirmed conclusions primarily obtained in cardiomyocyte cell culture in a time-course of cardiac maturation in mouse around birth. We provide insights into the combinatorial regulation by cardiac transcription factors and show that they can partially compensate each other's function. Genes regulated by multiple transcription factors are less likely differentially expressed in RNAi knockdown of one respective factor. In addition to the analysis of the individual transcription factors, we found that histone 3 acetylation correlates with Srf- and Gata4-dependent gene expression and is complementarily reduced in cardiac Srf knockdown. Further, we found that altered microRNA expression in Srf knockdown potentially explains up to 45% of indirect mRNA targets. Considering all three levels of regulation, we present an Srf-centered transcription network providing on a single-gene level insights into the regulatory circuits establishing respective mRNA profiles. In summary, we show the combinatorial contribution of four DNA-binding transcription factors in regulating the cardiac transcriptome and provide evidence that histone modifications and microRNAs modulate their functional consequence. This opens a new perspective to understand heart development and the complexity cardiovascular disorders.

  9. GATA4 gene mutation in congenital heart disease%先天性心脏病GATA4基因突变研究进展

    Institute of Scientific and Technical Information of China (English)

    张艳丽

    2015-01-01

    GATA4 gene mutations are common in children with congenital heart disease.More than 120 mutations have been found in ventricular septal defect,atrial septal defects and the tetralogy of fallot.But the relationship between genotype and clinical phenotype has not yet been elucidated.This article summarizes the published germline and somatic mutations of GATA4 gene in human congenital heart disease,and provides insight into the phenotypic spectrum of GATA4 gene mutation.%GATA4基因突变在先天性心脏病患儿中较为常见.目前为止,已发现超过120个突变位点,其中在室间隔缺损、房室间隔缺损或法洛四联症患者中多见,但突变基因型与临床表型间的关系至今仍未阐明.该文总结了在人类先天性心脏病中已发表的GATA4基因突变位点,并绘制出功能性改变的基因突变图谱.

  10. Cardiomyocyte protection by GATA-4 gene engineered mesenchymal stem cells is partially mediated by translocation of miR-221 in microvesicles.

    Directory of Open Access Journals (Sweden)

    Bin Yu

    Full Text Available INTRODUCTION: microRNAs (miRs, a novel class of small non-coding RNAs, are involved in cell proliferation, differentiation, development, and death. In this study, we found that miR-221 translocation by microvesicles (MVs plays an important role in cardioprotection mediated by GATA-4 overexpressed mesenchymal stem cells (MSC. METHODS AND RESULTS: Adult rat bone marrow MSC and neonatal rat ventricle cardiomyocytes (CM were harvested as primary cultures. MSC were transduced with GATA-4 (MSC(GATA-4 using the murine stem cell virus (pMSCV retroviral expression system. Empty vector transfection was used as a control (MSC(Null. The expression of miRs was assessed by real-time PCR and localized using in situ hybridization (ISH. MVs collected from MSC cultures were characterized by expression of CD9, CD63, and HSP70, and photographed with electron microscopy. Cardioprotection during hypoxia afforded by conditioned medium (CdM from MSC cultures was evaluated by lactate dehydrogenase (LDH release, MTS uptake by CM, and caspase 3/7 activity. Expression of miR-221/222 was significantly higher in MSC than in CM and miR-221 was upregulated in MSC(GATA-4. MSC overexpression of miR-221 significantly enhanced cardioprotection by reducing the expression of p53 upregulated modulator of apoptosis (PUMA. Moreover, expression of PUMA was significantly decreased in CM co-cultured with MSC. MVs derived from MSC expressed high levels of miR-221, and were internalized quickly by CM as documented in images obtained from a Time-Lapse Imaging System. CONCLUSIONS: Our results demonstrate that cardioprotection by MSC(GATA-4 may be regulated in part by a transfer of anti-apoptotic miRs contained within MVs.

  11. Mechanical stretch-induced vascular hypertrophy occurs through modulation of leptin synthesis-mediated ROS formation and GATA-4 nuclear translocation

    Science.gov (United States)

    Ghantous, Crystal M.; Kobeissy, Firas H.; Soudani, Nadia; Rahman, Farah A.; Al-Hariri, Mustafa; Itani, Hana A.; Sabra, Ramzi; Zeidan, Asad

    2015-01-01

    Background: Obesity and hypertension are associated with increased leptin production contributing to cardiovascular remodeling. Mechanisms involving mechanical stretch-induced leptin production and the cross talk between signaling pathways leading to vascular remodeling have not been fully elucidated. Methods and Results: Rat portal vein (RPV) organ culture was used to investigate the effect of mechanical stretch on leptin protein expression in vascular smooth muscle cells (VSMCs). Moreover, the involvement of reactive oxygen species (ROS), the RhoA/ROCK pathway, actin cytoskeleton dynamics and the transcriptional factor GATA-4 activation in mechanical stretch-induced vascular remodeling were investigated. Stretching the RPV for 1 or 24 h significantly increased leptin protein level and ROS formation in VSMCs, which was prevented by 1 h pretreatment with the ROCK inhibitor Y-27632 and the actin cytoskeleton depolymerization agent cytochalasin D. Moreover, Western blotting and immunohistochemistry revealed that mechanical stretch or treatment with 3.1 nmol/L leptin for 24 h significantly increased actin polymerization, as reflected by an increase in the F-actin to G-actin ratio. Increases in blood vessels’ wet weight and [3H]-leucine incorporation following a 24 h treatment with conditioned media from cultured stretched RPVs indicated RPV hypertrophy. This effect was prevented by 1 h pretreatment with anti-leptin antibody, indicating leptin’s crucial role in promoting VSMC hypertrophy. As an index of GATA-4 activation, GATA-4 nuclear translocation was assessed by immunohistochemistry method. Pretreating VSMC with leptin for 1 h significantly activated GATA-4 nuclear translocation, which was potently attenuated by the NADPH oxidase inhibitor apocynin, Y-27632, and cytochalasin D. Conclusion: Our results demonstrate that ROS formation, RhoA/ROCK pathway, and GATA-4 activation play a pivotal role in mechanical stretch-induced leptin synthesis leading to VSMC

  12. BMP-mediated induction of GATA4/5/6 blocks somitic responsiveness to SHH.

    Science.gov (United States)

    Daoud, Georges; Kempf, Hervé; Kumar, Deepak; Kozhemyakina, Elena; Holowacz, Tamara; Kim, Dae-Won; Ionescu, Andreia; Lassar, Andrew B

    2014-10-01

    The relative timing of SHH and BMP signals controls whether presomitic mesoderm (PSM) cells will adopt either a chondrogenic or lateral plate mesoderm fate. Here we document that SHH-mediated induction of Nkx3.2 maintains the competence of somitic cells to initiate chondrogenesis in response to subsequent BMP signals by repressing BMP-dependent induction of GATA genes. Conversely, administration of BMP signals to PSM or forced expression of GATA family members in chick PSM explants blocks induction of hedgehog-dependent gene expression. We demonstrate that GATA factors can interact with Gli factors and can recruit the transcriptional co-factor FOG1 (ZFPM1) to the regulatory region of the mouse Gli1 gene, repressing the induction of Gli1 by SHH by binding to both GATA and Gli binding sites. Knockdown of FOG1 reverses the ability of GATA factors to repress Gli1 expression. Our findings uncover a novel role for GATA transcription factors as repressors of hedgehog signaling, and document that NKX3.2 maintains the ability of sclerotomal cells to express SHH transcriptional targets in the presence of BMP signals by repressing the induction of Gata4/5/6.

  13. Novel frem1-related mouse phenotypes and evidence of genetic interactions with gata4 and slit3.

    Directory of Open Access Journals (Sweden)

    Tyler F Beck

    Full Text Available The FRAS1-related extracellular matrix 1 (FREM1 gene encodes an extracellular matrix protein that plays a critical role in the development of multiple organ systems. In humans, recessive mutations in FREM1 cause eye defects, congenital diaphragmatic hernia, renal anomalies and anorectal malformations including anteriorly placed anus. A similar constellation of findings-microphthalmia, cryptophthalmos, congenital diaphragmatic hernia, renal agenesis and rectal prolapse-have been described in FREM1-deficient mice. In this paper, we identify a homozygous Frem1 missense mutation (c.1687A>T, p.Ile563Phe in an N-ethyl-N-nitrosourea (ENU-derived mouse strain, crf11, with microphthalmia, cryptophthalmos, renal agenesis and rectal prolapse. This mutation affects a highly conserved residue in FREM1's third CSPG domain. The p.Ile563Phe change is predicted to be deleterious and to cause decreased FREM1 protein stability. The crf11 allele also fails to complement the previously described eyes2 allele of Frem1 (p.Lys826* providing further evidence that the crf11 phenotype is due to changes affecting Frem1 function. We then use mice bearing the crf11 and eyes2 alleles to identify lung lobulation defects and decreased anogenital distance in males as novel phenotypes associated with FREM1 deficiency in mice. Due to phenotypic overlaps between FREM1-deficient mice and mice that are deficient for the retinoic acid-responsive transcription factor GATA4 and the extracellular matrix protein SLIT3, we also perform experiments to look for in vivo genetic interactions between the genes that encode these proteins. These experiments reveal that Frem1 interacts genetically with Gata4 in the development of lung lobulation defects and with Slit3 in the development of renal agenesis. These results demonstrate that FREM1-deficient mice faithfully recapitulate many of the phenotypes seen in individuals with FREM1 deficiency and that variations in GATA4 and SLIT3 expression

  14. hHO-1 combined with GATA-4 transduction promotes myocardial transdifferentiation and anti- apoptosis of rat mesenchymal stem cells

    Directory of Open Access Journals (Sweden)

    Ning-bo DENG

    2017-06-01

    Full Text Available Objectives To explore if the rat bone marrow mesenchymal stem cells (BMSCs modified by human heme oxygenase 1 (hHO-1 gene combined with GATA-4 gene may promote the ability of anti-apoptosis and myocardial transdifferentiation in vitro in hypoxia ischemic environment. Methods The rat BMSCs were isolated and cultured by whole bone marrow adherence and identified in vitro, and then were transfected with recombinant adenovirus; Western blotting was used to determinate the optimal time of gene expression; the genetically modified BMSCs were taken to hypoxia serum-free conditions simulating ischemia hypoxia microenvironment in vivo; CCK-8 kit and trypan blue staining were performed to detect the 12, 24, 48 and 72h survival rates in hypoxia ischemia respectively; flow cytometry was used to detect the apoptosis of BMSCs in hypoxia ischemia for 24h. The cardiomyocyte-specific cardiac troponin I (cTnI was detected by Western blotting and cellular immunofluorescence. Results The 12, 24, 48 and 72h survival rates were higher in hHO-1+GATA-4 group cultured in ischemia and hypoxia condition than in hHO-1 group (P<0.05 and GATA-4 group (P<0.05. After 24h cultivation in ischemia hypoxia condition, the apoptotic rates were lower in hHO-1+GATA-4 group than in hHO-1 group (P<0.05 and GATA-4 group (P<0.05. No significant difference existed in cTnI expressions between GATA-4 group and hHO-1+GATA-4 group. Conclusion Compared with transfection of hHO-1 or GATA-4 single gene, hHO-1 combined with GATA-4 transduction can significantly increase the survival rate of BMSCs in hypoxia ischemic condition, but myocardial transdifferentiation does not increase significantly. DOI: 10.11855/j.issn.0577-7402.2017.04.08

  15. Expression analysis and localization of wt1, ad4bp/sf-1 and gata4 in the testis of catfish, Clarias batrachus: Impact of wt1-esiRNA silencing.

    Science.gov (United States)

    Murugananthkumar, Raju; Senthilkumaran, Balasubramanian

    2016-08-15

    In teleosts, a comprehensive role or interaction of wt1, ad4bp/sf-1 and gata4 genes in relation to gonadal development and/or recrudescence was never attempted. Present study aimed to identify the involvement of these genes during testicular development of catfish, Clarias batrachus. Dominant expression of wt1 and gata4 was observed in developing and adult testis, while ad4bp/sf-1 showed steady expression. Localization of these genes in adult testis revealed their presence in spermatogonia, spermatocytes and interstitial/Leydig cells. Significant high expression during pre-spawning and spawning phases, and upregulated levels of these genes after hCG induction authenticated gonadotropic regulation. Transient silencing of wt1-esiRNA displayed decrease in wt1 expression, which further downregulated the expression of ad4bp/sf-1 and gata4, and certain steroidogenic enzyme genes related to androgen production. These results suggest that wt1 might target ad4bp/sf-1 and gata4 expression, and also have regulatory influence either indirectly or directly on the steroidogenic enzyme genes of catfish.

  16. GATA4 and NKX2.5 gene analysis in Chinese Uygur patients with congenital heart disease

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei-min; LI Xiao-feng; MA Zhong-yuan; ZHANG Jing; ZHOU Si-hai; LI Tao; SHI Lin; LI Zhong-zhi

    2009-01-01

    Background Congenital heart disease (CHD) is the most common developmental anomaly in newborns. The germline mutations in GATA4 and NKX2.5 genes have been identified as responsible for CHD. The frequency of GATA4 and NKX2.5 mutations in Chinese Uygur patients with CHD and the correlation between their genotype and CHD phenotype are unknown.Methods We examined the coding region of GATA4 and NKX2.5 genes in 62 Chinese Uygur patients with CHD and 117 Chinese Uygur individuals as the controls by denaturing high performance liquid chromatography (DHPLC) and sequencing.Results Two heterozygous missense mutations of c.1220C>A and c.1273G>A in GATA4 gene, which cause the amino acid residue changes of P407Q and D425N in GATA4, were found in a patient with tetralogy of Fallot and a patient with ventricular septal defect, respectively. The two patients did not have atrioventricular conduct defects or non-cardiac abnormalities. The two mutations are expected to affect the protein function. There were no reported NKX2.5 mutations in the patients.Conclusion Our results provided the primary data on CHD phenotype associated with GATA4 mutation in the Chinese Uygur population.

  17. miR-200c and GATA binding protein 4 regulate human embryonic stem cell renewal and differentiation

    Directory of Open Access Journals (Sweden)

    Hsiao-Ning Huang

    2014-03-01

    Full Text Available Human embryonic stem cells (hESCs are functionally unique for their self-renewal ability and pluripotency, but the molecular mechanisms giving rise to these properties are not fully understood. hESCs can differentiate into embryoid bodies (EBs containing ectoderm, mesoderm, and endoderm. In the miR-200 family, miR-200c was especially enriched in undifferentiated hESCs and significantly downregulated in EBs. The knockdown of the miR-200c in hESCs downregulated Nanog expression, upregulated GATA binding protein 4 (GATA4 expression, and induced hESC apoptosis. The knockdown of GATA4 rescued hESC apoptosis induced by downregulation of miR-200c. miR-200c directly targeted the 3′-untranslated region of GATA4. Interestingly, the downregulation of GATA4 significantly inhibited EB formation in hESCs. Overexpression of miR-200c inhibited EB formation and repressed the expression of ectoderm, endoderm, and mesoderm markers, which could partially be rescued by ectopic expression of GATA4. Fibroblast growth factor (FGF and activin A/nodal can sustain hESC renewal in the absence of feeder layer. Inhibition of transforming growth factor-β (TGF-β/activin A/nodal signaling by SB431542 treatment downregulated the expression of miR-200c. Overexpression of miR-200c partially rescued the expression of Nanog/phospho-Smad2 that was downregulated by SB431542 treatment. Our observations have uncovered novel functions of miR-200c and GATA4 in regulating hESC renewal and differentiation.

  18. Multiplex Ligation-Dependent Probe Amplification Analysis of GATA4 Gene Copy Number Variations in Patients with Isolated Congenital Heart Disease

    Directory of Open Access Journals (Sweden)

    Valentina Guida

    2010-01-01

    Full Text Available GATA4 mutations are found in patients with different isolated congenital heart defects (CHDs, mostly cardiac septal defects and tetralogy of Fallot. In addition, GATA4 is supposed to be the responsible gene for the CHDs in the chromosomal 8p23 deletion syndrome, which is recognized as a malformation syndrome with clinical symptoms of facial anomalies, microcephaly, mental retardation, and congenital heart defects. Thus far, no study has been carried out to investigate the role of GATA4 copy number variations (CNVs in non-syndromic CHDs. To explore the possible occurrence of GATA4 gene CNVs in isolated CHDs, we analyzed by multiplex ligation-dependent probe amplification (MLPA a cohort of 161 non-syndromic patients with cardiac anomalies previously associated with GATA4 gene mutations. The patients were mutation-negative for GATA4, NKX2.5, and FOG2 genes after screening with denaturing high performance liquid chromatography. MLPA analysis revealed that normalized MLPA signals were all found within the normal range values for all exons in all patients, excluding a major contribution of GATA4 gene CNVs in CHD pathogenesis.

  19. Subculture of Germ Cell-Derived Colonies with GATA4-Positive Feeder Cells from Neonatal Pig Testes

    Directory of Open Access Journals (Sweden)

    Kyung Hoon Lee

    2016-01-01

    Full Text Available Enrichment of spermatogonial stem cells is important for studying their self-renewal and differentiation. Although germ cell-derived colonies (GDCs have been successfully cultured from neonatal pig testicular cells under 31°C conditions, the short period of in vitro maintenance (<2 months limited their application to further investigations. To develop a culture method that allows for in vitro maintenance of GDCs for long periods, we subcultured the GDCs with freshly prepared somatic cells from neonatal pig testes as feeder cells. The subcultured GDCs were maintained up to passage 13 with the fresh feeder cells (FFCs and then frozen. Eight months later, the frozen GDCs could again form the colonies on FFCs as shown in passages 1 to 13. Immunocytochemistry data revealed that the FFCs expressed GATA-binding protein 4 (GATA4, which is also detected in the cells of neonatal testes and total testicular cells, and that the expression of GATA4 was decreased in used old feeder cells. The subcultured GDCs in each passage had germ and stem cell characteristics, and flow cytometric analyses revealed that ~60% of these cells were GFRα-1 positive. In conclusion, neonatal pig testes-derived GDCs can be maintained for long periods with GATA4-expressing testicular somatic cells.

  20. Subculture of Germ Cell-Derived Colonies with GATA4-Positive Feeder Cells from Neonatal Pig Testes.

    Science.gov (United States)

    Lee, Kyung Hoon; Lee, Won Young; Kim, Jin Hoi; Park, Chan Kyu; Do, Jeong Tae; Kim, Jae Hwan; Choi, Young Suk; Kim, Nam Hyung; Song, Hyuk

    2016-01-01

    Enrichment of spermatogonial stem cells is important for studying their self-renewal and differentiation. Although germ cell-derived colonies (GDCs) have been successfully cultured from neonatal pig testicular cells under 31°C conditions, the short period of in vitro maintenance (subcultured the GDCs with freshly prepared somatic cells from neonatal pig testes as feeder cells. The subcultured GDCs were maintained up to passage 13 with the fresh feeder cells (FFCs) and then frozen. Eight months later, the frozen GDCs could again form the colonies on FFCs as shown in passages 1 to 13. Immunocytochemistry data revealed that the FFCs expressed GATA-binding protein 4 (GATA4), which is also detected in the cells of neonatal testes and total testicular cells, and that the expression of GATA4 was decreased in used old feeder cells. The subcultured GDCs in each passage had germ and stem cell characteristics, and flow cytometric analyses revealed that ~60% of these cells were GFRα-1 positive. In conclusion, neonatal pig testes-derived GDCs can be maintained for long periods with GATA4-expressing testicular somatic cells.

  1. 应用 TALEN 技术敲除 gata4基因建立斑马鱼先天性心脏病模型%Knockout gata4 gene and establish ment of a zebrafish model of congenital heart disease by TALEN

    Institute of Scientific and Technical Information of China (English)

    刘静; 何嘉玲; 暴国; 李楠; 王天奇; 张长勇; 孙德明

    2015-01-01

    Objective To establish a gata4 gene knockout zebrafish model of congenital heart disease, and construct transcription activator-like effector nuclease ( TALEN) vectors targeting gata4 gene.Method We construct TALEN vectors targeting zabrafish gata4 gene using unit assembly method and the in vitro-transcribed TALEN mRNAs were microinjected into one-cell stage zebrafish embryos.The efficiency of TALEN was identified by injected embryos, and mutations of zebrafish were screened and confirmed the different types through PCR and enzyme digestion.Results We successfully constructed correct targeting vectors by enzyme digestion and sequencing, and the gene knockout efficiency was 35.18%.We screened the mutant zebrafish and confirmed different types of gata4 gene mutations.Conclusions A gata4 knockout zebrafish model is successfully established, it can provide a good animal model for further research of congenital heart diseases.%目的:人工构建TALEN靶向敲除载体敲除gata4基因,建立斑马鱼先天性心脏病动物模型。方法采用单元组装法构建靶向敲除gata4基因的载体,将其体外转录成TALEN mRNAs,通过显微注射的方式注入单细胞期受精卵中,胚胎检测TALEN的敲除效率,再通过剪尾、酶切、测序筛选发生基因突变的斑马鱼及突变的类型。结果酶切、测序结果证实成功构建出正确的 gata4靶向敲除载体,注入斑马鱼受精卵中,发生基因敲除的效率为35.18%,通过剪尾、PCR、酶切检测成功地筛选出了发生基因突变的斑马鱼,测序结果显示出不同种类的gata4基因突变。结论成功构建gata4基因敲除的斑马鱼动物模型,为进一步研究人类gata4基因突变引起先天性心脏病的发病机制提供了良好的动物模型。

  2. Gut microbiota inhibit Asbt-dependent intestinal bile acid reabsorption via Gata4

    NARCIS (Netherlands)

    Out, Carolien; Patankar, Jay V.; Doktorova, Marcela; Boesjes, Marije; Bos, Trijnie; de Boer, Sanna; Havinga, Rick; Wolters, Henk; Boverhof, Renze; van Dijk, Theo H.; Smoczek, Anna; Bleich, Andre; Sachdev, Vinay; Kratky, Dagmar; Kuipers, Folkert; Verkade, Henkjan J.; Groen, Albert K.

    2015-01-01

    Background & Aims: Regulation of bile acid homeostasis in mammals is a complex process regulated via extensive cross-talk between liver, intestine and intestinal microbiota. Here we studied the effects of gut microbiota on bile acid homeostasis in mice. Methods: Bile acid homeostasis was assessed in

  3. Mutational Analysis of GATA4 and NKX2.5 Genes in Dilated ...

    African Journals Online (AJOL)

    Tropical Journal of Pharmaceutical Research February 2016; 15 (2): 285-292. ISSN: 1596-5996 (print); ... in regulating survival and hypertrophic growth of the adult heart. .... USA), 125 mmol/l of each dNTP (Roche,. Germany), 1.5 mmol/l ...

  4. Protein-altering and regulatory genetic variants near GATA4 implicated in bicuspid aortic valve

    DEFF Research Database (Denmark)

    Yang, Bo; Zhou, Wei-Wu; Jiao, Jiao

    2017-01-01

    Bicuspid aortic valve (BAV) is a heritable congenital heart defect and an important risk factor for valvulopathy and aortopathy. Here we report a genome-wide association scan of 466 BAV cases and 4,660 age, sex and ethnicity-matched controls with replication in up to 1,326 cases and 8,103 control...

  5. Protective Effects of Folic Acid on Cardiac Development Related Genes GATA-4 and NKx2.5 Expression of Offspring Rats with Maternal Coxsackievirus B3 Infection%柯萨奇B3病毒对心脏发育因子GATA-4、NKx2.5表达的影响及叶酸对其保护作用

    Institute of Scientific and Technical Information of China (English)

    薛雅馨; 仇小强; 余红平; 谭盛葵

    2013-01-01

    Objective To investigate the effects of oral folic acid on cardiac development related gene expression of offspring in an experimental model of coxsackievirus B3(CVB3) infection of pregnant rats. Methods SD female rats were randomized into control group, folic acid group, CVB3 group and CVB3+folic acid group. The female rats were given folic acid by gavage for 2 weeks before pregnancy in folic acid group and CVB3+folic acid group. After conception for 7 days, rat model was established by intraperitoneal injection of CVB3 for 5 days in CVB3 group and CVB3+folic acid group. After nat-ural childbirth neonatal heart was taken and stored in liquid nitrogen. The morphological changes of neonatal rat myocardial tissues were observed by HE staining. The expressions of GATA-4 and NKx2.5 mRNA were detected by RT-PCR and West-ern blot assay. Results There was significant myocardial injury, such as myocardial fiber disarray and myocardial fiber breakage, in neonatal rats in CVB3 group. These damages were improved in CVB3+folic acid group. The expression levels of GATA-4 and NKx2.5 genes in myocardial tissues were significantly lower in CVB3 group than those of control group (P<0.05). The expression levels of GATA-4 and NKx2.5 proteins in myocardial tissues were significantly higher in CVB3+folic acid group than those of CVB3 group (P<0.05). Conclusion CVB3 infection in the early pregnancy inhibited the expres-sion of neonatal rat cardiac development factor. Folic acid supplementation has obvious protective effects on the neonatal rat cardiac development.%目的:探讨叶酸对孕期感染柯萨奇B3病毒(CVB3)的新生鼠心脏发育因子GATA-4、NKx2.5的基因与蛋白表达的影响。方法 SD雌鼠分为对照组、叶酸组、CVB3组、CVB3+叶酸组。叶酸组及CVB3+叶酸组孕前给予叶酸灌胃2周;CVB3组及CVB3+叶酸组孕第7天腹腔注射CVB3,连续5 d,自然分娩后取新生鼠心脏组织,病理切片HE染色观察新生鼠心脏组织形态

  6. Function of GATA Factors in the Adult Mouse Liver

    Science.gov (United States)

    Zheng, Rena; Rebolledo-Jaramillo, Boris; Zong, Yiwei; Wang, Liqing; Russo, Pierre; Hancock, Wayne; Stanger, Ben Z.; Hardison, Ross C.; Blobel, Gerd A.

    2013-01-01

    GATA transcription factors and their Friend of Gata (FOG) cofactors control the development of diverse tissues. GATA4 and GATA6 are essential for the expansion of the embryonic liver bud, but their expression patterns and functions in the adult liver are unclear. We characterized the expression of GATA and FOG factors in whole mouse liver and purified hepatocytes. GATA4, GATA6, and FOG1 are the most prominently expressed family members in whole liver and hepatocytes. GATA4 chromatin immunoprecipitation followed by high throughput sequencing (ChIP-seq) identified 4409 occupied sites, associated with genes enriched in ontologies related to liver function, including lipid and glucose metabolism. However, hepatocyte-specific excision of Gata4 had little impact on gross liver architecture and function, even under conditions of regenerative stress, and, despite the large number of GATA4 occupied genes, resulted in relatively few changes in gene expression. To address possible redundancy between GATA4 and GATA6, both factors were conditionally excised. Surprisingly, combined Gata4,6 loss did not exacerbate the phenotype resulting from Gata4 loss alone. This points to the presence of an unusually robust transcriptional network in adult hepatocytes that ensures the maintenance of liver function. PMID:24367609

  7. Optical conductivity measurements of GaTa4Se8 under high pressure: evidence of a bandwidth-controlled insulator-to-metal Mott transition.

    Science.gov (United States)

    Ta Phuoc, V; Vaju, C; Corraze, B; Sopracase, R; Perucchi, A; Marini, C; Postorino, P; Chligui, M; Lupi, S; Janod, E; Cario, L

    2013-01-18

    The optical properties of a GaTa(4)Se(8) single crystal are investigated under high pressure. At ambient pressure, the optical conductivity exhibits a charge gap of ≈0.12 eV and a broad midinfrared band at ≈0.55 eV. As pressure is increased, the low energy spectral weight is strongly enhanced and the optical gap is rapidly filled, pointing to an insulator to metal transition around 6 GPa. The overall evolution of the optical conductivity demonstrates that GaTa(4)Se(8) is a Mott insulator which undergoes a bandwidth-controlled Mott metal-insulator transition under pressure, in remarkably good agreement with theory. With the use of our optical data and ab initio band structure calculations, our results were successfully compared to the (U/D, T/D) phase diagram predicted by dynamical mean field theory for strongly correlated systems.

  8. FACTORS REGULATING LIBERAL TRANSLATION

    Institute of Scientific and Technical Information of China (English)

    龚海红

    2012-01-01

    Literal translation and liberal translation are two important methods and both play key roles in translation.However,some textbooks say that most translations are literal translations while others maintain most are liberal ones,besides,some others suggest a combination of the two.This paper focuses on the facts that regulate liberal translation.Because of the differences in culture,society,history,geography,and so on,there exists a great difference between Chinese language and English language,which does naturally lead to the liberal translation.

  9. Regulation of transcription factor during liver development%肝脏发育过程中转录因子的调控

    Institute of Scientific and Technical Information of China (English)

    王敏君; 陈费; 向导; 刘长城; 何志颖; 王欣; 胡以平

    2011-01-01

    肝脏的发育经历了一系列内胚层和中胚层之间复杂的相互作用,其中转录因子扮演着重要角色.肝脏发育主要可分为两个阶段,首先是前肠内胚层感受心脏中胚层的信号而建立"响应态(competence)",肝向特化基因逐渐表达并形成新生肝芽.此阶段受到转录调控网络的控制,其中FoxA家族,锌指结构转录因子GATA4/6,同源结构域因子Hhex、Onecutl、Onecut2和Proxl发挥了重要的作用.其次是肝脏内细胞群体如肝细胞和胆管细胞的分化成熟阶段.这个过程的完成主要受肝富集转录因子.HNF1α、HNF4、HNF6和C/EBPα的调控.本文概述了肝脏发育中复杂的转录调控网络及其发挥的作用.%Liver development comprises a series of reciprocal interactions between embryonic endoderm and nearby mesoderm, and it is known that transcription factors play important roles in this process. Liver development mainly includes two stages. The first stage is the establishment of competence in the foregut to respond to signals from cardiac mesoderm. After the foregut closure, the endoderm cells are specialized to hepatic development, and thereafter the liver bud formed under the influence of transcriptional networks including FoxA family, zinc finger transcription factor GATA4/6, homeodomain factor Hhex, Onecut1, Onecut2 and Prox1. The second stage is the differentiation and maturation of hepatocytes and cholangiocytes. In this stage, the cellular responses to inductive signals is regulated by liver enriched transcription factors including CCAAT/enhancer binding protein (C/EBP), hepatic nuclear factor 1 (HNF-1), HNF-4 and HNF-6. This review summarizes the complex networks of transcription factors in the regulation of liver development.

  10. Transition from Mott insulator to superconductor in GaNb4Se8 and GaTa4Se8 under high pressure.

    Science.gov (United States)

    Abd-Elmeguid, M M; Ni, B; Khomskii, D I; Pocha, R; Johrendt, D; Wang, X; Syassen, K

    2004-09-17

    Electronic conduction in GaM4Se8 (M=Nb,Ta) compounds with the fcc GaMo4S8-type structure originates from hopping of localized unpaired electrons (S=1 / 2) among widely separated tetrahedral M4 metal clusters. We show that under pressure these systems transform from Mott insulators to a metallic and superconducting state with T(C)=2.9 and 5.8 K at 13 and 11.5 GPa for GaNb4Se8 and GaTa4Se8, respectively. The occurrence of superconductivity is shown to be connected with a pressure-induced decrease of the MSe6 octahedral distortion and simultaneous softening of the phonon associated with M-Se bonds.

  11. Exogenous Nkx2.5- or GATA-4-transfected rabbit bone marrow mesenchymal stem cells and myocardial cell co-culture on the treatment of myocardial infarction in rabbits.

    Science.gov (United States)

    Li, Pu; Zhang, Lei

    2015-08-01

    The present study aimed to investigate the effects of Nkx2.5 or GATA-4 transfection with myocardial extracellular environment co-culture on the transformation of bone marrow mesenchymal stem cells (BMSCs) into differentiated cardiomyocytes. Nkx2.5 or GATA-4 were transfected into myocardial extracellular environment co-cultured BMSCs, and then injected into the periphery of infarcted myocardium of a myocardial infarction rabbit model. The effects of these gene transfections and culture on the infarcted myocardium were observed and the results may provide an experimental basis for the efficient myocardial cell differentiation of BMSCs. The present study also suggested that these cells may provide a source and clinical basis for myocardial injury repair via stem cell transplantation. The present study examined whether Nkx2.5 or GATA-4 exogenous gene transfection with myocardial cell extracellular environment co-culture were able to induce the differentiation of BMSCs into cardiac cells. In addition, the effect of these transfected BMSCs on the repair of the myocardium following myocardial infarction was determined using New Zealand rabbit models. The results demonstrated that myocardial cell differentiation was significantly less effective following exogenous gene transfection of Nkx2.5 or GATA-4 alone compared with that of transfection in combination with extracellular environment co-culture. In addition, the results of the present study showed that exogenous gene transfection of Nkx2.5 or GATA-4 into myocardial cell extracellular environment co-cultured BMSCs was able to significantly enhance the ability to repair, mitigating the death of myocardial cells and activation of the myocardium in rabbits with myocardial infarction compared with those of the rabbits transplanted with untreated BMSCs. In conclusion, the exogenous Nkx2.5 and GATA-4 gene transfection into myocardial extracellular environment co-cultured BMSCs induced increased differentiation into myocardial

  12. Fibroblast Growth Factors and Vascular Endothelial Growth Factor Promote Cardiac Reprogramming under Defined Conditions

    Directory of Open Access Journals (Sweden)

    Hiroyuki Yamakawa

    2015-12-01

    Full Text Available Fibroblasts can be directly reprogrammed into cardiomyocyte-like cells (iCMs by overexpression of cardiac transcription factors, including Gata4, Mef2c, and Tbx5; however, this process is inefficient under serum-based culture conditions, in which conversion of partially reprogrammed cells into fully reprogrammed functional iCMs has been a major hurdle. Here, we report that a combination of fibroblast growth factor (FGF 2, FGF10, and vascular endothelial growth factor (VEGF, termed FFV, promoted cardiac reprogramming under defined serum-free conditions, increasing spontaneously beating iCMs by 100-fold compared with those under conventional serum-based conditions. Mechanistically, FFV activated multiple cardiac transcriptional regulators and converted partially reprogrammed cells into functional iCMs through the p38 mitogen-activated protein kinase and phosphoinositol 3-kinase/AKT pathways. Moreover, FFV enabled cardiac reprogramming with only Mef2c and Tbx5 through the induction of cardiac reprogramming factors, including Gata4. Thus, defined culture conditions promoted the quality of cardiac reprogramming, and this finding provides new insight into the mechanism of cardiac reprogramming.

  13. GATA Transcription Factors in Tissue Homeostasis and Pathology of the Gastrointestinal Tract and Liver

    OpenAIRE

    Haveri, Hanna

    2008-01-01

    Mammalian gastrointestinal tract and liver are self-renewing organs that are able to sustain themselves due to stem cells present in their tissues. In constant, inflammation-related epithelial damage, vigorous activation of stem cells may lead to their uncontrolled proliferation, and further, to cancer. GATA-4, GATA-5, and GATA-6 regulate cell proliferation and differentiation in many mammalian organs. Lack of GATA-4 or GATA-6 leads to defective endodermal development and cell differentiation...

  14. Unity power factor switching regulator

    Science.gov (United States)

    Rippel, Wally E. (Inventor)

    1983-01-01

    A single or multiphase boost chopper regulator operating with unity power factor, for use such as to charge a battery is comprised of a power section for converting single or multiphase line energy into recharge energy including a rectifier (10), one inductor (L.sub.1) and one chopper (Q.sub.1) for each chopper phase for presenting a load (battery) with a current output, and duty cycle control means (16) for each chopper to control the average inductor current over each period of the chopper, and a sensing and control section including means (20) for sensing at least one load parameter, means (22) for producing a current command signal as a function of said parameter, means (26) for producing a feedback signal as a function of said current command signal and the average rectifier voltage output over each period of the chopper, means (28) for sensing current through said inductor, means (18) for comparing said feedback signal with said sensed current to produce, in response to a difference, a control signal applied to the duty cycle control means, whereby the average inductor current is proportionate to the average rectifier voltage output over each period of the chopper, and instantaneous line current is thereby maintained proportionate to the instantaneous line voltage, thus achieving a unity power factor. The boost chopper is comprised of a plurality of converters connected in parallel and operated in staggered phase. For optimal harmonic suppression, the duty cycles of the switching converters are evenly spaced, and by negative coupling between pairs 180.degree. out-of-phase, peak currents through the switches can be reduced while reducing the inductor size and mass.

  15. Factors that regulate embryonic gustatory development

    Directory of Open Access Journals (Sweden)

    Krimm Robin F

    2007-09-01

    Full Text Available Abstract Numerous molecular factors orchestrate the development of the peripheral taste system. The unique anatomy/function of the taste system makes this system ideal for understanding the mechanisms by which these factors function; yet the taste system is underutilized for this role. This review focuses on some of the many factors that are known to regulate gustatory development, and discusses a few topics where more work is needed. Some attention is given to factors that regulate epibranchial placode formation, since gustatory neurons are thought to be primarily derived from this region. Epibranchial placodes appear to arise from a pan-placodal region and a number of regulatory factors control the differentiation of individual placodes. Gustatory neuron differentiation is regulated by a series of transcription factors and perhaps bone morphongenic proteins (BMP. As neurons differentiate, they also proliferate such that their numbers exceed those in the adult, and this is followed by developmental death. Some of these cell-cycling events are regulated by neurotrophins. After gustatory neurons become post-mitotic, axon outgrowth occurs. Axons are guided by multiple chemoattractive and chemorepulsive factors, including semaphorins, to the tongue epithelium. Brain derived neurotrophic factor (BDNF, functions as a targeting factor in the final stages of axon guidance and is required for gustatory axons to find and innervate taste epithelium. Numerous factors are involved in the development of gustatory papillae including Sox-2, Sonic hedge hog and Wnt-β-catenin signaling. It is likely that just as many factors regulate taste bud differentiation; however, these factors have not yet been identified. Studies examining the molecular factors that regulate terminal field formation in the nucleus of the solitary tract are also lacking. However, it is possible that some of the factors that regulate geniculate ganglion development, outgrowth, guidance and

  16. Negative Fgf8-Bmp2 feed-back is regulated by miR-130 during early cardiac specification.

    Science.gov (United States)

    Lopez-Sanchez, Carmen; Franco, Diego; Bonet, Fernando; Garcia-Lopez, Virginio; Aranega, Amelia; Garcia-Martinez, Virginio

    2015-10-01

    It is known that secreted proteins from the anterior lateral endoderm, FGF8 and BMP2, are involved in mesodermal cardiac differentiation, which determines the first cardiac field, defined by the expression of the earliest specific cardiac markers Nkx-2.5 and Gata4. However, the molecular mechanisms responsible for early cardiac development still remain unclear. At present, microRNAs represent a novel layer of complexity in the regulatory networks controlling gene expression during cardiovascular development. This paper aims to study the role of miR130 during early cardiac specification. Our model is focused on developing chick at gastrula stages. In order to identify those regulatory factors which are involved in cardiac specification, we conducted gain- and loss-of-function experiments in precardiac cells by administration of Fgf8, Bmp2 and miR130, through in vitro electroporation technique and soaked beads application. Embryos were subjected to in situ hybridization, immunohistochemistry and qPCR procedures. Our results reveal that Fgf8 suppresses, while Bmp2 induces, the expression of Nkx-2.5 and Gata4. They also show that Fgf8 suppresses Bmp2, and vice versa. Additionally, we observed that Bmp2 regulates miR-130 -a putative microRNA that targets Erk1/2 (Mapk1) 3'UTR, recognizing its expression in precardiac cells which overlap with Erk1/2 pattern. Finally, we evidence that miR-130 is capable to inhibit Erk1/2 and Fgf8, resulting in an increase of Bmp2, Nkx-2.5 and Gata4. Our data present miR-130 as a necessary linkage in the control of Fgf8 signaling, mediated by Bmp2, establishing a negative feed-back loop responsible to achieve early cardiac specification.

  17. Protein Synthesis Initiation Factors: Phosphorylation and Regulation

    Energy Technology Data Exchange (ETDEWEB)

    Karen S. Browning

    2009-06-15

    The initiation of the synthesis of proteins is a fundamental process shared by all living organisms. Each organism has both shared and unique mechanisms for regulation of this vital process. Higher plants provide for a major amount of fixation of carbon from the environment and turn this carbon into food and fuel sources for our use. However, we have very little understanding of how plants regulate the synthesis of the proteins necessary for these metabolic processes. The research carried out during the grant period sought to address some of these unknowns in the regulation of protein synthesis initiation. Our first goal was to determine if phosphorylation plays a significant role in plant initiation of protein synthesis. The role of phosphorylation, although well documented in mammalian protein synthesis regulation, is not well studied in plants. We showed that several of the factors necessary for the initiation of protein synthesis were targets of plant casein kinase and showed differential phosphorylation by the plant specific isoforms of this kinase. In addition, we identified and confirmed the phosphorylation sites in five of the plant initiation factors. Further, we showed that phosphorylation of one of these factors, eIF5, affected the ability of the factor to participate in the initiation process. Our second goal was to develop a method to make initiation factor 3 (eIF3) using recombinant methods. To date, we successfully cloned and expressed 13/13 subunits of wheat eIF3 in E. coli using de novo gene construction methods. The final step in this process is to place the subunits into three different plasmid operons for co-expression. Successful completion of expression of eIF3 will be an invaluable tool to the plant translation community.

  18. PCBs alter gene expression of nuclear transcription factors and other heart-specific genes in cultures of primary cardiomyocytes: possible implications for cardiotoxicity.

    Science.gov (United States)

    Borlak, J; Thum, T

    2002-12-01

    1. Polychlorinated biphenyls (PCBs) are well-known environmental pollutants that bioaccumulate mainly in the fatty tissue of animals and humans. Although contamination occurs primarily via the food chain, waste combustion leads to airborne PCBs. From epidemiological studies, there is substantial evidence that cardiovascular disease is linked to air pollution, but little is known about the underlying molecular events. 2. We investigated the effects of Aroclor 1254, a complex mixture of >80 PCB isomers and congeners, on the expression of nuclear transcription factors (GATA-4, Nkx-2.5, MEF-2c, OCT-1) and of downstream target genes (atrial and brain natriuretic peptide, alpha- and beta-myosin heavy chain, alpha-cardiac and alpha-skeletal actin), which play an important role in cardiac biology. 3. We treated cultures of primary cardiomyocytes of adult rats with Aroclor 1254 (10.0 micro M) and found significant induction of the transcription factor genes GATA-4 and MEF-2c and of genes regulated by these factors, i.e. atrial natriuretic peptide, brain-type natriuretic peptide, alpha- and beta-myosin heavy chain, and skeletal alpha actin. 4. We have shown PCBs to modulate expression of genes coding for programmes of cellular differentiation and stress (e.g. atrial natriuretic peptide, brain-type natriuretic peptide) and these alterations may be important in the increase of cardiovascular disease in polluted areas.

  19. Essential role for the planarian intestinal GATA transcription factor in stem cells and regeneration.

    Science.gov (United States)

    Flores, Natasha M; Oviedo, Néstor J; Sage, Julien

    2016-10-01

    The cellular turnover of adult tissues and injury-induced repair proceed through an exquisite integration of proliferation, differentiation, and survival signals that involve stem/progenitor cell populations, their progeny, and differentiated tissues. GATA factors are DNA binding proteins that control stem cells and the development of tissues by activating or repressing transcription. Here we examined the role of GATA transcription factors in Schmidtea mediterranea, a freshwater planarian that provides an excellent model to investigate gene function in adult stem cells, regeneration, and differentiation. Smed-gata4/5/6, the homolog of the three mammalian GATA-4,-5,-6 factors is expressed at high levels in differentiated gut cells but also at lower levels in neoblast populations, the planarian stem cells. Smed-gata4/5/6 knock-down results in broad differentiation defects, especially in response to injury. These defects are not restricted to the intestinal lineage. In particular, at late time points during the response to injury, loss of Smed-gata4/5/6 leads to decreased neoblast proliferation and to gene expression changes in several neoblast subpopulations. Thus, Smed-gata4/5/6 plays a key evolutionary conserved role in intestinal differentiation in planarians. These data further support a model in which defects in the intestinal lineage can indirectly affect other differentiation pathways in planarians.

  20. Regulation of antimicrobial resistance by extracytoplasmic function (ECF) sigma factors.

    Science.gov (United States)

    Woods, Emily C; McBride, Shonna M

    2017-01-30

    Extracytoplasmic function (ECF) sigma factors are a subfamily of σ(70) sigma factors that activate genes involved in stress-response functions. In many bacteria, ECF sigma factors regulate resistance to antimicrobial compounds. This review will summarize the ECF sigma factors that regulate antimicrobial resistance in model organisms and clinically relevant pathogens.

  1. Fibroblast growth factor signaling in metabolic regulation

    Directory of Open Access Journals (Sweden)

    Vera eNies

    2016-01-01

    Full Text Available The prevalence of obesity is a growing health problem. Obesity is strongly associated with several comorbidities, such as non-alcoholic fatty liver disease, certain cancers, insulin resistance and type 2 diabetes, which all reduce life expectancy and life quality. Several drugs have been put forward in order to treat these diseases, but many of them have detrimental side effects. The unexpected role of the family of fibroblast growth factors in the regulation of energy metabolism provides new approaches to the treatment of metabolic diseases, and offers a valuable tool to gain more insight into metabolic regulation. The known beneficial effects of FGF19 and FGF21 on metabolism, together with recently discovered similar effects of FGF1 suggest that FGFs and their derivatives carry great potential as novel therapeutics to treat metabolic conditions. To facilitate the development of new therapies with improved targeting and minimal side effects, a better understanding of the molecular mechanism of action of FGFs is needed.In this review we will discuss what is currently known about the physiological roles of FGF signaling in tissues important for metabolic homeostasis. In addition, we will discuss current concepts regarding their pharmacological properties and effector tissues in the context of metabolic disease. Also the recent progress in the development of FGF variants will be reviewed. Our goal is to provide a comprehensive overview of the current concepts and consensuses regarding FGF signaling in metabolic health and disease, and to provide starting points for the development of FGF-based therapies against metabolic conditions.

  2. GATA6 is a crucial regulator of Shh in the limb bud.

    Directory of Open Access Journals (Sweden)

    Elena Kozhemyakina

    2014-01-01

    Full Text Available In the limb bud, patterning along the anterior-posterior (A-P axis is controlled by Sonic Hedgehog (Shh, a signaling molecule secreted by the "Zone of Polarizing Activity", an organizer tissue located in the posterior margin of the limb bud. We have found that the transcription factors GATA4 and GATA6, which are key regulators of cell identity, are expressed in an anterior to posterior gradient in the early limb bud, raising the possibility that GATA transcription factors may play an additional role in patterning this tissue. While both GATA4 and GATA6 are expressed in an A-P gradient in the forelimb buds, the hindlimb buds principally express GATA6 in an A-P gradient. Thus, to specifically examine the role of GATA6 in limb patterning we generated Prx1-Cre; GATA6(fl/fl mice, which conditionally delete GATA6 from their developing limb buds. We found that these animals display ectopic expression of both Shh and its transcriptional targets specifically in the anterior mesenchyme of the hindlimb buds. Loss of GATA6 in the developing limbs results in the formation of preaxial polydactyly in the hindlimbs. Conversely, forced expression of GATA6 throughout the limb bud represses expression of Shh and results in hypomorphic limbs. We have found that GATA6 can bind to chromatin (isolated from limb buds encoding either Shh or Gli1 regulatory elements that drive expression of these genes in this tissue, and demonstrated that GATA6 works synergistically with FOG co-factors to repress expression of luciferase reporters driven by these sequences. Most significantly, we have found that conditional loss of Shh in limb buds lacking GATA6 prevents development of hindlimb polydactyly in these compound mutant embryos, indicating that GATA6 expression in the anterior region of the limb bud blocks hindlimb polydactyly by repressing ectopic expression of Shh.

  3. GATA6 is a crucial regulator of Shh in the limb bud.

    Science.gov (United States)

    Kozhemyakina, Elena; Ionescu, Andreia; Lassar, Andrew B

    2014-01-01

    In the limb bud, patterning along the anterior-posterior (A-P) axis is controlled by Sonic Hedgehog (Shh), a signaling molecule secreted by the "Zone of Polarizing Activity", an organizer tissue located in the posterior margin of the limb bud. We have found that the transcription factors GATA4 and GATA6, which are key regulators of cell identity, are expressed in an anterior to posterior gradient in the early limb bud, raising the possibility that GATA transcription factors may play an additional role in patterning this tissue. While both GATA4 and GATA6 are expressed in an A-P gradient in the forelimb buds, the hindlimb buds principally express GATA6 in an A-P gradient. Thus, to specifically examine the role of GATA6 in limb patterning we generated Prx1-Cre; GATA6(fl/fl) mice, which conditionally delete GATA6 from their developing limb buds. We found that these animals display ectopic expression of both Shh and its transcriptional targets specifically in the anterior mesenchyme of the hindlimb buds. Loss of GATA6 in the developing limbs results in the formation of preaxial polydactyly in the hindlimbs. Conversely, forced expression of GATA6 throughout the limb bud represses expression of Shh and results in hypomorphic limbs. We have found that GATA6 can bind to chromatin (isolated from limb buds) encoding either Shh or Gli1 regulatory elements that drive expression of these genes in this tissue, and demonstrated that GATA6 works synergistically with FOG co-factors to repress expression of luciferase reporters driven by these sequences. Most significantly, we have found that conditional loss of Shh in limb buds lacking GATA6 prevents development of hindlimb polydactyly in these compound mutant embryos, indicating that GATA6 expression in the anterior region of the limb bud blocks hindlimb polydactyly by repressing ectopic expression of Shh.

  4. AMP-activated protein kinase-regulated activation of the PGC-1alpha promoter in skeletal muscle cells.

    Directory of Open Access Journals (Sweden)

    Isabella Irrcher

    Full Text Available The mechanisms by which PGC-1alpha gene expression is controlled in skeletal muscle remains largely undefined. Thus, we sought to investigate the transcriptional regulation of PGC-1alpha using AICAR, an activator of AMPK, that is known to increase PGC-1alpha expression. A 2.2 kb fragment of the human PGC-1alpha promoter was cloned and sequence analysis revealed that this TATA-less sequence houses putative consensus sites including a GC-box, a CRE, several IRSs, a SRE, binding sites for GATA, MEF2, p 53, NF-kappaB, and EBox binding proteins. AMPK activation for 24 hours increased PGC-1alpha promoter activity with concomitant increases in mRNA expression. The effect of AICAR on transcriptional activation was mediated by an overlapping GATA/EBox binding site at -495 within the PGC-1alpha promoter based on gel shift analyses that revealed increases in GATA/EBox DNA binding. Mutation of the EBox within the GATA/EBox binding site in the promoter reduced basal promoter activity and completely abolished the AICAR effect. Supershift analyses identified USF-1 as a DNA binding transcription factor potentially involved in regulating PGC-1alpha promoter activity, which was confirmed in vivo by ChIP. Overexpression of either GATA-4 or USF-1 alone increased the p851 PGC-1alpha promoter activity by 1.7- and 2.0-fold respectively, while co-expression of GATA-4 and USF-1 led to an additive increase in PGC-1alpha promoter activity. The USF-1-mediated increase in PGC-1alpha promoter activation led to similar increases at the mRNA level. Our data identify a novel AMPK-mediated regulatory pathway that regulates PGC-1alpha gene expression. This could represent a potential therapeutic target to control PGC-1alpha expression in skeletal muscle.

  5. Gravity, a regulation factor in the differentiation of rat bone marrow mesenchymal stem cells

    Directory of Open Access Journals (Sweden)

    Wan Yu-Min

    2009-09-01

    Full Text Available Abstract Background Stem cell therapy has emerged as a potential therapeutic option for tissue engineering and regenerative medicine, but many issues remain to be resolved, such as the amount of seed cells, committed differentiation and the efficiency. Several previous studies have focused on the study of chemical inducement microenvironments. In the present study, we investigated the effects of gravity on the differentiation of bone marrow mesenchymal stem cells (BMSCs into force-sensitive or force-insensitive cells. Methods and results Rat BMSCs (rBMSCs were cultured under hypergravity or simulated microgravity (SMG conditions with or without inducement medium. The expression levels of the characteristic proteins were measured and analyzed using immunocytochemical, RT-PCR and Western-blot analyses. After treatment with 5-azacytidine and hypergravity, rBMSCs expressed more characteristic proteins of cardiomyocytes such as cTnT, GATA4 and β-MHC; however, fewer such proteins were seen with SMG. After treating rBMSCs with osteogenic inducer and hypergravity, there were marked increases in the expression levels of ColIA1, Cbfa1 and ALP. Reverse results were obtained with SMG. rBMSCs treated with adipogenic inducer and SMG expressed greater levels of PPARgamma. Greater levels of Cbfa1- or cTnT-positive cells were observed under hypergravity without inducer, as shown by FACS analysis. These results indicate that hypergravity induces differentiation of rBMSCs into force-sensitive cells (cardiomyocytes and osteoblasts, whereas SMG induces force-insensitive cells (adipocytes. Conclusion Taken together, we conclude that gravity is an important factor affecting the differentiation of rBMSCs; this provides a new avenue for mechanistic studies of stem cell differentiation and a new approach to obtain more committed differentiated or undifferentiated cells.

  6. Regulation of the Ets transcription factor Tel

    NARCIS (Netherlands)

    Roukens, Mark Guido

    2010-01-01

    In this thesis we report novel studies on the molecular regulation of the transcriptional repressor Tel (Translocation Ets Leukemia). The work in this thesis is presented as follows: Chapter 1 is an introduction which summarizes the literature about Tel and its Drosophila orthologue Yan as it was k

  7. Regulation of alternative sigma factor use.

    Science.gov (United States)

    Österberg, Sofia; del Peso-Santos, Teresa; Shingler, Victoria

    2011-01-01

    Alternative bacterial sigma factors bind the catalytic core RNA polymerase to confer promoter selectivity on the holoenzyme. The different holoenzymes are thus programmed to recognize the distinct promoter classes in the genome to allow coordinated activation of discrete sets of genes needed for adaptive responses. To form the holoenzymes, the different sigma factors must be available to compete for their common substrate (core RNA polymerase). This review highlights (a) the roles of antisigma factors in controlling the availability of alternative sigma factors and (b) the involvement of diverse regulatory molecules that promote the use of alternative sigma factors through subversion of the domineering housekeeping σ(70). The latter include the nucleotide alarmone ppGpp and small proteins (DksA, Rsd, and Crl), which directly target the transcriptional machinery to mediate their effects.

  8. Nuclear transport factors: global regulation of mitosis.

    Science.gov (United States)

    Forbes, Douglass J; Travesa, Anna; Nord, Matthew S; Bernis, Cyril

    2015-08-01

    The unexpected repurposing of nuclear transport proteins from their function in interphase to an equally vital and very different set of functions in mitosis was very surprising. The multi-talented cast when first revealed included the import receptors, importin alpha and beta, the small regulatory GTPase RanGTP, and a subset of nuclear pore proteins. In this review, we report that recent years have revealed new discoveries in each area of this expanding story in vertebrates: (a) The cast of nuclear import receptors playing a role in mitotic spindle regulation has expanded: both transportin, a nuclear import receptor, and Crm1/Xpo1, an export receptor, are involved in different aspects of spindle assembly. Importin beta and transportin also regulate nuclear envelope and pore assembly. (b) The role of nucleoporins has grown to include recruiting the key microtubule nucleator - the γ-TuRC complex - and the exportin Crm1 to the mitotic kinetochores of humans. Together they nucleate microtubule formation from the kinetochores toward the centrosomes. (c) New research finds that the original importin beta/RanGTP team have been further co-opted by evolution to help regulate other cellular and organismal activities, ranging from the actual positioning of the spindle within the cell perimeter, to regulation of a newly discovered spindle microtubule branching activity, to regulation of the interaction of microtubule structures with specific actin structures. (d) Lastly, because of the multitudinous roles of karyopherins throughout the cell cycle, a recent large push toward testing their potential as chemotherapeutic targets has begun to yield burgeoning progress in the clinic.

  9. Regulated assembly of transcription factors and control of transcription initiation.

    Science.gov (United States)

    Beckett, D

    2001-11-30

    Proteins that function in regulation of transcription initiation are typically homo or hetero-oligomeric. Results of recent biophysical studies of transcription regulators indicate that the assembly of these proteins is often subject to regulation. This regulation of assembly dictates the frequency of transcription initiation via its influence on the affinity of a transcription regulator for DNA and its affect on target site selection. Factors that modulate transcription factor assembly include binding of small molecules, post-translational modification, DNA binding and interactions with other proteins. Here, the results of recent structural and/or thermodynamic studies of a number of transcription regulators that are subject to regulated assembly are reviewed. The accumulated data indicate that this phenomenon is ubiquitous and that mechanisms utilized in eukaryotes and prokaryotes share common features. Copyright 2001 Academic Press.

  10. Transcription factor regulation by mechanical stress.

    Science.gov (United States)

    Mendez, Melissa G; Janmey, Paul A

    2012-05-01

    New technologies and interest in cell mechanics are generating exciting new discoveries about how material properties and forces affect biological structure and function. Mechanical forces are transduced via a variety of mechanisms, recently beginning to be revealed, into signals capable of altering cell function and structure. Responses to physical stimuli occur at multiple levels, from changes in the structures of single proteins to global cascades capable of altering cell proliferation and differentiation. This review describes recent findings in which physical stimuli were shown to modulate transcription factor activity, including that of armadillo/β-catenin, serum response factor (SRF), yes-associated protein (YAP) and nuclear factor κB (NF-κB). Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Plastid sigma factors: Their individual functions and regulation in transcription.

    Science.gov (United States)

    Chi, Wei; He, Baoye; Mao, Juan; Jiang, Jingjing; Zhang, Lixin

    2015-09-01

    Sigma factors are the predominant factors involved in transcription regulation in bacteria. These factors can recruit the core RNA polymerase to promoters with specific DNA sequences and initiate gene transcription. The plastids of higher plants originating from an ancestral cyanobacterial endosymbiont also contain sigma factors that are encoded by a small family of nuclear genes. Although all plastid sigma factors contain sequences conserved in bacterial sigma factors, a considerable number of distinct traits have been acquired during evolution. The present review summarises recent advances concerning the regulation of the structure, function and activity of plastid sigma factors since their discovery nearly 40 years ago. We highlight the specialised roles and overlapping redundant functions of plastid sigma factors according to their promoter selectivity. We also focus on the mechanisms that modulate the activity of sigma factors to optimise plastid function in response to developmental cues and environmental signals. This article is part of a Special Issue entitled: Chloroplast Biogenesis.

  12. Environmental factors regulating soil organic matter chlorination

    Science.gov (United States)

    Svensson, Teresia; Montelius, Malin; Reyier, Henrik; Rietz, Karolina; Karlsson, Susanne; Lindberg, Cecilia; Andersson, Malin; Danielsson, Åsa; Bastviken, David

    2016-04-01

    Natural chlorination of organic matter is common in soils. Despite the widespread abundance of soil chlorinated soil organic matter (SOM), frequently exceeding soil chloride abundance in surface soils, and a common ability of microorganisms to produce chlorinated SOM, we lack fundamental knowledge about dominating processes and organisms responsible for the chlorination. To take one step towards resolving the terrestrial chlorine (Cl) puzzle, this study aims to analyse how environmental factors influence chlorination of SOM. Four factors were chosen for this study: soil moisture (W), nitrogen (N), chloride (Cl) and organic matter quality (C). These factors are all known to be important for soil processes. Laboratory incubations with 36Cl as a Cl tracer were performed in a two soil incubation experiments. It was found that addition of chloride and nitrogen seem to hamper the chlorination. For the C treatment, on the other hand, the results show that chlorination is enhanced by increased availability of labile organic matter (glucose and maltose). Even higher chlorination was observed when nitrogen and water were added in combination with labile organic matter. The effect that more labile organic matter strongly stimulated the chlorination rates was confirmed by the second separate experiment. These results indicate that chlorination was not primarily a way to cut refractory organic matter into digestible molecules, representing one previous hypothesis, but is related with microbial metabolism in other ways that will be further discussed in our presentation.

  13. BATF: Bringing (in) Another Th17-regulating Factor

    Institute of Scientific and Technical Information of China (English)

    Gustavo J. Martinez; Chen Dong

    2009-01-01

    T helper (Th) 17 cells are a recently identified subset of T cells that regulate tissue inflammation, and RORγt and RORα have been shown to be Th17-specific transcription factors that mediate Th17 cell generation. A new study of Batf-deficient mice shows that this AP-1 family transcription factor also regulates Th17 cell differentiation by binding to Th17-associated gene promoters and by maintaining RORa and RORgt expression, shedding new lights on current clinical modulation of Th17 cell function in inflammatory diseases.

  14. Beclin 1 regulates growth factor receptor signaling in breast cancer.

    Science.gov (United States)

    Rohatgi, R A; Janusis, J; Leonard, D; Bellvé, K D; Fogarty, K E; Baehrecke, E H; Corvera, S; Shaw, L M

    2015-10-16

    Beclin 1 is a haploinsufficient tumor suppressor that is decreased in many human tumors. The function of beclin 1 in cancer has been attributed primarily to its role in the degradative process of macroautophagy. However, beclin 1 is a core component of the vacuolar protein sorting 34 (Vps34)/class III phosphatidylinositoI-3 kinase (PI3KC3) and Vps15/p150 complex that regulates multiple membrane-trafficking events. In the current study, we describe an alternative mechanism of action for beclin 1 in breast cancer involving its control of growth factor receptor signaling. We identify a specific stage of early endosome maturation that is regulated by beclin 1, the transition of APPL1-containing phosphatidyIinositol 3-phosphate-negative (PI3P(-)) endosomes to PI3P(+) endosomes. Beclin 1 regulates PI3P production in response to growth factor stimulation to control the residency time of growth factor receptors in the PI3P(-)/APPL(+)-signaling-competent compartment. As a result, suppression of BECN1 sustains growth factor-stimulated AKT and ERK activation resulting in increased breast carcinoma cell invasion. In human breast tumors, beclin 1 expression is inversely correlated with AKT and ERK phosphorylation. Our data identify a novel role for beclin 1 in regulating growth factor signaling and reveal a mechanism by which loss of beclin 1 expression would enhance breast cancer progression.

  15. Regulation of spermatogenesis by paracrine/autocrine testicular factors

    Institute of Scientific and Technical Information of China (English)

    MahmoudHuleihel; EitanLunenfeld

    2004-01-01

    Spermatogenesis is a complex process regulated by endocrine and testicular paracrine/autocrine factors.Gonadotropins are involved in the regulation of several testicular paracrine factors, mainly of the IL-1 family and testicular hormones. Testicular cytokines and growth factors (such as IL-1, IL-6, TNF, IFN-T, LIF and SCF) were shown to affect both the germ cell proliferation and the Leydig and Sertoli cells functions and secretion. Cytokines and growth factors are produced by immune cells and in the interstitial and seminiferous tubular compartments by various testicular cells, including Sertoli, Leydig, peritubular cells, spermatogonia, differentiated spermatogonia and even spermatozoa. Corresponding cytokine and growth factor receptors were demonstrated on some of the testicular cells. These cytokines also control the secretion of the gonadotropins and testosterone in the testis. Under pathological conditions the levels of pro-inflammatory cytokines are increased and negatively affected spermatogenesis. Thus,the expression levels and the mechanisms involved in the regulation of testicular paracrine/autocrine factors should be considered in future therapeutic strategies for male infertility. (Asian J Androl 2004 Sep; 6: 259-268)

  16. Myocardin-related transcription factor regulates Nox4 protein expression

    DEFF Research Database (Denmark)

    Rozycki, Matthew; Bialik, Janne Folke; Speight, Pam

    2016-01-01

    TGFβ-induced expression of the NADPH oxidase Nox4 is essential for fibroblast-myofibroblast transition. Rho has been implicated in Nox4 regulation, but the underlying mechanisms are largely unknown. Myocardin-related transcription factor (MRTF), a Rho/actin polymerization-controlled coactivator...... translocation of MRTF. Because the Nox4 promoter harbors a serum response factor/MRTF cis-element (CC(A/T)6GG box), we asked if MRTF (and thus cytoskeleton organization) could regulate Nox4 expression. We show that Nox4 protein is robustly induced in kidney tubular cells exclusively by combined application...... of contact uncoupling and TGFβ. Nox4 knockdown abrogates epithelial-myofibroblast transition-associated reactive oxygen species production. Laser capture microdissection reveals increased Nox4 expression in the tubular epithelium also during obstructive nephropathy. MRTF down-regulation/inhibition suppresses...

  17. Redox-dependent regulation of epidermal growth factor receptor signaling

    Directory of Open Access Journals (Sweden)

    David E. Heppner

    2016-08-01

    Full Text Available Tyrosine phosphorylation-dependent cell signaling represents a unique feature of multicellular organisms, and is important in regulation of cell differentiation and specialized cell functions. Multicellular organisms also contain a diverse family of NADPH oxidases (NOXs that have been closely linked with tyrosine kinase-based cell signaling and regulate tyrosine phosphorylation via reversible oxidation of cysteine residues that are highly conserved within many proteins involved in this signaling pathway. An example of redox-regulated tyrosine kinase signaling involves the epidermal growth factor receptor (EGFR, a widely studied receptor system with diverse functions in normal cell biology as well as pathologies associated with oxidative stress such as cancer. The purpose of this Graphical Redox Review is to highlight recently emerged concepts with respect to NOX-dependent regulation of this important signaling pathway.

  18. Brain-derived neurotrophic factor, food intake regulation, and obesity.

    Science.gov (United States)

    Rosas-Vargas, Haydeé; Martínez-Ezquerro, José Darío; Bienvenu, Thierry

    2011-08-01

    Brain-derived neurotrophic factor (BDNF) is a neurotrophin that plays a fundamental role in development and plasticity of the central nervous system (CNS). It is currently recognized as a major participant in the regulation of food intake. Multiple studies have shown that different regulators of appetite such as leptin, insulin and pancreatic polypeptide (PP) potentially exert anorexigenic effects through BDNF. Low circulating levels of BDNF are associated with a higher risk of eating disorders such as anorexia nervosa (AN) and bulimia nervosa (BN). Strict food restriction reduces BDNF and may trigger binge-eating episodes and weight gain. The existence of mutations that cause haploinsufficiency of BDNF as well as some genetic variants, notably the BDNF p.Val66Met polymorphism, are also associated with the development of obese phenotypes and hyperphagia. However, association of the Met allele with AN and BN, which have different phenotypic characteristics, shows clearly the existence of other relevant factors that regulate eating behavior. This may, in part, be explained by the epigenetic regulation of BDNF through mechanisms like DNA methylation and histone acetylation. Environmental factors, primarily during early development, are crucial to the establishment of these stable but reversible changes that alter the transcriptional expression and are transgenerationally heritable, with potential concomitant effects on the development of eating disorders and body weight control.

  19. Crystal Structure of the Pseudomonas aeruginosa Virulence Factor Regulator

    Energy Technology Data Exchange (ETDEWEB)

    Cordes, Timothy J.; Worzalla, Gregory A.; Ginster, Aaron M.; Forest, Katrina T. (UW)

    2012-09-07

    Virulence factor regulator (Vfr) enhances Pseudomonas aeruginosa pathogenicity through its role as a global transcriptional regulator. The crystal structure of Vfr shows that it is a winged-helix DNA-binding protein like its homologue cyclic AMP receptor protein (CRP). In addition to an expected primary cyclic AMP-binding site, a second ligand-binding site is nestled between the N-terminal domain and the C-terminal helix-turn-helix domain. Unlike CRP, Vfr is a symmetric dimer in the absence of DNA. Removal of seven disordered N-terminal residues of Vfr prvents the growth of P. aeruginosa.

  20. Some cultural factors affecting costs of fertility regulation.

    Science.gov (United States)

    Nag, M

    1984-01-01

    This paper presents a framework of the costs or constraints in the use of fertility regulation, reviews the existing knowledge on the subject in a cross-cultural context, and indicates the need for further studies. It is suggested that the apparent contradiction noted in fertility surveys between a couple's desire to have no more children or to postpone the next birth and actual behavior can be explained by the costs involved in the use of fertility regulation methods. The costs of fertility regulation can be broadly classified into 4 categories: 1) physical/health (disruption of menstrual cycle, side effects and health hazards of contraceptive methods, perceived health hazards based on ethno-physical concepts, and sacrifice of sexual pleasure); 2) psychic (violation of sexual modesty and human dignity, conflict with religious beliefs; 3) social opinion (challenges to spouse and sex role expectations, challenges to social influence group); and 4) economic (money, time). The economic costs of fertility regulation to individuals vary greatly according to the presence or absence of public sector family planning programs. A substantial part of these costs could be eliminated by national and international programs. So far, no study has focused on the costs of fertility regulation and factors affecting them. A methodology that combines elements of both a questionnaire survey and anthropological investigation and collects data on both the individual and community levels may be most amenable to assessing the impact of costs on the use or nonuse of fertility regulation.

  1. Scl binds to primed enhancers in mesoderm to regulate hematopoietic and cardiac fate divergence.

    Science.gov (United States)

    Org, Tõnis; Duan, Dan; Ferrari, Roberto; Montel-Hagen, Amelie; Van Handel, Ben; Kerényi, Marc A; Sasidharan, Rajkumar; Rubbi, Liudmilla; Fujiwara, Yuko; Pellegrini, Matteo; Orkin, Stuart H; Kurdistani, Siavash K; Mikkola, Hanna Ka

    2015-03-12

    Scl/Tal1 confers hemogenic competence and prevents ectopic cardiomyogenesis in embryonic endothelium by unknown mechanisms. We discovered that Scl binds to hematopoietic and cardiac enhancers that become epigenetically primed in multipotent cardiovascular mesoderm, to regulate the divergence of hematopoietic and cardiac lineages. Scl does not act as a pioneer factor but rather exploits a pre-established epigenetic landscape. As the blood lineage emerges, Scl binding and active epigenetic modifications are sustained in hematopoietic enhancers, whereas cardiac enhancers are decommissioned by removal of active epigenetic marks. Our data suggest that, rather than recruiting corepressors to enhancers, Scl prevents ectopic cardiogenesis by occupying enhancers that cardiac factors, such as Gata4 and Hand1, use for gene activation. Although hematopoietic Gata factors bind with Scl to both activated and repressed genes, they are dispensable for cardiac repression, but necessary for activating genes that enable hematopoietic stem/progenitor cell development. These results suggest that a unique subset of enhancers in lineage-specific genes that are accessible for regulators of opposing fates during the time of the fate decision provide a platform where the divergence of mutually exclusive fates is orchestrated.

  2. Differential gene expression regulated by oscillatory transcription factors.

    Directory of Open Access Journals (Sweden)

    Luca Cerone

    Full Text Available Cells respond to changes in the internal and external environment by a complex regulatory system whose end-point is the activation of transcription factors controlling the expression of a pool of ad-hoc genes. Recent experiments have shown that certain stimuli may trigger oscillations in the concentration of transcription factors such as NF-κB and p53 influencing the final outcome of the genetic response. In this study we investigate the role of oscillations in the case of three different well known gene regulatory mechanisms using mathematical models based on ordinary differential equations and numerical simulations. We considered the cases of direct regulation, two-step regulation and feed-forward loops, and characterized their response to oscillatory input signals both analytically and numerically. We show that in the case of indirect two-step regulation the expression of genes can be turned on or off in a frequency dependent manner, and that feed-forward loops are also able to selectively respond to the temporal profile of oscillating transcription factors.

  3. Epithelial Barrier Regulation by Hypoxia-Inducible Factor.

    Science.gov (United States)

    Glover, Louise E; Colgan, Sean P

    2017-09-01

    Mucosal tissues represent surfaces that are exposed to the outside world and provide a conduit for internal and external communication. Tissues such as the intestine and the lung are lined by layer(s) of epithelial cells that, when organized in three dimensions, provide a critical barrier to the flux of luminal contents. This selective barrier is provided through the regulated expression of junctional proteins and mucins. Tissue oxygen metabolism is central to the maintenance of homeostasis in the mucosa. In some organs (e.g., the colon), low baseline Po2 determines tissue metabolism and results in basal expression of the transcription factor, hypoxia-inducible factor (HIF), which is enhanced after ischemia/inflammation. Recent studies have indicated that HIF contributes fundamentally to the expression of barrier-related genes and in the regulation of barrier-adaptive responses within the mucosa. Here, we briefly review recent literature on the topic of hypoxia and HIF regulation of barrier in mucosal health and during disease.

  4. FOXO Transcription Factors: Their Clinical Significance and Regulation

    Directory of Open Access Journals (Sweden)

    Yu Wang

    2014-01-01

    Full Text Available Members of the class O of forkhead box transcription factors (FOXO have important roles in metabolism, cellular proliferation, stress resistance, and apoptosis. The activity of FOXOs is tightly regulated by posttranslational modification, including phosphorylation, acetylation, and ubiquitylation. Activation of cell survival pathways such as phosphoinositide-3-kinase/AKT/IKK or RAS/mitogen-activated protein kinase phosphorylates FOXOs at different sites which regulate FOXOs nuclear localization or degradation. FOXO transcription factors are upregulated in a number of cell types including hepatocytes, fibroblasts, osteoblasts, keratinocytes, endothelial cells, pericytes, and cardiac myocytes. They are involved in a number of pathologic and physiologic processes that include proliferation, apoptosis, autophagy, metabolism, inflammation, cytokine expression, immunity, differentiation, and resistance to oxidative stress. These processes impact a number of clinical conditions such as carcinogenesis, diabetes, diabetic complications, cardiovascular disease, host response, and wound healing. In this paper, we focus on the potential role of FOXOs in different disease models and the regulation of FOXOs by various stimuli.

  5. Role of PDI in regulating tissue factor: FVIIa activity.

    Science.gov (United States)

    Popescu, Narcis I; Lupu, Cristina; Lupu, Florea

    2010-04-01

    Cell exposed tissue factor (TF) is generally in a low procoagulant ("cryptic") state, and requires an activation step (decryption) to exhibit its full procoagulant potential. Recent data suggest that TF decryption may be regulated by the redox environment through the oxidoreductase activity of protein disulfide isomerase (PDI). In this article we review PDI contribution to different models of TF decryption, namely the disulfide switch model and the phosphatidylserine dynamics, and hypothesize on PDI contribution to TF self-association and association with lipid domains. Experimental evidence debate the disulfide switch model of TF decryption and its regulation by PDI. More recently we showed that PDI oxidoreductase activity regulates the phosphatidylserine equilibrium at the plasma membrane. Interestingly, PDI reductase activity could maintain TF in the reduced monomeric form, while also maintaining low exposure of PS, both states correlated with low procoagulant function. In contrast, PDI inhibition or oxidants may promote the adverse effects with a net increase in coagulation. The relative contribution of disulfide isomerization and PS exposure needs to be further analyzed to understand the redox control of TF procoagulant function. For the moment however TF regulation remains cryptic.

  6. Dynamic regulation of transcription factors by nucleosome remodeling.

    Science.gov (United States)

    Li, Ming; Hada, Arjan; Sen, Payel; Olufemi, Lola; Hall, Michael A; Smith, Benjamin Y; Forth, Scott; McKnight, Jeffrey N; Patel, Ashok; Bowman, Gregory D; Bartholomew, Blaine; Wang, Michelle D

    2015-06-05

    The chromatin landscape and promoter architecture are dominated by the interplay of nucleosome and transcription factor (TF) binding to crucial DNA sequence elements. However, it remains unclear whether nucleosomes mobilized by chromatin remodelers can influence TFs that are already present on the DNA template. In this study, we investigated the interplay between nucleosome remodeling, by either yeast ISW1a or SWI/SNF, and a bound TF. We found that a TF serves as a major barrier to ISW1a remodeling, and acts as a boundary for nucleosome repositioning. In contrast, SWI/SNF was able to slide a nucleosome past a TF, with concurrent eviction of the TF from the DNA, and the TF did not significantly impact the nucleosome positioning. Our results provide direct evidence for a novel mechanism for both nucleosome positioning regulation by bound TFs and TF regulation via dynamic repositioning of nucleosomes.

  7. MGMT expression: insights into its regulation. 1. Epigenetic factors

    Directory of Open Access Journals (Sweden)

    Iatsyshyna A. P.

    2013-03-01

    Full Text Available O6-methylguanine-DNA methyltransferase (MGMT is the DNA repair enzyme responsible for removing of alkylation adducts from the O6-guanine in DNA. Despite MGMT prevents mutations and cell death, this enzyme can provide resistance of cancer cells to alkylating agents of chemotherapy. The high intra- and inter-individual variations in the human MGMT expression level have been observed indicating to a complicated regulation of this gene. This review is focused on the study of epigenetic factors which could be potentially involved in regulation of the human MGMT gene expression. These include chromatin remodeling via histone modifications and DNA methylation of promoter region and gene body, as well as RNA-based mechanisms, alternative splicing, protein post- translational modifications, and other.

  8. Regulation of the Hippo Pathway Transcription Factor TEAD.

    Science.gov (United States)

    Lin, Kimberly C; Park, Hyun Woo; Guan, Kun-Liang

    2017-09-27

    The TEAD transcription factor family is best known for transcriptional output of the Hippo signaling pathway and has been implicated in processes such as development, cell growth and proliferation, tissue homeostasis, and regeneration. Our understanding of the functional importance of TEADs has increased dramatically since its initial discovery three decades ago. The majority of our knowledge of TEADs is in the context of Hippo signaling as nuclear DNA-binding proteins passively activated by Yes-associated protein (YAP) and transcriptional activator with PDZ-binding domain (TAZ), transcription coactivators downstream of the Hippo pathway. However, recent studies suggest that TEAD itself is actively regulated. Here, we highlight evidence demonstrating Hippo-independent regulation of TEADs and the potential impacts these studies may have on new cancer therapeutics. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Regulation of Memory Formation by the Transcription Factor XBP1.

    Science.gov (United States)

    Martínez, Gabriela; Vidal, René L; Mardones, Pablo; Serrano, Felipe G; Ardiles, Alvaro O; Wirth, Craig; Valdés, Pamela; Thielen, Peter; Schneider, Bernard L; Kerr, Bredford; Valdés, Jose L; Palacios, Adrian G; Inestrosa, Nibaldo C; Glimcher, Laurie H; Hetz, Claudio

    2016-02-16

    Contextual memory formation relies on the induction of new genes in the hippocampus. A polymorphism in the promoter of the transcription factor XBP1 was identified as a risk factor for Alzheimer's disease and bipolar disorders. XBP1 is a major regulator of the unfolded protein response (UPR), mediating adaptation to endoplasmic reticulum (ER) stress. Using a phenotypic screen, we uncovered an unexpected function of XBP1 in cognition and behavior. Mice lacking XBP1 in the nervous system showed specific impairment of contextual memory formation and long-term potentiation (LTP), whereas neuronal XBP1s overexpression improved performance in memory tasks. Gene expression analysis revealed that XBP1 regulates a group of memory-related genes, highlighting brain-derived neurotrophic factor (BDNF), a key component in memory consolidation. Overexpression of BDNF in the hippocampus reversed the XBP1-deficient phenotype. Our study revealed an unanticipated function of XBP1 in cognitive processes that is apparently unrelated to its role in ER stress. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  10. Regulation of Memory Formation by the Transcription Factor XBP1

    Directory of Open Access Journals (Sweden)

    Gabriela Martínez

    2016-02-01

    Full Text Available Contextual memory formation relies on the induction of new genes in the hippocampus. A polymorphism in the promoter of the transcription factor XBP1 was identified as a risk factor for Alzheimer’s disease and bipolar disorders. XBP1 is a major regulator of the unfolded protein response (UPR, mediating adaptation to endoplasmic reticulum (ER stress. Using a phenotypic screen, we uncovered an unexpected function of XBP1 in cognition and behavior. Mice lacking XBP1 in the nervous system showed specific impairment of contextual memory formation and long-term potentiation (LTP, whereas neuronal XBP1s overexpression improved performance in memory tasks. Gene expression analysis revealed that XBP1 regulates a group of memory-related genes, highlighting brain-derived neurotrophic factor (BDNF, a key component in memory consolidation. Overexpression of BDNF in the hippocampus reversed the XBP1-deficient phenotype. Our study revealed an unanticipated function of XBP1 in cognitive processes that is apparently unrelated to its role in ER stress.

  11. Hydrogen peroxide sensing, signaling and regulation of transcription factors

    Directory of Open Access Journals (Sweden)

    H. Susana Marinho

    2014-01-01

    Full Text Available The regulatory mechanisms by which hydrogen peroxide (H2O2 modulates the activity of transcription factors in bacteria (OxyR and PerR, lower eukaryotes (Yap1, Maf1, Hsf1 and Msn2/4 and mammalian cells (AP-1, NRF2, CREB, HSF1, HIF-1, TP53, NF-κB, NOTCH, SP1 and SCREB-1 are reviewed. The complexity of regulatory networks increases throughout the phylogenetic tree, reaching a high level of complexity in mammalians. Multiple H2O2 sensors and pathways are triggered converging in the regulation of transcription factors at several levels: (1 synthesis of the transcription factor by upregulating transcription or increasing both mRNA stability and translation; (ii stability of the transcription factor by decreasing its association with the ubiquitin E3 ligase complex or by inhibiting this complex; (iii cytoplasm–nuclear traffic by exposing/masking nuclear localization signals, or by releasing the transcription factor from partners or from membrane anchors; and (iv DNA binding and nuclear transactivation by modulating transcription factor affinity towards DNA, co-activators or repressors, and by targeting specific regions of chromatin to activate individual genes. We also discuss how H2O2 biological specificity results from diverse thiol protein sensors, with different reactivity of their sulfhydryl groups towards H2O2, being activated by different concentrations and times of exposure to H2O2. The specific regulation of local H2O2 concentrations is also crucial and results from H2O2 localized production and removal controlled by signals. Finally, we formulate equations to extract from typical experiments quantitative data concerning H2O2 reactivity with sensor molecules. Rate constants of 140 M−1 s−1 and ≥1.3 × 103 M−1 s−1 were estimated, respectively, for the reaction of H2O2 with KEAP1 and with an unknown target that mediates NRF2 protein synthesis. In conclusion, the multitude of H2O2 targets and mechanisms provides an opportunity for

  12. Regulation of cardiac microRNAs by serum response factor

    Directory of Open Access Journals (Sweden)

    Wei Jeanne Y

    2011-02-01

    Full Text Available Abstract Serum response factor (SRF regulates certain microRNAs that play a role in cardiac and skeletal muscle development. However, the role of SRF in the regulation of microRNA expression and microRNA biogenesis in cardiac hypertrophy has not been well established. In this report, we employed two distinct transgenic mouse models to study the impact of SRF on cardiac microRNA expression and microRNA biogenesis. Cardiac-specific overexpression of SRF (SRF-Tg led to altered expression of a number of microRNAs. Interestingly, downregulation of miR-1, miR-133a and upregulation of miR-21 occurred by 7 days of age in these mice, long before the onset of cardiac hypertrophy, suggesting that SRF overexpression impacted the expression of microRNAs which contribute to cardiac hypertrophy. Reducing cardiac SRF level using the antisense-SRF transgenic approach (Anti-SRF-Tg resulted in the expression of miR-1, miR-133a and miR-21 in the opposite direction. Furthermore, we observed that SRF regulates microRNA biogenesis, specifically the transcription of pri-microRNA, thereby affecting the mature microRNA level. The mir-21 promoter sequence is conserved among mouse, rat and human; one SRF binding site was found to be in the mir-21 proximal promoter region of all three species. The mir-21 gene is regulated by SRF and its cofactors, including myocardin and p49/Strap. Our study demonstrates that the downregulation of miR-1, miR-133a, and upregulation of miR-21 can be reversed by one single upstream regulator, SRF. These results may help to develop novel therapeutic interventions targeting microRNA biogenesis.

  13. The molecular clock regulates circadian transcription of tissue factor gene.

    Science.gov (United States)

    Oishi, Katsutaka; Koyanagi, Satoru; Ohkura, Naoki

    2013-02-01

    Tissue factor (TF) is involved in endotoxin-induced inflammation and mortality. We found that the circadian expression of TF mRNA, which peaked at the day to night transition (activity onset), was damped in the liver of Clock mutant mice. Luciferase reporter and chromatin immunoprecipitation analyses using embryonic fibroblasts derived from wild-type or Clock mutant mice showed that CLOCK is involved in transcription of the TF gene. Furthermore, the results of real-time luciferase reporter experiments revealed that the circadian expression of TF mRNA is regulated by clock molecules through a cell-autonomous mechanism via an E-box element located in the promoter region.

  14. Transcription factors regulating B cell fate in the germinal centre.

    Science.gov (United States)

    Recaldin, T; Fear, D J

    2016-01-01

    Diversification of the antibody repertoire is essential for the normal operation of the vertebrate adaptive immune system. Following antigen encounter, B cells are activated, proliferate rapidly and undergo two diversification events; somatic hypermutation (followed by selection), which enhances the affinity of the antibody for its cognate antigen, and class-switch recombination, which alters the effector functions of the antibody to adapt the response to the challenge faced. B cells must then differentiate into antibody-secreting plasma cells or long-lived memory B cells. These activities take place in specialized immunological environments called germinal centres, usually located in the secondary lymphoid organs. To complete the germinal centre activities successfully, a B cell adopts a transcriptional programme that allows it to migrate to specific sites within the germinal centre, proliferate, modify its DNA recombination and repair pathways, alter its apoptotic potential and finally undergo terminal differentiation. To co-ordinate these processes, B cells employ a number of 'master regulator' transcription factors which mediate wholesale transcriptomic changes. These master transcription factors are mutually antagonistic and form a complex regulatory network to maintain distinct gene expression programs. Within this network, multiple points of positive and negative feedback ensure the expression of the 'master regulators', augmented by a number of 'secondary' factors that reinforce these networks and sense the progress of the immune response. In this review we will discuss the different activities B cells must undertake to mount a successful T cell-dependent immune response and describe how a regulatory network of transcription factors controls these processes.

  15. Regulation of gonadotropins by corticotropin-releasing factor and urocortin

    Directory of Open Access Journals (Sweden)

    Kazunori eKageyama

    2013-02-01

    Full Text Available While stress activates the hypothalamic-pituitary-adrenal (HPA axis, it suppresses the hypothalamic-pituitary-gonadal (HPG axis. Corticotropin-releasing factor (CRF is a major regulatory peptide in the HPA axis during stress. Urocortin1 (Ucn1, a member of the CRF family of peptides, has a variety of physiological functions and both CRF and Ucn1 contribute to the stress response via G protein-coupled seven transmembrane receptors. Ucn2 and Ucn3, which belong to a separate paralogous lineage from CRF, are highly selective for the CRF type 2 receptor (CRF2 receptor. The HPA and HPG axes interact with each other, and gonadal function and reproduction are suppressed in response to various stressors. In this review, we focus on the regulation of gonadotropins by CRF and Ucn2 in pituitary gonadotrophs and of gonadotropin-releasing hormone (GnRH via CRF receptors in the hypothalamus. In corticotrophs, stress-induced increases in CRF stimulate Ucn2 production, which leads to the inhibition of gonadotropin secretion via the CRF2 receptor in the pituitary. GnRH in the hypothalamus is regulated by a variety of stress conditions. CRF is also involved in the suppression of the HPG axis, especially the GnRH pulse generator, via CRF receptors in the hypothalamus. Thus, complicated regulation of GnRH in the hypothalamus and gonadotropins in the pituitary via CRF receptors contributes to stress responses and adaptation of gonadal functions.

  16. Fibroblast Growth Factor 21 Mediates Glycemic Regulation by Hepatic JNK

    Directory of Open Access Journals (Sweden)

    Santiago Vernia

    2016-03-01

    Full Text Available The cJun NH2-terminal kinase (JNK-signaling pathway is implicated in metabolic syndrome, including dysregulated blood glucose concentration and insulin resistance. Fibroblast growth factor 21 (FGF21 is a target of the hepatic JNK-signaling pathway and may contribute to the regulation of glycemia. To test the role of FGF21, we established mice with selective ablation of the Fgf21 gene in hepatocytes. FGF21 deficiency in the liver caused marked loss of FGF21 protein circulating in the blood. Moreover, the protective effects of hepatic JNK deficiency to suppress metabolic syndrome in high-fat diet-fed mice were not observed in mice with hepatocyte-specific FGF21 deficiency, including reduced blood glucose concentration and reduced intolerance to glucose and insulin. Furthermore, we show that JNK contributes to the regulation of hepatic FGF21 expression during fasting/feeding cycles. These data demonstrate that the hepatokine FGF21 is a key mediator of JNK-regulated metabolic syndrome.

  17. Regulation of the fetal hemoglobin silencing factor BCL11A

    Science.gov (United States)

    Basak, Anindita; Sankaran, Vijay G.

    2016-01-01

    The clinical severity of sickle cell disease and β-thalassemia, the major disorders of β-globin, can be ameliorated by increased production of fetal hemoglobin (HbF). Here, we provide a brief overview of the fetal-to-adult hemoglobin switch that occurs in humans shortly after birth and review our current understanding of one of the most potent known regulators of this switching process, the multiple zinc finger–containing transcription factor BCL11A. Originally identified in genome-wide association studies, multiple orthogonal lines of evidence have validated BCL11A as a key regulator of hemoglobin switching and as a promising therapeutic target for HbF induction. We discuss recent studies that have highlighted its importance in silencing the HbF-encoding genes and discuss opportunities that exist to further understand the regulation of BCL11A and its mechanism of action, which could provide new insight into opportunities to induce HbF for therapeutic purposes. PMID:26963603

  18. Thyroid hormones regulate fibroblast growth factor receptor signaling during chondrogenesis.

    Science.gov (United States)

    Barnard, Joanna C; Williams, Allan J; Rabier, Bénédicte; Chassande, Olivier; Samarut, Jacques; Cheng, Sheue-Yann; Bassett, J H Duncan; Williams, Graham R

    2005-12-01

    Childhood hypothyroidism causes growth arrest with delayed ossification and growth-plate dysgenesis, whereas thyrotoxicosis accelerates ossification and growth. Thyroid hormone (T(3)) regulates chondrocyte proliferation and is essential for hypertrophic differentiation. Fibroblast growth factors (FGFs) are also important regulators of chondrocyte proliferation and differentiation, and activating mutations of FGF receptor-3 (FGFR3) cause achondroplasia. We investigated the hypothesis that T(3) regulates chondrogenesis via FGFR3 in ATDC5 cells, which undergo a defined program of chondrogenesis. ATDC5 cells expressed two FGFR1, four FGFR2, and one FGFR3 mRNA splice variants throughout chondrogenesis, and expression of each isoform was stimulated by T(3) during the first 6-12 d of culture, when T(3) inhibited proliferation by 50%. FGFR3 expression was also increased in cells treated with T(3) for 21 d, when T(3) induced an earlier onset of hypertrophic differentiation and collagen X expression. FGFR3 expression was reduced in growth plates from T(3) receptor alpha-null mice, which exhibit skeletal hypothyroidism, but was increased in T(3) receptor beta(PV/PV) mice, which display skeletal thyrotoxicosis. These findings indicate that FGFR3 is a T(3)-target gene in chondrocytes. In further experiments, T(3) enhanced FGF2 and FGF18 activation of the MAPK-signaling pathway but inhibited their activation of signal transducer and activator of transcription-1. FGF9 did not activate MAPK or signal transducer and activator of transcription-1 pathways in the absence or presence of T(3). Thus, T(3) exerted differing effects on FGFR activation during chondrogenesis depending on which FGF ligand stimulated the FGFR and which downstream signaling pathway was activated. These studies identify novel interactions between T(3) and FGFs that regulate chondrocyte proliferation and differentiation during chondrogenesis.

  19. Contribution of thermal and nonthermal factors to the regulation of body temperature in humans

    National Research Council Canada - National Science Library

    Igor B. Mekjavic; Ola Eiken

    2006-01-01

    .... This reciprocal inhibition theory, presumably reflecting the manner in which thermal factors contribute to homeothermy in humans, does not incorporate the effect of nonthermal factors on temperature regulation...

  20. A new FACS approach isolates hESC derived endoderm using transcription factors.

    Directory of Open Access Journals (Sweden)

    Yuqiong Pan

    Full Text Available We show that high quality microarray gene expression profiles can be obtained following FACS sorting of cells using combinations of transcription factors. We use this transcription factor FACS (tfFACS methodology to perform a genomic analysis of hESC-derived endodermal lineages marked by combinations of SOX17, GATA4, and CXCR4, and find that triple positive cells have a much stronger definitive endoderm signature than other combinations of these markers. Additionally, SOX17(+ GATA4(+ cells can be obtained at a much earlier stage of differentiation, prior to expression of CXCR4(+ cells, providing an important new tool to isolate this earlier definitive endoderm subtype. Overall, tfFACS represents an advancement in FACS technology which broadly crosses multiple disciplines, most notably in regenerative medicine to redefine cellular populations.

  1. Interplay of mitochondria apoptosis regulatory factors and microRNAs in valvular heart disease.

    Science.gov (United States)

    Jan, Muhammad Ishtiaq; Khan, Riaz Anwar; Ali, Tahir; Bilal, Muhammad; Bo, Long; Sajid, Abdul; Malik, Abdul; Urehman, Naseeb; Waseem, Nayyar; Nawab, Javed; Ali, Murad; Majeed, Abdul; Ahmad, Hamid; Aslam, Sohail; Hamera, Sadia; Sultan, Aneesa; Anees, Mariam; Javed, Qamar; Murtaza, Iram

    2017-09-06

    Valvular heart disease (VHD) is an active process involving a wide range of pathological changes. The major complications of VHD are stenosis and regurgitation, which are macroscopic phenomena, induced in part through cellular changes. Altered expression of mitochondria associated genes causes membrane potential depolarization, leading to the increased levels of apoptosis observed in cardiac dysfunction. Objective of this study is to find molecular medicine candidates that can control expression of the key mitochondria apoptosis regulatory genes. Present study aims to assess the way microRNA are involved in regulating mitochondrial apoptosis regulatory genes and observation of their expression in the heart valve dysfunction. Apoptotic genes PUMA and DRP1 were found to be highly expressed, whereas anti-apoptotic gene ARC was down regulated. The expression level of GATA-4 transcription factor was also reduced in cardiac valve tissues. MicroRNAs miR-15a and miR-29a were repressed, while miR-214 was up regulated. Furthermore, study showed that PUMA, DRP1 and ARC expression might be attenuated by their respective miRNAs. Our results indicate that mitochondria regulatory genes might be controlled by miR-15a, miR-29a and miR-214, in VHD patients. Present study may provide platform for future research regarding potential therapeutic role of miRNAs in CVDs. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Activating transcription factor 4 regulates osteoclast differentiation in mice

    Science.gov (United States)

    Cao, Huiling; Yu, Shibing; Yao, Zhi; Galson, Deborah L.; Jiang, Yu; Zhang, Xiaoyan; Fan, Jie; Lu, Binfeng; Guan, Youfei; Luo, Min; Lai, Yumei; Zhu, Yibei; Kurihara, Noriyoshi; Patrene, Kenneth; Roodman, G. David; Xiao, Guozhi

    2010-01-01

    Activating transcription factor 4 (ATF4) is a critical transcription factor for osteoblast (OBL) function and bone formation; however, a direct role in osteoclasts (OCLs) has not been established. Here, we targeted expression of ATF4 to the OCL lineage using the Trap promoter or through deletion of Atf4 in mice. OCL differentiation was drastically decreased in Atf4–/– bone marrow monocyte (BMM) cultures and bones. Coculture of Atf4–/– BMMs with WT OBLs or a high concentration of RANKL failed to restore the OCL differentiation defect. Conversely, Trap-Atf4-tg mice displayed severe osteopenia with dramatically increased osteoclastogenesis and bone resorption. We further showed that ATF4 was an upstream activator of the critical transcription factor Nfatc1 and was critical for RANKL activation of multiple MAPK pathways in OCL progenitors. Furthermore, ATF4 was crucial for M-CSF induction of RANK expression on BMMs, and lack of ATF4 caused a shift in OCL precursors to macrophages. Finally, ATF4 was largely modulated by M-CSF signaling and the PI3K/AKT pathways in BMMs. These results demonstrate that ATF4 plays a direct role in regulating OCL differentiation and suggest that it may be a therapeutic target for treating bone diseases associated with increased OCL activity. PMID:20628199

  3. Myeloid Colony Stimulating Factors as Regulators of Macrophage Polarization

    Directory of Open Access Journals (Sweden)

    Thomas A Hamilton

    2014-11-01

    Full Text Available The scope of functional heterogeneity in macrophages has been defined by two polarized end states known as M1 and M2, which exhibit the pro-inflammatory activities necessary for host defense and the tissue repair activities required for tissue repair respectively. Macrophage populations in different tissue locations exist in distinct phenotypic states across this M1/M2 spectrum and the development and abundance of individual subsets result from the local and systemic action of myeloid colony stimulating factors (CSFs including M-CSF and GM-CSF. These factors have relatively non-overlapping roles in the differentiation and maintenance of specific macrophage subsets. Furthermore there is now evidence that CSFs may also regulate macrophage phenotype during challenge. Cell culture studies from multiple laboratories demonstrate that macrophages developed in the presence of GM-CSF exhibit amplified response to M1 polarizing stimuli while M-CSF potentiates responses to M2 stimuli. As a consequence these factors can be important determinants of the magnitude and duration of both acute and chronic inflammatory pathology and may, therefore, be potential targets for therapeutic manipulation in specific human disease settings.

  4. Activating transcription factor 4 regulates osteoclast differentiation in mice.

    Science.gov (United States)

    Cao, Huiling; Yu, Shibing; Yao, Zhi; Galson, Deborah L; Jiang, Yu; Zhang, Xiaoyan; Fan, Jie; Lu, Binfeng; Guan, Youfei; Luo, Min; Lai, Yumei; Zhu, Yibei; Kurihara, Noriyoshi; Patrene, Kenneth; Roodman, G David; Xiao, Guozhi

    2010-08-01

    Activating transcription factor 4 (ATF4) is a critical transcription factor for osteoblast (OBL) function and bone formation; however, a direct role in osteoclasts (OCLs) has not been established. Here, we targeted expression of ATF4 to the OCL lineage using the Trap promoter or through deletion of Atf4 in mice. OCL differentiation was drastically decreased in Atf4-/- bone marrow monocyte (BMM) cultures and bones. Coculture of Atf4-/- BMMs with WT OBLs or a high concentration of RANKL failed to restore the OCL differentiation defect. Conversely, Trap-Atf4-tg mice displayed severe osteopenia with dramatically increased osteoclastogenesis and bone resorption. We further showed that ATF4 was an upstream activator of the critical transcription factor Nfatc1 and was critical for RANKL activation of multiple MAPK pathways in OCL progenitors. Furthermore, ATF4 was crucial for M-CSF induction of RANK expression on BMMs, and lack of ATF4 caused a shift in OCL precursors to macrophages. Finally, ATF4 was largely modulated by M-CSF signaling and the PI3K/AKT pathways in BMMs. These results demonstrate that ATF4 plays a direct role in regulating OCL differentiation and suggest that it may be a therapeutic target for treating bone diseases associated with increased OCL activity.

  5. Tumor necrosis factor receptor-associated factor 3 is a positive regulator of pathological cardiac hypertrophy.

    Science.gov (United States)

    Jiang, Xi; Deng, Ke-Qiong; Luo, Yuxuan; Jiang, Ding-Sheng; Gao, Lu; Zhang, Xiao-Fei; Zhang, Peng; Zhao, Guang-Nian; Zhu, Xueyong; Li, Hongliang

    2015-08-01

    Cardiac hypertrophy, a common early symptom of heart failure, is regulated by numerous signaling pathways. Here, we identified tumor necrosis factor receptor-associated factor 3 (TRAF3), an adaptor protein in tumor necrosis factor-related signaling cascades, as a key regulator of cardiac hypertrophy in response to pressure overload. TRAF3 expression was upregulated in hypertrophied mice hearts and failing human hearts. Four weeks after aortic banding, cardiac-specific conditional TRAF3-knockout mice exhibited significantly reduced cardiac hypertrophy, fibrosis, and dysfunction. Conversely, transgenic mice overexpressing TRAF3 in the heart developed exaggerated cardiac hypertrophy in response to pressure overload. TRAF3 also promoted an angiotensin II- or phenylephrine-induced hypertrophic response in isolated cardiomyocytes. Mechanistically, TRAF3 directly bound to TANK-binding kinase 1 (TBK1), causing increased TBK1 phosphorylation in response to hypertrophic stimuli. This interaction between TRAF3 and TBK1 further activated AKT signaling, which ultimately promoted the development of cardiac hypertrophy. Our findings not only reveal a key role of TRAF3 in regulating the hypertrophic response but also uncover TRAF3-TBK1-AKT as a novel signaling pathway in the development of cardiac hypertrophy and heart failure. This pathway may represent a potential therapeutic target for this pathological process.

  6. Regulation of stem cell factor expression in inflammation and asthma

    Directory of Open Access Journals (Sweden)

    Carla A Da Silva

    2005-03-01

    Full Text Available Stem cell factor (SCF is a major mast cell growth factor, which could be involved in the local increase of mast cell number in the asthmatic airways. In vivo, SCF expression increases in asthmatic patients and this is reversed after treatment with glucocorticoids. In vitro in human lung fibroblasts in culture, IL-1beta, a pro-inflammatory cytokine, confirms this increased SCF mRNA and protein expression implying the MAP kinases p38 and ERK1/2 very early post-treatment, and glucocorticoids confirm this decrease. Surprisingly, glucocorticoids potentiate the IL-1beta-enhanced SCF expression at short term treatment, implying increased SCF mRNA stability and SCF gene transcription rate. This potentiation involves p38 and ERK1/2. Transfection experiments with the SCF promoter including intron1 also confirm this increase and decrease of SCF expression by IL-1beta and glucocorticoids, and the potentiation by glucocorticoids of the IL-1beta-induced SCF expression. Deletion of the GRE or kappaB sites abolishes this potentiation, and the effect of IL-1beta or glucocorticoids alone. DNA binding of GR and NF-kappaB are also demonstrated for these effects. In conclusion, this review concerns new mechanisms of regulation of SCF expression in inflammation that could lead to potential therapeutic strategy allowing to control mast cell number in the asthmatic airways.

  7. Retinoic acid regulates the expression of photoreceptor transcription factor NRL.

    Science.gov (United States)

    Khanna, Hemant; Akimoto, Masayuki; Siffroi-Fernandez, Sandrine; Friedman, James S; Hicks, David; Swaroop, Anand

    2006-09-15

    NRL (neural retina leucine zipper) is a key basic motif-leucine zipper (bZIP) transcription factor, which orchestrates rod photoreceptor differentiation by activating the expression of rod-specific genes. The deletion of Nrl in mice results in functional cones that are derived from rod precursors. However, signaling pathways modulating the expression or activity of NRL have not been elucidated. Here, we show that retinoic acid (RA), a diffusible factor implicated in rod development, activates the expression of NRL in serum-deprived Y79 human retinoblastoma cells and in primary cultures of rat and porcine photoreceptors. The effect of RA is mimicked by TTNPB, a RA receptor agonist, and requires new protein synthesis. DNaseI footprinting and electrophoretic mobility shift assays (EMSA) using bovine retinal nuclear extract demonstrate that RA response elements (RAREs) identified within the Nrl promoter bind to RA receptors. Furthermore, in transiently transfected Y79 and HEK293 cells the activity of Nrl-promoter driving a luciferase reporter gene is induced by RA, and this activation is mediated by RAREs. Our data suggest that signaling by RA via RA receptors regulates the expression of NRL, providing a framework for delineating early steps in photoreceptor cell fate determination.

  8. An EJC factor RBM8a regulates anxiety behaviors.

    Science.gov (United States)

    Alachkar, A; Jiang, D; Harrison, M; Zhou, Y; Chen, G; Mao, Y

    2013-07-01

    Neuroplasticity depends on the precise timing of gene expression, which requires accurate control of mRNA stability and rapid elimination of abnormal mRNA. Nonsense-mediated mRNA decay (NMD) is an RNA surveillance mechanism that ensures the speedy degradation of mRNAs carrying premature termination codons (PTCs). This mechanism relies on several key Exon Junction Complex (EJC) factors to distinguish PTCs from normal stop codons. NMD degrades not only aberrant transcripts carrying PTCs, but also normal transcripts harboring a normal stop codon [1]. Intriguingly, mutations in an NMD factor, Upf3b, have been found in patients with autism [2, 3]. A binding partner of Upf3b, RBM8a, is located in the 1q21.1 copy-number variation (CNV) associated with mental retardation, autism [4], schizophrenia [5], and microcephaly [6]. However, the functions of EJC factors and their roles in behavioral regulation are still elusive. RBM8a protein is a core component of the EJC that plays an important role in NMD. Recent genetic study indicated that RBM8a gain-of-function significantly associated with intellectual disability [7]. In this study we investigated the effect of RBM8a overexpression on affective behaviors in mice. Lentivirus expressing RBM8a was infused into the hippocampus of adult mice to conduct behavioral studies including social interaction, open field, elevated plus maze, and forced swimming tests. Our results showed that overexpression of RBM8a in the mouse dentate gyrus (DG) leads to increased anxiety-like behavior, abnormal social interaction and decreased immobile time in forced swimming test (FST). To examine the underlying mechanism, we found that overexpressing RBM8a in cultured primary neurons lead to significant higher frequency of miniature excitatory postsynaptic currents (mEPSCs). To explore the underlying mechanism of RBM8a mediated behavioral changes, RNA-immunoprecipitation (RNA-IP) detected that RBM8a binds to CaMK2, GluR1 and Egr1 mRNA, suggesting that

  9. From tyrosine to melanin: Signaling pathways and factors regulating melanogenesis

    Directory of Open Access Journals (Sweden)

    Zuzanna Rzepka

    2016-06-01

    Full Text Available Melanins are natural pigments of skin, hair and eyes and can be classified into two main types: brown to black eumelanin and yellow to reddish-brown pheomelanin. Biosynthesis of melanins takes place in melanosomes, which are specialized cytoplasmic organelles of melanocytes - dendritic cells located in the basal layer of the epidermis, uveal tract of the eye, hair follicles, as well as in the inner ear, central nervous system and heart. Melanogenesis is a multistep process and begins with the conversion of amino acid L-tyrosine to DOPAquinone. The addition of cysteine or glutathione to DOPAquinone leads to the intermediates formation, followed by subsequent transformations and polymerization to the final product, pheomelanin. In the absence of thiol compounds DOPAquinone undergoes an intramolecular cyclization and oxidation to form DOPAchrome, which is then converted to 5,6-dihydroksyindole (DHI or 5,6-dihydroxyindole-2-carboxylic acid (DHICA. Eumelanin is formed by polymerization of DHI and DHICA and their quinones. Regulation of melanogenesis is achieved by physical and biochemical factors. The article presents the intracellular signaling pathways: cAMP/PKA/CREB/MITF cascade, MAP kinases cascade, PLC/DAG/PKCβ cascade and NO/cGMP/PKG cascade, which are involved in the regulation of expression and activity of the melanogenesis-related proteins by ultraviolet radiation and endogenous agents (cytokines, hormones. Activity of the key melanogenic enzyme, tyrosinase, is also affected by pH and temperature. Many pharmacologically active substances are able to inhibit or stimulate melanin biosynthesis, as evidenced by in vitro studies on cultured pigment cells.

  10. Norepinephrine Regulates Condylar Bone Loss via Comorbid Factors.

    Science.gov (United States)

    Jiao, K; Niu, L; Xu, X; Liu, Y; Li, X; Tay, F R; Wang, M

    2015-06-01

    Degenerative changes of condylar subchondral bone occur frequently in temporomandibular disorders. Although psychologic stresses and occlusal abnormalities have been implicated in temporomandibular disorder, it is not known if these risks represent synergistic comorbid factors that are involved in condylar subchondral bone degradation that is regulated by the sympathetic nervous system. In the present study, chronic immobilization stress (CIS), chemical sympathectomy, and unilateral anterior crossbite (UAC) were sequentially applied in a murine model. Norepinephrine contents in the subjects' serum and condylar subchondral bone were detected by ELISA; bone and cartilage remodeling parameters and related gene expression in the subchondral bone were examined. Subchondral bone loss and increased subchondral bone norepinephrine level were observed in the CIS and UAC groups. These groups exhibited decreased bone mineral density, volume fraction, and bone formation rate; decreased expressions of osterix, collagen I, and osteocalcin; but increased trabecular separation, osteoclast number and surface, and RANKL expression. Combined CIS + UAC produced more severe subchondral bone loss, higher bone norepinephrine level, and decreased chondrocyte density and cartilage thickness when compared to CIS or UAC alone. Sympathectomy simultaneously prevented subchondral bone loss and decreased bone norepinephrine level in all experimental subgroups when compared to the vehicle-treated counterparts. Norepinephrine also decreased mRNA expression of osterix, collagen I, and osteocalcin by mesenchymal stem cells at 7 and 14 d of stimulation and increased the expression of RANKL and RANKL/OPG ratio by mesenchymal stem cells at 2 h. In conclusion, CIS and UAC synergistically promote condylar subchondral bone loss and cartilage degradation; such processes are partially regulated by norepinephrine within subchondral bone.

  11. Kruppel-like factor 2 is required for normal mouse cardiac development.

    Directory of Open Access Journals (Sweden)

    Aditi R Chiplunkar

    Full Text Available Krüppel-like factor 2 (KLF2 is expressed in endothelial cells in the developing heart, particularly in areas of high shear stress, such as the atrioventricular (AV canal. KLF2 ablation leads to myocardial thinning, high output cardiac failure and death by mouse embryonic day 14.5 (E14.5 in a mixed genetic background. This work identifies an earlier and more fundamental role for KLF2 in mouse cardiac development in FVB/N mice. FVB/N KLF2-/- embryos die earlier, by E11.5. E9.5 FVB/N KLF2-/- hearts have multiple, disorganized cell layers lining the AV cushions, the primordia of the AV valves, rather than the normal single layer. By E10.5, traditional and endothelial-specific FVB/N KLF2-/- AV cushions are hypocellular, suggesting that the cells accumulating at the AV canal have a defect in endothelial to mesenchymal transformation (EMT. E10.5 FVB/N KLF2-/- hearts have reduced glycosaminoglycans in the cardiac jelly, correlating with the reduced EMT. However, the number of mesenchymal cells migrating from FVB/N KLF2-/- AV explants into a collagen matrix is reduced considerably compared to wild-type, suggesting that the EMT defect is not due solely to abnormal cardiac jelly. Echocardiography of E10.5 FVB/N KLF2-/- embryos indicates that they have abnormal heart function compared to wild-type. E10.5 C57BL/6 KLF2-/- hearts have largely normal AV cushions. However, E10.5 FVB/N and C57BL/6 KLF2-/- embryos have a delay in the formation of the atrial septum that is not observed in a defined mixed background. KLF2 ablation results in reduced Sox9, UDP-glucose dehydrogenase (Ugdh, Gata4 and Tbx5 mRNA in FVB/N AV canals. KLF2 binds to the Gata4, Tbx5 and Ugdh promoters in chromatin immunoprecipitation assays, indicating that KLF2 could directly regulate these genes. In conclusion, KLF2-/- heart phenotypes are genetic background-dependent. KLF2 plays a role in EMT through its regulation of important cardiovascular genes.

  12. Factors affecting the regulation of pacing: current perspectives

    Directory of Open Access Journals (Sweden)

    Mauger AR

    2014-09-01

    Full Text Available Alexis R Mauger Endurance Research Group, School of Sport and Exercise Sciences, Faculty of Science, University of Kent, Chatham, UK Abstract: During prolonged dynamic and rhythmic exercise, muscular pain and discomfort arises as a result of an increased concentration of deleterious metabolites. Sensed by peripheral nociceptors and transmitted via afferent feedback to the brain, this provides important information regarding the physiological state of the muscle. These sensations ultimately contribute to what is termed "exercise-induced pain". Despite being well recognized by athletes and coaches, and suggested to be integral to exercise performance, this construct has largely escaped attention in experimental work. This perspective article highlights the current understanding of pacing in endurance performance, and the causes of exercise-induced pain. A new perspective is described, which proposes how exercise-induced pain may be a contributing factor in helping individuals to regulate their work rate during exercise and thus provides an important construct in pacing. Keywords: pain, exercise-induced pain, discomfort, exercise performance, self-paced

  13. Forkhead transcription factor foxe1 regulates chondrogenesis in zebrafish.

    Science.gov (United States)

    Nakada, Chisako; Iida, Atsumi; Tabata, Yoko; Watanabe, Sumiko

    2009-12-15

    Forkhead transcription factor (Fox) e1 is a causative gene for Bamforth-Lazarus syndrome, which is characterized by hypothyroidism and cleft palate. Applying degenerate polymerase chain reaction using primers specific for the conserved forkhead domain, we identified zebrafish foxe1 (foxe1). Foxe1 is expressed in the thyroid, pharynx, and pharyngeal skeleton during development; strongly expressed in the gill and weakly expressed in the brain, eye, and heart in adult zebrafish. A loss of function of foxe1 by morpholino antisense oligo (MO) exhibited abnormal craniofacial development, shortening of Meckel's cartilage and the ceratohyals, and suppressed chondrycytic proliferation. However, at 27 hr post fertilization, the foxe1 MO-injected embryos showed normal dlx2, hoxa2, and hoxb2 expression, suggesting that the initial steps of pharyngeal skeletal development, including neural crest migration and specification of the pharyngeal arch occurred normally. In contrast, at 2 dpf, a severe reduction in the expression of sox9a, colIIaI, and runx2b, which play roles in chondrocytic proliferation and differentiation, was observed. Interestingly, fgfr2 was strongly upregulated in the branchial arches of the foxe1 MO-injected embryos. Unlike Foxe1-null mice, normal thyroid development in terms of morphology and thyroid-specific marker expression was observed in foxe1 MO-injected zebrafish embryos. Taken together, our results indicate that Foxe1 plays an important role in chondrogenesis during development of the pharyngeal skeleton in zebrafish, probably through regulation of fgfr2 expression. Furthermore, the roles reported for FOXE1 in mammalian thyroid development may have been acquired during evolution.

  14. Exploring the factors influencing clinical students' self-regulated learning

    NARCIS (Netherlands)

    Berkhout, J.J.; Helmich, E.; Teunissen, P.W.; Berg, J.W. Ten; Vleuten, C.P.M. van der; Jaarsma, A.D.

    2015-01-01

    OBJECTIVES: The importance of self-regulated learning (SRL) has been broadly recognised by medical education institutions and regulatory bodies. Supporting the development of SRL skills has proven difficult because self-regulation is a complex interactive process and we know relatively little about

  15. Exploring the factors influencing clinical students' self-regulated learning

    NARCIS (Netherlands)

    Berkhout, J.J.; Helmich, E.; Teunissen, P.W.; Berg, J.W. Ten; Vleuten, C.P.M. van der; Jaarsma, A.D.

    2015-01-01

    OBJECTIVES: The importance of self-regulated learning (SRL) has been broadly recognised by medical education institutions and regulatory bodies. Supporting the development of SRL skills has proven difficult because self-regulation is a complex interactive process and we know relatively little about

  16. Regulation of growth factor receptor degradation by ADP-ribosylation factor domain protein (ARD) 1.

    Science.gov (United States)

    Meza-Carmen, Victor; Pacheco-Rodriguez, Gustavo; Kang, Gi Soo; Kato, Jiro; Donati, Chiara; Zhang, Chun-Yi; Vichi, Alessandro; Payne, D Michael; El-Chemaly, Souheil; Stylianou, Mario; Moss, Joel; Vaughan, Martha

    2011-06-28

    ADP-ribosylation factor domain protein 1 (ARD1) is a 64-kDa protein containing a functional ADP-ribosylation factor (GTP hydrolase, GTPase), GTPase-activating protein, and E3 ubiquitin ligase domains. ARD1 activation by the guanine nucleotide-exchange factor cytohesin-1 was known. GTPase and E3 ligase activities of ARD1 suggest roles in protein transport and turnover. To explore this hypothesis, we used mouse embryo fibroblasts (MEFs) from ARD1-/- mice stably transfected with plasmids for inducible expression of wild-type ARD1 protein (KO-WT), or ARD1 protein with inactivating mutations in E3 ligase domain (KO-E3), or containing persistently active GTP-bound (KO-GTP), or inactive GDP-bound (KO-GDP) GTPase domains. Inhibition of proteasomal proteases in mifepristone-induced KO-WT, KO-GDP, or KO-GTP MEFs resulted in accumulation of these ARD1 proteins, whereas KO-E3 accumulated without inhibitors. All data were consistent with the conclusion that ARD1 regulates its own steady-state levels in cells by autoubiquitination. Based on reported growth factor receptor-cytohesin interactions, EGF receptor (EGFR) was investigated in induced MEFs. Amounts of cell-surface and total EGFR were higher in KO-GDP and lower in KO-GTP than in KO-WT MEFs, with levels in both mutants greater (p = 0.001) after proteasomal inhibition. Significant differences among MEF lines in content of TGF-β receptor III were similar to those in EGFR, albeit not as large. Differences in amounts of insulin receptor mirrored those in EGFR, but did not reach statistical significance. Overall, the capacity of ARD1 GTPase to cycle between active and inactive forms and its autoubiquitination both appear to be necessary for the appropriate turnover of EGFR and perhaps additional growth factor receptors.

  17. SCN5A variant that blocks fibroblast growth factor homologous factor regulation causes human arrhythmia

    Science.gov (United States)

    Musa, Hassan; Kline, Crystal F.; Sturm, Amy C.; Murphy, Nathaniel; Adelman, Sara; Wang, Chaojian; Yan, Haidun; Johnson, Benjamin L.; Csepe, Thomas A.; Kilic, Ahmet; Higgins, Robert S. D.; Janssen, Paul M. L.; Fedorov, Vadim V.; Weiss, Raul; Salazar, Christina; Hund, Thomas J.; Pitt, Geoffrey S.; Mohler, Peter J.

    2015-01-01

    Nav channels are essential for metazoan membrane depolarization, and Nav channel dysfunction is directly linked with epilepsy, ataxia, pain, arrhythmia, myotonia, and irritable bowel syndrome. Human Nav channelopathies are primarily caused by variants that directly affect Nav channel permeability or gating. However, a new class of human Nav channelopathies has emerged based on channel variants that alter regulation by intracellular signaling or cytoskeletal proteins. Fibroblast growth factor homologous factors (FHFs) are a family of intracellular signaling proteins linked with Nav channel regulation in neurons and myocytes. However, to date, there is surprisingly little evidence linking Nav channel gene variants with FHFs and human disease. Here, we provide, to our knowledge, the first evidence that mutations in SCN5A (encodes primary cardiac Nav channel Nav1.5) that alter FHF binding result in human cardiovascular disease. We describe a five*generation kindred with a history of atrial and ventricular arrhythmias, cardiac arrest, and sudden cardiac death. Affected family members harbor a novel SCN5A variant resulting in p.H1849R. p.H1849R is localized in the central binding core on Nav1.5 for FHFs. Consistent with these data, Nav1.5 p.H1849R affected interaction with FHFs. Further, electrophysiological analysis identified Nav1.5 p.H1849R as a gain-of-function for INa by altering steady-state inactivation and slowing the rate of Nav1.5 inactivation. In line with these data and consistent with human cardiac phenotypes, myocytes expressing Nav1.5 p.H1849R displayed prolonged action potential duration and arrhythmogenic afterdepolarizations. Together, these findings identify a previously unexplored mechanism for human Nav channelopathy based on altered Nav1.5 association with FHF proteins. PMID:26392562

  18. Microbiota regulate intestinal epithelial gene expression by suppressing the transcription factor Hepatocyte nuclear factor 4 alpha

    Science.gov (United States)

    Davison, James M.; Lickwar, Colin R.; Song, Lingyun; Breton, Ghislain; Crawford, Gregory E.; Rawls, John F.

    2017-01-01

    Microbiota influence diverse aspects of intestinal physiology and disease in part by controlling tissue-specific transcription of host genes. However, host genomic mechanisms mediating microbial control of intestinal gene expression are poorly understood. Hepatocyte nuclear factor 4 (HNF4) is the most ancient family of nuclear receptor transcription factors with important roles in human metabolic and inflammatory bowel diseases, but a role in host response to microbes is unknown. Using an unbiased screening strategy, we found that zebrafish Hnf4a specifically binds and activates a microbiota-suppressed intestinal epithelial transcriptional enhancer. Genetic analysis revealed that zebrafish hnf4a activates nearly half of the genes that are suppressed by microbiota, suggesting microbiota negatively regulate Hnf4a. In support, analysis of genomic architecture in mouse intestinal epithelial cells disclosed that microbiota colonization leads to activation or inactivation of hundreds of enhancers along with drastic genome-wide reduction of HNF4A and HNF4G occupancy. Interspecies meta-analysis suggested interactions between HNF4A and microbiota promote gene expression patterns associated with human inflammatory bowel diseases. These results indicate a critical and conserved role for HNF4A in maintaining intestinal homeostasis in response to microbiota. PMID:28385711

  19. ATF2, a paradigm of the multifaceted regulation of transcription factors in biology and disease.

    Science.gov (United States)

    Watson, Gregory; Ronai, Ze'ev; Lau, Eric

    2017-02-15

    Stringent transcriptional regulation is crucial for normal cellular biology and organismal development. Perturbations in the proper regulation of transcription factors can result in numerous pathologies, including cancer. Thus, understanding how transcription factors are regulated and how they are dysregulated in disease states is key to the therapeutic targeting of these factors and/or the pathways that they regulate. Activating transcription factor 2 (ATF2) has been studied in a number of developmental and pathological conditions. Recent findings have shed light on the transcriptional, post-transcriptional, and post-translational regulatory mechanisms that influence ATF2 function, and thus, the transcriptional programs coordinated by ATF2. Given our current knowledge of its multiple levels of regulation and function, ATF2 represents a paradigm for the mechanistic complexity that can regulate transcription factor function. Thus, increasing our understanding of the regulation and function of ATF2 will provide insights into fundamental regulatory mechanisms that influence how cells integrate extracellular and intracellular signals into a genomic response through transcription factors. Characterization of ATF2 dysfunction in the context of pathological conditions, particularly in cancer biology and response to therapy, will be important in understanding how pathways controlled by ATF2 or other transcription factors might be therapeutically exploited. In this review, we provide an overview of the currently known upstream regulators and downstream targets of ATF2.

  20. Identification of Telomerase Components and Telomerase Regulating Factors in Yeast

    Science.gov (United States)

    1998-07-01

    required for telomere function. To further explore the mechanism of telomere replication, I identified CDCl3 and EST2 interacting proteins via yeast two...hybrid screens. Characterization of the EST2 interacting proteins may reveal additional telomerase components or regulators. STNl, a high-copy

  1. Transcription Factor Families Regulate the Anthocyanin Biosynthetic Pathway in Capsicum

    Science.gov (United States)

    Anthocyanin structural gene transcription requires the expression of at least one member of each of three transcription factor families - MYC, MYB and WD40. These transcription factors form a complex that binds to structural gene promoters, thereby modulating gene expression. Capsicum annuum display...

  2. Genome Binding and Gene Regulation by Stem Cell Transcription Factors

    NARCIS (Netherlands)

    J.H. Brandsma (Johan)

    2016-01-01

    markdownabstractNearly all cells of an individual organism contain the same genome. However, each cell type transcribes a different set of genes due to the presence of different sets of cell type-specific transcription factors. Such transcription factors bind to regulatory regions such as promoters

  3. Activation of the control reporter plasmids pRL-TK and pRL-SV40 by multiple GATA transcription factors can lead to aberrant normalization of transfection efficiency

    Directory of Open Access Journals (Sweden)

    Strauss Jerome F

    2004-04-01

    Full Text Available Abstract Background Members of the GATA transcription factor family have been used in many transfection studies to investigate their roles in the regulation of gene expression. To correct for variations in transfection efficiency, the Renilla luciferase encoding plasmids pRL-TK and pRL-SV40 are commonly used as normalization controls. Results We report here that plasmids expressing GATA-4 or GATA-6 transcription factor increased Renilla luciferase gene expression by 2 to 8 fold when co-transfected with pRL-TK or pRL-SV40. This alteration of the control reporter gene activity was shown to cause erroneous normalization of transfection efficiency and thus misinterpretation of results in a transactivation assay. To circumvent the problem, we generated two mutant control plasmids from which putative GATA response elements were deleted. These deletions rendered pRL-SV40 unresponsive to GATA transcription factor stimulation and reduced the response of pRL-TK. A database search also indicates that consensus GATA binding sequences are present in other commercially available Renilla luciferase encoding plasmids; therefore, the latter can potentially be transactivated by GATA transcription factors. Conclusion Taken together, these findings highlight the importance of the selection of an appropriate control reporter plasmid for the normalization of transfection efficiency.

  4. Oxygen Tension Regulates the Expression of Angiogenesis Factor by Macrophages

    Science.gov (United States)

    Knighton, David R.; Hunt, Thomas K.; Scheuenstuhl, Heinz; Halliday, Betty J.; Werb, Zena; Banda, Michael J.

    1983-09-01

    When cultured in a hypoxic environment similar to that found in the center of a wound, macrophages secreted active angiogenesis factor into the medium. Under conditions similar to those of well-oxygenated tissue, macrophages did not secrete active angiogenesis factor. Macrophages that secreted the factor at hypoxic conditions stopped secreting it when returned to room air. Thus the control of angiogenesis in wound healing may be the result of macrophages responding to tissue oxygen tension without the necessity of interacting with other cell types or biochemical signals.

  5. Oxygen tension regulates the expression angiogenesis factor by macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Knighton, D.R.; Hunt, T.K.; Scheuenstuhl, H.; Halliday, B.J.; Werb, Z.; Banda, M.J.

    1983-09-23

    When cultured in a hypoxic environment similar to that found in the center of a wound, macrophages secreted active angiogenesis factor into the medium. Under conditions similar to those of well-oxygenated tissue, macrophages did not secrete active angiogenesis factor. Macrophages that secreted the factor at hyposic conditions stopped secreting it when returned to room air. Thus the control of angiogenesis in wound healing may be the result of macrophages responding to tissue oxygen tension without the necessity of interacting with other cell types or biochemical signals.

  6. Oxygen tension regulated the expression of angiogenesis factor by macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Knighton, D.R.; Hunt, T.K.; Scheuenstuhl, H.; Halliday, B.J.; Werb, Z.; Banda, M.J.

    1983-09-23

    When cultured in a hypoxic environment similar to that found in the center of a wound, macrophages secreted active angiogenesis factor into the medium. Under conditions similar to those of well-oxygenated tissue, macrophages did not secrete active angiogenesis factor. Macrophages that secreted the factor at hypoxic conditions stopped secreting it when returned to room air. Thus the control of angiogenesis in wound healing may be the result of macrophages responding to tissue oxygen tension without the necessity of interacting with other cell types or biochemical signals.

  7. Auxiliary splice factor U2AF26 and transcription factor Gfi1 cooperate directly in regulating CD45 alternative splicing.

    NARCIS (Netherlands)

    Heyd, F.; Dam, G.B. ten; Moroy, T.

    2006-01-01

    By alternative splicing, different isoforms of the transmembrane tyrosine phosphatase CD45 are generated that either enhance or limit T cell receptor signaling. We report here that CD45 alternative splicing is regulated by cooperative action of the splice factor U2AF26 and the transcription factor G

  8. Cardiovascular risk factors regulate the expression of vascular endothelin receptors

    DEFF Research Database (Denmark)

    Xu, Cang-Bao; Sun, Yang; Edvinsson, Lars

    2010-01-01

    , cigarette smoking and hypertension (both strongly related to arterial wall injury), inflammation and atherosclerosis. The vascular endothelin receptors are a protein family that belongs to the larger family of G-protein coupled receptors. They mediate vascular smooth muscle contraction, proliferation......-activated protein kinase pathways and downstream transcription factors such as nuclear factor-kappaB. Understanding the mechanisms involved in vascular endothelin receptor upregulation during cardiovascular disease may provide novel therapeutic approaches....

  9. Lipopolysaccharide and tumor necrosis factor regulate Parkin expression via nuclear factor-kappa B.

    Directory of Open Access Journals (Sweden)

    Thi A Tran

    Full Text Available Inflammation and oxidative stress have been implicated in the pathophysiology of Parkinson's disease (PD and inhibition of microglial activation attenuates degeneration of dopaminergic (DA neurons in animal models of PD. Loss-of-function mutations in the parkin gene, which encodes an E3 ubiquitin ligase, cause autosomal recessive parkinsonism. While most studies on Parkin have focused on its function in neurons, here we demonstrate that Parkin mRNA and protein is detectable in brain-resident microglia and peripheral macrophages. Using pharmacologic and genetic approaches, we found that Parkin levels are regulated by inflammatory signaling. Specifically, exposure to LPS or Tumor Necrosis Factor (TNF induced a transient and dose-dependent decrease in Parkin mRNA and protein in microglia, macrophages and neuronal cells blockable by inhibitors of Nuclear Factor-Kappa B (NF-κB signaling and not observed in MyD88-null cells. Moreover, using luciferase reporter assays, we identified an NF-κB response element in the mouse parkin promoter responsible for mediating the transcriptional repression, which was abrogated when the consensus sequence was mutated. Functionally, activated macrophages from Parkin-null mice displayed increased levels of TNF, IL-1β, and iNOS mRNA compared to wild type macrophages but no difference in levels of Nrf2, HO-1, or NQO1. One implication of our findings is that chronic inflammatory conditions may reduce Parkin levels and phenocopy parkin loss-of-function mutations, thereby increasing the vulnerability for degeneration of the nigrostriatal pathway and development of PD.

  10. Factors Influencing Self-Regulation in E-Learning 2.0: Confirmatory Factor Model

    Science.gov (United States)

    Zhao, Hong

    2016-01-01

    The importance of self-regulation in e-learning has been well noted in research. Relevant studies have shown a consistent positive correlation between learners' self-regulation and their success rate in e-learning. Increasing attention has been paid to developing learners' self-regulated abilities in e-learning. For students, what and how to learn…

  11. Cytokines and growth factors which regulate bone cell function

    Science.gov (United States)

    Seino, Yoshiki

    Everybody knows that growth factors are most important in making bone. Hormones enhance bone formation from a long distance. Growth factors promote bone formation as an autocrine or paracrine factor in nearby bone. BMP-2 through BMP-8 are in the TGF-β family. BMP makes bone by enchondral ossification. In bone, IGF-II is most abundant, second, TGF-β, and third IGF-I. TGF-β enhances bone formation mainly by intramembranous ossification in vivo. TGF-β affects both cell proliferation and differentiation, however, TGF-β mainly enhances bone formation by intramembranous ossification. Interestingly, TGF-β is increased by estrogen(E 2), androgen, vitamin D, TGF-β and FGF. IGF-I and IGF-II also enhance bone formation. At present it remains unclear why IGF-I is more active in bone formation than IGF-II, although IGF-II is more abundant in bone compared to IGF-I. However, if only type I receptor signal transduction promotes bone formation, the strong activity of IGF-I in bone formation is understandable. GH, PTH and E 2 promotes IGF-I production. Recent data suggest that hormones containing vitamin D or E 2 enhance bone formation through growth factors. Therefore, growth factors are the key to clarifying the mechanism of bone formation.

  12. Regulation of mechano growth factor in skeletal muscle and heart

    NARCIS (Netherlands)

    Ottens, M.

    2010-01-01

    The mechano growth factor (MGF) is expressed in mechanically overloaded skeletal muscle. MGF was discovered in 1996 as an alternative splice product of the IGF-1 gene. Since then, its significance has been investigated particularly in skeletal muscle, because the local expression of MGF could

  13. New sides of an old factor: TFIIA : function and regulation

    NARCIS (Netherlands)

    Hoiby, Torill

    2005-01-01

    TFIIA was originally identified as one of the general transcription factors, activating transcription by stabilizing TBP binding to DNA and through functioning as a co-activator and anti-repressor. Its classification as such was recently disputed by observations showing that TFIIA is involved in tra

  14. Regulation of mechano growth factor in skeletal muscle and heart

    NARCIS (Netherlands)

    Ottens, M.

    2010-01-01

    The mechano growth factor (MGF) is expressed in mechanically overloaded skeletal muscle. MGF was discovered in 1996 as an alternative splice product of the IGF-1 gene. Since then, its significance has been investigated particularly in skeletal muscle, because the local expression of MGF could provid

  15. Nrf2 transcription factor gene regulates basal transcription of ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... In contrast, there was no obvious effect on SOD2 in the Nrf2(+/+) mouse brain by any of the chemicals used . Key words: Nuclear ..... necrosis factor, selected anticancer drugs, and ionizing radiation. FASEB J. 7: 361-368.

  16. Yamanaka factors critically regulate the developmental signaling network in mouse embryonic stem cells

    Institute of Scientific and Technical Information of China (English)

    Xiaosong Liu; Jinyan Huang; Taotao Chen; Ying Wang; Shunmei Xin; Jian Li; Gang Pei; Jiuhong Kang

    2008-01-01

    Yamanaka factors (Oct3/4,Sox2,KIf4,c-Myc) are highly expressed in embryonic stem (ES) cells,and their overexpression can induce pluripotency in both mouse and human somatic cells,indicating that these factors regulate the developmental signaling network necessary for ES cell pluripotency.However,systemic analysis of the signaling pathways regulated by Yamanaka factors has not yet been fully described.In this study,we identified the target promoters of endogenous Yamanaka factors on a whole genome scale using ChIP (chromatin immunoprecipitation)-on-chip in E14.1 mouse ES cells,and we found that these four factors co-occupied 58 promoters.Interestingly,when Oct4 and Sox2 were analyzed as core factors,Kif4 functioned to enhance the core factors for development regulation,whereas c-Myc seemed to play a distinct role in regulating metabolism.The pathway analysis revealed that Yamanaka factors collectively regulate a developmental signaling network composed of 16 developmental signaling pathways,nine of which represent earlier unknown pathways in ES cells,including apoptosis and cellcycle pathways.We further analyzed data from a recent study examining Yamanaka factors in mouse ES cells.Interestingly,this analysis also revealed 16 developmental signaling pathways,of which 14 pathways overlap with the ones revealed by this study,despite that the target genes and the signaling pathways regulated by each individual Yamanaka factor differ significantly between these two datasets.We suggest that Yamanaka factors critically regulate a developmental signaling network composed of approximately a dozen crucial developmental signaling pathways to maintain the pluripotency of ES cells and probably also to induce pluripotent stem cells.

  17. Regulation of energy metabolism by the extracytoplasmic function (ECF σ factors of Arcobacter butzleri.

    Directory of Open Access Journals (Sweden)

    Irati Martinez-Malaxetxebarria

    Full Text Available The extracytoplasmic function (ECF σ factors are fundamental for bacterial adaptation to distinct environments and for survival under different stress conditions. The emerging pathogen Arcobacter butzleri possesses seven putative pairs of σ/anti-σ factors belonging to the ECF family. Here, we report the identification of the genes regulated by five out of the seven A. butzleri ECF σ factors. Three of the ECF σ factors play an apparent role in transport, energy generation and the maintenance of redox balance. Several genes like the nap, sox and tct genes are regulated by more than one ECF σ factor, indicating that the A. butzleri ECF σ factors form a network of overlapping regulons. In contrast to other eubacteria, these A. butzleri ECF regulons appear to primarily regulate responses to changing environments in order to meet metabolic needs instead of an obvious role in stress adaptation.

  18. Transcription Factor Substitution during the Evolution of Fungal Ribosome Regulation

    OpenAIRE

    Hogues, Hervé; Lavoie, Hugo; Sellam, Adnane; Mangos, Maria; Roemer, Terry; Purisima, Enrico; Nantel, André; Whiteway, Malcolm

    2008-01-01

    Coordinated ribosomal protein (RP) gene expression is crucial for cellular viability, but the transcriptional network controlling this regulon has only been well characterized in the yeast Saccharomyces cerevisiae. We have used whole-genome transcriptional and location profiling to establish that, in Candida albicans, the RP regulon is controlled by the Myb domain protein Tbf1 working in conjunction with Cbf1. These two factors bind both the promoters of RP genes and the rDNA locus; Tbf1 acti...

  19. An Expandable, Inducible Hemangioblast State Regulated by Fibroblast Growth Factor

    Directory of Open Access Journals (Sweden)

    David T. Vereide

    2014-12-01

    Full Text Available During development, the hematopoietic and vascular lineages are thought to descend from common mesodermal progenitors called hemangioblasts. Here we identify six transcription factors, Gata2, Lmo2, Mycn, Pitx2, Sox17, and Tal1, that “trap” murine cells in a proliferative state and endow them with a hemangioblast potential. These “expandable” hemangioblasts (eHBs are capable, once released from the control of the ectopic factors, to give rise to functional endothelial cells, multilineage hematopoietic cells, and smooth muscle cells. The eHBs can be derived from embryonic stem cells, from fetal liver cells, or poorly from fibroblasts. The eHBs reveal a central role for fibroblast growth factor, which not only promotes their expansion, but also facilitates their ability to give rise to endothelial cells and leukocytes, but not erythrocytes. This study serves as a demonstration that ephemeral progenitor states can be harnessed in vitro, enabling the creation of tractable progenitor cell lines.

  20. Sequences, expression patterns and regulation of the corticotropin releasing factor system in a teleost

    OpenAIRE

    Chen, Chun-Chun; Fernald, Russell D.

    2008-01-01

    Corticotropin-releasing factor (CRF) is well known for its role in regulating the stress response in vertebrate species by controlling release of glucocorticoids. CRF also influences other physiological processes via two distinct CRF receptors (CRF-Rs) and is co-regulated by a CRF binding protein (CRFBP). Although CRF was first discovered in mammals, it is important for the regulation of the stress response, motor behavior, and appetite in all vertebrates. However, it is unclear how the actio...

  1. Age-Related Differences in Emotion Regulation Strategies: Examining the Role of Contextual Factors

    Science.gov (United States)

    Schirda, Brittney; Valentine, Thomas R.; Aldao, Amelia; Prakash, Ruchika Shaurya

    2016-01-01

    Increasing age is characterized by greater positive affective states. However, there is mixed evidence on the implementation of emotion regulation strategies across the life span. To clarify the discrepancies in the literature, we examined the modulating influence of contextual factors in understanding emotion regulation strategy use in older and…

  2. The Influence of Demographic Risk Factors on Children's Behavioral Regulation in Prekindergarten and Kindergarten

    Science.gov (United States)

    Wanless, Shannon B.; McClelland, Megan M.; Tominey, Shauna L.; Acock, Alan C.

    2011-01-01

    Research Findings: The present study examined the role of demographic risk factors in the development of children's behavioral regulation. We investigated whether being from a low-income family and being an English language learner (ELL) predicted behavioral regulation between prekindergarten and kindergarten. Results indicated that children from…

  3. The Plasmid-Encoded Regulator Activates Factors Conferring Lysozyme Resistance on Enteropathogenic Escherichia coli Strains▿

    Science.gov (United States)

    Salinger, Nina; Kokona, Bashkim; Fairman, Robert; Okeke, Iruka N.

    2009-01-01

    We demonstrate that enhanced lysozyme resistance of enteropathogenic Escherichia coli requires the plasmid-encoded regulator, Per, and is mediated by factors outside the locus for enterocyte effacement. EspC, a Per-activated serine protease autotransporter protein, conferred enhanced resistance on nonpathogenic E. coli, and a second Per-regulated, espC-independent lysozyme resistance mechanism was identified. PMID:18997020

  4. The plasmid-encoded regulator activates factors conferring lysozyme resistance on enteropathogenic Escherichia coli strains.

    Science.gov (United States)

    Salinger, Nina; Kokona, Bashkim; Fairman, Robert; Okeke, Iruka N

    2009-01-01

    We demonstrate that enhanced lysozyme resistance of enteropathogenic Escherichia coli requires the plasmid-encoded regulator, Per, and is mediated by factors outside the locus for enterocyte effacement. EspC, a Per-activated serine protease autotransporter protein, conferred enhanced resistance on nonpathogenic E. coli, and a second Per-regulated, espC-independent lysozyme resistance mechanism was identified.

  5. JUNGBRUNNEN1, a Reactive Oxygen Species–Responsive NAC Transcription Factor, Regulates Longevity in Arabidopsis

    NARCIS (Netherlands)

    Wu, A.; Devi Allu, A.; Garapati, P.; Siddiqui, H.; Dortay, H.; Zanor, M.I.; Amparo Asensi-Fabado, M.; Munne´ -Bosch, S.; Antonio, C.; Tohge, T.; Fernie, A.R.; Kaufmann, K.; Xue, G.P.; Mueller-Roeber, B.; Balazadeh, S.

    2012-01-01

    The transition from juvenility through maturation to senescence is a complex process that involves the regulation of longevity. Here, we identify JUNGBRUNNEN1 (JUB1), a hydrogen peroxide (H2O2)-induced NAC transcription factor, as a central longevity regulator in Arabidopsis thaliana. JUB1

  6. Abscisic acid coordinates nod factor and cytokinin signaling during the regulation of nodulation in Medicago truncatula.

    Science.gov (United States)

    Ding, Yiliang; Kalo, Peter; Yendrek, Craig; Sun, Jongho; Liang, Yan; Marsh, John F; Harris, Jeanne M; Oldroyd, Giles E D

    2008-10-01

    Nodulation is tightly regulated in legumes to ensure appropriate levels of nitrogen fixation without excessive depletion of carbon reserves. This balance is maintained by intimately linking nodulation and its regulation with plant hormones. It has previously been shown that ethylene and jasmonic acid (JA) are able to regulate nodulation and Nod factor signal transduction. Here, we characterize the nature of abscisic acid (ABA) regulation of nodulation. We show that application of ABA inhibits nodulation, bacterial infection, and nodulin gene expression in Medicago truncatula. ABA acts in a similar manner as JA and ethylene, regulating Nod factor signaling and affecting the nature of Nod factor-induced calcium spiking. However, this action is independent of the ethylene signal transduction pathway. We show that genetic inhibition of ABA signaling through the use of a dominant-negative allele of ABSCISIC ACID INSENSITIVE1 leads to a hypernodulation phenotype. In addition, we characterize a novel locus of M. truncatula, SENSITIVITY TO ABA, that dictates the sensitivity of the plant to ABA and, as such, impacts the regulation of nodulation. We show that ABA can suppress Nod factor signal transduction in the epidermis and can regulate cytokinin induction of the nodule primordium in the root cortex. Therefore, ABA is capable of coordinately regulating the diverse developmental pathways associated with nodule formation and can intimately dictate the nature of the plants' response to the symbiotic bacteria.

  7. JUNGBRUNNEN1, a Reactive Oxygen Species–Responsive NAC Transcription Factor, Regulates Longevity in Arabidopsis

    NARCIS (Netherlands)

    Wu, A.; Devi Allu, A.; Garapati, P.; Siddiqui, H.; Dortay, H.; Zanor, M.I.; Amparo Asensi-Fabado, M.; Munne´ -Bosch, S.; Antonio, C.; Tohge, T.; Fernie, A.R.; Kaufmann, K.; Xue, G.P.; Mueller-Roeber, B.; Balazadeh, S.

    2012-01-01

    The transition from juvenility through maturation to senescence is a complex process that involves the regulation of longevity. Here, we identify JUNGBRUNNEN1 (JUB1), a hydrogen peroxide (H2O2)-induced NAC transcription factor, as a central longevity regulator in Arabidopsis thaliana. JUB1 overexpre

  8. Transcription Factor Tfe3 Directly Regulates Pgc-1alpha in Muscle.

    Science.gov (United States)

    Salma, Nunciada; Song, Jun S; Arany, Zoltan; Fisher, David E

    2015-10-01

    The microphthalmia (MiT) family of transcription factors is an important mediator of metabolism. Family members Mitf and Tfeb directly regulate the expression of the master regulator of metabolism, peroxisome-proliferator activated receptor gamma coactivator-1 alpha (Pgc-1alpha), in melanomas and in the liver, respectively. Pgc-1alpha is enriched in tissues with high oxidative capacity and plays an important role in the regulation of mitochondrial biogenesis and cellular metabolism. In skeletal muscle, Pgc-1alpha affects many aspects of muscle functionally such as endurance, fiber-type switching, and insulin sensitivity. Tfe3 also regulates muscle metabolic genes that enhance insulin sensitivity in skeletal muscle. Tfe3 has not yet been shown to regulate Pgc-1alpha expression. Our results reported here show that Tfe3 directly regulates Pgc-1alpha expression in myotubes. Tfe3 ectopic expression induces Pgc-1alpha, and Tfe3 silencing suppresses Pgc-1alpha expression. This regulation is direct, as shown by Tfe3's binding to E-boxes on the Pgc-1alpha proximal promoter. We conclude that Tfe3 is a critical transcription factor that regulates Pgc-1alpha gene expression in myotubes. Since Pgc-1alpha coactivates numerous biological programs in diverse tissues, the regulation of its expression by upstream transcription factors such Tfe3 implies potential opportunities for the treatment of diseases where modulation of Pgc-1alpha expression may have important clinical outcomes.

  9. Recent Insights into Insulin-Like Growth Factor Binding Protein 2 Transcriptional Regulation

    OpenAIRE

    Shin, Minsang; Kang, Hye Suk; Park, Jae-Hyung; Bae, Jae-Hoon; Song, Dae-Kyu; Im, Seung-Soon

    2017-01-01

    Insulin-like growth factor binding proteins (IGFBPs) are major regulators of insulin-like growth factor bioavailability and activity in metabolic signaling. Seven IGFBP family isoforms have been identified. Recent studies have shown that IGFBPs play a pivotal role in metabolic signaling and disease, including the pathogenesis of obesity, diabetes, and cancer. Although many studies have documented the various roles played by IGFBPs, transcriptional regulation of IGFBPs is not well understood. ...

  10. Transcription factors, sucrose, and sucrose metabolic genes interact to regulate potato phenylpropanoid metabolism

    OpenAIRE

    2013-01-01

    Much remains unknown about how transcription factors and sugars regulate phenylpropanoid metabolism in tuber crops like potato (Solanum tuberosum). Based on phylogeny and protein similarity to known regulators of phenylpropanoid metabolism, 15 transcription factors were selected and their expression was compared in white, yellow, red, and purple genotypes with contrasting phenolic and anthocyanin profiles. Red and purple genotypes had increased phenylalanine ammonia lyase (PAL) enzyme activit...

  11. Regulation of gonadotropins by corticotropin-releasing factor and urocortin

    OpenAIRE

    Kageyama, Kazunori

    2013-01-01

    While stress activates the hypothalamic–pituitary–adrenal (HPA) axis, it suppresses the hypothalamic–pituitary–gonadal (HPG) axis. Corticotropin-releasing factor (CRF) is a major regulatory peptide in the HPA axis during stress. Urocortin 1 (Ucn1), a member of the CRF family of peptides, has a variety of physiological functions and both CRF and Ucn1 contribute to the stress response via G protein-coupled seven transmembrane receptors. Ucn2 and Ucn3, which belong to a separate paralogous linea...

  12. Regulation of voltage-gated sodium channel expression in cancer: hormones, growth factors and auto-regulation.

    Science.gov (United States)

    Fraser, Scott P; Ozerlat-Gunduz, Iley; Brackenbury, William J; Fitzgerald, Elizabeth M; Campbell, Thomas M; Coombes, R Charles; Djamgoz, Mustafa B A

    2014-03-19

    Although ion channels are increasingly being discovered in cancer cells in vitro and in vivo, and shown to contribute to different aspects and stages of the cancer process, much less is known about the mechanisms controlling their expression. Here, we focus on voltage-gated Na(+) channels (VGSCs) which are upregulated in many types of carcinomas where their activity potentiates cell behaviours integral to the metastatic cascade. Regulation of VGSCs occurs at a hierarchy of levels from transcription to post-translation. Importantly, mainstream cancer mechanisms, especially hormones and growth factors, play a significant role in the regulation. On the whole, in major hormone-sensitive cancers, such as breast and prostate cancer, there is a negative association between genomic steroid hormone sensitivity and functional VGSC expression. Activity-dependent regulation by positive feedback has been demonstrated in strongly metastatic cells whereby the VGSC is self-sustaining, with its activity promoting further functional channel expression. Such auto-regulation is unlike normal cells in which activity-dependent regulation occurs mostly via negative feedback. Throughout, we highlight the possible clinical implications of functional VGSC expression and regulation in cancer.

  13. Circadian factor BMAL1 in histaminergic neurons regulates sleep architecture.

    Science.gov (United States)

    Yu, Xiao; Zecharia, Anna; Zhang, Zhe; Yang, Qianzi; Yustos, Raquel; Jager, Polona; Vyssotski, Alexei L; Maywood, Elizabeth S; Chesham, Johanna E; Ma, Ying; Brickley, Stephen G; Hastings, Michael H; Franks, Nicholas P; Wisden, William

    2014-12-01

    Circadian clocks allow anticipation of daily environmental changes. The suprachiasmatic nucleus (SCN) houses the master clock, but clocks are also widely expressed elsewhere in the body. Although some peripheral clocks have established roles, it is unclear what local brain clocks do. We tested the contribution of one putative local clock in mouse histaminergic neurons in the tuberomamillary nucleus to the regulation of the sleep-wake cycle. Histaminergic neurons are silent during sleep, and start firing after wake onset; the released histamine, made by the enzyme histidine decarboxylase (HDC), enhances wakefulness. We found that hdc gene expression varies with time of day. Selectively deleting the Bmal1 (also known as Arntl or Mop3) clock gene from histaminergic cells removes this variation, producing higher HDC expression and brain histamine levels during the day. The consequences include more fragmented sleep, prolonged wake at night, shallower sleep depth (lower nonrapid eye movement [NREM] δ power), increased NREM-to-REM transitions, hindered recovery sleep after sleep deprivation, and impaired memory. Removing BMAL1 from histaminergic neurons does not, however, affect circadian rhythms. We propose that for mammals with polyphasic/nonwake consolidating sleep, the local BMAL1-dependent clock directs appropriately timed declines and increases in histamine biosynthesis to produce an appropriate balance of wake and sleep within the overall daily cycle of rest and activity specified by the SCN.

  14. Regulation of archicortical arealization by the transcription factor Zbtb20.

    Science.gov (United States)

    Rosenthal, Eva H; Tonchev, Anton B; Stoykova, Anastassia; Chowdhury, Kamal

    2012-11-01

    The molecular mechanisms of regionalization of the medial pallium (MP), the anlage of the hippocampus, and transitional (cingulate and retrosplenial) cortices are largely unknown. Previous analyses have outlined an important role of the transcription factor (TF) Zbtb20 for hippocampal CA1 field specification (Nielsen et al. (2007) Development 134:1133-1140; Nielsen et al. (2010) Cereb Cortex 20:1904-1914; Xie et al. (2010) Proc Natl Acad Sci USA 107:6510-6515). Here, we present novel data showing that Zbtb20 exhibits a ventral(high)-to-dorsal(low) gradient of expression in MP progenitors as well as an expression in postmitotic cells at the transitional cortex/neocortex border. Our detailed pattern analysis revealed that in Zbtb20 loss-of-function the molecular borders between neocortical, transitional, and hippocampal fields are progressively shifted ventrally, leading to an ectopic positioning of all dorsal fields into the neighboring ventrally located areas. Thus, in addition to its known importance for the specification of the hippocampal CA1 sector, the graded expression of TF Zbtb20 in ventricular zone of MP appears to translate early positional information for establishment of all developing MP fields. Our data also suggest that the signaling factor Wnt3a is a putative molecular partner of TF Zbtb20 in this patterning process. Copyright © 2012 Wiley Periodicals, Inc.

  15. Human factors regulation in response to advanced reactor design trends

    Energy Technology Data Exchange (ETDEWEB)

    Innes, L.; Harrison, F. (Atomic Energy Control Board, Ottawa, Ontario (Canada)); Rhodes, W. (Rhodes Associates Inc., Willowdale, Ontario (Canada))

    1993-01-01

    This paper presents the direction being taken in the Canadian regulatory program to guide the incorporation of human factors principles, knowledge, information, and methods in activities such as those that address the design and implementation of the advanced control room (ACR) in nuclear power plants. Within the current activity in the international nuclear industry aimed at the development of ACR concepts, the steps that are being taken to develop design review guidelines for ACRs, such as the work sponsored by the U.S. Nuclear Regulatory Commission are filling an identified important need. The salient feature of most ACR projects is the increased use of digital technology for the analysis, synthesis, management, and display of information. The greatly increased functionality of the devices that can be introduced during such projects allows changes to be made at the design and implementation stages that are not necessarily based on prior function allocation or task analyses.

  16. Nuclear factor Y regulates ancient budgerigar hepadnavirus core promoter activity.

    Science.gov (United States)

    Shen, Zhongliang; Liu, Yanfeng; Luo, Mengjun; Wang, Wei; Liu, Jing; Liu, Wei; Pan, Shaokun; Xie, Youhua

    2016-09-16

    Endogenous viral elements (EVE) in animal genomes are the fossil records of ancient viruses and provide invaluable information on the origin and evolution of extant viruses. Extant hepadnaviruses include avihepadnaviruses of birds and orthohepadnaviruses of mammals. The core promoter (Cp) of hepadnaviruses is vital for viral gene expression and replication. We previously identified in the budgerigar genome two EVEs that contain the full-length genome of an ancient budgerigar hepadnavirus (eBHBV1 and eBHBV2). Here, we found eBHBV1 Cp and eBHBV2 Cp were active in several human and chicken cell lines. A region from nt -85 to -11 in eBHBV1 Cp was critical for the promoter activity. Bioinformatic analysis revealed a putative binding site of nuclear factor Y (NF-Y), a ubiquitous transcription factor, at nt -64 to -50 in eBHBV1 Cp. The NF-Y core binding site (ATTGG, nt -58 to -54) was essential for eBHBV1 Cp activity. The same results were obtained with eBHBV2 Cp and duck hepatitis B virus Cp. The subunit A of NF-Y (NF-YA) was recruited via the NF-Y core binding site to eBHBV1 Cp and upregulated the promoter activity. Finally, the NF-Y core binding site is conserved in the Cps of all the extant avihepadnaviruses but not of orthohepadnaviruses. Interestingly, a putative and functionally important NF-Y core binding site is located at nt -21 to -17 in the Cp of human hepatitis B virus. In conclusion, our findings have pinpointed an evolutionary conserved and functionally critical NF-Y binding element in the Cps of avihepadnaviruses.

  17. GABAergic stimulation regulates the phenotype of hippocampal interneurons through the regulation of brain-derived neurotrophic factor.

    Science.gov (United States)

    Marty, S; Berninger, B; Carroll, P; Thoenen, H

    1996-03-01

    Gamma-Aminobutyric acid (GABA) switches from enhancing to repressing brain-derived neurotrophic factor (BDNF) mRNA synthesis during the maturation of hippocampal neurons in vitro. Interneurons do not produce BDNF themselves, but BDNF enhances their differentiation. Therefore, the question arose whether hippocampal interneurons regulate their phenotype by regulating BDNF expression and release from adjacent cells. The GABA(A) receptor agonist muscimol and BDNF increased the size and neuropeptide Y (NPY) immunoreactivity of hippocampal interneurons. However, GABAergic stimulation failed to increase NPY immunoreactivity in cultures from BDNF knockout embryos. At later developmental stages, when GABA represses BDNF synthesis, treatment with muscimol induced a decrease in cell size and NPY immunoreactivity of interneurons. Interneurons might thus control their phenotype through the regulation of BDNF synthesis in, and release from, their target neurons.

  18. Contribution of thermal and nonthermal factors to the regulation of body temperature in humans.

    Science.gov (United States)

    Mekjavic, Igor B; Eiken, Ola

    2006-06-01

    The set point has been used to define the regulated level of body temperature, suggesting that displacements of core temperature from the set point initiate heat production (HP) and heat loss (HL) responses. Human and animal experiments have demonstrated that the responses of sweating and shivering do not coincide at a set point but rather establish a thermoeffector threshold zone. Neurophysiological studies have demonstrated that the sensor-to-effector pathways for HP and HL overlap and, in fact, mutually inhibit each other. This reciprocal inhibition theory, presumably reflecting the manner in which thermal factors contribute to homeothermy in humans, does not incorporate the effect of nonthermal factors on temperature regulation. The present review examines the actions of these nonthermal factors within the context of neuronal models of temperature regulation, suggesting that examination of these factors may provide further insights into the nature of temperature regulation. It is concluded that, although there is no evidence to doubt the existence of the HP and HL pathways reciprocally inhibiting one another, it appears that such a mechanism is of little consequence when comparing the effects of nonthermal factors on the thermoregulatory system, since most of these factors seem to exert their influence in the region after the reciprocal cross-inhibition. At any given moment, both thermal and several nonthermal factors will be acting on the thermoregulatory system. It may, therefore, not be appropriate to dismiss the contribution of either when discussing the regulation of body temperature in humans.

  19. Regulation of the transforming growth factor β pathway by reversible ubiquitylation.

    Science.gov (United States)

    Al-Salihi, Mazin A; Herhaus, Lina; Sapkota, Gopal P

    2012-05-01

    The transforming growth factor β (TGFβ) signalling pathway plays a central role during embryonic development and in adult tissue homeostasis. It regulates gene transcription through a signalling cascade from cell surface receptors to intracellular SMAD transcription factors and their nuclear cofactors. The extent, duration and potency of signalling in response to TGFβ cytokines are intricately regulated by complex biochemical processes. The corruption of these regulatory processes results in aberrant TGFβ signalling and leads to numerous human diseases, including cancer. Reversible ubiquitylation of pathway components is a key regulatory process that plays a critical role in ensuring a balanced response to TGFβ signals. Many studies have investigated the mechanisms by which various E3 ubiquitin ligases regulate the turnover and activity of TGFβ pathway components by ubiquitylation. Moreover, recent studies have shed new light into their regulation by deubiquitylating enzymes. In this report, we provide an overview of current understanding of the regulation of TGFβ signalling by E3 ubiquitin ligases and deubiquitylases.

  20. In Silico Identification of Co-transcribed Core Cell Cycle Regulators and Transcription Factors in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Regulatory networks involving transcription factors and core cell cycle regulators are expected to play crucial roles in plant growth and development. In this report, we describe the identification of two groups of co-transcribed core cell cycle regulators and transcription factors via a two-step in silico screening. The core cell cycle regulators include TARDY ASYNCHRONOUS MEIOSIS (CYCA1;2), CYCB1;1, CYCB2;1, CDKB1;2, and CDKB2;2 while the transcription factors include CURLY LEAF, AINTEGUMENTA, a MYB protein, two Forkhead-associated domain proteins, and a SCARECROW family protein. Promoter analysis revealed a potential web of cross- and self-regulations among the identified proteins. Because one criterion for screening for these genes is that they are predominantly transcribed in young organs but not in mature organs, these genes are likely to be particularly involved in Arabidopsis organ growth.

  1. RpoN Regulates Virulence Factors of Pseudomonas aeruginosa via Modulating the PqsR Quorum Sensing Regulator.

    Science.gov (United States)

    Cai, Zhao; Liu, Yang; Chen, Yicai; Yam, Joey Kuok Hoong; Chew, Su Chuen; Chua, Song Lin; Wang, Ke; Givskov, Michael; Yang, Liang

    2015-11-30

    The alternative sigma factor RpoN regulates many cell functions, such as motility, quorum sensing, and virulence in the opportunistic pathogen Pseudomonas aeruginosa (P. aeruginosa). P. aeruginosa often evolves rpoN-negative variants during the chronic infection in cystic fibrosis patients. It is unclear how RpoN interacts with other regulatory mechanisms to control virulence of P. aeruginosa. In this study, we show that RpoN modulates the function of PqsR, a quorum sensing receptor regulating production of virulence factors including the phenazine pyocyanin. The ∆rpoN mutant is able to synthesize 4-quinolone signal molecule HHQ but unable to activate PqsR and Pseudomonas quinolone signal (pqs) quorum sensing. The ∆rpoN mutant produces minimal level of pyocyanin and is unable to produce the anti-staphylococcal agents. Providing pqsR in trans in the ∆rpoN mutant restores its pqs quorum sensing and virulence factor production to the wild-type level. Our study provides evidence that RpoN has a regulatory effect on P. aeruginosa virulence through modulating the function of the PqsR quorum sensing regulator.

  2. RpoN Regulates Virulence Factors of Pseudomonas aeruginosa via Modulating the PqsR Quorum Sensing Regulator

    Directory of Open Access Journals (Sweden)

    Zhao Cai

    2015-11-01

    Full Text Available The alternative sigma factor RpoN regulates many cell functions, such as motility, quorum sensing, and virulence in the opportunistic pathogen Pseudomonas aeruginosa (P. aeruginosa. P. aeruginosa often evolves rpoN-negative variants during the chronic infection in cystic fibrosis patients. It is unclear how RpoN interacts with other regulatory mechanisms to control virulence of P. aeruginosa. In this study, we show that RpoN modulates the function of PqsR, a quorum sensing receptor regulating production of virulence factors including the phenazine pyocyanin. The ∆rpoN mutant is able to synthesize 4-quinolone signal molecule HHQ but unable to activate PqsR and Pseudomonas quinolone signal (pqs quorum sensing. The ∆rpoN mutant produces minimal level of pyocyanin and is unable to produce the anti-staphylococcal agents. Providing pqsR in trans in the ∆rpoN mutant restores its pqs quorum sensing and virulence factor production to the wild-type level. Our study provides evidence that RpoN has a regulatory effect on P. aeruginosa virulence through modulating the function of the PqsR quorum sensing regulator.

  3. Inferring yeast cell cycle regulators and interactions using transcription factor activities

    Directory of Open Access Journals (Sweden)

    Galbraith Simon J

    2005-06-01

    Full Text Available Abstract Background Since transcription factors are often regulated at the post-transcriptional level, their activities, rather than expression levels may provide valuable information for investigating functions and their interactions. The recently developed Network Component Analysis (NCA and its generalized form (gNCA provide a robust framework for deducing the transcription factor activities (TFAs from various types of DNA microarray data and transcription factor-gene connectivity. The goal of this work is to demonstrate the utility of TFAs in inferring transcription factor functions and interactions in Saccharomyces cerevisiae cell cycle regulation. Results Using gNCA, we determined 74 TFAs from both wild type and fkh1 fkh2 deletion mutant microarray data encompassing 1529 ORFs. We hypothesized that transcription factors participating in the cell cycle regulation exhibit cyclic activity profiles. This hypothesis was supported by the TFA profiles of known cell cycle factors and was used as a basis to uncover other potential cell cycle factors. By combining the results from both cluster analysis and periodicity analysis, we recovered nearly 90% of the known cell cycle regulators, and identified 5 putative cell cycle-related transcription factors (Dal81, Hap2, Hir2, Mss11, and Rlm1. In addition, by analyzing expression data from transcription factor knockout strains, we determined 3 verified (Ace2, Ndd1, and Swi5 and 4 putative interaction partners (Cha4, Hap2, Fhl1, and Rts2 of the forkhead transcription factors. Sensitivity of TFAs to connectivity errors was determined to provide confidence level of these predictions. Conclusion By subjecting TFA profiles to analyses based upon physiological signatures we were able to identify cell cycle related transcription factors consistent with current literature, transcription factors with potential cell cycle dependent roles, and interactions between transcription factors.

  4. Factors regulating Hb F synthesis in thalassemic diseases

    Directory of Open Access Journals (Sweden)

    Lerone Maria

    2002-02-01

    Full Text Available Abstract Background The thalassemic syndromes originate from mutations of the globin genes that cause, besides the characteristic clinical picture, also an increased Hb F amount. It is not yet clear if there are more factors, besides the beta globin genotype, determining the Hb F production. We have tried to find out if there are relations between total Hb and Hb F, between erythropoietin (Epo and Hb F, between Hb F and point mutations of the gamma gene promoters. Materials and Methods Hematologic parameters, iron status, alpha/non-alpha globin ratio, Epo level, and thalassemic defects of the alpha-, beta-, and gamma-globin genes were explored using standard methods in patients affected by thalassemic diseases. Ninety-five non thalassemic individuals have been examined as controls. Results Two clinical variants of beta-thalassemia intermedia referred to as beta-thal int sub-silent and evident are associated with distinct sets of mutations of the beta-globin gene. Silent beta thal mutations are invariably associated with sub-silent beta thal int; beta° or severe beta+ thal mutations are associated with evident beta thal int (88% and almost invariably (98% with thalassemia major. A positive correlation was observed between the severity of the disease and the Hb F level, but no correlation was found between the Hb F and erythropoietin (Epo level. The mutation Ggamma -158 C→T was detected in 26.9% of patients affected by beta-thal int sub-silent and evident, respectively, but only in 2% of patients with thalassemia major. Conclusions The severity of beta-thal int and the increased Hb F level are strictly dependent from the type of beta-globin gene mutations. No relation is found between Hb F synthesis and Epo secretion. The mutation Ggamma -158 C→T, common among patients affected by beta-thal int and very rare in thal major patients, does not seem, in this study, to influence the Hb F content in beta thal int patients.

  5. Splicing factor SR34b mutation reduces cadmium tolerance in Arabidopsis by regulating iron-regulated transporter 1 gene

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wentao; Du, Bojing; Liu, Di; Qi, Xiaoting, E-mail: qixiaoting@cnu.edu.cn

    2014-12-12

    Highlights: • Arabidopsis splicing factor SR34b gene is cadmium-inducible. • SR34b T-DNA insertion mutant is sensitive to cadmium due to high cadmium uptake. • SR34b is a regulator of cadmium transporter IRT1 at the posttranscription level. • These results highlight the roles of splicing factors in cadmium tolerance of plant. - Abstract: Serine/arginine-rich (SR) proteins are important splicing factors. However, the biological functions of plant SR proteins remain unclear especially in abiotic stresses. Cadmium (Cd) is a non-essential element that negatively affects plant growth and development. In this study, we provided clear evidence for SR gene involved in Cd tolerance in planta. Systemic expression analysis of 17 Arabidopsis SR genes revealed that SR34b is the only SR gene upregulated by Cd, suggesting its potential roles in Arabidopsis Cd tolerance. Consistent with this, a SR34b T-DNA insertion mutant (sr34b) was moderately sensitive to Cd, which had higher Cd{sup 2+} uptake rate and accumulated Cd in greater amounts than wild-type. This was due to the altered expression of iron-regulated transporter 1 (IRT1) gene in sr34b mutant. Under normal growth conditions, IRT1 mRNAs highly accumulated in sr34b mutant, which was a result of increased stability of IRT1 mRNA. Under Cd stress, however, sr34b mutant plants had a splicing defect in IRT1 gene, thus reducing the IRT1 mRNA accumulation. Despite of this, sr34b mutant plants still constitutively expressed IRT1 proteins under Cd stress, thereby resulting in Cd stress-sensitive phenotype. We therefore propose the essential roles of SR34b in posttranscriptional regulation of IRT1 expression and identify it as a regulator of Arabidopsis Cd tolerance.

  6. Integration of the Transcription Factor-Regulated and Epigenetic Mechanisms in the Control of Keratinocyte Differentiation

    Science.gov (United States)

    Botchkarev, Vladimir A.

    2016-01-01

    The epidermal differentiation program is regulated at several levels including signaling pathways, lineage-specific transcription factors, and epigenetic regulators that establish well-coordinated process of terminal differentiation resulting in formation of the epidermal barrier. The epigenetic regulatory machinery operates at several levels including modulation of covalent DNA/histone modifications, as well as through higher-order chromatin remodeling to establish long-range topological interactions between the genes and their enhancer elements. Epigenetic regulators exhibit both activating and repressive effects on chromatin in keratinocytes (KCs): whereas some of them promote terminal differentiation, the others stimulate proliferation of progenitor cells, as well as inhibit premature activation of terminal differentiation-associated genes. Transcription factor-regulated and epigenetic mechanisms are highly connected, and the p63 transcription factor has an important role in the higher-order chromatin remodeling of the KC-specific gene loci via direct control of the genome organizer Satb1 and ATP-dependent chromatin remodeler Brg1. However, additional efforts are required to fully understand the complexity of interactions between distinct transcription factors and epigenetic regulators in the control of KC differentiation. Further understanding of these interactions and their alterations in different pathological skin conditions will help to progress toward the development of novel approaches for the treatment of skin disorders by targeting epigenetic regulators and modulating chromatin organization in KCs. PMID:26551942

  7. Environmental Contaminants and microRNA Regulation: Transcription Factors as Regulators of Toxicant-Altered microRNA Expression

    Science.gov (United States)

    Sollome, James; Martin, Elizabeth; Sethupathy, Praveen; Fry, Rebecca C.

    2016-01-01

    MicroRNAs (miRNAs) regulate gene expression by binding mRNA transcripts and inhibiting translation and/or inducing degradation of the associated transcripts. Expression levels of miRNAs have been shown to be altered in response to environmental toxicants, thus impacting cellular function and influencing disease risk. Transcription factors (TFs) are known to be altered in response to environmental toxicants and play a critical role in the regulation of miRNA expression. To date, environmentally-responsive TFs that are important for regulating miRNAs remain understudied. In a state-of-the-art analysis, we utilized in silico bioinformatic analysis to characterize potential transcriptional regulators of environmentally-responsive miRNAs. Using the miRStart database, genomic sequences of promoter regions for all available human miRNAs (n=847) were identified and promoter regions were defined as −1000/+500 base pairs from the transcription start site. Subsequently, the promoter region sequences of environmentally-responsive miRNAs (n=128) were analyzed using enrichment analysis to determine overrepresented TF binding sites (TFBS). While most (56/73) TFs differed across environmental contaminants, a set of 17 TFs was enriched for promoter binding among miRNAs responsive to numerous environmental contaminants. Of these, one TF was common to miRNAs altered by the majority of environmental contaminants, namely SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily A, member 3 (SMARCA3). These identified TFs represent candidate common transcriptional regulators of miRNAs perturbed by environmental toxicants. PMID:27292125

  8. NUCLEAR FACTOR Y, Subunit C (NF-YC Transcription Factors Are Positive Regulators of Photomorphogenesis in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Zachary A Myers

    2016-09-01

    Full Text Available Recent reports suggest that NF-Y transcription factors are positive regulators of skotomorphogenesis in Arabidopsis thaliana. Three NF-YC genes (NF-YC3, NF-YC4, and NF-YC9 are known to have overlapping functions in photoperiod dependent flowering and previous studies demonstrated that they interact with basic leucine zipper (bZIP transcription factors. This included ELONGATED HYPOCOTYL 5 (HY5, which has well-demonstrated roles in photomorphogenesis. Similar to hy5 mutants, we report that nf-yc3 nf-yc4 nf-yc9 triple mutants failed to inhibit hypocotyl elongation in all tested light wavelengths. Surprisingly, nf-yc3 nf-yc4 nf-yc9 hy5 mutants had synergistic defects in light perception, suggesting that NF-Ys represent a parallel light signaling pathway. As with other photomorphogenic transcription factors, nf-yc3 nf-yc4 nf-yc9 triple mutants also partially suppressed the short hypocotyl and dwarf rosette phenotypes of CONSTITUTIVE PHOTOMORPHOGENIC 1 (cop1 mutants. Thus, our data strongly suggest that NF-Y transcription factors have important roles as positive regulators of photomorphogenesis, and in conjunction with other recent reports, implies that the NF-Y are multifaceted regulators of early seedling development.

  9. Understanding Transcription Factor Regulation by Integrating Gene Expression and DNase I Hypersensitive Sites

    Directory of Open Access Journals (Sweden)

    Guohua Wang

    2015-01-01

    Full Text Available Transcription factors are proteins that bind to DNA sequences to regulate gene transcription. The transcription factor binding sites are short DNA sequences (5–20 bp long specifically bound by one or more transcription factors. The identification of transcription factor binding sites and prediction of their function continue to be challenging problems in computational biology. In this study, by integrating the DNase I hypersensitive sites with known position weight matrices in the TRANSFAC database, the transcription factor binding sites in gene regulatory region are identified. Based on the global gene expression patterns in cervical cancer HeLaS3 cell and HelaS3-ifnα4h cell (interferon treatment on HeLaS3 cell for 4 hours, we present a model-based computational approach to predict a set of transcription factors that potentially cause such differential gene expression. Significantly, 6 out 10 predicted functional factors, including IRF, IRF-2, IRF-9, IRF-1 and IRF-3, ICSBP, belong to interferon regulatory factor family and upregulate the gene expression levels responding to the interferon treatment. Another factor, ISGF-3, is also a transcriptional activator induced by interferon alpha. Using the different transcription factor binding sites selected criteria, the prediction result of our model is consistent. Our model demonstrated the potential to computationally identify the functional transcription factors in gene regulation.

  10. Regulation of angiogenesis in human skeletal muscle with specific focus on pro- angiogenic and angiostatic factors

    DEFF Research Database (Denmark)

    Høier, Birgitte

    It is well established that acute exercise promotes an angiogenic response and that a period of exercise training results in capillary growth. Skeletal muscle angiogenesis is a complex process that requires a coordinated interplay of multiple factors and compounds to ensure proper vascular function......, the findings of simultaneously enhanced pro-angiogenic and angiostatic factors in response to acute exercise before training points to that the angiogenic process is highly regulated even when capillary growth is required. The attenuated response in some of the pro-angiogenic factors after training...... and a concurrent increase in the angiostatic factors occur when capillary growth no longer is required. Thus the balance of pro-angiogenic and angiostatic factors is a determining regulator of exercise-induced angiogenesis in human skeletal muscle....

  11. Systems analysis of multiple regulator perturbations allows discovery of virulence factors in Salmonella

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Hyunjin; Ansong, Charles; McDermott, Jason E.; Gritsenko, Marina A.; Smith, Richard D.; Heffron, Fred; Adkins, Joshua N.

    2011-06-28

    Background: Systemic bacterial infections are highly regulated and complex processes that are orchestrated by numerous virulence factors. Genes that are coordinately controlled by the set of regulators required for systemic infection are potentially required for pathogenicity. Results: In this study we present a systems biology approach in which sample-matched multi-omic measurements of fourteen virulence-essential regulator mutants were coupled with computational network analysis to efficiently identify Salmonella virulence factors. Immunoblot experiments verified network-predicted virulence factors and a subset was determined to be secreted into the host cytoplasm, suggesting that they are virulence factors directly interacting with host cellular components. Two of these, SrfN and PagK2, were required for full mouse virulence and were shown to be translocated independent of either of the type III secretion systems in Salmonella or the type III injectisome-related flagellar mechanism. Conclusions: Integrating multi-omic datasets from Salmonella mutants lacking virulence regulators not only identified novel virulence factors but also defined a new class of translocated effectors involved in pathogenesis. The success of this strategy at discovery of known and novel virulence factors suggests that the approach may have applicability for other bacterial pathogens.

  12. Systems analysis of multiple regulator perturbations allows discovery of virulence factors in Salmonella

    Directory of Open Access Journals (Sweden)

    Heffron Fred

    2011-06-01

    Full Text Available Abstract Background Systemic bacterial infections are highly regulated and complex processes that are orchestrated by numerous virulence factors. Genes that are coordinately controlled by the set of regulators required for systemic infection are potentially required for pathogenicity. Results In this study we present a systems biology approach in which sample-matched multi-omic measurements of fourteen virulence-essential regulator mutants were coupled with computational network analysis to efficiently identify Salmonella virulence factors. Immunoblot experiments verified network-predicted virulence factors and a subset was determined to be secreted into the host cytoplasm, suggesting that they are virulence factors directly interacting with host cellular components. Two of these, SrfN and PagK2, were required for full mouse virulence and were shown to be translocated independent of either of the type III secretion systems in Salmonella or the type III injectisome-related flagellar mechanism. Conclusions Integrating multi-omic datasets from Salmonella mutants lacking virulence regulators not only identified novel virulence factors but also defined a new class of translocated effectors involved in pathogenesis. The success of this strategy at discovery of known and novel virulence factors suggests that the approach may have applicability for other bacterial pathogens.

  13. Serum response factor play a regulative role in the gene expression in heart failure

    Institute of Scientific and Technical Information of China (English)

    Xiaoxia WU; Guang ZHI; Tao WAN; Jiajin WU

    2005-01-01

    To investigate the relationship between transcription factor and the change of protein expression levels in heart failure. Methods Bioinformatic method was used to analyze the data of binding-sites on the 5 ' flaking regions of four genes whose mRNA level changed in failing heart from three databases about nucleic acid-EMBL, transcriptional regulation factor-TRANSFAC and protein-SWISS-PORT.The expression level of selected transcription factor was determined by immunohischemical method.Results Nine transcription factors were inferred to influence the proteins' levels in occurrence and development of heart failure.Serum response factor (SRF) was selected from the nine factors and assayed. The results showed that there was a higher level of SRF in healthy group than in chronic heart failure (CHF), and the level was associated with the degree of CHF. It was also found that there was a relative higher level of SRF in the acute myocardial infarction (AMI) than that in CHF, but which was lower than the healthy. Conclusion It showed that SRF had a quantitative change in the development of heart failure, and suggested SRF might play an important regulative role in heart failure. The expression changes of proteins related to myocardial function might be regulated by the quantitative change of transcription factor(s).

  14. Witnessing Partner Violence in Childhood: Factors Influencing Emotion Regulation Difficulties in College Students

    OpenAIRE

    Amatya, Kaushalendra

    2014-01-01

    Witnessing partner violence (WPV) in childhood and adolescence can have significant impact on psychological functioning throughout development. Studies have shown that parenting factors, perceived social support, coping strategies, age at exposure, and gender can influence the relationship between WPV and outcomes. Although WPV can have serious implications towards emotion regulation abilities, empirical research on the link between WPV and emotion regulation is inadequate. The current stu...

  15. Oncogenic BRAF regulates melanoma proliferation through the lineage specific factor MITF.

    Directory of Open Access Journals (Sweden)

    Claudia Wellbrock

    Full Text Available The Microphthalmia-associated transcription factor (MITF is an important regulator of cell-type specific functions in melanocytic cells. MITF is essential for the survival of pigmented cells, but whereas high levels of MITF drive melanocyte differentiation, lower levels are required to permit proliferation and survival of melanoma cells. MITF is phosphorylated by ERK, and this stimulates its activation, but also targets it for degradation through the ubiquitin-proteosome pathway, coupling MITF degradation to its activation. We have previously shown that because ERK is hyper-activated in melanoma cells in which BRAF is mutated, the MITF protein is constitutively down-regulated. Here we describe another intriguing aspect of MITF regulation by oncogenic BRAF in melanoma cells. We show oncogenic BRAF up-regulates MITF transcription through ERK and the transcription factor BRN2 (N-Oct3. In contrast, we show that in melanocytes this pathway does not exist because BRN2 is not expressed, demonstrating that MITF regulation is a newly acquired function of oncogenic BRAF that is not performed by the wild-type protein. Critically, in melanoma cells MITF is required downstream of oncogenic BRAF because it regulates expression of key cell cycle regulatory proteins such as CDK2 and CDK4. Wild-type BRAF does not regulate this pathway in melanocytes. Thus, we show that oncogenic BRAF exerts exquisite control over MITF on two levels. It downregulates the protein by stimulating its degradation, but then counteracts this by increasing transcription through BRN2. Our data suggest that oncogenic BRAF plays a critical role in regulating MITF expression to ensure that its protein levels are compatible with proliferation and survival of melanoma cells. We propose that its ability to appropriate the regulation of this critical factor explains in part why BRAF is such a potent oncogene in melanoma.

  16. Growth factors and the kidney: regulation of epithelial cell movement and morphogenesis.

    Science.gov (United States)

    Cantley, L G

    1996-12-01

    The control of epithelial cell movement and shape change is complex and requires regulation of a broad range of events including cell-cell adhesion contacts, cell-substratum interactions, and the actin cytoskeleton. Utilizing the hepatocyte growth factor tyrosine kinase receptor, c-met, the present review examines how growth factor receptors activate intracellular signaling pathways, which can then regulate the events necessary for epithelial cells to disassemble their existing structure, undergo extensive shape change and cell body movement, and reassemble into a polarized epithelium. The role of growth factor-mediated activation of the phosphoinositide 3-kinase, phospholipase C-gamma, c-src family members, and ras family members is addressed in relation to integrin-mediated cell-basement membrane contacts, cadherin-mediated cell-cell adhesions, and regulation of the actin cytoskeleton.

  17. Research on the Influencing Factors of Rural Low-carbon Economic Development and Government Regulation

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    This paper analyses the main factors causing sluggish development of rural low-carbon economy in China as follows:the rural energy structure is irrational;the infrastructure and technology are relatively backward;system of laws,regulations and policy is not sound;fund-raising mechanism develops slowly;farmers’ low-carbon awareness and ability are limited.On the basis of these unfavorable factors,from the perspective of government regulation,feasible strategies are put forward in line with the actual situation of rural low-carbon economic development in China.

  18. A Novel extracytoplasmic function (ECF sigma factor regulates virulence in Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    María A Llamas

    2009-09-01

    Full Text Available Next to the two-component and quorum sensing systems, cell-surface signaling (CSS has been recently identified as an important regulatory system in Pseudomonas aeruginosa. CSS systems sense signals from outside the cell and transmit them into the cytoplasm. They generally consist of a TonB-dependent outer membrane receptor, a sigma factor regulator (or anti-sigma factor in the cytoplasmic membrane, and an extracytoplasmic function (ECF sigma factor. Upon perception of the extracellular signal by the receptor the ECF sigma factor is activated and promotes the transcription of a specific set of gene(s. Although most P. aeruginosa CSS systems are involved in the regulation of iron uptake, we have identified a novel system involved in the regulation of virulence. This CSS system, which has been designated PUMA3, has a number of unusual characteristics. The most obvious difference is the receptor component which is considerably smaller than that of other CSS outer membrane receptors and lacks a beta-barrel domain. Homology modeling of PA0674 shows that this receptor is predicted to be a bilobal protein, with an N-terminal domain that resembles the N-terminal periplasmic signaling domain of CSS receptors, and a C-terminal domain that resembles the periplasmic C-terminal domains of the TolA/TonB proteins. Furthermore, the sigma factor regulator both inhibits the function of the ECF sigma factor and is required for its activity. By microarray analysis we show that PUMA3 regulates the expression of a number of genes encoding potential virulence factors, including a two-partner secretion (TPS system. Using zebrafish (Danio rerio embryos as a host we have demonstrated that the P. aeruginosa PUMA3-induced strain is more virulent than the wild-type. PUMA3 represents the first CSS system dedicated to the transcriptional activation of virulence functions in a human pathogen.

  19. Regulation of cell proliferation by the E2F transcription factors

    DEFF Research Database (Denmark)

    Helin, K

    1998-01-01

    demonstrated that individual members of the E2F transcription factor family are likely to have distinct roles in mammalian development and homeostasis. Additional mechanisms regulating the activity of the E2F transcription factors have been reported, including subcellular localization and proteolysis of the E2......Experimental data generated in the past year have further emphasized the essential role for the E2F transcription factors in the regulation of cell proliferation. Genetic studies have shown that E2F activity is required for normal development in fruitflies, and the generation of E2F-1(-/-) mice has......Fs in the proteasomes. Novel target genes for the E2F transcription factors have been identified that link the E2Fs directly to the initiation of DNA replication....

  20. Effects of dietary factors on energy regulation: Consideration of multiple- versus single-dietary-factor models

    Science.gov (United States)

    While short-term studies demonstrate consistent effects of dietary protein, fiber, glycemic index and energy density on energy intake, long-term effectiveness trials typically indicate small or non-significant effects of these dietary factors on long-term weight change. In consequence, most lifestyl...

  1. Chondrocyte Regulation by IL-I and IGF-I: Interconnection Between Anabolic and Catabolic Factors

    OpenAIRE

    Porter, Ryan Michael

    2005-01-01

    Articular cartilage functions to reduce the mechanical stresses associated with diarthrodial joint movement, protecting these joints over a lifetime of use. Tissue function is maintained through the balance between synthesis and resorption (i.e., metabolism) of extracellular matrix (ECM) by articular chondrocytes (ACs). Two important hormonal regulators of cartilage metabolism are interleukin-1 (IL-1) and insulin-like growth factor-I (IGF-I). These factors have antagonistic effects on chondro...

  2. TRPC3 Regulates Release of Brain-Derived Neurotrophic Factor From Human Airway Smooth Muscle

    OpenAIRE

    Vohra, Pawan K.; Thompson, Michael A.; Sathish, Venkatachalem; Kiel, Alexander; Jerde, Calvin; Pabelick, Christina M.; Singh, Brij B.; Prakash, Y. S.

    2013-01-01

    Exogenous brain-derived neurotrophic factor (BDNF) enhances Ca2+ signaling and cell proliferation in human airway smooth muscle (ASM), especially with inflammation. Human ASM also expresses BDNF, raising the potential for autocrine/paracrine effects. The mechanisms by which ASM BDNF secretion occurs are not known. Transient receptor potential channels (TRPCs) regulate a variety of intracellular processes including store-operated Ca2+ entry (SOCE; including in ASM) and secretion of factors suc...

  3. 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...

  4. Distinct and shared transcriptomes are regulated by microphthalmia-associated transcription factor isoforms in mast cells.

    Science.gov (United States)

    Shahlaee, Amir H; Brandal, Stephanie; Lee, Youl-Nam; Jie, Chunfa; Takemoto, Clifford M

    2007-01-01

    The Microphthalmia-associated transcription factor (Mitf) is an essential basic helix-loop-helix leucine zipper transcription factor for mast cell development. Mice deficient in Mitf harbor a severe mast cell deficiency, and Mitf-mutant mast cells cultured ex vivo display a number of functional defects. Therefore, an understanding of the genetic program regulated by Mitf may provide important insights into mast cell differentiation. Multiple, distinct isoforms of Mitf have been identified in a variety of cell types; we found that Mitf-a, Mitf-e, and Mitf-mc were the major isoforms expressed in mast cells. To determine the physiologic function of Mitf in mast cells, we restored expression of these isoforms in primary mast cells from Mitf(-/-) mice. We found that these isoforms restored granular morphology and integrin-mediated migration. By microarray analysis, proteases, signaling molecules, cell surface receptor, and transporters comprised the largest groups of genes up-regulated by all isoforms. Furthermore, we found that isoforms also regulated distinct genes sets, suggesting separable biological activities. This work defines the transcriptome regulated by Mitf in mast cells and supports its role as master regulator of mast cell differentiation. Expression of multiple isoforms of this transcription factor may provide for redundancy of biological activities while also allowing diversity of function.

  5. MiRNA-directed regulation of VEGF and other angiogenic factors under hypoxia.

    Directory of Open Access Journals (Sweden)

    Zhong Hua

    Full Text Available MicroRNAs (miRNAs are a class of 20-24 nt non-coding RNAs that regulate gene expression primarily through post-transcriptional repression or mRNA degradation in a sequence-specific manner. The roles of miRNAs are just beginning to be understood, but the study of miRNA function has been limited by poor understanding of the general principles of gene regulation by miRNAs. Here we used CNE cells from a human nasopharyngeal carcinoma cell line as a cellular system to investigate miRNA-directed regulation of VEGF and other angiogenic factors under hypoxia, and to explore the principles of gene regulation by miRNAs. Through computational analysis, 96 miRNAs were predicted as putative regulators of VEGF. But when we analyzed the miRNA expression profile of CNE and four other VEGF-expressing cell lines, we found that only some of these miRNAs could be involved in VEGF regulation, and that VEGF may be regulated by different miRNAs that were differentially chosen from 96 putative regulatory miRNAs of VEGF in different cells. Some of these miRNAs also co-regulate other angiogenic factors (differential regulation and co-regulation principle. We also found that VEGF was regulated by multiple miRNAs using different combinations, including both coordinate and competitive interactions. The coordinate principle states that miRNAs with independent binding sites in a gene can produce coordinate action to increase the repressive effect of miRNAs on this gene. By contrast, the competitive principle states when multiple miRNAs compete with each other for a common binding site, or when a functional miRNA competes with a false positive miRNA for the same binding site, the repressive effects of miRNAs may be decreased. Through the competitive principle, false positive miRNAs, which cannot directly repress gene expression, can sometimes play a role in miRNA-mediated gene regulation. The competitive principle, differential regulation, multi-miRNA binding sites, and false

  6. Low- and high-dose hydrogen peroxide regulation of transcription factor NF-E2-related factor 2

    Institute of Scientific and Technical Information of China (English)

    NING Jiao-lin; MO Li-wen; LAI Xi-nan

    2010-01-01

    Background Reactive oxygen species (ROS) may play both physiological and pathophysiological roles. Transcription factor NF-E2-related factor 2 (Nrf2) regulates antioxidant response element (ARE)-mediated genes expression and coordinates induction of chemoprotective proteins in response to physical and chemical stresses. The exact role of Nrf2 in cellular responses to different levels of oxidative stresses remains unknown.Methods Rat pulmonary microvascular endothelial cells were cultured and treated with 0 mmol/L, 0.125 mmol/L, 0.25 mmol/L, 0.5 mmol/L, 1.0 mmol/L and 2.0 mmol/L hydrogen peroxide solution for 2 hours. Nrf2 gene expression was assayed by reverse transcription-PCR, Nrf2-ARE binding activity was assayed with electrophoretic mobility shift assay (EMSA), and localization of Nrf2 was detected with immunohistochemistry.Results Low and moderate (0.125 mmol/L, 0.25 mmol/L and 0.5 mmol/L) doses hydrogen peroxide exposure of rat pulmonary microvascular endothelial cells led to the nuclear accumulation of Nrf2, increased activity of transcription regulation and up-regulation of ARE-medicated gene expression. In contrast, high doses of hydrogen peroxide (1 mmol/L, 2 mmol/L) exposure of the cells led to the nuclear exclusion of Nrf2, decreased activity transcription regulation and down-regulation of ARE-mediated gene expression.Conclusion Low and moderate doses of hydrogen peroxide play protective roles by increasing transcription activity of Nrf2, whereas high- dose hydrogen peroxide plays a deleterious role by decreasing transcription activity of Nrf2.

  7. The Plant Heat Stress Transcription Factors (HSFs): Structure, Regulation, and Function in Response to Abiotic Stresses.

    Science.gov (United States)

    Guo, Meng; Liu, Jin-Hong; Ma, Xiao; Luo, De-Xu; Gong, Zhen-Hui; Lu, Ming-Hui

    2016-01-01

    Abiotic stresses such as high temperature, salinity, and drought adversely affect the survival, growth, and reproduction of plants. Plants respond to such unfavorable changes through developmental, physiological, and biochemical ways, and these responses require expression of stress-responsive genes, which are regulated by a network of transcription factors (TFs), including heat stress transcription factors (HSFs). HSFs play a crucial role in plants response to several abiotic stresses by regulating the expression of stress-responsive genes, such as heat shock proteins (Hsps). In this review, we describe the conserved structure of plant HSFs, the identification of HSF gene families from various plant species, their expression profiling under abiotic stress conditions, regulation at different levels and function in abiotic stresses. Despite plant HSFs share highly conserved structure, their remarkable diversification across plants reflects their numerous functions as well as their integration into the complex stress signaling and response networks, which can be employed in crop improvement strategies via biotechnological intervention.

  8. The plant heat stress transcription factors (HSFs: structure, regulation and function in response to abiotic stresses

    Directory of Open Access Journals (Sweden)

    Meng eGuo

    2016-02-01

    Full Text Available Abiotic stresses such as high temperature, salinity and drought adversely affect the survival, growth and reproduction of plants. Plants respond to such unfavorable changes through developmental, physiological and biochemical ways, and these responses require expression of stress-responsive genes, which are regulated by a network of transcription factors (TFs, including heat stress transcription factors (HSFs. HSFs play a crucial role in plants response to several abiotic stresses by regulating the expression of stress-responsive genes, such as heat shock proteins (Hsps. In this review, we describe the conserved structure of plant HSFs, the identification of HSF gene families from various plant species, their expression profiling under abiotic stress conditions, regulation at different levels and function in abiotic stresses. Despite plant HSFs share highly conserved structure, their remarkable diversification across plants reflects their numerous functions as well as their integration into the complex stress signaling and response networks, which can be employed in crop improvement strategies via biotechnological intervention.

  9. C/EBPβ regulates transcription factors critical for proliferation and survival of multiple myeloma cells

    Science.gov (United States)

    Pal, Rekha; Janz, Martin; Galson, Deborah L.; Gries, Margarete; Li, Shirong; Jöhrens, Korinna; Anagnostopoulos, Ioannis; Dörken, Bernd; Mapara, Markus Y.; Borghesi, Lisa; Kardava, Lela; Roodman, G. David; Milcarek, Christine

    2009-01-01

    CCAAT/enhancer-binding protein β (C/EBPβ), also known as nuclear factor–interleukin-6 (NF-IL6), is a transcription factor that plays an important role in the regulation of growth and differentiation of myeloid and lymphoid cells. Mice deficient in C/EBPβ show impaired generation of B lymphocytes. We show that C/EBPβ regulates transcription factors critical for proliferation and survival in multiple myeloma. Multiple myeloma cell lines and primary multiple myeloma cells strongly expressed C/EBPβ, whereas normal B cells and plasma cells had little or no detectable levels of C/EBPβ. Silencing of C/EBPβ led to down-regulation of transcription factors such as IRF4, XBP1, and BLIMP1 accompanied by a strong inhibition of proliferation. Further, silencing of C/EBPβ led to a complete down-regulation of antiapoptotic B-cell lymphoma 2 (BCL2) expression. In chromatin immunoprecipitation assays, C/EBPβ directly bound to the promoter region of IRF4, BLIMP1, and BCL2. Our data indicate that C/EBPβ is involved in the regulatory network of transcription factors that are critical for plasma cell differentiation and survival. Targeting C/EBPβ may provide a novel therapeutic strategy in the treatment of multiple myeloma. PMID:19717648

  10. Factor structure of the Self-Regulation Questionnaire (SRQ) at Spanish universities.

    Science.gov (United States)

    Pichardo, Carmen; Justicia, Fernando; de la Fuente, Jesús; Martínez-Vicente, José Manuel; Berbén, Ana B G

    2014-08-04

    The Self-Regulation Questionnaire (SRQ) has been used in psychology research during the last decade. The instrument has been used in a variety of life domains: psychological well-being, dispositional happiness, depressive symptoms and career adaptability. This investigation studies the factor structure and internal consistency of the SRQ, extracting a short version in the Spanish context and examining its relation to academic variables (self-regulated learning and grades). The analysis started from a version with 63 items, representing seven conceptual dimensions. This version was administered to a sample of 834 students from Education and Psychology. The data from the above-mentioned sample were randomly divided into two sets, each containing 50% of the students (n = 417): exploratory and confirmatory. In the exploratory sample, exploratory factor analysis findings suggested a more parsimonious measurement model, with 17 items and 4 first-order factors. The confirmatory sample was used in the confirmatory factor analysis. The results show evidence for the internal consistency of the Short Self-Regulation Questionnaire (SSRQ) in the Spanish context, with indices greater than .90 and errors around .05. Regarding academic variables, both versions are related to self-regulated learning (r = .40, p < .01) and students' grades (r = .15, p < .01). Differences from other studies done in North America are discussed, as well as similarities to a study from North-West University (in South Africa).

  11. Differential Regulation of Brain-Derived Neurotrophic Factor Transcripts during the Consolidation of Fear Learning

    Science.gov (United States)

    Ressler, Kerry J.; Rattiner, Lisa M.; Davis, Michael

    2004-01-01

    Brain-derived neurotrophic factor (BDNF) has been implicated as a molecular mediator of learning and memory. The BDNF gene contains four differentially regulated promoters that generate four distinct mRNA transcripts, each containing a unique noncoding 5[prime]-exon and a common 3[prime]-coding exon. This study describes novel evidence for the…

  12. Undifferentiated Embryonic Cell Transcription Factor 1 Regulates ESC Chromatin Organization and Gene Expression

    NARCIS (Netherlands)

    Kooistra, Susanne M.; van den Boom, Vincent; Thummer, Rajkumar P.; Johannes, Frank; Wardenaar, Rene; Tesson, Bruno M.; Veenhoff, Liesbeth M.; Fusetti, Fabrizia; O'Neill, Laura P.; Turner, Bryan M.; de Haan, Gerald; Eggen, Bart J. L.; O’Neill, Laura P.

    2010-01-01

    Previous reports showed that embryonic stem (ES) cells contain hyperdynamic and globally transcribed chromatin-properties that are important for ES cell pluripotency and differentiation. Here, we demonstrate a role for undifferentiated embryonic cell transcription factor 1 (UTF1) in regulating ES ce

  13. Direct regulation of rRNA transcription by fibroblast growth factor 2.

    Science.gov (United States)

    Sheng, Zhi; Liang, Yanping; Lin, Chih-Yin; Comai, Lucio; Chirico, William J

    2005-11-01

    Fibroblast growth factor 2 (FGF-2), which is highly expressed in developing tissues and malignant cells, regulates cell growth, differentiation, and migration. Five isoforms (18 to approximately 34 kDa) of FGF-2 are derived from alternative initiation codons of a single mRNA. The 18-kDa FGF-2 isoform is released from cells by a nonclassical secretory pathway and regulates gene expression by binding to cell surface receptors. This isoform also localizes to the nucleolus, raising the possibility that it may directly regulate ribosome biogenesis, a rate-limiting process in cell growth. Although several growth factors have been shown to accumulate in the nucleolus, their function and mechanism of action remain unclear. Here we show that 18-kDa FGF-2 interacts with upstream binding factor (UBF), an architectural transcription factor essential for rRNA transcription. The maximal activation of rRNA transcription in vitro by 18-kDa FGF-2 requires UBF. The 18-kDa FGF-2 localizes to rRNA genes and is necessary for the full activation of pre-rRNA synthesis in vivo. Our results demonstrate that 18-kDa FGF-2 directly regulates rRNA transcription.

  14. Genome-Wide Association between Transcription Factor Expression and Chromatin Accessibility Reveals Regulators of Chromatin Accessibility

    Science.gov (United States)

    Rueedi, Rico

    2017-01-01

    To better understand genome regulation, it is important to uncover the role of transcription factors in the process of chromatin structure establishment and maintenance. Here we present a data-driven approach to systematically characterise transcription factors that are relevant for this process. Our method uses a linear mixed modelling approach to combine datasets of transcription factor binding motif enrichments in open chromatin and gene expression across the same set of cell lines. Applying this approach to the ENCODE dataset, we confirm already known and imply numerous novel transcription factors that play a role in the establishment or maintenance of open chromatin. In particular, our approach rediscovers many factors that have been annotated as pioneer factors. PMID:28118358

  15. Mechanically stimulated bone cells secrete paracrine factors that regulate osteoprogenitor recruitment, proliferation, and differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Brady, Robert T. [Tissue Engineering Research Group, Dept. of Anatomy, Royal College of Surgeons in Ireland (Ireland); Trinity Centre for Bioengineering, School of Engineering, Trinity College Dublin (Ireland); Advanced Materials and BioEngineering Research Centre (AMBER), Trinity College Dublin & Royal College of Surgeons in Ireland (Ireland); Dept. of Mechanical, Aeronautical and Biomedical Engineering, University of Limerick (Ireland); O' Brien, Fergal J. [Tissue Engineering Research Group, Dept. of Anatomy, Royal College of Surgeons in Ireland (Ireland); Trinity Centre for Bioengineering, School of Engineering, Trinity College Dublin (Ireland); Advanced Materials and BioEngineering Research Centre (AMBER), Trinity College Dublin & Royal College of Surgeons in Ireland (Ireland); Hoey, David A., E-mail: david.hoey@ul.ie [Trinity Centre for Bioengineering, School of Engineering, Trinity College Dublin (Ireland); Dept. of Mechanical, Aeronautical and Biomedical Engineering, University of Limerick (Ireland); The Centre for Applied Biomedical Engineering Research, University of Limerick (Ireland); Materials & Surface Science Institute, University of Limerick (Ireland)

    2015-03-27

    Bone formation requires the recruitment, proliferation and osteogenic differentiation of mesenchymal progenitors. A potent stimulus driving this process is mechanical loading, yet the signalling mechanisms underpinning this are incompletely understood. The objective of this study was to investigate the role of the mechanically-stimulated osteocyte and osteoblast secretome in coordinating progenitor contributions to bone formation. Initially osteocytes (MLO-Y4) and osteoblasts (MC3T3) were mechanically stimulated for 24hrs and secreted factors within the conditioned media were collected and used to evaluate mesenchymal stem cell (MSC) and osteoblast recruitment, proliferation and osteogenesis. Paracrine factors secreted by mechanically stimulated osteocytes significantly enhanced MSC migration, proliferation and osteogenesis and furthermore significantly increased osteoblast migration and proliferation when compared to factors secreted by statically cultured osteocytes. Secondly, paracrine factors secreted by mechanically stimulated osteoblasts significantly enhanced MSC migration but surprisingly, in contrast to the osteocyte secretome, inhibited MSC proliferation when compared to factors secreted by statically cultured osteoblasts. A similar trend was observed in osteoblasts. This study provides new information on mechanically driven signalling mechanisms in bone and highlights a contrasting secretome between cells at different stages in the bone lineage, furthering our understanding of loading-induced bone formation and indirect biophysical regulation of osteoprogenitors. - Highlights: • Physically stimulated osteocytes secrete factors that regulate osteoprogenitors. • These factors enhance recruitment, proliferation and osteogenic differentiation. • Physically stimulated osteoblasts secrete factors that also regulate progenitors. • These factors enhance recruitment but inhibit proliferation of osteoprogenitors. • This study highlights a contrasting

  16. Synchronization of developmental processes and defense signaling by growth regulating transcription factors.

    Directory of Open Access Journals (Sweden)

    Jinyi Liu

    Full Text Available Growth regulating factors (GRFs are a conserved class of transcription factor in seed plants. GRFs are involved in various aspects of tissue differentiation and organ development. The implication of GRFs in biotic stress response has also been recently reported, suggesting a role of these transcription factors in coordinating the interaction between developmental processes and defense dynamics. However, the molecular mechanisms by which GRFs mediate the overlaps between defense signaling and developmental pathways are elusive. Here, we report large scale identification of putative target candidates of Arabidopsis GRF1 and GRF3 by comparing mRNA profiles of the grf1/grf2/grf3 triple mutant and those of the transgenic plants overexpressing miR396-resistant version of GRF1 or GRF3. We identified 1,098 and 600 genes as putative targets of GRF1 and GRF3, respectively. Functional classification of the potential target candidates revealed that GRF1 and GRF3 contribute to the regulation of various biological processes associated with defense response and disease resistance. GRF1 and GRF3 participate specifically in the regulation of defense-related transcription factors, cell-wall modifications, cytokinin biosynthesis and signaling, and secondary metabolites accumulation. GRF1 and GRF3 seem to fine-tune the crosstalk between miRNA signaling networks by regulating the expression of several miRNA target genes. In addition, our data suggest that GRF1 and GRF3 may function as negative regulators of gene expression through their association with other transcription factors. Collectively, our data provide new insights into how GRF1 and GRF3 might coordinate the interactions between defense signaling and plant growth and developmental pathways.

  17. Regulation of ciliary neurotrophic factor receptor alpha in sciatic motor neurons following axotomy.

    Science.gov (United States)

    MacLennan, A J; Devlin, B K; Neitzel, K L; McLaurin, D L; Anderson, K J; Lee, N

    1999-01-01

    Spinal motor neurons are one of the few classes of neurons capable of regenerating axons following axotomy. Injury-induced expression of neurotrophic factors and corresponding receptors may play an important role in this rare ability. A wide variety of indirect data suggests that ciliary neurotrophic factor receptor alpha may critically contribute to the regeneration of injured spinal motor neurons. We used immunohistochemistry, in situ hybridization and retrograde tracing techniques to study the regulation of ciliary neurotrophic factor receptor alpha in axotomized sciatic motor neurons. Ciliary neurotrophic factor receptor alpha immunoreactivity, detected with two independent antisera, is increased in a subpopulation of caudal sciatic motor neuron soma one, two and six weeks after sciatic nerve transection and reattachment, while no changes are detected at one day and 15 weeks post-lesion. Ciliary neurotrophic factor receptor alpha messenger RNA levels are augmented in the same classes of neurons following an identical lesion, suggesting that increased synthesis contributes, at least in part, to the additional ciliary neurotrophic factor receptor alpha protein. Separating the proximal and distal nerve stumps with a plastic barrier does not noticeably affect the injury-induced change in ciliary neurotrophic factor receptor alpha regulation, thereby indicating that this injury response is not dependent on signals distal to the lesion traveling retrogradely through the nerve or signals generated by axonal growth through the distal nerve. The prolonged increases in ciliary neurotrophic factor receptor alpha protein and messenger RNA found in regenerating sciatic motor neurons contrast with the responses of non-regenerating central neurons, which are reported to display, at most, a short-lived increase in ciliary neurotrophic factor receptor alpha messenger RNA expression following injury. The present data are the first to demonstrate, in vivo, neuronal regulation of

  18. An Overview of the Importance of Conformational Flexibility in Gene Regulation by the Transcription Factors

    Directory of Open Access Journals (Sweden)

    Shagufta H. Khan

    2009-01-01

    Full Text Available A number of proteins with intrinsically disordered (ID regions/domains are reported to be found disproportionately higher in transcription factors. Available evidences suggest that presence of ID region/domain within a transcription factor plays an important role in its biological functions. These ID sequences provide large flexible surfaces that can allow them to make more efficient physical and functional interactions with their target partners. Since transcription factors regulate expression of target genes by interacting with specific coregulatory proteins, these ID regions/domains can be used as a platform for such large macromolecular interactions, and may represent a mechanism for regulation of cellular processes. The precise structural basis for the function of these ID regions/domains of the transcription factors remains to be determined. In the recent years there has been growing evidence suggesting that an induced fit-like process leads to imposition of folded functional structure in these ID domains on which large multiprotein complexes are built. These multiprotein complexes may eventually dictate the final outcome of the gene regulation by the transcription factors.

  19. Sox2, a key factor in the regulation of pluripotency and neural differentiation

    Institute of Scientific and Technical Information of China (English)

    Shuchen; Zhang; Wei; Cui

    2014-01-01

    Sex determining region Y-box 2(Sox2), a member of the SoxB1 transcription factor family, is an important transcriptional regulator in pluripotent stem cells(PSCs). Together with octamer-binding transcription factor 4 and Nanog, they co-operatively control gene expression in PSCs and maintain their pluripotency. Furthermore, Sox2 plays an essential role in somatic cell reprogram-ming, reversing the epigenetic configuration of differ-entiated cells back to a pluripotent embryonic state. In addition to its role in regulation of pluripotency, Sox2 is also a critical factor for directing the differentiation of PSCs to neural progenitors and for maintaining the properties of neural progenitor stem cells. Here, we review recent findings concerning the involvement of Sox2 in pluripotency, somatic cell reprogramming and neural differentiation as well as the molecular mecha-nisms underlying these roles.

  20. Zinc finger transcription factors displaced SREBP proteins as the major Sterol regulators during Saccharomycotina evolution.

    Directory of Open Access Journals (Sweden)

    Sarah L Maguire

    2014-01-01

    Full Text Available In most eukaryotes, including the majority of fungi, expression of sterol biosynthesis genes is regulated by Sterol-Regulatory Element Binding Proteins (SREBPs, which are basic helix-loop-helix transcription activators. However, in yeasts such as Saccharomyces cerevisiae and Candida albicans sterol synthesis is instead regulated by Upc2, an unrelated transcription factor with a Gal4-type zinc finger. The SREBPs in S. cerevisiae (Hms1 and C. albicans (Cph2 have lost a domain, are not major regulators of sterol synthesis, and instead regulate filamentous growth. We report here that rewiring of the sterol regulon, with Upc2 taking over from SREBP, likely occurred in the common ancestor of all Saccharomycotina. Yarrowia lipolytica, a deep-branching species, is the only genome known to contain intact and full-length orthologs of both SREBP (Sre1 and Upc2. Deleting YlUPC2, but not YlSRE1, confers susceptibility to azole drugs. Sterol levels are significantly reduced in the YlUPC2 deletion. RNA-seq analysis shows that hypoxic regulation of sterol synthesis genes in Y. lipolytica is predominantly mediated by Upc2. However, YlSre1 still retains a role in hypoxic regulation; growth of Y. lipolytica in hypoxic conditions is reduced in a Ylupc2 deletion and is abolished in a Ylsre1/Ylupc2 double deletion, and YlSre1 regulates sterol gene expression during hypoxia adaptation. We show that YlSRE1, and to a lesser extent YlUPC2, are required for switching from yeast to filamentous growth in hypoxia. Sre1 appears to have an ancestral role in the regulation of filamentation, which became decoupled from its role in sterol gene regulation by the arrival of Upc2 in the Saccharomycotina.

  1. Transcription factor ICBP90 regulates the MIF promoter and immune susceptibility locus.

    Science.gov (United States)

    Yao, Jie; Leng, Lin; Sauler, Maor; Fu, Weiling; Zheng, Junsong; Zhang, Yi; Du, Xin; Yu, Xiaoqing; Lee, Patty; Bucala, Richard

    2016-02-01

    The immunoregulatory cytokine macrophage migration inhibitory factor (MIF) is encoded in a functionally polymorphic locus that is linked to the susceptibility of autoimmune and infectious diseases. The MIF promoter contains a 4-nucleotide microsatellite polymorphism (-794 CATT) that repeats 5 to 8 times in the locus, with greater numbers of repeats associated with higher mRNA levels. Because there is no information about the transcriptional regulation of these common alleles, we used oligonucleotide affinity chromatography and liquid chromatography-mass spectrometry to identify nuclear proteins that interact with the -794 CATT5-8 site. An analysis of monocyte nuclear lysates revealed that the transcription factor ICBP90 (also known as UHRF1) is the major protein interacting with the MIF microsatellite. We found that ICBP90 is essential for MIF transcription from monocytes/macrophages, B and T lymphocytes, and synovial fibroblasts, and TLR-induced MIF transcription is regulated in an ICBP90- and -794 CATT5-8 length-dependent manner. Whole-genome transcription analysis of ICBP90 shRNA-treated rheumatoid synoviocytes uncovered a subset of proinflammatory and immune response genes that overlapped with those regulated by MIF shRNA. In addition, the expression levels of ICBP90 and MIF were correlated in joint synovia from patients with rheumatoid arthritis. These findings identify ICBP90 as a key regulator of MIF transcription and provide functional insight into the regulation of the polymorphic MIF locus.

  2. Regulation of Virulence of Entamoeba histolytica by the URE3-BP Transcription Factor.

    Science.gov (United States)

    Gilchrist, Carol A; Moore, Ellyn S; Zhang, Yan; Bousquet, Christina B; Lannigan, Joanne A; Mann, Barbara J; Petri, William A

    2010-05-18

    It is not understood why only some infections with Entamoeba histolytica result in disease. The calcium-regulated transcription factor upstream regulatory element 3-binding protein (URE3-BP) was initially identified by virtue of its role in regulating the expression of two amebic virulence genes, the Gal/GalNac lectin and ferredoxin. Here we tested whether this transcription factor has a broader role in regulating virulence. A comparison of in vivo to in vitro parasite gene expression demonstrated that 39% of in vivo regulated transcripts contained the URE3 motif recognized by URE3-BP, compared to 23% of all promoters (P < 0.0001). Amebae induced to express a dominant positive mutant form of URE3-BP had an increase in an elongated morphology (30% +/- 6% versus 14% +/- 5%; P = 0.001), a 2-fold competitive advantage at invading the intestinal epithelium (P = 0.017), and a 3-fold increase in liver abscess size (0.1 +/- 0.1 g versus 0.036 +/- 0.1 g; P = 0.03). These results support a role for URE3-BP in virulence regulation.

  3. Poplar MYB115 and MYB134 Transcription Factors Regulate Proanthocyanidin Synthesis and Structure.

    Science.gov (United States)

    James, Amy Midori; Ma, Dawei; Mellway, Robin; Gesell, Andreas; Yoshida, Kazuko; Walker, Vincent; Tran, Lan; Stewart, Don; Reichelt, Michael; Suvanto, Jussi; Salminen, Juha-Pekka; Gershenzon, Jonathan; Séguin, Armand; Constabel, C Peter

    2017-05-01

    The accumulation of proanthocyanidins is regulated by a complex of transcription factors composed of R2R3 MYB, basic helix-loop-helix, and WD40 proteins that activate the promoters of biosynthetic genes. In poplar (genus Populus), MYB134 is known to regulate proanthocyanidin biosynthesis by activating key flavonoid genes. Here, we characterize a second MYB regulator of proanthocyanidins, MYB115. Transgenic poplar overexpressing MYB115 showed a high-proanthocyanidin phenotype and reduced salicinoid accumulation, similar to the effects of MYB134 overexpression. Transcriptomic analysis of MYB115- and MYB134-overexpressing poplar plants identified a set of common up-regulated genes encoding proanthocyanidin biosynthetic enzymes and several novel uncharacterized MYB transcriptional repressors. Transient expression experiments demonstrated the capacity of both MYB134 and MYB115 to activate flavonoid promoters, but only in the presence of a basic helix-loop-helix cofactor. Yeast two-hybrid experiments confirmed the direct interaction of these transcription factors. The unexpected identification of dihydromyricetin in leaf extracts of both MYB115- and MYB134-overexpressing poplar led to the discovery of enhanced flavonoid B-ring hydroxylation and an increased proportion of prodelphinidins in proanthocyanidin of the transgenics. The dramatic hydroxylation phenotype of MYB115 overexpressors is likely due to the up-regulation of both flavonoid 3',5'-hydroxylases and cytochrome b5 Overall, this work provides new insight into the complexity of the gene regulatory network for proanthocyanidin synthesis in poplar. © 2017 American Society of Plant Biologists. All Rights Reserved.

  4. Endothelial heparan sulfate 6-O-sulfation levels regulate angiogenic responses of endothelial cells to fibroblast growth factor 2 and vascular endothelial growth factor

    NARCIS (Netherlands)

    Ferreras, C.; Rushton, G.; Cole, C.L.; Babur, Muhammad; Telfer, B.A.; Kuppevelt, A.H. van; Gardiner, J.M.; Williams, K.J.; Jayson, G.C.; Avizienyte, E.

    2012-01-01

    Fibroblast growth factor 2 (FGF2) and vascular endothelial growth factor 165 (VEGF(165)) are potent pro-angiogenic growth factors that play a pivotal role in tumor angiogenesis. The activity of these growth factors is regulated by heparan sulfate (HS), which is essential for the formation of FGF2/FG

  5. Hypoxia-inducible factor-2α is an essential catabolic regulator of inflammatory rheumatoid arthritis.

    Directory of Open Access Journals (Sweden)

    Je-Hwang Ryu

    2014-06-01

    Full Text Available Rheumatoid arthritis (RA is a systemic autoimmune disorder that manifests as chronic inflammation and joint tissue destruction. However, the etiology and pathogenesis of RA have not been fully elucidated. Here, we explored the role of the hypoxia-inducible factors (HIFs, HIF-1α (encoded by HIF1A and HIF-2α (encoded by EPAS1. HIF-2α was markedly up-regulated in the intimal lining of RA synovium, whereas HIF-1α was detected in a few cells in the sublining and deep layer of RA synovium. Overexpression of HIF-2α in joint tissues caused an RA-like phenotype, whereas HIF-1α did not affect joint architecture. Moreover, a HIF-2α deficiency in mice blunted the development of experimental RA. HIF-2α was expressed mainly in fibroblast-like synoviocytes (FLS of RA synovium and regulated their proliferation, expression of RANKL (receptor activator of nuclear factor-κB ligand and various catabolic factors, and osteoclastogenic potential. Moreover, HIF-2α-dependent up-regulation of interleukin (IL-6 in FLS stimulated differentiation of TH17 cells-crucial effectors of RA pathogenesis. Additionally, in the absence of IL-6 (Il6-/- mice, overexpression of HIF-2α in joint tissues did not cause an RA phenotype. Thus, our results collectively suggest that HIF-2α plays a pivotal role in the pathogenesis of RA by regulating FLS functions, independent of HIF-1α.

  6. Regulation of Steroidogenesis, Development, and Cell Differentiation by Steroidogenic Factor-1 and Liver Receptor Homolog-1.

    Science.gov (United States)

    Yazawa, Takashi; Imamichi, Yoshitaka; Miyamoto, Kaoru; Khan, Md Rafiqul Islam; Uwada, Junsuke; Umezawa, Akihiro; Taniguchi, Takanobu

    2015-08-01

    Steroidogenic factor-1 (SF-1) and liver receptor homolog-1 (LRH-1) belong to the nuclear receptor superfamily and are categorized as orphan receptors. In addition to other nuclear receptors, these play roles in various physiological phenomena by regulating the transcription of target genes. Both factors share very similar structures and exhibit common functions. Of these, the roles of SF-1 and LRH-1 in steroidogenesis are the most important, especially that of SF-1, which was originally discovered and named to reflect such roles. SF-1 and LRH-1 are essential for steroid hormone production in gonads and adrenal glands through the regulation of various steroidogenesis-related genes. As SF-1 is also necessary for the development of gonads and adrenal glands, it is also considered a master regulator of steroidogenesis. Recent studies have clearly demonstrated that LRH-1 also represents another master regulator of steroidogenesis, which similarly to SF-1, can induce differentiation of non-steroidogenic stem cells into steroidogenic cells. Here, we review the functions of both factors in these steroidogenesis-related phenomena.

  7. Regulation of vascular endothelial growth factor expression by homeodomain-interacting protein kinase-2

    Directory of Open Access Journals (Sweden)

    D'Orazi Gabriella

    2008-07-01

    Full Text Available Abstract Background Homeodomain-interacting protein kinase-2 (HIPK2 plays an essential role in restraining tumor progression as it may regulate, by itself or within multiprotein complexes, many proteins (mainly transcription factors involved in cell growth and apoptosis. This study takes advantage of the recent finding that HIPK2 may repress the β-catenin transcription activity. Thus, we investigated whether HIPK2 overexpression may down-regulate vascular endothelial growth factor (VEGF levels (a β-catenin target gene and the role of β-catenin in this regulation, in order to consider HIPK2 as a tool for novel anti-tumoral therapeutical approaches. Methods The regulation of VEGF expression by HIPK2 was evaluated by using luciferase assay with VEGF reporter construct, after overexpression of the β-catenin transcription factor. Relative quantification of VEGF and β-catenin mRNAs were assessed by reverse-transcriptase-PCR (RT-PCR analyses, following HIPK2 overexpression, while β-catenin protein levels were evaluated by western immunoblotting. Results HIPK2 overexpression in tumor cells downregulated VEGF mRNA levels and VEGF promoter activity. The VEGF downregulation was partly depending on HIPK2-mediated β-catenin regulation. Thus, HIPK2 could induce β-catenin protein degradation that was prevented by cell treatment with proteasome inhibitor MG132. The β-catenin degradation was dependent on HIPK2 catalytic activity and independent of p53 and glycogen synthase kinase 3β (GSK-3β activities. Conclusion These results suggest that VEGF might be a target of HIPK2, at least in part, through regulation of β-catenin activity. These findings support the function of HIPK2 as tumor suppressor and hypothesise a role for HIPK2 as antiangiogenic tool in tumor therapy approaches.

  8. Tumor necrosis factor beta and ultraviolet radiation are potent regulators of human keratinocyte ICAM-1 expression

    Energy Technology Data Exchange (ETDEWEB)

    Krutmann, J.; Koeck, A.S.; Schauer, E.; Parlow, F.; Moeller, A.K.; Kapp, A.; Foerster, E.S.; Schoepf, E.L.; Luger, T.A. (Univ. of Freiburg (Germany, F.R.))

    1990-08-01

    Intercellular adhesion molecule-1 (ICAM-1) functions as a ligand of leukocyte function-associated antigen-1 (LFA-1), as well as a receptor for human picorna virus, and its regulation thus affects various immunologic and inflammatory reactions. The weak, constitutive ICAM-1 expression on human keratinocytes (KC) can be up-regulated by cytokines such as interferon-gamma (IFN gamma) and tumor necrosis factor alpha (TNF alpha). In order to further examine the regulation of KC ICAM-1 expression, normal human KC or epidermoid carcinoma cells (KB) were incubated with different cytokines and/or exposed to ultraviolet (UV) radiation. Subsequently, ICAM-1 expression was monitored cytofluorometrically using a monoclonal anti-ICAM-1 antibody. Stimulation of cells with recombinant human (rh) interleukin (IL) 1 alpha, rhIL-4, rhIL-5, rhIL-6, rh granulocyte/macrophage colony-stimulating factor (GM-CSF), rh interferon alpha (rhIFN alpha), and rh transforming growth factor beta (TGF beta) did not increase ICAM-1 surface expression. In contrast, rhTNF beta significantly up-regulated ICAM-1 expression in a time- and dose-dependent manner. Moreover, the combination of rhTNF beta with rhIFN gamma increased the percentage of ICAM-1-positive KC synergistically. This stimulatory effect of rhTNF beta was further confirmed by the demonstration that rhTNF beta was capable of markedly enhancing ICAM-1 mRNA expression in KC. Finally, exposure of KC in vitro to sublethal doses of UV radiation (0-100 J/m2) prior to cytokine (rhIFN tau, rhTNF alpha, rhTNF beta) stimulation inhibited ICAM-1 up-regulation in a dose-dependent fashion. These studies identify TNF beta and UV light as potent regulators of KC ICAM-1 expression, which may influence both attachment and detachment of leukocytes and possibly viruses to KC.

  9. Transcription factors that directly regulate the expression of CSLA9 encoding mannan synthase in Arabidopsis thaliana.

    Science.gov (United States)

    Kim, Won-Chan; Reca, Ida-Barbara; Kim, Yongsig; Park, Sunchung; Thomashow, Michael F; Keegstra, Kenneth; Han, Kyung-Hwan

    2014-03-01

    Mannans are hemicellulosic polysaccharides that have a structural role and serve as storage reserves during plant growth and development. Previous studies led to the conclusion that mannan synthase enzymes in several plant species are encoded by members of the cellulose synthase-like A (CSLA) gene family. Arabidopsis has nine members of the CSLA gene family. Earlier work has shown that CSLA9 is responsible for the majority of glucomannan synthesis in both primary and secondary cell walls of Arabidopsis inflorescence stems. Little is known about how expression of the CLSA9 gene is regulated. Sequence analysis of the CSLA9 promoter region revealed the presence of multiple copies of a cis-regulatory motif (M46RE) recognized by transcription factor MYB46, leading to the hypothesis that MYB46 (At5g12870) is a direct regulator of the mannan synthase CLSA9. We obtained several lines of experimental evidence in support of this hypothesis. First, the expression of CSLA9 was substantially upregulated by MYB46 overexpression. Second, electrophoretic mobility shift assay (EMSA) was used to demonstrate the direct binding of MYB46 to the promoter of CSLA9 in vitro. This interaction was further confirmed in vivo by a chromatin immunoprecipitation assay. Finally, over-expression of MYB46 resulted in a significant increase in mannan content. Considering the multifaceted nature of MYB46-mediated transcriptional regulation of secondary wall biosynthesis, we reasoned that additional transcription factors are involved in the CSLA9 regulation. This hypothesis was tested by carrying out yeast-one hybrid screening, which identified ANAC041 and bZIP1 as direct regulators of CSLA9. Transcriptional activation assays and EMSA were used to confirm the yeast-one hybrid results. Taken together, we report that transcription factors ANAC041, bZIP1 and MYB46 directly regulate the expression of CSLA9.

  10. DNA Damage Follows Repair Factor Depletion and Portends Genome Variation in Cancer Cells after Pore Migration.

    Science.gov (United States)

    Irianto, Jerome; Xia, Yuntao; Pfeifer, Charlotte R; Athirasala, Avathamsa; Ji, Jiazheng; Alvey, Cory; Tewari, Manu; Bennett, Rachel R; Harding, Shane M; Liu, Andrea J; Greenberg, Roger A; Discher, Dennis E

    2017-01-23

    Migration through micron-size constrictions has been seen to rupture the nucleus, release nuclear-localized GFP, and cause localized accumulations of ectopic 53BP1-a DNA repair protein. Here, constricted migration of two human cancer cell types and primary mesenchymal stem cells (MSCs) increases DNA breaks throughout the nucleoplasm as assessed by endogenous damage markers and by electrophoretic "comet" measurements. Migration also causes multiple DNA repair proteins to segregate away from DNA, with cytoplasmic mis-localization sustained for many hours as is relevant to delayed repair. Partial knockdown of repair factors that also regulate chromosome copy numbers is seen to increase DNA breaks in U2OS osteosarcoma cells without affecting migration and with nucleoplasmic patterns of damage similar to constricted migration. Such depletion also causes aberrant levels of DNA. Migration-induced nuclear damage is nonetheless reversible for wild-type and sub-cloned U2OS cells, except for lasting genomic differences between stable clones as revealed by DNA arrays and sequencing. Gains and losses of hundreds of megabases in many chromosomes are typical of the changes and heterogeneity in bone cancer. Phenotypic differences that arise from constricted migration of U2OS clones are further illustrated by a clone with a highly elongated and stable MSC-like shape that depends on microtubule assembly downstream of the transcription factor GATA4. Such changes are consistent with reversion to a more stem-like state upstream of cancerous osteoblastic cells. Migration-induced genomic instability can thus associate with heritable changes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Arabidopsis MAP Kinase 4 regulates gene expression via transcription factor release in the nucleus

    DEFF Research Database (Denmark)

    Qiu, Jin-Long; Fiil, Berthe Katrine; Petersen, Klaus

    2008-01-01

    Plant and animal perception of microbes through pathogen surveillance proteins leads to MAP kinase signalling and the expression of defence genes. However, little is known about how plant MAP kinases regulate specific gene expression. We report that, in the absence of pathogens, Arabidopsis MAP...... supported by the suppression of PAD3 expression in mpk4-wrky33 double mutant backgrounds. Our data establish direct links between MPK4 and innate immunity and provide an example of how a plant MAP kinase can regulate gene expression by releasing transcription factors in the nucleus upon activation....

  12. Situational Awareness: Regulation of the Myb Transcription Factor in Differentiation, the Cell Cycle and Oncogenesis

    Energy Technology Data Exchange (ETDEWEB)

    George, Olivia L.; Ness, Scott A., E-mail: sness@salud.unm.edu [Department of Internal Medicine, Section of Molecular Medicine, University of New Mexico Health Sciences Center, MSC07 4025-CRF 121, 1 University of New Mexico, Albuquerque, NM 87131 (United States)

    2014-10-02

    This review summarizes the mechanisms that control the activity of the c-Myb transcription factor in normal cells and tumors, and discusses how c-Myb plays a role in the regulation of the cell cycle. Oncogenic versions of c-Myb contribute to the development of leukemias and solid tumors such as adenoid cystic carcinoma, breast cancer and colon cancer. The activity and specificity of the c-Myb protein seems to be controlled through changes in protein-protein interactions, so understanding how it is regulated could lead to the development of novel therapeutic strategies.

  13. Direct Regulation of rRNA Transcription by Fibroblast Growth Factor 2

    OpenAIRE

    Sheng, Zhi; Liang, Yanping; Lin, Chih-Yin; Comai, Lucio; Chirico, William J

    2005-01-01

    Fibroblast growth factor 2 (FGF-2), which is highly expressed in developing tissues and malignant cells, regulates cell growth, differentiation, and migration. Five isoforms (18 to ∼34 kDa) of FGF-2 are derived from alternative initiation codons of a single mRNA. The 18-kDa FGF-2 isoform is released from cells by a nonclassical secretory pathway and regulates gene expression by binding to cell surface receptors. This isoform also localizes to the nucleolus, raising the possibility that it may...

  14. Pleiohomeotic interacts with the core transcription elongation factor Spt5 to regulate gene expression in Drosophila.

    Directory of Open Access Journals (Sweden)

    Robert Harvey

    Full Text Available The early elongation checkpoint regulated by Positive Transcription Elongation Factor b (P-TEFb is a critical control point for the expression of many genes. Spt5 interacts directly with RNA polymerase II and has an essential role in establishing this checkpoint, and also for further transcript elongation. Here we demonstrate that Drosophila Spt5 interacts both physically and genetically with the Polycomb Group (PcG protein Pleiohomeotic (Pho, and the majority of Pho binding sites overlap with Spt5 binding sites across the genome in S2 cells. Our results indicate that Pho can interact with Spt5 to regulate transcription elongation in a gene specific manner.

  15. A multi-scale model of hepcidin promoter regulation reveals factors controlling systemic iron homeostasis.

    Directory of Open Access Journals (Sweden)

    Guillem Casanovas

    2014-01-01

    Full Text Available Systemic iron homeostasis involves a negative feedback circuit in which the expression level of the peptide hormone hepcidin depends on and controls the iron blood levels. Hepcidin expression is regulated by the BMP6/SMAD and IL6/STAT signaling cascades. Deregulation of either pathway causes iron-related diseases such as hemochromatosis or anemia of inflammation. We quantitatively analyzed how BMP6 and IL6 control hepcidin expression. Transcription factor (TF phosphorylation and reporter gene expression were measured under co-stimulation conditions, and the promoter was perturbed by mutagenesis. Using mathematical modeling, we systematically analyzed potential mechanisms of cooperative and competitive promoter regulation by the transcription factors, and experimentally validated the model predictions. Our results reveal that hepcidin cross-regulation primarily occurs by combinatorial transcription factor binding to the promoter, whereas signaling crosstalk is insignificant. We find that the presence of two BMP-responsive elements enhances the steepness of the promoter response towards the iron-sensing BMP signaling axis, which promotes iron homeostasis in vivo. IL6 co-stimulation reduces the promoter sensitivity towards the BMP signal, because the SMAD and STAT transcription factors compete for recruiting RNA polymerase to the transcription start site. This may explain why inflammatory signals disturb iron homeostasis in anemia of inflammation. Taken together, our results reveal why the iron homeostasis circuit is sensitive to perturbations implicated in disease.

  16. PAK1 negatively regulates the activity of the Rho exchange factor NET1.

    Science.gov (United States)

    Alberts, Arthur S; Qin, Huajun; Carr, Heather S; Frost, Jeffrey A

    2005-04-01

    Rho family small G-protein activity is controlled by guanine nucleotide exchange factors that stimulate the release of GDP, thus allowing GTP binding. Once activated, Rho proteins control cell signaling through interactions with downstream effector proteins, leading to changes in cytoskeletal organization and gene expression. The ability of Rho family members to modulate the activity of other Rho proteins is also intrinsic to these processes. In this work we show that the Rac/Cdc42hs-regulated protein kinase PAK1 down-regulates the activity of the RhoA-specific guanine nucleotide exchange factor NET1. Specifically, PAK1 phosphorylates NET1 on three sites in vitro: serines 152, 153, and 538. Replacement of serines 152 and 153 with glutamate residues down-regulates the activity of NET1 as an exchange factor in vitro and its ability to stimulate actin stress fiber formation in cells. Using a phospho-specific antibody that recognizes NET1 phosphorylated on serine 152, we show that PAK1 phosphorylates NET1 on this site in cells and that Rac1 stimulates serine 152 phosphorylation in a PAK1-dependent manner. Furthermore, coexpression of constitutively active PAK1 inhibits the ability of NET1 to stimulate actin polymerization only when serines 152 and 153 are present. These data provide a novel mechanism for the control of RhoA activity by Rac1 through the PAK-dependent phosphorylation of NET1 to reduce its activity as a guanine nucleotide exchange factor.

  17. Inter- and intra-combinatorial regulation by transcription factors and microRNAs

    Directory of Open Access Journals (Sweden)

    Chang Joseph T

    2007-10-01

    Full Text Available Abstract Background MicroRNAs (miRNAs are a novel class of non-coding small RNAs. In mammalian cells, miRNAs repress the translation of messenger RNAs (mRNAs or degrade mRNAs. miRNAs play important roles in development and differentiation, and they are also implicated in aging, and oncogenesis. Predictions of targets of miRNAs suggest that they may regulate more than one-third of all genes. The overall functions of mammalian miRNAs remain unclear. Combinatorial regulation by transcription factors alone or miRNAs alone offers a wide range of regulatory programs. However, joining transcriptional and post-transcriptional regulatory mechanisms enables higher complexity regulatory programs that in turn could give cells evolutionary advantages. Investigating coordinated regulation of genes by miRNAs and transcription factors (TFs from a statistical standpoint is a first step that may elucidate some of their roles in various biological processes. Results Here, we studied the nature and scope of coordination among regulators from the transcriptional and miRNA regulatory layers in the human genome. Our findings are based on genome wide statistical assessment of regulatory associations ("interactions" among the sets of predicted targets of miRNAs and sets of putative targets of transcription factors. We found that combinatorial regulation by transcription factor pairs and miRNA pairs is much more abundant than the combinatorial regulation by TF-miRNA pairs. In addition, many of the strongly interacting TF-miRNA pairs involve a subset of master TF regulators that co-regulate genes in coordination with almost any miRNA. Application of standard measures for evaluating the degree of interaction between pairs of regulators show that strongly interacting TF-miRNA, TF-TF or miRNA-miRNA pairs tend to include TFs or miRNAs that regulate very large numbers of genes. To correct for this potential bias we introduced an additional Bayesian measure that incorporates

  18. Eukaryotic elongation factor 2 kinase regulates the cold stress response by slowing translation elongation.

    Science.gov (United States)

    Knight, John R P; Bastide, Amandine; Roobol, Anne; Roobol, Jo; Jackson, Thomas J; Utami, Wahyu; Barrett, David A; Smales, C Mark; Willis, Anne E

    2015-01-15

    Cells respond to external stress conditions by controlling gene expression, a process which occurs rapidly via post-transcriptional regulation at the level of protein synthesis. Global control of translation is mediated by modification of translation factors to allow reprogramming of the translatome and synthesis of specific proteins that are required for stress protection or initiation of apoptosis. In the present study, we have investigated how global protein synthesis rates are regulated upon mild cooling. We demonstrate that although there are changes to the factors that control initiation, including phosphorylation of eukaryotic translation initiation factor 2 (eIF2) on the α-subunit, the reduction in the global translation rate is mediated by regulation of elongation via phosphorylation of eukaryotic elongation factor 2 (eEF2) by its specific kinase, eEF2K (eukaryotic elongation factor 2 kinase). The AMP/ATP ratio increases following cooling, consistent with a reduction in metabolic rates, giving rise to activation of AMPK (5'-AMP-activated protein kinase), which is upstream of eEF2K. However, our data show that the major trigger for activation of eEF2K upon mild cooling is the release of Ca2+ ions from the endoplasmic reticulum (ER) and, importantly, that it is possible to restore protein synthesis rates in cooled cells by inhibition of this pathway at multiple points. As cooling has both therapeutic and industrial applications, our data provide important new insights into how the cellular responses to this stress are regulated, opening up new possibilities to modulate these responses for medical or industrial use at physiological or cooler temperatures.

  19. Di (2-ethylhexyl) phthalate exposure during pregnancy disturbs temporal sex determination regulation in mice offspring.

    Science.gov (United States)

    Wang, Yongan; Liu, Wei; Yang, Qing; Yu, Mingxi; Zhang, Zhou

    2015-10-02

    Animal researches and clinical studies have supported the relevance between phthalates exposure and testicular dysgenesis syndrome (TDS). These disorders may comprise common origin in fetal life, especially during sex determination and differentiation, where the mechanism remains unclear. The present study evaluated the disturbances in gene regulatory networks of sex determination in fetal mouse by in utero Di (2-ethylhexyl) phthalate (DEHP) exposure. Temporal expression of key sex determination genes were examined during the critical narrow time window, using whole-mount in situ hybridization and quantitative-PCR. DEHP exposure resulted in significant reduction in mRNA of Sry during sex determination from gestation day (GD) 11.0 to 11.5 in male fetal mice, and the increasing of Sry expression to threshold level on GD 11.5 was delayed. Meanwhile, Gadd45g and Gata4, the upstream genes of Sry, and downstream gene Sox9 were also significantly downregulated in expression. In fetal females, the expression of Wnt4 and beta-catenin were up-regulated by DEHP exposure. Taken together, the results suggest that the potential mechanism of gonadal development disorder by DEHP may origin from repression of important male sex determination signaling pathway, involving Gadd45g → Gata4 → Sry → Sox9. The results would promote a better understanding of the association between phthalate esters (PAEs) exposure and the reductive disorder.

  20. The precise regulation of different COR genes by individual CBF transcription factors in Arabidopsis thaliana.

    Science.gov (United States)

    Shi, Yihao; Huang, Jiaying; Sun, Tianshu; Wang, Xuefei; Zhu, Chenqi; Ai, Yuxi; Gu, Hongya

    2017-02-01

    The transcription factors CBF1/2/3 are reported to play a dominant role in the cold responsive network of Arabidopsis by directly regulating the expression levels of cold responsive (COR) genes. In this study, we obtained CRISPR/Cas9-mediated loss-of-function mutants of cbf1∼3. Over 3,000 COR genes identified by RNA-seq analysis showed a slight but significant change in their expression levels in the mutants compared to the wild-type plants after being treated at 4 °C for 12 h. The C-repeat (CRT) motif (5'-CCGAC-3') was enriched in promoters of genes that were up-regulated by CBF2 and CBF3 but not in promoters of genes up-regulated by CBF1. These data suggest that CBF2 and CBF3 play a more important role in directing the cold response by regulating different sets of downstream COR genes. More than 2/3 of COR genes were co-regulated by two or three CBFs and were involved mainly in cellular signal transduction and metabolic processes; less than 1/3 of the genes were regulated by one CBF, and those genes up-regulated were enriched in cold-related abiotic stress responses. Our results indicate that CBFs play an important role in the trade-off between cold tolerance and plant growth through the precise regulation of COR genes in the complicated transcriptional network. © 2016 The Authors. Journal of Integrative Plant Biology Published by John Wiley & Sons Australia, Ltd on behalf of Institute of Botany, Chinese Academy of Sciences.

  1. Hypoxia-inducible factor prolyl 4-hydroxylases regulating erythropoiesis, and hypoxia-inducible lysyl oxidase regulating skeletal muscle development during embryogenesis

    OpenAIRE

    Laitala, A. (Anu)

    2014-01-01

    Abstract Erythropoiesis is the process of red blood cell production. The main regulator is the erythropoietin (EPO) hormone, which is strongly upregulated in low oxygen concentration (hypoxia) in cells via the hypoxia-inducible transcription factor HIF. The stability of HIF is regulated in an oxygen-dependent manner by three HIF prolyl 4-hydroxylases, all of which are known to participate in the regulation of erythropoiesis. A role in erythropoiesis of a fourth prolyl 4-hydroxylase, P4H-TM...

  2. Structure-mechanism-based engineering of chemical regulators targeting distinct pathological factors in Alzheimer's disease

    Science.gov (United States)

    Beck, Michael W.; Derrick, Jeffrey S.; Kerr, Richard A.; Oh, Shin Bi; Cho, Woo Jong; Lee, Shin Jung C.; Ji, Yonghwan; Han, Jiyeon; Tehrani, Zahra Aliakbar; Suh, Nayoung; Kim, Sujeong; Larsen, Scott D.; Kim, Kwang S.; Lee, Joo-Yong; Ruotolo, Brandon T.; Lim, Mi Hee

    2016-10-01

    The absence of effective therapeutics against Alzheimer's disease (AD) is a result of the limited understanding of its multifaceted aetiology. Because of the lack of chemical tools to identify pathological factors, investigations into AD pathogenesis have also been insubstantial. Here we report chemical regulators that demonstrate distinct specificity towards targets linked to AD pathology, including metals, amyloid-β (Aβ), metal-Aβ, reactive oxygen species, and free organic radicals. We obtained these chemical regulators through a rational structure-mechanism-based design strategy. We performed structural variations of small molecules for fine-tuning their electronic properties, such as ionization potentials and mechanistic pathways for reactivity towards different targets. We established in vitro and/or in vivo efficacies of the regulators for modulating their targets' reactivities, ameliorating toxicity, reducing amyloid pathology, and improving cognitive deficits. Our chemical tools show promise for deciphering AD pathogenesis and discovering effective drugs.

  3. Ion channels, guidance molecules, intracellular signaling and transcription factors regulating nervous and vascular system development.

    Science.gov (United States)

    Akita, Tenpei; Kumada, Tatsuro; Yoshihara, Sei-ichi; Egea, Joaquim; Yamagishi, Satoru

    2016-03-01

    Our sophisticated thoughts and behaviors are based on the miraculous development of our complex nervous network system, in which many different types of proteins and signaling cascades are regulated in a temporally and spatially ordered manner. Here we review our recent attempts to grasp the principles of nervous system development in terms of general cellular phenomena and molecules, such as volume-regulated anion channels, intracellular Ca(2+) and cyclic nucleotide signaling, the Npas4 transcription factor and the FLRT family of axon guidance molecules. We also present an example illustrating that the same FLRT family may regulate the development of vascular networks as well. The aim of this review is to open up new vistas for understanding the intricacy of nervous and vascular system development.

  4. Structure-mechanism-based engineering of chemical regulators targeting distinct pathological factors in Alzheimer's disease.

    Science.gov (United States)

    Beck, Michael W; Derrick, Jeffrey S; Kerr, Richard A; Oh, Shin Bi; Cho, Woo Jong; Lee, Shin Jung C; Ji, Yonghwan; Han, Jiyeon; Tehrani, Zahra Aliakbar; Suh, Nayoung; Kim, Sujeong; Larsen, Scott D; Kim, Kwang S; Lee, Joo-Yong; Ruotolo, Brandon T; Lim, Mi Hee

    2016-10-13

    The absence of effective therapeutics against Alzheimer's disease (AD) is a result of the limited understanding of its multifaceted aetiology. Because of the lack of chemical tools to identify pathological factors, investigations into AD pathogenesis have also been insubstantial. Here we report chemical regulators that demonstrate distinct specificity towards targets linked to AD pathology, including metals, amyloid-β (Aβ), metal-Aβ, reactive oxygen species, and free organic radicals. We obtained these chemical regulators through a rational structure-mechanism-based design strategy. We performed structural variations of small molecules for fine-tuning their electronic properties, such as ionization potentials and mechanistic pathways for reactivity towards different targets. We established in vitro and/or in vivo efficacies of the regulators for modulating their targets' reactivities, ameliorating toxicity, reducing amyloid pathology, and improving cognitive deficits. Our chemical tools show promise for deciphering AD pathogenesis and discovering effective drugs.

  5. 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.

  6. Trefoil factor 3 (TFF3 expression is regulated by insulin and glucose

    Directory of Open Access Journals (Sweden)

    Girolamo Jose Barrera Roa

    2013-04-01

    Full Text Available Introduction: Trefoil factors are effector molecules in gastrointestinal tract physiology. They are classified into three groups: the gastric peptides (TFF1, spasmolytic peptide (TFF2 and intestinal trefoil factor (TFF3. Previous studies have shown that trefoil factors are located and expressed in human endocrine pancreas suggesting that TFF3 play a role in: a pancreatic cells migration, b β-cell mitosis, and c pancreatic cells regeneration. We speculated that the presence of TFF3 in pancreas, could be associated to a possible regulation mechanism by insulin and glucose. To date, there are not reports whether the unbalance in carbohydrate metabolism observed in diabetes could affect the production or expression of TFF3.Methods: We determined the TFF3 levels and expression by immunoassay (ELISA and semi-quantitative RT-PCR technique respectively, of intestinal epithelial cells (HT-29 treated with glucose and insulin. Also,Real Time-PCR (RTq-PCR was done.Results: Increasing concentrations of glucose improved TFF3 expression and these levels were further elevated after insulin treatment. Insulin treatment also led to the up-regulation of human sodium/glucose transporter 1 (hSGLT1, which further increases intracellular glucose levels. Finally, we investigated theTFF3 levels in serum of diabetes mellitus type 1 (T1DM and healthy patients. Here we shown that serum TFF3 levels were down-regulated in T1DM and this levels were up-regulated after insulin treatment. Also, the TFF3 levels of healthy donors were up-regulated 2 h after breakfast.Conclusion: Our fi ndings suggest for the fi rst time that insulin signaling is important for TFF3 optimal expression in serum and intestinal epithelial cells.

  7. Factors that regulate insulin producing cells and their output in Drosophila

    Directory of Open Access Journals (Sweden)

    Dick R Nässel

    2013-09-01

    Full Text Available Insulin-like peptides (ILPs and growth factors (IGFs not only regulate development, growth, reproduction, metabolism, stress resistance, and lifespan, but also certain behaviors and cognitive functions. ILPs, IGFs, their tyrosine kinase receptors and downstream signaling components have been largely conserved over animal evolution. Eight ILPs have been identified in Drosophila (DILP1-8 and they display cell and stage-specific expression patterns. Only one insulin receptor, dInR, is known in Drosophila and most other invertebrates. Nevertheless the different DILPs are independently regulated transcriptionally and appear to have distinct functions, although some functional redundancy has been revealed. This review summarizes what is known about regulation of production and release of DILPs in Drosophila with focus on insulin signaling in the daily life of the fly. Under what conditions are DILP-producing cells (IPCs activated and which factors have been identified in control of IPC activity in larvae and adult flies? The brain IPCs that produce DILP2, 3 and 5 are indirectly targeted by DILP6 and a leptin-like factor from the fat body as well as directly by a few neurotransmitters and neuropeptides. Serotonin, octopamine, GABA, short neuropeptide F (sNPF, corazonin and tachykinin-related peptide have been identified in Drosophila as regulators of IPCs. The GABAergic cells that inhibit IPCs and DILP release are in turn targeted by a leptin-like peptide (unpaired 2 from the fat body, and the IPC-stimulating corazonin/sNPF neurons may be targeted by gut-derived peptides. We also discuss physiological conditions under which IPC activity may be regulated, including nutritional states, stress and diapause induction

  8. Stress-induced nuclear RNA degradation pathways regulate yeast bromodomain factor 2 to promote cell survival.

    Directory of Open Access Journals (Sweden)

    Kevin Roy

    2014-09-01

    Full Text Available Bromodomain proteins are key regulators of gene expression. How the levels of these factors are regulated in specific environmental conditions is unknown. Previous work has established that expression of yeast Bromodomain factor 2 (BDF2 is limited by spliceosome-mediated decay (SMD. Here we show that BDF2 is subject to an additional layer of post-transcriptional control through RNase III-mediated decay (RMD. We found that the yeast RNase III Rnt1p cleaves a stem-loop structure within the BDF2 mRNA to down-regulate its expression. However, these two nuclear RNA degradation pathways play distinct roles in the regulation of BDF2 expression, as we show that the RMD and SMD pathways of the BDF2 mRNA are differentially activated or repressed in specific environmental conditions. RMD is hyper-activated by salt stress and repressed by hydroxyurea-induced DNA damage while SMD is inactivated by salt stress and predominates during DNA damage. Mutations of cis-acting signals that control SMD and RMD rescue numerous growth defects of cells lacking Bdf1p, and show that SMD plays an important role in the DNA damage response. These results demonstrate that specific environmental conditions modulate nuclear RNA degradation pathways to control BDF2 expression and Bdf2p-mediated gene regulation. Moreover, these results show that precise dosage of Bromodomain factors is essential for cell survival in specific environmental conditions, emphasizing their importance for controlling chromatin structure and gene expression in response to environmental stress.

  9. Environmental factors related to water level regulation - a comparative study in northern Finland

    Energy Technology Data Exchange (ETDEWEB)

    Hellsten, S.K. [VTT Communities and Infrastructure. Water Engineering and Ecotechnology, Oulu (Finland)

    1997-12-31

    The environmental conditions of the littoral zone were studied in the regulated Lake Ontojaervi and the unregulated Lake Lentua in northern Finland. The general aims of the study were to analyse the environmental factors related to water level regulation in the littoral zone and to produce information for assessing the effects of hydroelectric development in northern lakes. The study was basically carried out by comparing the littoral environments of the two study lakes. The most visible effects of water level regulation were related to the raised water level, which yielded erosion of sandy shores at the beginning of the regulation. Another effect of lake regulation was the altered fluctuation of the water level, which led to bottom instability and increased the size of the frozen and ice penetration zones. The effect of ice penetration was also easy to recognize on the shores of Lake Ontojaervi, where the surface sediment was frozen to a greater depth and across wider areas than in Lake Lentua. Below the freezing zone, the ice just pressed down on the sediment. The shores of Lake Ontojaervi were steeper than those of Lake Lentua, which affected the distribution of bottom types, with sandy bottoms being more common in Lake Lentua than in Lake Ontojaervi. The factors related to site exposure included effective fetch and the shape of the shoreline. The sedimentation level correlated only with the slope and was not predicted by the fetch or shape. The vertical reduction of light was estimated on the basis of water colour. The main environmental factors from the two lakes were used in a discriminant analysis to predict the bottom type distribution of the littoral (r{sup 2} = 0.41). (orig.) 66 refs.

  10. Transcriptional Factor PU.1 Regulates Decidual C1q Expression in Early Pregnancy in Human.

    Science.gov (United States)

    Madhukaran, Shanmuga Priyaa; Kishore, Uday; Jamil, Kaiser; Teo, Boon Heng Dennis; Choolani, Mahesh; Lu, Jinhua

    2015-01-01

    C1q is the first recognition subcomponent of the complement classical pathway, which in addition to being synthesized in the liver, is also expressed by macrophages and dendritic cells (DCs). Trophoblast invasion during early placentation results in accumulation of debris that triggers the complement system. Hence, both early and late components of the classical pathway are widely distributed in the placenta and decidua. In addition, C1q has recently been shown to significantly contribute to feto-maternal tolerance, trophoblast migration, and spiral artery remodeling, although the exact mechanism remains unknown. Pregnancy in mice, genetically deficient in C1q, mirrors symptoms similar to that of human preeclampsia. Thus, regulated complement activation has been proposed as an essential requirement for normal successful pregnancy. Little is known about the molecular pathways that regulate C1q expression in pregnancy. PU.1, an Ets-family transcription factor, is required for the development of hematopoietic myeloid lineage immune cells, and its expression is tissue-specific. Recently, PU.1 has been shown to regulate C1q gene expression in DCs and macrophages. Here, we have examined if PU.1 transcription factor regulates decidual C1q expression. We used immune-histochemical analysis, PCR, and immunostaining to localize and study the gene expression of PU.1 transcription factor in early human decidua. PU.1 was highly expressed at gene and protein level in early human decidual cells including trophoblast and stromal cells. Surprisingly, nuclear as well as cytoplasmic PU.1 expression was observed. Decidual cells with predominantly nuclear PU.1 expression had higher C1q expression. It is likely that nuclear and cytoplasmic PU.1 localization has a role to play in early pregnancy via regulating C1q expression in the decidua during implantation.

  11. Trefoil factor 3 (TFF3 expression is regulated by insulin and glucose

    Directory of Open Access Journals (Sweden)

    Girolamo Jose Barrera Roa

    2013-04-01

    Full Text Available Introduction: Trefoil factors are effector molecules in gastrointestinal tract physiology. They are classified into three groups: the gastric peptides (TFF1, spasmolytic peptide (TFF2 and intestinal trefoil factor (TFF3. Previous studies have shown that trefoil factors are located and expressed in human endocrine pancreas suggesting that TFF3 play a role in: a pancreatic cells migration, b β-cell mitosis, and c pancreatic cells regeneration. We speculated that the presence of TFF3 in pancreas, could be associated to a possible regulation mechanism by insulin and glucose. To date, there are not reports whether the unbalance in carbohydrate metabolism observed in diabetes could affect the production or expression of TFF3.Methods: We determined the TFF3 levels and expression by immunoassay (ELISA and semi-quantitative RT-PCR technique respectively, of intestinal epithelial cells (HT-29 treated with glucose and insulin. Also,Real Time-PCR (RTq-PCR was done.Results: Increasing concentrations of glucose improved TFF3 expression and these levels were further elevated after insulin treatment. Insulin treatment also led to the up-regulation of human sodium/glucose transporter 1 (hSGLT1, which further increases intracellular glucose levels. Finally, we investigated theTFF3 levels in serum of diabetes mellitus type 1 (T1DM and healthy patients. Here we shown that serum TFF3 levels were down-regulated in T1DM and this levels were up-regulated after insulin treatment. Also, the TFF3 levels of healthy donors were up-regulated 2 h after breakfast.Conclusion: Our fi ndings suggest for the fi rst time that insulin signaling is important for TFF3 optimal expression in serum and intestinal epithelial cells.

  12. Interferon Regulatory Factor 7 Functions as a Novel Negative Regulator of Pathological Cardiac Hypertrophy

    Science.gov (United States)

    Jiang, Ding-Sheng; Liu, Yu; Zhou, Heng; Zhang, Yan; Zhang, Xiao-Dong; Zhang, Xiao-Fei; Chen, Ke; Gao, Lu; Peng, Juan; Gong, Hui; Chen, Yingjie; Yang, Qinglin; Liu, Peter P.; Fan, Guo-Chang; Zou, Yunzeng; Li, Hongliang

    2017-01-01

    Cardiac hypertrophy is a complex pathological process that involves multiple factors including inflammation and apoptosis. Interferon regulatory factor 7 (IRF7) is a multifunctional regulator that participates in immune regulation, cell differentiation, apoptosis, and oncogenesis. However, the role of IRF7 in cardiac hypertrophy remains unclear. We performed aortic banding in cardiac-specific IRF7 transgenic mice, IRF7 knockout mice, and the wild-type littermates of these mice. Our results demonstrated that IRF7 was downregulated in aortic banding–induced animal hearts and cardiomyocytes that had been treated with angiotensin II or phenylephrine for 48 hours. Accordingly, heart-specific overexpression of IRF7 significantly attenuated pressure overload–induced cardiac hypertrophy, fibrosis, and dysfunction, whereas loss of IRF7 led to opposite effects. Moreover, IRF7 protected against angiotensin II–induced cardiomyocyte hypertrophy in vitro. Mechanistically, we identified that IRF7-dependent cardioprotection was mediated through IRF7 binding to inhibitor of κB kinase-β, and subsequent nuclear factor-κB inactivation. In fact, blocking nuclear factor-κB signaling with cardiac-specific inhibitors of κBαS32A/S36A super-repressor transgene counteracted the adverse effect of IRF7 deficiency. Conversely, activation of nuclear factor-κB signaling via a cardiac-specific conditional inhibitor of κB kinase-βS177E/S181E (constitutively active) transgene negated the antihypertrophic effect of IRF7 overexpression. Our data demonstrate that IRF7 acts as a novel negative regulator of pathological cardiac hypertrophy by inhibiting nuclear factor-κB signaling and may constitute a potential therapeutic target for pathological cardiac hypertrophy. PMID:24396025

  13. Interferon regulatory factor 7 functions as a novel negative regulator of pathological cardiac hypertrophy.

    Science.gov (United States)

    Jiang, Ding-Sheng; Liu, Yu; Zhou, Heng; Zhang, Yan; Zhang, Xiao-Dong; Zhang, Xiao-Fei; Chen, Ke; Gao, Lu; Peng, Juan; Gong, Hui; Chen, Yingjie; Yang, Qinglin; Liu, Peter P; Fan, Guo-Chang; Zou, Yunzeng; Li, Hongliang

    2014-04-01

    Cardiac hypertrophy is a complex pathological process that involves multiple factors including inflammation and apoptosis. Interferon regulatory factor 7 (IRF7) is a multifunctional regulator that participates in immune regulation, cell differentiation, apoptosis, and oncogenesis. However, the role of IRF7 in cardiac hypertrophy remains unclear. We performed aortic banding in cardiac-specific IRF7 transgenic mice, IRF7 knockout mice, and the wild-type littermates of these mice. Our results demonstrated that IRF7 was downregulated in aortic banding-induced animal hearts and cardiomyocytes that had been treated with angiotensin II or phenylephrine for 48 hours. Accordingly, heart-specific overexpression of IRF7 significantly attenuated pressure overload-induced cardiac hypertrophy, fibrosis, and dysfunction, whereas loss of IRF7 led to opposite effects. Moreover, IRF7 protected against angiotensin II-induced cardiomyocyte hypertrophy in vitro. Mechanistically, we identified that IRF7-dependent cardioprotection was mediated through IRF7 binding to inhibitor of κB kinase-β, and subsequent nuclear factor-κB inactivation. In fact, blocking nuclear factor-κB signaling with cardiac-specific inhibitors of κBα(S32A/S36A) super-repressor transgene counteracted the adverse effect of IRF7 deficiency. Conversely, activation of nuclear factor-κB signaling via a cardiac-specific conditional inhibitor of κB kinase-β(S177E/S181E) (constitutively active) transgene negated the antihypertrophic effect of IRF7 overexpression. Our data demonstrate that IRF7 acts as a novel negative regulator of pathological cardiac hypertrophy by inhibiting nuclear factor-κB signaling and may constitute a potential therapeutic target for pathological cardiac hypertrophy.

  14. Structure, circadian regulation and bioinformatic analysis of the unique sigma factor gene in Chlamydomonas reinhardtii.

    Science.gov (United States)

    Carter, Matthew L; Smith, Annette C; Kobayashi, Hirokazu; Purton, Saul; Herrin, David L

    2004-01-01

    In higher plants, the transcription of plastid genes is mediated by at least two types of RNA polymerase (RNAP); a plastid-encoded bacterial RNAP in which promoter specificity is conferred by nuclear-encoded sigma factors, and a nuclear-encoded phage-like RNAP. Green algae, however, appear to possess only the bacterial enzyme. Since transcription of much, if not most, of the chloroplast genome in Chlamydomonas reinhardtii is regulated by the circadian clock and the nucleus, we sought to identify sigma factor genes that might be responsible for this regulation. We describe a nuclear gene (RPOD) that is predicted to encode an 80 kDa protein that, in addition to a predicted chloroplast transit peptide at the N-terminus, has the conserved motifs (2.1- 4.2) diagnostic of bacterial sigma-70 factors. We also identified two motifs not previously recognized for sigma factors, adjacent PEST sequences and a leucine zipper, both suggested to be involved in protein-protein interactions. PEST sequences were also found in approximately 40% of sigma factors examined, indicating they may be of general significance. Southern blot hybridization and BLAST searches of the genome and EST databases suggest that RPODmay be the only sigma factor gene in C. reinhardtii. The levels of RPODmRNA increased 2- 3-fold in the mid-to-late dark period of light-dark cycling cells, just prior to, or coincident with, the peak in chloroplast transcription. Also, the dark-period peak in RPOD mRNA persisted in cells shifted to continuous light or continuous dark for at least one cycle, indicating that RPODis under circadian clock control. These results suggest that regulation of RPODexpression contributes to the circadian clock's control of chloroplast transcription.

  15. Antiproliferative factor regulates connective tissue growth factor (CTGF/CCN2) expression in T24 bladder carcinoma cells

    Science.gov (United States)

    Matika, Christina A.; Wasilewski, Melissa; Arnott, John A.; Planey, Sonia Lobo

    2012-01-01

    Antiproliferative factor (APF) is a sialoglycopeptide elevated in the urine of patients with interstitial cystitis (IC)—a chronic, painful bladder disease of unknown etiology. APF inhibits the proliferation of normal bladder epithelial and T24 bladder carcinoma cells in vitro by binding to cytoskeleton-associated protein 4 (CKAP4) and altering the transcription of genes involved in proliferation, cellular adhesion, and tumorigenesis; however, specific molecular mechanisms and effector genes that control APF's antiproliferative effects are unknown. In this study, we found that there was a 7.5-fold up-regulation of connective tissue growth factor (CTGF/CCN2) expression in T24 bladder carcinoma cells treated with APF. Western blot revealed a dose-dependent increase in CCN2 protein levels, with secretion into the culture medium after APF treatment. CCN2 overexpression enhanced APF's antiproliferative activity, whereas CCN2 knockdown diminished APF-induced p53 expression. Using a luciferase reporter construct, we found that APF treatment resulted in fivefold activation of the CCN2 proximal promoter and, of importance, that small interfering RNA–mediated knockdown of CKAP4 inhibited CCN2 upregulation. In addition, we demonstrate that CKAP4 translocates to the nucleus and binds to the CCN2 proximal promoter in an APF-dependent manner, providing evidence that CCN2 regulation by APF involves CKAP4 nuclear translocation and binding to the CCN2 promoter. PMID:22438586

  16. Regulation of Hepatic Stellate Cells and Fibrogenesis by Fibroblast Growth Factors

    Directory of Open Access Journals (Sweden)

    Justin D. Schumacher

    2016-01-01

    Full Text Available Fibroblast growth factors (FGFs are a family of growth factors critically involved in developmental, physiological, and pathological processes, including embryogenesis, angiogenesis, wound healing, and endocrine functions. In the liver, several FGFs are produced basally by hepatocytes and hepatic stellate cells (HSCs. Upon insult to the liver, expression of FGFs in HSCs is greatly upregulated, stimulating hepatocyte regeneration and growth. Various FGF isoforms have also been shown to directly induce HSC proliferation and activation thereby enabling autocrine and paracrine regulation of HSC function. Regulation of HSCs by the endocrine FGFs, namely, FGF15/19 and FGF21, has also recently been identified. With the ability to modulate HSC proliferation and transdifferentiation, targeting FGF signaling pathways constitutes a promising new therapeutic strategy to treat hepatic fibrosis.

  17. The neglected role of insulin-like growth factors in the maternal circulation regulating fetal growth.

    Science.gov (United States)

    Sferruzzi-Perri, A N; Owens, J A; Pringle, K G; Roberts, C T

    2011-01-01

    Maternal insulin-like growth factors (IGFs) play a pivotal role in modulating fetal growth via their actions on both the mother and the placenta. Circulating IGFs influence maternal tissue growth and metabolism, thereby regulating nutrient availability for the growth of the conceptus. Maternal IGFs also regulate placental morphogenesis, substrate transport and hormone secretion, all of which influence fetal growth either via indirect effects on maternal substrate availability, or through direct effects on the placenta and its capacity to supply nutrients to the fetus. The extent to which IGFs influence the mother and/or placenta are dependent on the species and maternal factors, including age and nutrition. As altered fetal growth is associated with increased perinatal morbidity and mortality and a greater risk of developing degenerative diseases in adult life, understanding the role of maternal IGFs during pregnancy is essential in order to identify mechanisms underlying altered fetal growth and offspring programming.

  18. The Hv NAC6 transcription factor: a positive regulator of penetration resistance in barley and Arabidopsis

    DEFF Research Database (Denmark)

    Jensen, Michael Krogh; Rung, Jesper Henrik; Gregersen, Per Langkjaer

    2007-01-01

    Pathogens induce the expression of many genes encoding plant transcription factors, though specific knowledge of the biological function of individual transcription factors remains scarce. NAC transcription factors are encoded in plants by a gene family with proposed functions in both abiotic...... and biotic stress adaptation, as well as in developmental processes. In this paper, we provide convincing evidence that a barley NAC transcription factor has a direct role in regulating basal defence. The gene transcript was isolated by differential display from barley leaves infected with the biotrophic...... powdery mildew fungus, Blumeria graminis f.sp. hordei (Bgh). The full-length cDNA clone was obtained using 5'-RACE and termed HvNAC6, due to its high similarity to the rice homologue, OsNAC6. Gene silencing of HvNAC6 during Bgh inoculation compromises penetration resistance in barley epidermal cells...

  19. What Factors Influence the Relationship Between Feedback on Cognitive Performance and Subsequent Driving Self-Regulation?

    Science.gov (United States)

    Ackerman, Michelle L; Vance, David E; Ball, Karlene K

    2016-06-01

    Recent research indicates that providing feedback about cognitive abilities (i.e., UFOV® test performance) may change driving self-regulation; however, 42% of participants who received negative feedback failed to increase driving self-regulation (Ackerman, Ball, Crowe, Owsley, Vance, & Wadley, 2011). The current study extends those findings, using the same sample (N = 129) to investigate factors that may influence the relationship between feedback regarding cognitive abilities and driving self-regulation. Feedback by age and feedback by number of eye conditions showed significant interactions, and feedback by baseline driving exposure interaction approached significance. Older participants (80-94; n = 38) who received negative feedback significantly increased subsequent avoidance of challenging driving conditions relative to baseline. Participants with no reported eye conditions (n = 36) who received negative feedback significantly increased subsequent driving avoidance, and participants below median baseline driving exposure (n = 66) tended to increase subsequent driving avoidance. These results identify individual level factors that may influence the relationship between feedback regarding cognitive abilities and self-regulation and have implications for encouraging older adults to make informed decisions about appropriate driving behavior.

  20. Function and regulation of transcription factors involved in root apical meristem and stem cell maintenance

    Directory of Open Access Journals (Sweden)

    Rebecca Corinna Drisch

    2015-07-01

    Full Text Available Plant roots are essential for overall plant development, growth and performance by providing anchorage in the soil and uptake of nutrients and water. The primary root of higher plants derives from a group of pluripotent, mitotically active stem cells residing in the root apical meristem (RAM which provides the basis for growth, development and regeneration of the root. The stem cells in the Arabidopsis thaliana RAM are surrounding the quiescent center (QC, which consists of a group of rarely dividing cells. The QC maintains the stem cells in a non-cell-autonomous manner and prevents them from differentiation. The necessary dynamic but also tight regulation of the transition from stem cell fate to differentiation most likely requires complex regulatory mechanisms to integrate external and internal cues. Transcription factors play a central role in root development and are regulated by phytohormones, small signaling molecules and miRNAs. In this review we give a comprehensive overview about the function and regulation of specific transcription factors controlling stem cell fate and root apical meristem maintenance and discuss the possibility of TF complex formation, subcellular translocations and cell-to-cell movement functioning as another level of regulation.

  1. Regulation of root hair cell differentiation by R3 MYB transcription factors in tomato and Arabidopsis.

    Science.gov (United States)

    Tominaga-Wada, Rumi; Wada, Takuji

    2014-01-01

    CAPRICE (CPC) encodes a small protein with an R3 MYB motif and regulates root hair and trichome cell differentiation in Arabidopsis thaliana. Six additional CPC-like MYB proteins including TRIPTYCHON (TRY), ENHANCER OF TRY AND CPC1 (ETC1), ENHANCER OF TRY AND CPC2 (ETC2), ENHANCER OF TRY AND CPC3/CPC-LIKE MYB3 (ETC3/CPL3), TRICHOMELESS1 (TCL1), and TRICHOMELESS2/CPC-LIKE MYB4 (TCL2/CPL4) also have the ability to regulate root hair and/or trichome cell differentiation in Arabidopsis. In this review, we describe our latest findings on how CPC-like MYB transcription factors regulate root hair cell differentiation. Recently, we identified the tomato SlTRY gene as an ortholog of the Arabidopsis TRY gene. Transgenic Arabidopsis plants harboring SlTRY produced more root hairs, a phenotype similar to that of 35S::CPC transgenic plants. CPC is also known to be involved in anthocyanin biosynthesis. Anthocyanin accumulation was repressed in the SlTRY transgenic plants, suggesting that SlTRY can also influence anthocyanin biosynthesis. We concluded that tomato and Arabidopsis partially use similar transcription factors for root hair cell differentiation, and that a CPC-like R3 MYB may be a key common regulator of plant root-hair development.

  2. An R2R3-MYB transcription factor regulates carotenoid pigmentation in Mimulus lewisii flowers.

    Science.gov (United States)

    Sagawa, Janelle M; Stanley, Lauren E; LaFountain, Amy M; Frank, Harry A; Liu, Chang; Yuan, Yao-Wu

    2016-02-01

    Carotenoids are yellow, orange, and red pigments that contribute to the beautiful colors and nutritive value of many flowers and fruits. The structural genes in the highly conserved carotenoid biosynthetic pathway have been well characterized in multiple plant systems, but little is known about the transcription factors that control the expression of these structural genes. By analyzing a chemically induced mutant of Mimulus lewisii through bulk segregant analysis and transgenic experiments, we have identified an R2R3-MYB, Reduced Carotenoid Pigmentation 1 (RCP1), as the first transcription factor that positively regulates carotenoid biosynthesis during flower development. Loss-of-function mutations in RCP1 lead to down-regulation of all carotenoid biosynthetic genes and reduced carotenoid content in M. lewisii flowers, a phenotype recapitulated by RNA interference in the wild-type background. Overexpression of this gene in the rcp1 mutant background restores carotenoid production and, unexpectedly, results in simultaneous decrease of anthocyanin production in some transgenic lines by down-regulating the expression of an activator of anthocyanin biosynthesis. Identification of transcriptional regulators of carotenoid biosynthesis provides the 'toolbox' genes for understanding the molecular basis of flower color diversification in nature and for potential enhancement of carotenoid production in crop plants via genetic engineering. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  3. Proteomic analysis of polyribosomes identifies splicing factors as potential regulators of translation during mitosis.

    Science.gov (United States)

    Aviner, Ranen; Hofmann, Sarah; Elman, Tamar; Shenoy, Anjana; Geiger, Tamar; Elkon, Ran; Ehrlich, Marcelo; Elroy-Stein, Orna

    2017-06-02

    Precise regulation of mRNA translation is critical for proper cell division, but little is known about the factors that mediate it. To identify mRNA-binding proteins that regulate translation during mitosis, we analyzed the composition of polysomes from interphase and mitotic cells using unbiased quantitative mass-spectrometry (LC-MS/MS). We found that mitotic polysomes are enriched with a subset of proteins involved in RNA processing, including alternative splicing and RNA export. To demonstrate that these may indeed be regulators of translation, we focused on heterogeneous nuclear ribonucleoprotein C (hnRNP C) as a test case and confirmed that it is recruited to elongating ribosomes during mitosis. Then, using a combination of pulsed SILAC, metabolic labeling and ribosome profiling, we showed that knockdown of hnRNP C affects both global and transcript-specific translation rates and found that hnRNP C is specifically important for translation of mRNAs that encode ribosomal proteins and translation factors. Taken together, our results demonstrate how proteomic analysis of polysomes can provide insight into translation regulation under various cellular conditions of interest and suggest that hnRNP C facilitates production of translation machinery components during mitosis to provide daughter cells with the ability to efficiently synthesize proteins as they enter G1 phase. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  4. Regulation and role of a STE12-like transcription factor from the plant pathogen Colletotrichum lindemuthianum.

    Science.gov (United States)

    Wong Sak Hoi, Joanne; Herbert, Corentin; Bacha, Nafees; O'Connell, Richard; Lafitte, Claude; Borderies, Gisèle; Rossignol, Michel; Rougé, Pierre; Dumas, Bernard

    2007-04-01

    In phytopathogenic fungi, STE12-like genes encode transcription factors essential for appressorium-mediated host penetration. However, their regulation and downstream targets are still unknown. In the present study, a STE12-like gene (CLSTE12) from Colletotrichum lindemuthianum was isolated. We identified a spliced variant whose expression was negatively regulated during early stages of pathogenesis, whereas the correctly spliced mRNA remained expressed up to the penetration step, suggesting distinct roles for these two transcripts. Indeed, the full-length sequence was able to complement a yeast STE12 mutant, whereas overexpression of the transcript variant had a dominant-negative effect on yeast invasive growth and C. lindemuthianum pathogenicity. To further investigate the downstream genes that could be regulated by CLSTE12, disruption mutants were generated. Phenotypic analyses of the mutants revealed reduced pectinase activity and conidial adhesion to polystyrene. Analysis of cell surface proteins allowed the identification of a major protein, Clsp1p, which was absent from the mutants. Clsp1p belongs to a new family of wall-associated proteins only found in euascomycetous fungi. Overall, these results suggest that the activity of CLSTE12 can be modulated by a regulated alternative splicing mechanism and that this factor is involved in the production of cell surface proteins and host cell wall degrading enzymes.

  5. 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.

  6. Quantitative Population Epigenetics in Screening and Development of Regulator-Active Factors of the Farming System

    OpenAIRE

    Stauss, R.

    2013-01-01

    Likewise, index selection based on statistical genetic theory in plant and animal breeding the methodology "Quantitative Population Epigenetics" can be appropriated to improve efficiency in screening and development of regulator-active factors of the farming system for potential to enhance quantitative characters such as yield, standability and resistance to unfavorable environmental influences (e.g., water stress, cold temperatures, disease resistance). For example, as was shown for an ef...

  7. Prostaglandin E2 regulates macrophage colony stimulating factor secretion by human bone marrow stromal cells.

    Science.gov (United States)

    Besse, A; Trimoreau, F; Faucher, J L; Praloran, V; Denizot, Y

    1999-07-08

    Bone marrow stromal cells regulate marrow haematopoiesis by secreting growth factors such as macrophage colony stimulating factor (M-CSF) that regulates the proliferation, differentiation and several functions of cells of the mononuclear-phagocytic lineage. By using a specific ELISA we found that their constitutive secretion of M-CSF is enhanced by tumour necrosis factor-alpha (TNF-alpha). The lipid mediator prostaglandin E2 (PGE2) markedly reduces in a time- and dose-dependent manner the constitutive and TNF-alpha-induced M-CSF synthesis by bone marrow stromal cells. In contrast, other lipid mediators such as 12-HETE, 15-HETE, leukotriene B4, leukotriene C4 and lipoxin A4 have no effect. EP2/EP4 selective agonists (11-deoxy PGE1 and 1-OH PGE1) and EP2 agonist (19-OH PGE2) inhibit M-CSF synthesis by bone marrow stromal cells while an EP1/EP3 agonist (sulprostone) has no effect. Stimulation with PGE2 induces an increase of intracellular cAMP levels in bone marrow stromal cells. cAMP elevating agents (forskolin and cholera toxin) mimic the PGE2-induced inhibition of M-CSF production. In conclusion, PGE2 is a potent regulator of M-CSF production by human bone marrow stromal cells, its effects being mediated via cAMP and PGE receptor EP2/EP4 subtypes.

  8. An NAC transcription factor controls ethylene-regulated cell expansion in flower petals.

    Science.gov (United States)

    Pei, Haixia; Ma, Nan; Tian, Ji; Luo, Jing; Chen, Jiwei; Li, Jing; Zheng, Yi; Chen, Xiang; Fei, Zhangjun; Gao, Junping

    2013-10-01

    Cell expansion is crucial for plant growth. It is well known that the phytohormone ethylene functions in plant development as a key modulator of cell expansion. However, the role of ethylene in the regulation of this process remains unclear. In this study, 2,189 ethylene-responsive transcripts were identified in rose (Rosa hybrida) petals using transcriptome sequencing and microarray analysis. Among these transcripts, an NAC (for no apical meristem [NAM], Arabidopsis transcription activation factor [ATAF], and cup-shaped cotyledon [CUC])-domain transcription factor gene, RhNAC100, was rapidly and dramatically induced by ethylene in the petals. Interestingly, accumulation of the RhNAC100 transcript was modulated by ethylene via microRNA164-dependent posttranscriptional regulation. Overexpression of RhNAC100 in Arabidopsis (Arabidopsis thaliana) substantially reduced the petal size by repressing petal cell expansion. By contrast, silencing of RhNAC100 in rose petals using virus-induced gene silencing significantly increased petal size and promoted cell expansion in the petal abaxial subepidermis (P cellulose synthase and two aquaporin genes (Rosa hybrida Cellulose Synthase2 and R. hybrida Plasma Membrane Intrinsic Protein1;1/2;1) were identified as targets of RhNAC100. Our results suggest that ethylene regulates cell expansion by fine-tuning the microRNA164/RhNAC100 module and also provide new insights into the function of NAC transcription factors.

  9. Hierarchical Interactions of Homeodomain and Forkhead Transcription Factors in Regulating Odontogenic Gene Expression*

    Science.gov (United States)

    Venugopalan, Shankar R.; Li, Xiao; Amen, Melanie A.; Florez, Sergio; Gutierrez, Diana; Cao, Huojun; Wang, Jianbo; Amendt, Brad A.

    2011-01-01

    FoxJ1 is a forkhead transcription factor expressed in multiple tissues during development and a major regulator of cilia development. FoxJ1−/− mice present with defects in odontogenesis, and we correlate these defects to hierarchical interactions between homeodomain factors Pitx2 and Dlx2 with FoxJ1 in regulating their expression through direct physical interactions. Chromatin immunoprecipitation assays reveal endogenous Pitx2 and Dlx2 binding to the Dlx2 promoter and Dlx2 binding to the FoxJ1 promoter as well as Dlx2 and FoxJ1 binding to the amelogenin promoter. PITX2 activation of the Dlx2 promoter is attenuated by a direct Dlx2 physical interaction with PITX2. Dlx2 autoregulates its promoter, and Dlx2 transcriptionally activates the downstream gene FoxJ1. Dlx2 and FoxJ1 physically interact and synergistically regulate both Dlx2 and FoxJ1 promoters. Dlx2 and FoxJ1 also activate the amelogenin promoter, and amelogenin is required for enamel formation and late stage tooth development. FoxJ1−/− mice maxillary and mandibular incisors are reduced in length and width and have reduced amelogenin expression. FoxJ1−/− mice show a reduced and defective ameloblast layer, revealing a biological effect of these transcription factor hierarchies during tooth morphogenesis. These transcriptional mechanisms may contribute to other developmental processes such as neuronal, pituitary, and heart development. PMID:21504905

  10. Regulation of Nox enzymes expression in vascular pathophysiology: Focusing on transcription factors and epigenetic mechanisms.

    Science.gov (United States)

    Manea, Simona-Adriana; Constantin, Alina; Manda, Gina; Sasson, Shlomo; Manea, Adrian

    2015-08-01

    NADPH oxidases (Nox) represent a family of hetero-oligomeric enzymes whose exclusive biological function is the generation of reactive oxygen species (ROS). Nox-derived ROS are essential modulators of signal transduction pathways that control key physiological activities such as cell growth, proliferation, migration, differentiation, and apoptosis, immune responses, and biochemical pathways. Enhanced formation of Nox-derived ROS, which is generally associated with the up-regulation of different Nox subtypes, has been established in various pathologies, namely cardiovascular diseases, diabetes, obesity, cancer, and neurodegeneration. The detrimental effects of Nox-derived ROS are related to alterations in cell signalling and/or direct irreversible oxidative damage of nucleic acids, proteins, carbohydrates, and lipids. Thus, understanding of transcriptional regulation mechanisms of Nox enzymes have been extensively investigated in an attempt to find ways to counteract the excessive formation of Nox-derived ROS in various pathological states. Despite the numerous existing data, the molecular pathways responsible for Nox up-regulation are not completely understood. This review article summarizes some of the recent advances and concepts related to the regulation of Nox expression in the vascular pathophysiology. It highlights the role of transcription factors and epigenetic mechanisms in this process. Identification of the signalling molecules involved in Nox up-regulation, which is associated with the onset and development of cardiovascular dysfunction may contribute to the development of novel strategies for the treatment of cardiovascular diseases.

  11. Orthologous transcription factors in bacteria have different functions and regulate different genes.

    Directory of Open Access Journals (Sweden)

    Morgan N Price

    2007-09-01

    Full Text Available Transcription factors (TFs form large paralogous gene families and have complex evolutionary histories. Here, we ask whether putative orthologs of TFs, from bidirectional best BLAST hits (BBHs, are evolutionary orthologs with conserved functions. We show that BBHs of TFs from distantly related bacteria are usually not evolutionary orthologs. Furthermore, the false orthologs usually respond to different signals and regulate distinct pathways, while the few BBHs that are evolutionary orthologs do have conserved functions. To test the conservation of regulatory interactions, we analyze expression patterns. We find that regulatory relationships between TFs and their regulated genes are usually not conserved for BBHs in Escherichia coli K12 and Bacillus subtilis. Even in the much more closely related bacteria Vibrio cholerae and Shewanella oneidensis MR-1, predicting regulation from E. coli BBHs has high error rates. Using gene-regulon correlations, we identify genes whose expression pattern differs between E. coli and S. oneidensis. Using literature searches and sequence analysis, we show that these changes in expression patterns reflect changes in gene regulation, even for evolutionary orthologs. We conclude that the evolution of bacterial regulation should be analyzed with phylogenetic trees, rather than BBHs, and that bacterial regulatory networks evolve more rapidly than previously thought.

  12. Regulation of Nox enzymes expression in vascular pathophysiology: Focusing on transcription factors and epigenetic mechanisms

    Directory of Open Access Journals (Sweden)

    Simona-Adriana Manea

    2015-08-01

    Full Text Available NADPH oxidases (Nox represent a family of hetero-oligomeric enzymes whose exclusive biological function is the generation of reactive oxygen species (ROS. Nox-derived ROS are essential modulators of signal transduction pathways that control key physiological activities such as cell growth, proliferation, migration, differentiation, and apoptosis, immune responses, and biochemical pathways. Enhanced formation of Nox-derived ROS, which is generally associated with the up-regulation of different Nox subtypes, has been established in various pathologies, namely cardiovascular diseases, diabetes, obesity, cancer, and neurodegeneration. The detrimental effects of Nox-derived ROS are related to alterations in cell signalling and/or direct irreversible oxidative damage of nucleic acids, proteins, carbohydrates, and lipids. Thus, understanding of transcriptional regulation mechanisms of Nox enzymes have been extensively investigated in an attempt to find ways to counteract the excessive formation of Nox-derived ROS in various pathological states. Despite the numerous existing data, the molecular pathways responsible for Nox up-regulation are not completely understood. This review article summarizes some of the recent advances and concepts related to the regulation of Nox expression in the vascular pathophysiology. It highlights the role of transcription factors and epigenetic mechanisms in this process. Identification of the signalling molecules involved in Nox up-regulation, which is associated with the onset and development of cardiovascular dysfunction may contribute to the development of novel strategies for the treatment of cardiovascular diseases.

  13. MicroRNA-24 Regulates Osteogenic Differentiation via Targeting T-Cell Factor-1

    Directory of Open Access Journals (Sweden)

    Weigong Zhao

    2015-05-01

    Full Text Available MicroRNAs (miRNAs have been reported to have diverse biological roles in regulating many biological processes, including osteogenic differentiation. In the present study, we identified that miR-24 was a critical regulator during osteogenic differentiation. We found that overexpression of miR-24 significantly inhibited osteogenic differentiation, which decreased alkaline phosphatase activity, matrix mineralization and the expression of osteogenic differentiation markers. In contrast, inhibition of miR-24 exhibited an opposite effect. Furthermore, we delineated that miR-24 regulates post-transcriptionals of T-cell factor-1 (Tcf-1 via targeting the 3'-untranslated region (UTR of Tcf-1 mRNA. MiR-24 was further found to regulate the protein expression of Tcf-1 in the murine osteoprogenitors cells and bone mesenchymal stem cells. Additionally, the positive effect of miR-24 suppression on osteoblast differentiation was apparently abrogated by Tcf-1 silencing. Taken together, our data suggest that miR-24 participates in osteogenic differentiation by targeting and regulating Tcf-1 expression in osteoblastic cells.

  14. Myogenic factors that regulate expression of muscle-specific microRNAs.

    Science.gov (United States)

    Rao, Prakash K; Kumar, Roshan M; Farkhondeh, Mina; Baskerville, Scott; Lodish, Harvey F

    2006-06-01

    Since their discovery as key regulators of early animal development, microRNAs now are recognized as widespread regulators of gene expression. Despite their abundance, little is known regarding the regulation of microRNA biogenesis. We show that three highly conserved muscle-specific microRNAs, miR-1, miR-133 and miR-206, are robustly induced during the myoblast-myotube transition, both in primary human myoblasts and in the mouse mesenchymal C2C12 stem cell line. These microRNAs were not induced during osteogenic conversion of C2C12 cells. Moreover, both loci encoding miR-1, miR-1-1, and miR-1-2, and two of the three encoding miR-133, miR-133a-1 and miR-133a-2, are strongly induced during myogenesis. Some of the induced microRNAs are in intergenic regions, whereas two are transcribed in the opposite direction to the nonmuscle-specific gene in which they are embedded. By using CHIP analysis, we demonstrate that the myogenic factors Myogenin and MyoD bind to regions upstream of these microRNAs and, therefore, are likely to regulate their expression. Because miR-1 and miR-206 are predicted to repress similar mRNA targets, our work suggests that induction of these microRNAs is important in regulating the expression of muscle-specific proteins.

  15. Mxi1 regulates cell proliferation through insulin-like growth factor binding protein-3

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Je Yeong; Yoo, Kyung Hyun [Department of Biological Science, Sookmyung Women' s University, Seoul (Korea, Republic of); Lee, Han-Woong [Department of Biochemistry, Yonsei University, Seoul (Korea, Republic of); Park, Jong Hoon, E-mail: parkjh@sookmyung.ac.kr [Department of Biological Science, Sookmyung Women' s University, Seoul (Korea, Republic of)

    2011-11-11

    Highlights: Black-Right-Pointing-Pointer Mxi1 regulates cell proliferation. Black-Right-Pointing-Pointer Expression of IGFBP-3 is regulated by Mxi1. Black-Right-Pointing-Pointer Inactivation of Mxi1 reduces IGFBP-3 expression in vitro and in vivo. -- Abstract: Mxi1, a member of the Myc-Max-Mad network, is an antagonist of the c-Myc oncogene and is associated with excessive cell proliferation. Abnormal cell proliferation and tumorigenesis are observed in organs of Mxi1-/- mice. However, the Mxi1-reltaed mechanism of proliferation is unclear. The present study utilized microarray analysis using Mxi1 mouse embryonic fibroblasts (MEFs) to identify genes associated with cell proliferation. Among these genes, insulin-like growth factor binding protein-3 (IGFBP-3) was selected as a candidate gene for real-time PCR to ascertain whether IGFBP-3 expression is regulated by Mxi1. Expression of IGFBP-3 was decreased in Mxi1-/- MEFs and Mxi1-/- mice, and the gene was regulated by Mxi1 in Mxi1 MEFs. Furthermore, proliferation pathways related to IGFBP-3 were regulated in Mxi1-/- mice compared to Mxi1+/+ mice. To determine the effect of Mxi1 inactivation on the induction of cell proliferation, a proliferation assay is performed in both Mxi1 MEFs and Mxi1 mice. Cell viability was regulated by Mxi1 in Mxi1 MEFs and number of PCNA-positive cells was increased in Mxi1-/- mice compared to Mxi1+/+ mice. Moreover, the IGFBP-3 level was decreased in proliferation defect regions in Mxi1-/- mice. The results support the suggestion that inactivation of Mxi1 has a positive effect on cell proliferation by down-regulating IGFBP-3.

  16. The transcription factor p8 regulates autophagy during diapause embryo formation in Artemia parthenogenetica.

    Science.gov (United States)

    Lin, Cheng; Jia, Sheng-Nan; Yang, Fan; Jia, Wen-Huan; Yu, Xiao-Jian; Yang, Jin-Shu; Yang, Wei-Jun

    2016-07-01

    Autophagy is an essential homeostatic process by which cytoplasmic components, including macromolecules and organelles, are degraded by lysosome. Increasing evidence suggests that phosphorylated AMP-activated protein kinase (p-AMPK) and target of rapamycin (TOR) play key roles in the regulation of autophagy. However, the regulation of autophagy in quiescent cells remains unclear, despite the fact that autophagy is known to be critical for normal development, regeneration, and degenerative diseases. Here, crustacean Artemia parthenogenetica was used as a model system because they produced and released encysted embryos that enter a state of obligate dormancy in cell quiescence to withstand various environmental threats. We observed that autophagy was increased before diapause stage but dropped to extremely low level in diapause cysts in Artemia. Western blot analyses indicated that the regulation of autophagy was AMPK/TOR independent during diapause embryo formation. Importantly, the level of p8 (Ar-p8), a stress-inducible transcription cofactor, was elevated at the stage just before diapause and was absent in encysted embryos, indicating that Ar-p8 may regulate autophagy. The results of Ar-p8 knockdown revealed that Ar-p8 regulated autophagy during diapause formation in Artemia. Moreover, we observed that activating transcription factors 4 and 6 (ATF4 and ATF6) responded to Ar-p8-regulated autophagy, indicating that autophagy targeted endoplasmic reticulum (ER) during diapause formation in Artemia. Additionally, AMPK/TOR-independent autophagy was validated in human gastric cancer MKN45 cells overexpressing Ar-p8. The findings presented here may provide insights into the role of p8 in regulating autophagy in quiescent cells.

  17. The transcription factor AREB1 regulates primary metabolic pathways in tomato fruits.

    Science.gov (United States)

    Bastías, Adriana; Yañez, Mónica; Osorio, Sonia; Arbona, Vicent; Gómez-Cadenas, Aurelio; Fernie, Alisdair R; Casaretto, José A

    2014-06-01

    Tomato fruit development is regulated both by the action of plant hormones and by tight genetic control. Recent studies suggest that abscisic acid (ABA) signalling may affect different aspects of fruit maturation. Previously, it was shown that SlAREB1, an ABA-regulated transcription factor involved in stress-induced responses, is expressed in seeds and in fruit tissues in tomato. Here, the role of SlAREB1 in regulating the expression of genes relevant for primary metabolic pathways and affecting the metabolic profile of the fruit was investigated using transgenic tomato lines. Metabolite profiling using gas chromatography-time of flight mass spectrometry (GC-TOF-MS) and non-targeted liquid chromatography-mass spectrometry (LC-MS) was performed on pericarp tissue from fruits harvested at three stages of fruit development. Principal component analysis of the data could distinguish the metabolite profiles of non-transgenic fruits from those that overexpress and down-regulate SlAREB1. Overexpression of SlAREB1 resulted in increased content of organic acids, hexoses, hexose-phosphates, and amino acids in immature green, mature green, and red ripe fruits, and these modifications correlated with the up-regulation of enzyme-encoding genes involved in primary carbohydrate and amino acid metabolism. A non-targeted LC-MS analysis indicated that the composition of secondary metabolites is also affected in transgenic lines. In addition, gene expression data revealed that some genes associated with fruit ripening are also up-regulated in SlAREB1-overexpressing lines compared with wild-type and antisense lines. Taken together, the results suggest that SlAREB1 participates in the regulation of the metabolic programming that takes place during fruit ripening and that may explain part of the role of ABA in fruit development in tomato.

  18. Identification and transcript profiles of citrus growth-regulating factor genes involved in the regulation of leaf and fruit development.

    Science.gov (United States)

    Liu, Xiao; Guo, Ling-Xia; Jin, Long-Fei; Liu, Yong-Zhong; Liu, Tao; Fan, Yu-Hua; Peng, Shu-Ang

    2016-10-01

    Growth-regulating factor (GRF) is an important protein in GA-mediated response, with key roles in plant growth and development. However, it is not known whether or how the GRF proteins in citrus to regulate organ size. In this study, nine citrus GRF genes (CsGRF1-9) were validated from the 'Anliu' sweet orange (AL, Citrus sinensis cv. Anliu) by PCR amplification. They all contain two conserved motifs (QLQ and WRC) and have 3-4 exons. The transcript levels of genes were detected by qRT-PCR. Transcript analysis showed that (1) CsGRF 1, 2, 5, 6, 7, and 9 expressed predominantly in young leaf, CsGRF 3 and 4 expressed predominantly in fruit immature juice sacs and CsGRF 8 expressed predominantly in root; (2) all citrus GRF genes had significantly higher expression in young leaves than mature leaf; (3) in juice sacs, the transcript levels of CsGRF1, 4, 5, 6, and 8 increased significantly while the transcript levels of CsGRF2, 3, 7, and 9 had no significant change from 80 DAF to 100 DAF. Besides, GA3 treatment did not affect the transcript levels of CsGRF5 and CsGRF6 but significantly increased the transcript levels of the other seven CsGRF genes in young leaves. These results suggested that all CsGRF genes involve in the leaf development, CsGRF1, 4, 5, 6, and 8 act developmentally whilst CsGRF2, 3, 7, and 9 play fundamental roles in fruit cell enlargement, which may be through GA pathway or GA-independent pathway.

  19. Protein-Protein Interactions in the Regulation of WRKY Transcription Factors

    Institute of Scientific and Technical Information of China (English)

    Yingjun Chi; Yan Yang; Yuan Zhou; Jie Zhou; Baofang Fan; Jing-Quan Yu; Zhixiang Chen

    2013-01-01

    It has been almost 20 years since the first report of a WRKY transcription factor,SPF1,from sweet potato.Great progress has been made since then in establishing the diverse biological roles of WRKY transcription factors in plant growth,development,and responses to biotic and abiotic stress.Despite the functional diversity,almost all analyzed WRKY proteins recognize the TrGACC/T W-box sequences and,therefore,mechanisms other than mere recognition of the core W-box promoter elements are necessary to achieve the regulatory specificity of WRKY transcription factors.Research over the past several years has revealed that WRKY transcription factors physically interact with a wide range of proteins with roles in signaling,transcription,and chromatin remodeling.Studies of WRKY-interacting proteins have provided important insights into the regulation and mode of action of members of the important family of transcription factors.It has also emerged that the slightly varied WRKY domains and other protein motifs conserved within each of the seven WRKY subfamilies participate in protein-protein interactions and mediate complex functional interactions between WRKY proteins and between WRKY and other regulatory proteins in the modulation of important biological processes.In this review,we summarize studies of protein-protein interactions for WRKY transcription factors and discuss how the interacting partners contribute,at different levels,to the establishment of the complex regulatory and functional network of WRKY transcription factors.

  20. Transcription factor NFE2L2/NRF2 is a regulator of macroautophagy genes

    Science.gov (United States)

    Pajares, Marta; Jiménez-Moreno, Natalia; García-Yagüe, Ángel J.; Escoll, Maribel; de Ceballos, María L.; Van Leuven, Fred; Rábano, Alberto; Yamamoto, Masayuki; Rojo, Ana I.; Cuadrado, Antonio

    2016-01-01

    ABSTRACT Autophagy is a highly coordinated process that is controlled at several levels including transcriptional regulation. Here, we identify the transcription factor NFE2L2/NRF2 (nuclear factor, erythroid 2 like 2) as a regulator of autophagy gene expression and its relevance in a mouse model of Alzheimer disease (AD) that reproduces impaired APP (amyloid β precursor protein) and human (Hs)MAPT/TAU processing, clearance and aggregation. We screened the chromatin immunoprecipitation database ENCODE for 2 proteins, MAFK and BACH1, that bind the NFE2L2-regulated enhancer antioxidant response element (ARE). Using a script generated from the JASPAR's consensus ARE sequence, we identified 27 putative AREs in 16 autophagy-related genes. Twelve of these sequences were validated as NFE2L2 regulated AREs in 9 autophagy genes by additional ChIP assays and quantitative RT-PCR on human and mouse cells after NFE2L2 activation with sulforaphane. Mouse embryo fibroblasts of nfe2l2-knockout mice exhibited reduced expression of autophagy genes, which was rescued by an NFE2L2 expressing lentivirus, and impaired autophagy flux when exposed to hydrogen peroxide. NFE2L2-deficient mice co-expressing HsAPPV717I and HsMAPTP301L, exhibited more intracellular aggregates of these proteins and reduced neuronal levels of SQSTM1/p62, CALCOCO2/NDP52, ULK1, ATG5 and GABARAPL1. Also, colocalization of HsAPPV717I and HsMAPTP301L with the NFE2L2-regulated autophagy marker SQSTM1/p62 was reduced in the absence of NFE2L2. In AD patients, neurons expressing high levels of APP or MAPT also expressed SQSTM1/p62 and nuclear NFE2L2, suggesting their attempt to degrade intraneuronal aggregates through autophagy. This study shows that NFE2L2 modulates autophagy gene expression and suggests a new strategy to combat proteinopathies. PMID:27427974

  1. An R2R3-MYB Transcription Factor Regulates Eugenol Production in Ripe Strawberry Fruit Receptacles.

    Science.gov (United States)

    Medina-Puche, Laura; Molina-Hidalgo, Francisco Javier; Boersma, Maaike; Schuurink, Robert C; López-Vidriero, Irene; Solano, Roberto; Franco-Zorrilla, José-Manuel; Caballero, José Luis; Blanco-Portales, Rosario; Muñoz-Blanco, Juan

    2015-06-01

    Eugenol is a volatile phenylpropanoid that contributes to flower and ripe fruit scent. In ripe strawberry (Fragaria × ananassa) fruit receptacles, eugenol is biosynthesized by eugenol synthase (FaEGS2). However, the transcriptional regulation of this process is still unknown. We have identified and functionally characterized an R2R3 MYB transcription factor (emission of benzenoid II [FaEOBII]) that seems to be the orthologous gene of PhEOBII from Petunia hybrida, which contributes to the regulation of eugenol biosynthesis in petals. The expression of FaEOBII was ripening related and fruit receptacle specific, although high expression values were also found in petals. This expression pattern of FaEOBII correlated with eugenol content in both fruit receptacle and petals. The expression of FaEOBII was repressed by auxins and activated by abscisic acid, in parallel to the ripening process. In ripe strawberry receptacles, where the expression of FaEOBII was silenced, the expression of cinnamyl alcohol dehydrogenase1 and FaEGS2, two structural genes involved in eugenol production, was down-regulated. A subsequent decrease in eugenol content in ripe receptacles was also observed, confirming the involvement of FaEOBII in eugenol metabolism. Additionally, the expression of FaEOBII was under the control of FaMYB10, another R2R3 MYB transcription factor that regulates the early and late biosynthetic genes from the flavonoid/phenylpropanoid pathway. In parallel, the amount of eugenol in FaMYB10-silenced receptacles was also diminished. Taken together, these data indicate that FaEOBII plays a regulating role in the volatile phenylpropanoid pathway gene expression that gives rise to eugenol production in ripe strawberry receptacles.

  2. The Ets transcription factor EHF as a regulator of cornea epithelial cell identity.

    Science.gov (United States)

    Stephens, Denise N; Klein, Rachel Herndon; Salmans, Michael L; Gordon, William; Ho, Hsiang; Andersen, Bogi

    2013-11-29

    The cornea is the clear, outermost portion of the eye composed of three layers: an epithelium that provides a protective barrier while allowing transmission of light into the eye, a collagen-rich stroma, and an endothelium monolayer. How cornea development and aging is controlled is poorly understood. Here we characterize the mouse cornea transcriptome from early embryogenesis through aging and compare it with transcriptomes of other epithelial tissues, identifying cornea-enriched genes, pathways, and transcriptional regulators. Additionally, we profiled cornea epithelium and stroma, defining genes enriched in these layers. Over 10,000 genes are differentially regulated in the mouse cornea across the time course, showing dynamic expression during development and modest expression changes in fewer genes during aging. A striking transition time point for gene expression between postnatal days 14 and 28 corresponds with completion of cornea development at the transcriptional level. Clustering classifies co-expressed, and potentially co-regulated, genes into biologically informative categories, including groups that exhibit epithelial or stromal enriched expression. Based on these findings, and through loss of function studies and ChIP-seq, we show that the Ets transcription factor EHF promotes cornea epithelial fate through complementary gene activating and repressing activities. Furthermore, we identify potential interactions between EHF, KLF4, and KLF5 in promoting cornea epithelial differentiation. These data provide insights into the mechanisms underlying epithelial development and aging, identifying EHF as a regulator of cornea epithelial identity and pointing to interactions between Ets and KLF factors in promoting epithelial fate. Furthermore, this comprehensive gene expression data set for the cornea is a powerful tool for discovery of novel cornea regulators and pathways.

  3. The stress-regulated transcription factor CHOP promotes hepatic inflammatory gene expression, fibrosis, and oncogenesis.

    Directory of Open Access Journals (Sweden)

    Diane DeZwaan-McCabe

    Full Text Available Viral hepatitis, obesity, and alcoholism all represent major risk factors for hepatocellular carcinoma (HCC. Although these conditions also lead to integrated stress response (ISR or unfolded protein response (UPR activation, the extent to which these stress pathways influence the pathogenesis of HCC has not been tested. Here we provide multiple lines of evidence demonstrating that the ISR-regulated transcription factor CHOP promotes liver cancer. We show that CHOP expression is up-regulated in liver tumors in human HCC and two mouse models thereof. Chop-null mice are resistant to chemical hepatocarcinogenesis, and these mice exhibit attenuation of both apoptosis and cellular proliferation. Chop-null mice are also resistant to fibrosis, which is a key risk factor for HCC. Global gene expression profiling suggests that deletion of CHOP reduces the levels of basal inflammatory signaling in the liver. Our results are consistent with a model whereby CHOP contributes to hepatic carcinogenesis by promoting inflammation, fibrosis, cell death, and compensatory proliferation. They implicate CHOP as a common contributing factor in the development of HCC in a variety of chronic liver diseases.

  4. Digital power factor control and reactive power regulation for grid-connected photovoltaic inverter

    Energy Technology Data Exchange (ETDEWEB)

    Hassaine, L. [Power Electronics Systems Group, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911 Leganes, Madrid (Spain); Ecole Nationale Polytechnique, Hassen Badi, El Harrach, Alger (Algeria); Olias, E.; Quintero, J. [Power Electronics Systems Group, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911 Leganes, Madrid (Spain); Haddadi, M. [Ecole Nationale Polytechnique, Hassen Badi, El Harrach, Alger (Algeria)

    2009-01-15

    The overall efficiency of photovoltaic (PV) systems connected to the grid depends on the efficiency of direct current (DC) of the solar modules to alternate current (AC) inverter conversion. The requirements for inverter connection include: maximum power point, high efficiency, control power injected into the grid, high power factor and low total harmonic distortion of the currents injected into the grid. An approach to power factor control and reactive power regulation for PV systems connected to the grid using field programmable gate array (FPGA) is proposed. According to the grid demands; both the injected active and reactive powers are controlled. In this paper, a new digital control strategy for a single-phase inverter is carried out. This control strategy is based on the phase shift between the inverter output voltage and the grid voltage, and the digital sinusoidal pulse width modulation (DSPWM) patterns, in order to control the power factor for a wide range of the inverter output current and consequently the control and the regulation of the reactive power will be achieved. The advantage of the proposed control strategy is its implementation around simple digital circuits. In this work, a simulation study of this strategy has been realized using Matlab/Simulink and PSIM. In order to validate its performance, this control has been implemented in a FPGA. Experimental tests have been carried out demonstrating the viability of this control in order to control the power factor and the injected power into the grid. (author)

  5. Human factor H-related protein 2 (CFHR2 regulates complement activation.

    Directory of Open Access Journals (Sweden)

    Hannes U Eberhardt

    Full Text Available Mutations and deletions within the human CFHR gene cluster on chromosome 1 are associated with diseases, such as dense deposit disease, CFHR nephropathy or age-related macular degeneration. Resulting mutant CFHR proteins can affect complement regulation. Here we identify human CFHR2 as a novel alternative pathway complement regulator that inhibits the C3 alternative pathway convertase and terminal pathway assembly. CFHR2 is composed of four short consensus repeat domains (SCRs. Two CFHR2 molecules form a dimer through their N-terminal SCRs, and each of the two C-terminal ends can bind C3b. C3b bound CFHR2 still allows C3 convertase formation but the CFHR2 bound convertases do not cleave the substrate C3. Interestingly CFHR2 hardly competes off factor H from C3b. Thus CFHR2 likely acts in concert with factor H, as CFHR2 inhibits convertases while simultaneously allowing factor H assisted degradation by factor I.

  6. A Myb transcription factor regulates genes of the phenylalanine pathway in maritime pine.

    Science.gov (United States)

    Craven-Bartle, Blanca; Pascual, M Belen; Cánovas, Francisco M; Avila, Concepción

    2013-06-01

    During the life cycles of conifer trees, such as maritime pine (Pinus pinaster Ait.), large quantities of carbon skeletons are irreversibly immobilized in the wood. In energetic terms this is an expensive process, in which carbon from photosynthesis is channelled through the shikimate pathway for the biosynthesis of phenylpropanoids. This crucial metabolic pathway is finely regulated, primarily through transcriptional control, and because phenylalanine is the precursor for phenylpropanoid biosynthesis, the precise regulation of phenylalanine synthesis and use should occur simultaneously. The promoters of three genes encoding the enzymes prephenate aminotransferase (PAT), phenylalanine ammonia lyase (PAL) and glutamine synthetase (GS1b) contain AC elements involved in the transcriptional activation mediated by R2R3-Myb factors. We have examined the capacity of the R2R3-Myb transcription factors Myb1, Myb4 and Myb8 to co-regulate the expression of PAT, PAL and GS1b. Only Myb8 was able to activate the transcription of the three genes. Moreover, the expression of this transcription factor is higher in lignified tissues, in which a high demand for phenylpropanoids exits. In a gain-of-function experiment, we have shown that Myb8 can specifically bind a well-conserved eight-nucleotide-long AC-II element in the promoter regions of PAT, PAL and GS1b, thereby activating their expression. Our results show that Myb8 regulates the expression of these genes involved in phenylalanine metabolism, which is required for channelling photosynthetic carbon to promote wood formation. The co-localization of PAT, PAL, GS1b and MYB8 transcripts in vascular cells further supports this conclusion.

  7. NF-κB Regulates B-Cell-Derived Nerve Growth Factor Expression

    Institute of Scientific and Technical Information of China (English)

    Klaus Heese; Noriko Inoue; Tohru Sawada

    2006-01-01

    In the mammalian brain, four neurotrophins have been identified: nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3) and neurotrophin-4/5 (NT-4/5). NGF exerts an important role in the development and functions of the central and peripheral nervous system. However, it has recently been documented that several types of immune cells, such as mast cells, lymphocytes, basophils and eosinophils, produce,store and release NGF. Accumulating preclinical and clinical data indicate that dysfunctions of NGF and the other neurotrophins may contribute to impaired immune responses and concentration of NGF frequently correlates with disease severity. Thus, the aim of this study was to elucidate the potential signaling mechanisms of cytokineneurotrophins interactions contributing to increased NGF levels. Our data show that the transcription factorNF-κB plays a pivotal role in regulating B-cell-derived NGF expression.

  8. Nuclear Factor-κB: Activation and Regulation during Toll-like Receptor Signaling

    Institute of Scientific and Technical Information of China (English)

    Ruaidhrí J. Carmody; Youhai H. Chen

    2007-01-01

    Toll-like receptors (TLRs) recognize distinct microbial components to initiate the innate and adaptive immune responses. TLR activation culminates in the expression of appropriate pro-inflammatory and immunomodulatory factors to meet pathogenic challenges. The transcription factor NF-κB is the master regulator of all TLR-induced responses and its activation is the pivotal event in TLR-mediated activation of the innate immune response. Many of the key molecular events required for TLR-induced NF-κB activation have been elucidated. However, much remain to be learned about the ability of TLRs to generate pathogen-specific responses using a limited number of transcription factors. This review will focus on our current understanding of NF-κB activation by TLRs and potential mechanisms for achieving a signal-specific response through NF-κB.

  9. Circadian regulation of chloroplastic f and m thioredoxins through control of the CCA1 transcription factor.

    Science.gov (United States)

    Barajas-López, Juan de Dios; Serrato, Antonio Jesus; Cazalis, Roland; Meyer, Yves; Chueca, Ana; Reichheld, Jean Philippe; Sahrawy, Mariam

    2011-03-01

    Chloroplastic thioredoxins f and m (TRX f and TRX m) mediate light regulation of carbon metabolism through the activation of Calvin cycle enzymes. The role of TRX f and m in the activation of Calvin cycle enzymes is best known among the TRX family. However, the discoveries of new potential targets extend the functions of chloroplastic TRXs to other processes in non-photosynthetic tissues. As occurs with numerous chloroplast proteins, their expression comes under light regulation. Here, the focus is on the light regulation of TRX f and TRX m in pea and Arabidopsis during the day/night cycle that is maintained during the subjective night. In pea (Pisum sativum), TRX f and TRX m1 expression is shown to be governed by a circadian oscillation exerted at both the transcriptional and protein levels. Binding shift assays indicate that this control probably involves the interaction of the CCA1 transcription factor and an evening element (EE) located in the PsTRX f and PsTRX m1 promoters. In Arabidopsis, among the multigene family of TRX f and TRX m, AtTRX f2 and AtTRX m2 mRNA showed similar circadian oscillatory regulation, suggesting that such regulation is conserved in plants. However, this oscillation was disrupted in plants overexpressing CCA1 (cca1-ox) or repressing CCA1 and LHY (cca1-lhy). The physiological role of the oscillatory regulation of chloroplastic TRX f and TRX m in plants during the day/night cycle is discussed.

  10. Reciprocal regulation of transcription factors and PLC isozyme gene expression in adult cardiomyocytes.

    Science.gov (United States)

    Singal, Tushi; Dhalla, Naranjan S; Tappia, Paramjit S

    2010-06-01

    By employing a pharmacological approach, we have shown that phospholipase C (PLC) activity is involved in the regulation of gene expression of transcription factors such as c-Fos and c-Jun in cardiomyocytes in response to norepinephrine (NE). However, there is no information available regarding the identity of specific PLC isozymes involved in the regulation of c-Fos and c-Jun or on the involvement of these transcription factors in PLC isozyme gene expression in adult cardiomyocytes. In this study, transfection of cardiomyocytes with PLC isozyme specific siRNA was found to prevent the NE-mediated increases in the corresponding PLC isozyme gene expression, protein content and activity. Unlike PLC gamma(1) gene, silencing of PLC beta(1), beta(3) and delta(1) genes with si RNA prevented the increases in c-Fos and c-Jun gene expression in response to NE. On the other hand, transfection with c-Jun si RNA suppressed the NE-induced increase in c-Jun as well as PLC beta(1), beta(3) and delta(1) gene expression, but had no effect on PLC gamma(1) gene expression. Although transfection of cardiomyocytes with c-Fos si RNA prevented NE-induced expression of c-Fos, PLC beta(1) and PLC beta(3) genes, it did not affect the increases in PLC delta(1) and PLC gamma(1) gene expression. Silencing of either c-Fos or c-Jun also depressed the NE-mediated increases in PLC beta(1), beta(3) and gamma(1) protein content and activity in an isozyme specific manner. Furthermore, silencing of all PLC isozymes as well as of c-Fos and c-Jun resulted in prevention of the NE-mediated increase in atrial natriuretic factor gene expression. These findings, by employing gene silencing techniques, demonstrate that there occurs a reciprocal regulation of transcription factors and specific PLC isozyme gene expression in cardiomyocytes.

  11. Regulation of extracellular matrix genes by arecoline in primary gingival fibroblasts requires epithelial factors.

    Science.gov (United States)

    Thangjam, G S; Agarwal, P; Balapure, A K; Rao, S Girish; Kondaiah, P

    2009-12-01

    Oral submucous fibrosis, a disease of collagen disorder, has been attributed to arecoline present in the saliva of betel quid chewers. However, the molecular basis of the action of arecoline in the pathogenesis of oral submucous fibrosis is poorly understood. The basic aim of our study was to elucidate the mechanism underlying the action of arecoline on the expression of genes in oral fibroblasts. Human keratinocytes (HaCaT cells) and primary human gingival fibroblasts were treated with arecoline in combination with various pathway inhibitors, and the expression of transforming growth factor-beta isoform genes and of collagen isoforms was assessed using reverse transcription-polymerase chain reaction analysis. We observed the induction of transforming growth factor-beta2 by arecoline in HaCaT cells and this induction was found to be caused by activation of the M-3 muscarinic acid receptor via the induction of calcium and the protein kinase C pathway. Most importantly, we showed that transforming growth factor-beta2 was significantly overexpressed in oral submucous fibrosis tissues (p = 0.008), with a median of 2.13 (n = 21) compared with 0.75 (n = 18) in normal buccal mucosal tissues. Furthermore, arecoline down-regulated the expression of collagens 1A1 and 3A1 in human primary gingival fibroblasts; however these collagens were induced by arecoline in the presence of spent medium of cultured human keratinocytes. Treatment with a transforming growth factor-beta blocker, transforming growth factor-beta1 latency-associated peptide, reversed this up-regulation of collagen, suggesting a role for profibrotic cytokines, such as transforming growth factor-beta, in the induction of collagens. Taken together, our data highlight the importance of arecolineinduced epithelial changes in the pathogenesis of oral submucous fibrosis.

  12. An extracytoplasmic function sigma factor, σ(25), differentially regulates avermectin and oligomycin biosynthesis in Streptomyces avermitilis.

    Science.gov (United States)

    Luo, Shuai; Sun, Di; Zhu, Jianya; Chen, Zhi; Wen, Ying; Li, Jilun

    2014-08-01

    σ(25) is an extracytoplasmic function (ECF) σ factor in the bacterium Streptomyces avermitilis that plays a differential regulatory role in avermectin and oligomycin biosynthesis. Gene deletion, complementation, and overexpression experiments showed that σ(25) inhibited avermectin production but promoted oligomycin production. σ(25) indirectly inhibited avermectin production by affecting the transcription of the pathway-specific activator gene aveR, whereas it directly activated oligomycin production by initiating transcription of the pathway-specific activator gene olmRI. The divergently transcribed genes smrAB are located upstream of sig25 and encode a putative two-component system (TCS). σ(25) was found to initiate its own transcription, and its expression was directly activated by SmrA. The precise SmrA-binding sites in the region upstream of sig25 were determined by DNase I footprinting assays and identified two direct repeat sequences CTGTGA-n5-CTGTGA, suggesting that SmrA regulates sig25 transcription by binding to these direct repeats. The deletion of smrAB had the similar effect on avermectin and oligomycin A production to the deletion of sig25, indicating that σ(25) and SmrAB function similarly in the regulation of antibiotic production. These findings helpfully clarify the regulation of antibiotic biosynthesis by an ECF σ factor-TCS signal transduction system in S. avermitilis.

  13. Negative transcriptional regulation of mitochondrial transcription factor A (TFAM) by nuclear TFAM

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Jin; Kang, Young Cheol; Park, Wook-Ha; Jeong, Jae Hoon; Pak, Youngmi Kim, E-mail: ykpak@khu.ac.kr

    2014-07-18

    Highlights: • TFAM localizes in nuclei and mitochondria of neuronal cells. • Nuclear TFAM does not bind the Tfam promoter. • Nuclear TFAM reduced the Tfam promoter activity via suppressing NRF-1 activity. • A novel self-negative feedback regulation of Tfam gene expression is explored. • FAM may play different roles depending on its subcellular localizations. - Abstract: The nuclear DNA-encoded mitochondrial transcription factor A (TFAM) is synthesized in cytoplasm and transported into mitochondria. TFAM enhances both transcription and replication of mitochondrial DNA. It is unclear, however, whether TFAM plays a role in regulating nuclear gene expression. Here, we demonstrated that TFAM was localized to the nucleus and mitochondria by immunostaining, subcellular fractionation, and TFAM-green fluorescent protein hybrid protein studies. In HT22 hippocampal neuronal cells, human TFAM (hTFAM) overexpression suppressed human Tfam promoter-mediated luciferase activity in a dose-dependent manner. The mitochondria targeting sequence-deficient hTFAM also repressed Tfam promoter activity to the same degree as hTFAM. It indicated that nuclear hTFAM suppressed Tfam expression without modulating mitochondrial activity. The repression required for nuclear respiratory factor-1 (NRF-1), but hTFAM did not bind to the NRF-1 binding site of its promoter. TFAM was co-immunoprecipitated with NRF-1. Taken together, we suggest that nuclear TFAM down-regulate its own gene expression as a NRF-1 repressor, showing that TFAM may play different roles depending on its subcellular localizations.

  14. The bHLH transcription factor POPEYE regulates response to iron deficiency in Arabidopsis roots.

    Science.gov (United States)

    Long, Terri A; Tsukagoshi, Hironaka; Busch, Wolfgang; Lahner, Brett; Salt, David E; Benfey, Philip N

    2010-07-01

    Global population increases and climate change underscore the need for better comprehension of how plants acquire and process nutrients such as iron. Using cell type-specific transcriptional profiling, we identified a pericycle-specific iron deficiency response and a bHLH transcription factor, POPEYE (PYE), that may play an important role in this response. Functional analysis of PYE suggests that it positively regulates growth and development under iron-deficient conditions. Chromatin immunoprecipitation-on-chip analysis and transcriptional profiling reveal that PYE helps maintain iron homeostasis by regulating the expression of known iron homeostasis genes and other genes involved in transcription, development, and stress response. PYE interacts with PYE homologs, including IAA-Leu Resistant3 (ILR3), another bHLH transcription factor that is involved in metal ion homeostasis. Moreover, ILR3 interacts with a third protein, BRUTUS (BTS), a putative E3 ligase protein, with metal ion binding and DNA binding domains, which negatively regulates the response to iron deficiency. PYE and BTS expression is also tightly coregulated. We propose that interactions among PYE, PYE homologs, and BTS are important for maintaining iron homeostasis under low iron conditions.

  15. Transcription factor KLF4 regulates microRNA-544 that targets YWHAZ in cervical cancer.

    Science.gov (United States)

    Mao, Langyong; Zhang, Yan; Deng, Xiaolong; Mo, Wenjuan; Yu, Yao; Lu, Hong

    2015-01-01

    The deregulation of microRNAs has been demonstrated in various tumor processes. Here, we report that microRNA-544 (miR-544) is decreased in cervical cancer tissues compared with normal cervical tissues. To identify the mechanisms involved in miR-544 deregulation, we studied the regulation of miR-544 expression at the transcriptional level. We first identified the transcriptional start site of miR-544 by 5' rapid amplification of cDNA ends and subsequently determined the miR-544 promoter. We discovered that the transcription factor Krueppel-like factor 4 (KLF4) is involved in the transcriptional regulation of miR-544 through interaction with the miR-544 promoter. In addition, we found that miR-544 directly targets the YWHAZ oncogene and functions as a tumor suppressor in cervical cancer cells. miR-544 is involved in cell cycle regulation and suppresses cervical cancer cell proliferation, colony formation, migration and invasion in a manner associated with YWHAZ downregulation. In summary, our findings demonstrate that KLF4 upregulates miR-544 transcription by activating the miR-544 promoter and that miR-544 functions as a tumor suppressor by targeting YWHAZ. Therefore, miR-544 may be a potential novel therapeutic target and prognostic marker for cervical cancer.

  16. Hypoxia-inducible factor directs POMC gene to mediate hypothalamic glucose sensing and energy balance regulation.

    Science.gov (United States)

    Zhang, Hai; Zhang, Guo; Gonzalez, Frank J; Park, Sung-Min; Cai, Dongsheng

    2011-07-01

    Hypoxia-inducible factor (HIF) is a nuclear transcription factor that responds to environmental and pathological hypoxia to induce metabolic adaptation, vascular growth, and cell survival. Here we found that HIF subunits and HIF2α in particular were normally expressed in the mediobasal hypothalamus of mice. Hypothalamic HIF was up-regulated by glucose to mediate the feeding control of hypothalamic glucose sensing. Two underlying molecular pathways were identified, including suppression of PHDs by glucose metabolites to prevent HIF2α degradation and the recruitment of AMPK and mTOR/S6K to regulate HIF2α protein synthesis. HIF activation was found to directly control the transcription of POMC gene. Genetic approach was then employed to develop conditional knockout mice with HIF inhibition in POMC neurons, revealing that HIF loss-of-function in POMC neurons impaired hypothalamic glucose sensing and caused energy imbalance to promote obesity development. The metabolic effects of HIF in hypothalamic POMC neurons were independent of leptin signaling or pituitary ACTH pathway. Hypothalamic gene delivery of HIF counteracted overeating and obesity under conditions of nutritional excess. In conclusion, HIF controls hypothalamic POMC gene to direct the central nutrient sensing in regulation of energy and body weight balance.

  17. Hypoxia-inducible factor directs POMC gene to mediate hypothalamic glucose sensing and energy balance regulation.

    Directory of Open Access Journals (Sweden)

    Hai Zhang

    2011-07-01

    Full Text Available Hypoxia-inducible factor (HIF is a nuclear transcription factor that responds to environmental and pathological hypoxia to induce metabolic adaptation, vascular growth, and cell survival. Here we found that HIF subunits and HIF2α in particular were normally expressed in the mediobasal hypothalamus of mice. Hypothalamic HIF was up-regulated by glucose to mediate the feeding control of hypothalamic glucose sensing. Two underlying molecular pathways were identified, including suppression of PHDs by glucose metabolites to prevent HIF2α degradation and the recruitment of AMPK and mTOR/S6K to regulate HIF2α protein synthesis. HIF activation was found to directly control the transcription of POMC gene. Genetic approach was then employed to develop conditional knockout mice with HIF inhibition in POMC neurons, revealing that HIF loss-of-function in POMC neurons impaired hypothalamic glucose sensing and caused energy imbalance to promote obesity development. The metabolic effects of HIF in hypothalamic POMC neurons were independent of leptin signaling or pituitary ACTH pathway. Hypothalamic gene delivery of HIF counteracted overeating and obesity under conditions of nutritional excess. In conclusion, HIF controls hypothalamic POMC gene to direct the central nutrient sensing in regulation of energy and body weight balance.

  18. Regulation of Hippo pathway transcription factor TEAD by p38 MAPK-induced cytoplasmic translocation.

    Science.gov (United States)

    Lin, Kimberly C; Moroishi, Toshiro; Meng, Zhipeng; Jeong, Han-Sol; Plouffe, Steven W; Sekido, Yoshitaka; Han, Jiahuai; Park, Hyun Woo; Guan, Kun-Liang

    2017-07-28

    The Hippo pathway controls organ size and tissue homeostasis, with deregulation leading to cancer. The core Hippo components in mammals are composed of the upstream serine/threonine kinases Mst1/2, MAPK4Ks and Lats1/2. Inactivation of these upstream kinases leads to dephosphorylation, stabilization, nuclear translocation and thus activation of the major functional transducers of the Hippo pathway, YAP and its paralogue TAZ. YAP/TAZ are transcription co-activators that regulate gene expression primarily through interaction with the TEA domain DNA-binding family of transcription factors (TEAD). The current paradigm for regulation of this pathway centres on phosphorylation-dependent nucleocytoplasmic shuttling of YAP/TAZ through a complex network of upstream components. However, unlike other transcription factors, such as SMAD, NF-κB, NFAT and STAT, the regulation of TEAD nucleocytoplasmic shuttling has been largely overlooked. In the present study, we show that environmental stress promotes TEAD cytoplasmic translocation via p38 MAPK in a Hippo-independent manner. Importantly, stress-induced TEAD inhibition predominates YAP-activating signals and selectively suppresses YAP-driven cancer cell growth. Our data reveal a mechanism governing TEAD nucleocytoplasmic shuttling and show that TEAD localization is a critical determinant of Hippo signalling output.

  19. Transcription factor p63 bookmarks and regulates dynamic enhancers during epidermal differentiation.

    Science.gov (United States)

    Kouwenhoven, Evelyn N; Oti, Martin; Niehues, Hanna; van Heeringen, Simon J; Schalkwijk, Joost; Stunnenberg, Hendrik G; van Bokhoven, Hans; Zhou, Huiqing

    2015-07-01

    The transcription factor p63 plays a pivotal role in keratinocyte proliferation and differentiation in the epidermis. However, how p63 regulates epidermal genes during differentiation is not yet clear. Using epigenome profiling of differentiating human primary epidermal keratinocytes, we characterized a catalog of dynamically regulated genes and p63-bound regulatory elements that are relevant for epithelial development and related diseases. p63-bound regulatory elements occur as single or clustered enhancers, and remarkably, only a subset is active as defined by the co-presence of the active enhancer mark histone modification H3K27ac in epidermal keratinocytes. We show that the dynamics of gene expression correlates with the activity of p63-bound enhancers rather than with p63 binding itself. The activity of p63-bound enhancers is likely determined by other transcription factors that cooperate with p63. Our data show that inactive p63-bound enhancers in epidermal keratinocytes may be active during the development of other epithelial-related structures such as limbs and suggest that p63 bookmarks genomic loci during the commitment of the epithelial lineage and regulates genes through temporal- and spatial-specific active enhancers.

  20. Characterization of the Methylation Status of and Myogenic Regulator Factors in Cell Myogenic Differentiation

    Directory of Open Access Journals (Sweden)

    Zhe Chao

    2016-07-01

    Full Text Available Epigenetic processes in the development of skeletal muscle have been appreciated for over a decade. DNA methylation is a major epigenetic modification important for regulating gene expression and suppressing spurious transcription. Up to now, the importance of epigenetic marks in the regulation of Pax7 and myogenic regulatory factors (MRFs expression is far less explored. In the present study, semi-quantitative the real-time polymerase chain reaction (RT-PCR analyses showed MyoD and Myf5 were expressed in activated and quiescent C2C12 cells. MyoG was expressed in a later stage of myogenesis. Pax7 was weakly expressed in differentiated C2C12 cells. To further understand the regulation of expression of these genes, the DNA methylation status of Pax7, MyoD, and Myf5 was determined by bisulfite sequencing PCR. During the C2C12 myoblasts fusion process, the changes of promoter and exon 1 methylation of Pax7, MyoD, and Myf5 genes were observed. In addition, an inverse relationship of low methylation and high expression was found. These results suggest that DNA methylation may be an important mechanism regulating Pax7 and MRFs transcription in cell myogenic differentiation.

  1. The E2F-DP1 Transcription Factor Complex Regulates Centriole Duplication in Caenorhabditis elegans.

    Science.gov (United States)

    Miller, Jacqueline G; Liu, Yan; Williams, Christopher W; Smith, Harold E; O'Connell, Kevin F

    2016-01-15

    Centrioles play critical roles in the organization of microtubule-based structures, from the mitotic spindle to cilia and flagella. In order to properly execute their various functions, centrioles are subjected to stringent copy number control. Central to this control mechanism is a precise duplication event that takes place during S phase of the cell cycle and involves the assembly of a single daughter centriole in association with each mother centriole . Recent studies have revealed that posttranslational control of the master regulator Plk4/ZYG-1 kinase and its downstream effector SAS-6 is key to ensuring production of a single daughter centriole. In contrast, relatively little is known about how centriole duplication is regulated at a transcriptional level. Here we show that the transcription factor complex EFL-1-DPL-1 both positively and negatively controls centriole duplication in the Caenorhabditis elegans embryo. Specifically, we find that down regulation of EFL-1-DPL-1 can restore centriole duplication in a zyg-1 hypomorphic mutant and that suppression of the zyg-1 mutant phenotype is accompanied by an increase in SAS-6 protein levels. Further, we find evidence that EFL-1-DPL-1 promotes the transcription of zyg-1 and other centriole duplication genes. Our results provide evidence that in a single tissue type, EFL-1-DPL-1 sets the balance between positive and negative regulators of centriole assembly and thus may be part of a homeostatic mechanism that governs centriole assembly.

  2. Trefoil factor 3 peptide regulates migration via a Twist-dependent pathway in gastric cell.

    Science.gov (United States)

    Zheng, Qianqian; Gao, Jian; Li, Honglin; Guo, Wendong; Mao, Qi; Gao, Enhui; Zhu, Ya-qin

    2013-08-16

    Trefoil factor 3 (TFF3) is a member of the TFF-domain peptide family and essential in regulating cell migration and maintaining mucosal integrity in gastrointestinal tract. However, the role of TFF3 and its downstream regulating mechanisms in cancer cell migration remain unclear. We previously reported that TFF3 prolonged the up-regulation of Twist protein to modulate IL-8 secretion in intestinal epithelial cells. In this study, we investigated the role of Twist protein in TFF3-induced migration of SGC7901 cells. While Twist was activated by TFF3, siRNA-mediated knockdown of Twist abolished TFF3-induced cell migration. Furthermore, the migration related marker CK-8 as well as ZO-1 and MMP-9 was also regulated by TFF3 via a Twist-dependent mechanism. Our study suggests that Twist, as an important potential downstream effector, plays a key role in TFF3-modulated metastasis in gastric cancer and can be a promising therapeutic target against intestinal-type gastric cancer.

  3. Sigma-1 Receptors Regulate Bcl-2 Expression by Reactive Oxygen Species-Dependent Transcriptional Regulation of Nuclear Factor κB

    Science.gov (United States)

    Meunier, Johann

    2010-01-01

    The expression of Bcl-2, the major antiapoptotic member of the Bcl-2 family, is under complex controls of several factors, including reactive oxygen species (ROS). The σ-1 receptor (Sig-1R), which was recently identified as a novel molecular chaperone at the mitochondria-associated endoplasmic reticulum membrane (MAM), has been shown to exert robust cellular protective actions. However, mechanisms underlying the antiapoptotic action of the Sig-1R remain to be clarified. Here, we found that the Sig-1R promotes cellular survival by regulating the Bcl-2 expression in Chinese hamster ovary cells. Although both Sig-1Rs and Bcl-2 are highly enriched at the MAM, Sig-1Rs neither associate physically with Bcl-2 nor regulate stability of Bcl-2 proteins. However, Sig-1Rs tonically regulate the expression of Bcl-2 proteins. Knockdown of Sig-1Rs down-regulates whereas overexpression of Sig-1Rs up-regulates bcl-2 mRNA, indicating that the Sig-1R transcriptionally regulates the expression of Bcl-2. The effect of Sig-1R small interfering RNA down-regulating Bcl-2 was blocked by ROS scavengers and by the inhibitor of the ROS-inducible transcription factor nuclear factor κB (NF-κB). Knockdown of Sig-1Rs up-regulates p105, the precursor of NF-κB, while concomitantly decreasing inhibitor of nuclear factor-κBα. Sig-1R knockdown also accelerates the conversion of p105 to the active form p50. Lastly, we showed that knockdown of Sig-1Rs potentiates H2O2-induced apoptosis; the action is blocked by either the NF-κB inhibitor oridonin or overexpression of Bcl-2. Thus, these findings suggest that Sig-1Rs promote cell survival, at least in part, by transcriptionally regulating Bcl-2 expression via the ROS/NF-κB pathway. PMID:19855099

  4. Mga2 transcription factor regulates an oxygen-responsive lipid homeostasis pathway in fission yeast

    DEFF Research Database (Denmark)

    Burr, Risa; Stewart, Emerson V; Shao, Wei

    2016-01-01

    Eukaryotic lipid synthesis is oxygen-dependent with cholesterol synthesis requiring 11 oxygen molecules and fatty acid desaturation requiring 1 oxygen molecule per double bond. Accordingly, organisms evaluate oxygen availability to control lipid homeostasis. The sterol regulatory element......-binding protein (SREBP) transcription factors regulate lipid homeostasis. In mammals, SREBP-2 controls cholesterol biosynthesis, whereas SREBP-1 controls triacylglycerol and glycerophospholipid biosynthesis. In the fission yeast Schizosaccharomyces pombe, the SREBP-2 homolog Sre1 regulates sterol homeostasis....... In the absence of mga2, fission yeast exhibited growth defects under both normoxia and low oxygen conditions. Mga2 transcriptional targets were enriched for lipid metabolism genes, and mga2Δ cells showed disrupted triacylglycerol and glycerophospholipid homeostasis, most notably with an increase in fatty acid...

  5. A bacteriophage transcription regulator inhibits bacterial transcription initiation by σ-factor displacement.

    Science.gov (United States)

    Liu, Bing; Shadrin, Andrey; Sheppard, Carol; Mekler, Vladimir; Xu, Yingqi; Severinov, Konstantin; Matthews, Steve; Wigneshweraraj, Sivaramesh

    2014-04-01

    Bacteriophages (phages) appropriate essential processes of bacterial hosts to benefit their own development. The multisubunit bacterial RNA polymerase (RNAp) enzyme, which catalyses DNA transcription, is targeted by phage-encoded transcription regulators that selectively modulate its activity. Here, we describe the structural and mechanistic basis for the inhibition of bacterial RNAp by the transcription regulator P7 encoded by Xanthomonas oryzae phage Xp10. We reveal that P7 uses a two-step mechanism to simultaneously interact with the catalytic β and β' subunits of the bacterial RNAp and inhibits transcription initiation by inducing the displacement of the σ(70)-factor on initial engagement of RNAp with promoter DNA. The new mode of interaction with and inhibition mechanism of bacterial RNAp by P7 underscore the remarkable variety of mechanisms evolved by phages to interfere with host transcription.

  6. COX assembly factor ccdc56 regulates mitochondrial morphology by affecting mitochondrial recruitment of Drp1.

    Science.gov (United States)

    Ban-Ishihara, Reiko; Tomohiro-Takamiya, Shiho; Tani, Motohiro; Baudier, Jacques; Ishihara, Naotada; Kuge, Osamu

    2015-10-07

    Mitochondria are dynamic organelles that alter their morphology in response to cellular signaling and differentiation through balanced fusion and fission. In this study, we found that the mitochondrial inner membrane ATPase ATAD3A interacted with ccdc56/MITRAC12/COA3, a subunit of the cytochrome oxidase (COX)-assembly complex. Overproduction of ccdc56 in HeLa cells resulted in fragmented mitochondrial morphology, while mitochondria were highly elongated in ccdc56-repressed cells by the defective recruitment of the fission factor Drp1. We also found that mild and chronic inhibition of COX led to mitochondrial elongation, as seen in ccdc56-repressed cells. These results indicate that ccdc56 positively regulates mitochondrial fission via regulation of COX activity and the mitochondrial recruitment of Drp1, and thus, suggest a novel relationship between COX assembly and mitochondrial morphology.

  7. [Shifts in metabolism and its regulation under the effect of spaceflight factors].

    Science.gov (United States)

    Larina, I M; Nichiporuk, I A; Veselova, O M; Vasilieva, G Yu; Popova, I A

    2013-01-01

    The review deals with the results of studying the adaptive changes in metabolism and its neuroendocrine regulation in humans and animals under the effect of spaceflight factors and ground-based simulation of the gravitational unloading. The majority of the investigations were concerned with the water-electrolyte and mineral turnover, as well as protein, lipid and carbohydrates metabolism. Biochemical measurements of the body liquids (blood, urine and saliva) before, in and after space flight or in ground simulation experiments were used as indictors of the status of sympathoadrenal, hypothalamo-pituitary-adrenal and other systems involved in systemic regulation of metabolism, and also strength of stress-reaction to adversities. The authors generalized data on the interrelation and interaction of the neuroendocrine and psychophysiological status both in the real and simulated conditions of space flight.

  8. Regulation of neural gene transcription by optogenetic inhibition of the RE1-silencing transcription factor.

    Science.gov (United States)

    Paonessa, Francesco; Criscuolo, Stefania; Sacchetti, Silvio; Amoroso, Davide; Scarongella, Helena; Pecoraro Bisogni, Federico; Carminati, Emanuele; Pruzzo, Giacomo; Maragliano, Luca; Cesca, Fabrizia; Benfenati, Fabio

    2016-01-01

    Optogenetics provides new ways to activate gene transcription; however, no attempts have been made as yet to modulate mammalian transcription factors. We report the light-mediated regulation of the repressor element 1 (RE1)-silencing transcription factor (REST), a master regulator of neural genes. To tune REST activity, we selected two protein domains that impair REST-DNA binding or recruitment of the cofactor mSin3a. Computational modeling guided the fusion of the inhibitory domains to the light-sensitive Avena sativa light-oxygen-voltage-sensing (LOV) 2-phototrophin 1 (AsLOV2). By expressing AsLOV2 chimeras in Neuro2a cells, we achieved light-dependent modulation of REST target genes that was associated with an improved neural differentiation. In primary neurons, light-mediated REST inhibition increased Na(+)-channel 1.2 and brain-derived neurotrophic factor transcription and boosted Na(+) currents and neuronal firing. This optogenetic approach allows the coordinated expression of a cluster of genes impinging on neuronal activity, providing a tool for studying neuronal physiology and correcting gene expression changes taking place in brain diseases.

  9. Muscle sympathetic nerve activity and volume regulating factors in healthy pregnant and non-pregnant women.

    Science.gov (United States)

    Charkoudian, Nisha; Usselman, Charlotte W; Skow, Rachel J; Staab, Jeffery S; Julian, Colleen Glyde; Stickland, Michael K; Chari, Radha S; Khurana, Rshmi; Davidge, Sandra T; Davenport, Margie H; Steinback, Craig D

    2017-07-21

    Healthy, normotensive human pregnancies are associated with striking increases in both plasma volume and vascular sympathetic nerve activity (SNA). In non-pregnant humans, volume regulatory factors including plasma osmolality, vasopressin and the renin-angiotensin-aldosterone system have important modulatory effects on control of sympathetic outflow. We hypothesized that pregnancy would be associated with changes in the relationships between SNA (measured as muscle SNA) and volume regulating factors, including plasma osmolality, plasma renin activity and arginine vasopressin (AVP). We studied 46 healthy, normotensive young women (23 pregnant and 23 non-pregnant). We measured SNA, arterial pressure, plasma osmolality, plasma renin activity, AVP and other volume regulatory factors in resting, semi-recumbent posture. Pregnant women had significantly higher resting SNA (38 ± 12 vs. non-pregnant: 23 ± 6 bursts/minute), lower osmolality and higher plasma renin activity and aldosterone (all P pregnant] vs. 5.17 ± 2.03 [pregnant], P > 0.05). However, regression analysis detected a significant relationship between individual values for SNA and AVP in pregnant (r = 0.71, P pregnant women (r = 0.04). No relationships were found for other variables. These data suggest that the link between AVP release and resting SNA becomes stronger in pregnancy, which may contribute importantly to blood pressure regulation in healthy women during pregnancy. Copyright © 2017, American Journal of Physiology-Heart and Circulatory Physiology.

  10. Transcription factor KLF7 regulates differentiation of neuroectodermal and mesodermal cell lineages

    Energy Technology Data Exchange (ETDEWEB)

    Caiazzo, Massimiliano, E-mail: caiazzo@igb.cnr.it [Institute of Genetics and Biophysics ' A. Buzzati-Traverso,' CNR, 80131 Naples (Italy); Istituto di diagnosi e cura ' Hermitage Capodimonte,' 80131 Naples (Italy); Colucci-D' Amato, Luca, E-mail: luca.colucci@unina2.it [Institute of Genetics and Biophysics ' A. Buzzati-Traverso,' CNR, 80131 Naples (Italy); Dipartimento di Scienze della Vita, Seconda Universita di Napoli, 81100 Caserta (Italy); Esposito, Maria T., E-mail: maria_teresa.esposito@kcl.ac.uk [CEINGE Biotecnologie Avanzate, 80145 Naples (Italy); Parisi, Silvia, E-mail: parisi@ceinge.unina.it [CEINGE Biotecnologie Avanzate, 80145 Naples (Italy); Stifani, Stefano, E-mail: stefano.stifani@mcgill.ca [Centre for Neuronal Survival, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada H3A 2B4 (Canada); Ramirez, Francesco, E-mail: francesco.ramirez@mssm.edu [Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, NY 10029 (United States); Porzio, Umberto di, E-mail: diporzio@igb.cnr.it [Institute of Genetics and Biophysics ' A. Buzzati-Traverso,' CNR, 80131 Naples (Italy)

    2010-08-15

    Previous gene targeting studies in mice have implicated the nuclear protein Krueppel-like factor 7 (KLF7) in nervous system development while cell culture assays have documented its involvement in cell cycle regulation. By employing short hairpin RNA (shRNA)-mediated gene silencing, here we demonstrate that murine Klf7 gene expression is required for in vitro differentiation of neuroectodermal and mesodermal cells. Specifically, we show a correlation of Klf7 silencing with down-regulation of the neuronal marker microtubule-associated protein 2 (Map2) and the nerve growth factor (NGF) tyrosine kinase receptor A (TrkA) using the PC12 neuronal cell line. Similarly, KLF7 inactivation in Klf7-null mice decreases the expression of the neurogenic marker brain lipid-binding protein/fatty acid-binding protein 7 (BLBP/FABP7) in neural stem cells (NSCs). We also report that Klf7 silencing is detrimental to neuronal and cardiomyocytic differentiation of embryonic stem cells (ESCs), in addition to altering the adipogenic and osteogenic potential of mouse embryonic fibroblasts (MEFs). Finally, our results suggest that genes that are key for self-renewal of undifferentiated ESCs repress Klf7 expression in ESCs. Together with previous findings, these results provide evidence that KLF7 has a broad spectrum of regulatory functions, which reflect the discrete cellular and molecular contexts in which this transcription factor operates.

  11. Staphylococcus aureus SaeR/S-regulated factors reduce human neutrophil reactive oxygen species production.

    Science.gov (United States)

    Guerra, Fermin E; Addison, Conrad B; de Jong, Nienke W M; Azzolino, Joseph; Pallister, Kyler B; van Strijp, Jos A G; Voyich, Jovanka M

    2016-11-01

    Neutrophils are the first line of defense after a pathogen has breached the epithelial barriers, and unimpaired neutrophil functions are essential to clear infections. Staphylococcus aureus is a prevalent human pathogen that is able to withstand neutrophil killing, yet the mechanisms used by S. aureus to inhibit neutrophil clearance remain incompletely defined. The production of reactive oxygen species (ROS) is a vital neutrophil antimicrobial mechanism. Herein, we test the hypothesis that S. aureus uses the SaeR/S two-component gene regulatory system to produce virulence factors that reduce neutrophil ROS production. With the use of ROS probes, the temporal and overall production of neutrophil ROS was assessed during exposure to the clinically relevant S. aureus USA300 (strain LAC) and its isogenic mutant LACΔsaeR/S Our results demonstrated that SaeR/S-regulated factors do not inhibit neutrophil superoxide (O2(-)) production. However, subsequent neutrophil ROS production was significantly reduced during exposure to LAC compared with LACΔsaeR/S In addition, neutrophil H2O2 production was reduced significantly by SaeR/S-regulated factors by a mechanism independent of catalase. Consequently, the reduction in neutrophil H2O2 resulted in decreased production of the highly antimicrobial agent hypochlorous acid/hypochlorite anion (HOCl/(-)OCl). These findings suggest a new evasion strategy used by S. aureus to diminish a vital neutrophil antimicrobial mechanism. © Society for Leukocyte Biology.

  12. [Regulation of neurogenesis: factors affecting of new neurons formation in adult mammals brain].

    Science.gov (United States)

    Respondek, Michalina; Buszman, Ewa

    2015-12-31

    Neurogenesis is a complex and multi-step process of generating completely functional neurons. This process in adult brain is based on pluripotentional neuronal stem cells (NSC), which are able to proliferation and differentiation into mature neurons or glial cells. NSC are located in subgranular zone inside hippocampus and in subventricular zone. The new neurons formation depends on many endo- and exogenous factors which modulate each step of neurogenesis. This article describes the most important regulators of adult neurogenesis, mainly: neurotrophins, growth factors, hormones, neurotransmitters and microenvironment of NSC. Some drugs, especially antipsychotics, antidepressants and normothymics may affect the neurogenic properties of adult brain. Moreover pathological processes such as neuroinflammation, stroke or epilepsy are able to induce proliferation of NSC. The proneurogenic effects of psychotropic drugs and pathological processes are associated with their ability to increase some hormones and neurotrophins level, as well as with rising the expression of antiapoptotic Bcl-2 protein and metalloproteinase MMP-2. Additionaly, some drugs, for example haloperidol, are able to block prolactin and dopaminergic neuroblasts receptors. Down-regulation of adult neurogenesis is associated with alcohol abuse and high stress level. Negative effect of many drugs, such as cytostatics, COX-2 inhibitors and opioides was also observed. The proneurogenic effect of described factors suggest their broad therapeutic potential and gives a new perspective on an effective and modern treatment of many neuropsychiatric disorders. This effect can also help to clarify the pathogenesis of disorders associated with proliferation and degeneration of adult brain cells.

  13. Extracellular Matrix-Regulated Gene Expression RequiresCooperation of SWI/SNF and Transcription Factors

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Ren; Spencer, Virginia A.; Bissell, Mina J.

    2006-05-25

    Extracellular cues play crucial roles in the transcriptional regulation of tissue-specific genes, but whether and how these signals lead to chromatin remodeling is not understood and subject to debate. Using chromatin immunoprecipitation (ChIP) assays and mammary-specific genes as models, we show here that extracellular matrix (ECM) molecules and prolactin cooperate to induce histone acetylation and binding of transcription factors and the SWI/SNF complex to the {beta}- and ?-casein promoters. Introduction of a dominant negative Brg1, an ATPase subunit of SWI/SNF complex, significantly reduced both {beta}- and ?-casein expression, suggesting that SWI/SNF-dependent chromatin remodeling is required for transcription of mammary-specific genes. ChIP analyses demonstrated that the ATPase activity of SWI/SNF is necessary for recruitment of RNA transcriptional machinery, but not for binding of transcription factors or for histone acetylation. Coimmunoprecipitation analyses showed that the SWI/SNF complex is associated with STAT5, C/EBP{beta}, and glucocorticoid receptor (GR). Thus, ECM- and prolactin-regulated transcription of the mammary-specific casein genes requires the concerted action of chromatin remodeling enzymes and transcription factors.

  14. Brain-derived neurotrophic factor mediates the activity-dependent regulation of inhibition in neocortical cultures.

    Science.gov (United States)

    Rutherford, L C; DeWan, A; Lauer, H M; Turrigiano, G G

    1997-06-15

    The excitability of cortical circuits is modulated by interneurons that release the inhibitory neurotransmitter GABA. In primate and rodent visual cortex, activity deprivation leads to a decrease in the expression of GABA. This suggests that activity is able to adjust the strength of cortical inhibition, but this has not been demonstrated directly. In addition, the nature of the signal linking activity to GABA expression has not been determined. Activity is known to regulate the expression of the neurotrophin brain-derived neurotrophic factor (BDNF), and BDNF has been shown to influence the phenotype of GABAergic interneurons. We use a culture system from postnatal rat visual cortex to test the hypothesis that activity is regulating the strength of cortical inhibition through the regulation of BDNF. Cultures were double-labeled against GABA and the neuronal marker MAP2, and the percentage of neurons that were GABA-positive was determined. Blocking spontaneous activity in these cultures reversibly decreased the number of GABA-positive neurons without affecting neuronal survival. Voltage-clamp analysis of inhibitory currents demonstrated that activity blockade also decreased GABA-mediated inhibition onto pyramidal neurons and raised pyramidal neuron firing rates. All of these effects were prevented by incubation with BDNF during activity blockade, but not by neurotrophin 3 or nerve growth factor. Additionally, blockade of neurotrophin signaling mimicked the effects of activity blockade on GABA expression. These data suggest that activity regulates cortical inhibition through a BDNF-dependent mechanism and that this neurotrophin plays an important role in the control of cortical excitability.

  15. Regulation of chick early B-cell factor-1 gene expression in feather development.

    Science.gov (United States)

    El-Magd, Mohammed Abu; Sayed-Ahmed, Ahmed; Awad, Ashraf; Shukry, Mustafa

    2014-05-01

    The chick Ebf1 (early B-cell factor-1) gene is a member of a novel family of helix loop helix transcription factors. The expression profile, regulation and significance of this gene have been extensively studied in lymphatic, nervous, adipose and muscular tissues. However, cEbf1 expression, regulation and function in the feather of chick embryo have not yet been investigated. cEbf1 expression was first detected throughout the mesenchymal core of some few feather placodes (D7-D7.5). After feathers became mature and grew distally (D9 and D10), the mesenchymal expression of cEbf1 became confined to the caudal margin of the proximal half of all formed feather buds. Because this dynamic pattern of expression resembles that of Sonic Hedgehog (Shh) protein and bone morphogenetic protein (Bmp4) plus the crucial role of these two major signals in feather development, we hypothesized that cEbf1 expression in the feather may be regulated by Shh and Bmp4. In a feather explant culture system, Shh signals are necessary to initiate and maintain cEbf1 expression in the posterior half of the feather bud, while Bmp4 is crucial for the initial cEbf1 expression in the anterior half of the feather bud. Inhibition of Shh, not only down-regulates cEbf1, but also changes the morphology of feather buds, which become irregular and fused. This is the first study to demonstrate that cEbf1 expression in the feather bud is under the control of Shh and Bmp4 signals and that expression may play a role in the normal development of feathers.

  16. Regulation of antimycin biosynthesis by the orphan ECF RNA polymerase sigma factor σAntA

    Directory of Open Access Journals (Sweden)

    Ryan F. Seipke

    2014-02-01

    Full Text Available Antimycins are an extended family of depsipeptides that are made by filamentous actinomycete bacteria and were first isolated more than 60 years ago. Recently, antimycins have attracted renewed interest because of their activities against the anti-apoptotic machineries inside human cells which could make them promising anti-cancer compounds. The biosynthetic pathway for antimycins was recently characterised but very little is known about the organisation and regulation of the antimycin (ant gene cluster. Here we report that the ant gene cluster in Streptomyces albus is organized into four transcriptional units; the antBA, antCDE, antGF and antHIJKLMNO operons. Unusually for secondary metabolite clusters, the antG and antH promoters are regulated by an extracytoplasmic function (ECF RNA polymerase sigma factor named σAntA which represents a new sub-family of ECF σ factors that is only found in antimycin producing strains. We show that σAntA controls production of the unusual precursor 3-aminosalicylate which is absolutely required for the production of antimycins. σAntA is highly conserved in antimycin producing strains and the −10 and −35 elements at the σAntA regulated antG and antH promoters are also highly conserved suggesting a common mechanism of regulation. We also demonstrate that altering the C-terminal Ala-Ala residues found in all σAntA proteins to Asp-Asp increases expression of the antFG and antGHIJKLMNO operons and we speculate that this Ala-Ala motif may be a signal for the protease ClpXP.

  17. Fungal Morphology, Iron Homeostasis, and Lipid Metabolism Regulated by a GATA Transcription Factor in Blastomyces dermatitidis.

    Directory of Open Access Journals (Sweden)

    Amber J Marty

    2015-06-01

    Full Text Available In response to temperature, Blastomyces dermatitidis converts between yeast and mold forms. Knowledge of the mechanism(s underlying this response to temperature remains limited. In B. dermatitidis, we identified a GATA transcription factor, SREB, important for the transition to mold. Null mutants (SREBΔ fail to fully complete the conversion to mold and cannot properly regulate siderophore biosynthesis. To capture the transcriptional response regulated by SREB early in the phase transition (0-48 hours, gene expression microarrays were used to compare SREB∆ to an isogenic wild type isolate. Analysis of the time course microarray data demonstrated SREB functioned as a transcriptional regulator at 37°C and 22°C. Bioinformatic and biochemical analyses indicated SREB was involved in diverse biological processes including iron homeostasis, biosynthesis of triacylglycerol and ergosterol, and lipid droplet formation. Integration of microarray data, bioinformatics, and chromatin immunoprecipitation identified a subset of genes directly bound and regulated by SREB in vivo in yeast (37°C and during the phase transition to mold (22°C. This included genes involved with siderophore biosynthesis and uptake, iron homeostasis, and genes unrelated to iron assimilation. Functional analysis suggested that lipid droplets were actively metabolized during the phase transition and lipid metabolism may contribute to filamentous growth at 22°C. Chromatin immunoprecipitation, RNA interference, and overexpression analyses suggested that SREB was in a negative regulatory circuit with the bZIP transcription factor encoded by HAPX. Both SREB and HAPX affected morphogenesis at 22°C; however, large changes in transcript abundance by gene deletion for SREB or strong overexpression for HAPX were required to alter the phase transition.

  18. Proliferating cell nuclear antigen (PCNA): a key factor in DNA replication and cell cycle regulation.

    Science.gov (United States)

    Strzalka, Wojciech; Ziemienowicz, Alicja

    2011-05-01

    PCNA (proliferating cell nuclear antigen) has been found in the nuclei of yeast, plant and animal cells that undergo cell division, suggesting a function in cell cycle regulation and/or DNA replication. It subsequently became clear that PCNA also played a role in other processes involving the cell genome. This review discusses eukaryotic PCNA, with an emphasis on plant PCNA, in terms of the protein structure and its biochemical properties as well as gene structure, organization, expression and function. PCNA exerts a tripartite function by operating as (1) a sliding clamp during DNA synthesis, (2) a polymerase switch factor and (3) a recruitment factor. Most of its functions are mediated by its interactions with various proteins involved in DNA synthesis, repair and recombination as well as in regulation of the cell cycle and chromatid cohesion. Moreover, post-translational modifications of PCNA play a key role in regulation of its functions. Finally, a phylogenetic comparison of PCNA genes suggests that the multi-functionality observed in most species is a product of evolution. Most plant PCNAs exhibit features similar to those found for PCNAs of other eukaryotes. Similarities include: (1) a trimeric ring structure of the PCNA sliding clamp, (2) the involvement of PCNA in DNA replication and repair, (3) the ability to stimulate the activity of DNA polymerase δ and (4) the ability to interact with p21, a regulator of the cell cycle. However, many plant genomes seem to contain the second, probably functional, copy of the PCNA gene, in contrast to PCNA pseudogenes that are found in mammalian genomes.

  19. Regulation of coagulation factor XI expression by microRNAs in the human liver.

    Directory of Open Access Journals (Sweden)

    Salam Salloum-Asfar

    Full Text Available High levels of factor XI (FXI increase the risk of thromboembolic disease. However, the genetic and environmental factors regulating FXI expression are still largely unknown. The aim of our study was to evaluate the regulation of FXI by microRNAs (miRNAs in the human liver. In silico prediction yielded four miRNA candidates that might regulate FXI expression. HepG2 cells were transfected with miR-181a-5p, miR-23a-3p, miR-16-5p and miR-195-5p. We used mir-494, which was not predicted to bind to F11, as a negative control. Only miR-181a-5p caused a significant decrease both in FXI protein and F11 mRNA levels. In addition, transfection with a miR-181a-5p inhibitor in PLC/PRF/5 hepatic cells increased both the levels of F11 mRNA and extracellular FXI. Luciferase assays in human colon cancer cells deficient for Dicer (HCT-DK demonstrated a direct interaction between miR-181a-5p and 3'untranslated region of F11. Additionally, F11 mRNA levels were inversely and significantly correlated with miR-181a-5p levels in 114 healthy livers, but not with miR-494. This study demonstrates that FXI expression is directly regulated by a specific miRNA, miR-181a-5p, in the human liver. Future studies are necessary to further investigate the potential consequences of miRNA dysregulation in pathologies involving FXI.

  20. Ligand-specific sequential regulation of transcription factors for differentiation of MCF-7 cells

    Directory of Open Access Journals (Sweden)

    Toyoda Tetsuro

    2009-11-01

    Full Text Available Abstract Background Sharing a common ErbB/HER receptor signaling pathway, heregulin (HRG induces differentiation of MCF-7 human breast cancer cells while epidermal growth factor (EGF elicits proliferation. Although cell fates resulting from action of the aforementioned ligands completely different, the respective gene expression profiles in early transcription are qualitatively similar, suggesting that gene expression during late transcription, but not early transcription, may reflect ligand specificity. In this study, based on both the data from time-course quantitative real-time PCR on over 2,000 human transcription factors and microarray of all human genes, we identified a series of transcription factors which may control HRG-specific late transcription in MCF-7 cells. Results We predicted that four transcription factors including EGR4, FRA-1, FHL2, and DIPA should have responsibility of regulation in MCF-7 cell differentiation. Validation analysis suggested that one member of the activator protein 1 (AP-1 family, FOSL-1 (FRA-1 gene, appeared immediately following c-FOS expression, might be responsible for expression of transcription factor FHL2 through activation of the AP-1 complex. Furthermore, RNAi gene silencing of FOSL-1 and FHL2 resulted in increase of extracellular signal-regulated kinase (ERK phosphorylation of which duration was sustained by HRG stimulation. Conclusion Our analysis indicated that a time-dependent transcriptional regulatory network including c-FOS, FRA-1, and FHL2 is vital in controlling the ERK signaling pathway through a negative feedback loop for MCF-7 cell differentiation.

  1. B-GATA transcription factors - insights into their structure, regulation and role in plant development

    Directory of Open Access Journals (Sweden)

    Claus eSchwechheimer

    2015-02-01

    Full Text Available GATA transcription factors are evolutionarily conserved transcriptional regulators that recognize promoter elements with a G-A-T-A core sequence. In comparison to animal genomes, the GATA transcription factor family in plants is comparatively large with approximately 30 members. In spite of a long-standing interest of plant molecular biologists in GATA factors, only research conducted in the last years has led to reliable insights into their functions during plant development. Here, we review the current knowledge on B-GATAs, one of four GATA factor subfamilies from Arabidopsis thaliana. We show that B-GATAs can be subdivided based on structural features and their biological function into family members with a C-terminal LLM- (leucine-leucine-methionine domain or an N-terminal HAN- (HANABA TARANU domain. The paralogous GNC (GATA, NITRATE-INDUCIBLE, CARBON-METABOLISM INVOLVED and CGA1/GNL (CYTOKININ-INDUCED GATA1/GNC-LIKE are introduced as LLM-domain containing B-GATAs from Arabidopsis that control germination, greening, senescence and flowering time downstream from several growth regulatory signals including light and the hormones gibberellin, auxin, and cytokinin. Arabidopsis HAN and its monocot-specific paralogs from rice (NECK LEAF1, maize (TASSEL SHEATH1, and barley (THIRD OUTER GLUME are HAN-domain-containing B-GATAs with a predominant role in embryo development and floral development. We also review GATA23, a regulator of lateral root initiation from Arabidopsis, that is closely related to GNC and GNL but has a degenerate LLM-domain that is seemingly specific for the Brassicaceae family. The Brassicaceae-specific GATA23 together with the above-mentioned monocot-specific HAN-domain GATAs provide evidence that neofunctionalization of the B-GATAs was used during plant evolution to expand the functional repertoire of these transcription factors.

  2. DCLK1 regulates pluripotency and angiogenic factors via microRNA-dependent mechanisms in pancreatic cancer.

    Directory of Open Access Journals (Sweden)

    Sripathi M Sureban

    Full Text Available Stem cell pluripotency, angiogenesis and epithelial-mesenchymal transition (EMT have been shown to be significantly upregulated in pancreatic ductal adenocarcinoma (PDAC and many other aggressive cancers. The dysregulation of these processes is believed to play key roles in tumor initiation, progression, and metastasis, and is contributory to PDAC being the fourth leading cause of cancer-related deaths in the US. The tumor suppressor miRNA miR-145 downregulates critical pluripotency factors and oncogenes and results in repressed metastatic potential in PDAC. Additionally, the miR-200 family regulates several angiogenic factors which have been linked to metastasis in many solid tumors. We have previously demonstrated that downregulation of DCLK1 can upregulate critical miRNAs in both in vitro and in vivo cancer models and results in downregulation of c-MYC, KRAS, NOTCH1 and EMT-related transcription factors. A recent report has also shown that Dclk1 can distinguish between normal and tumor stem cells in Apc (min/+ mice and that ablation of Dclk1(+ cells resulted in regression of intestinal polyps without affecting homeostasis. Here we demonstrate that the knockdown of DCLK1 using poly(lactide-co-glycolide-encapsulated-DCLK1-siRNA results in AsPC1 tumor growth arrest. Examination of xenograft tumors revealed, (a increased miR-145 which results in decreased pluripotency maintenance factors OCT4, SOX2, NANOG, KLF4 as well as KRAS and RREB1; (b increased let-7a which results in decreased pluripotency factor LIN28B; and (c increased miR-200 which results in decreased VEGFR1, VEGFR2 and EMT-related transcription factors ZEB1, ZEB2, SNAIL and SLUG. Specificity of DCLK1 post-transcriptional regulation of the downstream targets of miR-145, miR-200 and let-7a was accomplished utilizing a luciferase-based reporter assay. We conclude that DCLK1 plays a significant master regulatory role in pancreatic tumorigenesis through the regulation of multiple tumor

  3. TRPC3 regulates release of brain-derived neurotrophic factor from human airway smooth muscle.

    Science.gov (United States)

    Vohra, Pawan K; Thompson, Michael A; Sathish, Venkatachalem; Kiel, Alexander; Jerde, Calvin; Pabelick, Christina M; Singh, Brij B; Prakash, Y S

    2013-12-01

    Exogenous brain-derived neurotrophic factor (BDNF) enhances Ca(2+) signaling and cell proliferation in human airway smooth muscle (ASM), especially with inflammation. Human ASM also expresses BDNF, raising the potential for autocrine/paracrine effects. The mechanisms by which ASM BDNF secretion occurs are not known. Transient receptor potential channels (TRPCs) regulate a variety of intracellular processes including store-operated Ca(2+) entry (SOCE; including in ASM) and secretion of factors such as cytokines. In human ASM, we tested the hypothesis that TRPC3 regulates BDNF secretion. At baseline, intracellular BDNF was present, and BDNF secretion was detectable by enzyme linked immunosorbent assay (ELISA) of cell supernatants or by real-time fluorescence imaging of cells transfected with GFP-BDNF vector. Exposure to the pro-inflammatory cytokine tumor necrosis factor-alpha (TNFα) (20ng/ml, 48h) or a mixture of allergens (ovalbumin, house dust mite, Alternaria, and Aspergillus extracts) significantly enhanced BDNF secretion and increased TRPC3 expression. TRPC3 knockdown (siRNA or inhibitor Pyr3; 10μM) blunted BDNF secretion, and prevented inflammation effects. Chelation of extracellular Ca(2+) (EGTA; 1mM) or intracellular Ca(2+) (BAPTA; 5μM) significantly reduced secreted BDNF, as did the knockdown of SOCE proteins STIM1 and Orai1 or plasma membrane caveolin-1. Functionally, secreted BDNF had autocrine effects suggested by phosphorylation of high-affinity tropomyosin-related kinase TrkB receptor, prevented by chelating extracellular BDNF with chimeric TrkB-Fc. These data emphasize the role of TRPC3 and Ca(2+) influx in the regulation of BDNF secretion by human ASM and the enhancing effects of inflammation. Given the BDNF effects on Ca(2+) and cell proliferation, BDNF secretion may contribute to altered airway structure and function in diseases such as asthma.

  4. VeA and LaeA transcriptional factors regulate ochratoxin A biosynthesis in Aspergillus carbonarius.

    Science.gov (United States)

    Crespo-Sempere, A; Marín, S; Sanchis, V; Ramos, A J

    2013-09-16

    Ochratoxin A (OTA) is a mycotoxin with nephrotoxic, teratogenic and immunotoxic properties which represents a serious risk for human and animal health. Aspergillus carbonarius is considered the main OTA-producing species in grapes and products such as raisins, wine or juices, although it has also been isolated from coffee, cocoa and cereals. Till now not much information is available about regulatory mechanisms of OTA production by A. carbonarius. A better understanding of how environmental factors influence OTA production and which genes are involved in its regulation could help us design new control strategies. In this study, we have evaluated the role of VeA and LaeA transcriptional factors, which have been shown to regulate secondary metabolism in response to light in A. carbonarius. To this aim, veA and laeA genes were deleted in an ochratoxigenic A. carbonarius strain by targeted gene replacement using Agrobacterium tumefaciens-mediated transformation. Loss of veA and laeA in A. carbonarius yields to an organism with slight differences in vegetative growth but a strong reduction in conidial production. A drastic decrease of OTA production that ranged from 68.5 to 99.4% in ΔveA and ΔlaeA null mutants was also observed, which was correlated with a downregulation of a nonribosomal peptide synthetase involved in OTA biosynthesis. These findings suggest that VeA and LaeA have an important role regulating conidiation and OTA biosynthesis in response to light in A. carbonarius in a similar way to other fungi where functions of VeA and LaeA have been previously described. This is the first report of a transcriptional factor governing the production of OTA by A. carbonarius. © 2013 Elsevier B.V. All rights reserved.

  5. Insulin-like growth factor-II regulates bone sialoprotein gene transcription.

    Science.gov (United States)

    Choe, Jin; Sasaki, Yoko; Zhou, Liming; Takai, Hideki; Nakayama, Yohei; Ogata, Yorimasa

    2016-09-01

    Insulin-like growth factor-I and -II (IGF-I and IGF-II) have been found in bone extracts of several different species, and IGF-II is the most abundant growth factor stored in bone. Bone sialoprotein (BSP) is a noncollagenous extracellular matrix glycoprotein associated with mineralized connective tissues. In this study, we have investigated the regulation of BSP transcription by IGF-II in rat osteoblast-like ROS17/2.8 cells. IGF-II (50 ng/ml) increased BSP mRNA and protein levels after 6-h stimulation, and enhanced luciferase activities of the constructs pLUC3 (-116 to +60), pLUC4 (-425 to +60), pLUC5 (-801 to +60) and pLUC6 (-938 to +60). Effects of IGF-II were inhibited by tyrosine kinase, extracellular signal-regulated kinase1/2 and phosphatidylinositol 3-kinase inhibitors, and abrogated by 2-bp mutations in cAMP response element (CRE), FGF2 response element (FRE) and homeodomain protein-binding site (HOX). The results of gel shift assays showed that nuclear proteins binding to CRE, FRE and HOX sites were increased by IGF-II (50 ng/ml) at 3 and 6 h. CREB1, phospho-CREB1, c-Fos and c-Jun antibodies disrupted the formation of the CRE-protein complexes. Dlx5 and Runx2 antibodies disrupted the FRE- and HOX-protein complex formations. These studies therefore demonstrated that IGF-II increased BSP transcription by targeting CRE, FRE and HOX elements in the proximal promoter of the rat BSP gene. Moreover, phospho-CREB1, c-Fos, c-Jun, Dlx5 and Runx2 transcription factors appear to be key regulators of IGF-II effects on BSP transcription.

  6. Identification of trans-acting factors regulating SamDC expression in Oryza sativa

    Energy Technology Data Exchange (ETDEWEB)

    Basu, Supratim, E-mail: supratim_genetics@yahoo.co.in [Department of Crop Soil and Environmental Sciences, University of Arkansas, Fayetteville, AR 72701 (United States); Division of Plant Biology, Bose Institute, Kolkata (India); Roychoudhury, Aryadeep [Post Graduate Department of Biotechnology, St. Xavier' s College (Autonomous), 30, Mother Teresa Sarani, Kolkata - 700016, West Bengal (India); Sengupta, Dibyendu N. [Division of Plant Biology, Bose Institute, Kolkata (India)

    2014-03-07

    Highlights: • Identification of cis elements responsible for SamDC expression by in silico analysis. • qPCR analysis of SamDC expression to abiotic and biotic stress treatments. • Detection of SamDC regulators using identified cis-elements as probe by EMSA. • Southwestern Blot analysis to predict the size of the trans-acting factors. - Abstract: Abiotic stress affects the growth and productivity of crop plants; to cope with the adverse environmental conditions, plants have developed efficient defense machinery comprising of antioxidants like phenolics and flavonoids, and osmolytes like polyamines. SamDC is a key enzyme in the polyamine biosynthesis pathway in plants. In our present communication we have done in silico analysis of the promoter region of SamDC to look for the presence of different cis-regulatory elements contributing to its expression. Based on the presence of different cis-regulatory elements we completed comparative analysis of SamDC gene expression in rice lamina of IR-29 and Nonabokra by qPCR in response to the abiotic stress treatments of salinity, drought, cold and the biotic stress treatments of ABA and light. Additionally, to explore the role of the cis-regulatory elements in regulating the expression of SamDC gene in plants we comparatively analyzed the binding of rice nuclear proteins prepared from IR-29 and Nonabokra undergoing various stress treatments. The intensity of the complex formed was low and inducible in IR-29 in contrast to Nonabokra. Southwestern blot analysis helped in predicting the size of the trans-acting factors binding to these cis-elements. To our knowledge this is the first report on the comprehensive analysis of SamDC gene expression in rice and identification of the trans-acting factors regulating its expression.

  7. An R2R3-MYB Transcription Factor Regulates Capsaicinoid Biosynthesis.

    Science.gov (United States)

    Arce-Rodríguez, Magda L; Ochoa-Alejo, Neftalí

    2017-07-01

    Capsaicinoids are responsible for the hot taste of chili peppers. They are restricted to the genus Capsicum and are synthesized by the acylation of the aromatic compound vanillylamine (derived from the phenylpropanoid pathway) with a branched-chain fatty acid by the catalysis of the putative enzyme capsaicinoid synthase. R2R3-MYB transcription factors have been reported in different species of plants as regulators of structural genes of the phenylpropanoid pathway; therefore, we hypothesized that MYB genes might be involved in the regulation of the biosynthesis of pungent compounds. In this study, an R2R3-MYB transcription factor gene, designated CaMYB31, was isolated and characterized in Capsicum annuum 'Tampiqueño 74'. Bioinformatic analysis suggested that CaMYB31 could be involved in secondary metabolism, stress and plant hormone responses, and development. CaMYB31 expression analysis from placental tissue of pungent and nonpungent chili pepper fruits showed a positive correlation with the structural genes Ca4H, Comt, Kas, pAmt, and AT3 expression and also with the content of capsaicin and dihydrocapsacin during fruit development. However, CaMYB31 also was expressed in vegetative tissues (leaves, roots, and stems). Moreover, CaMYB31 silencing significantly reduced the expression of capsaicinoid biosynthetic genes and the capsaicinoid content. Additionally, CaMYB31 expression was affected by the plant hormones indoleacetic acid, jasmonic acid, salicylic acid, and gibberellic acid or by wounding, temperature, and light, factors known to affect the production of capsaicinoids. These findings indicate that CaMYB31 is indeed involved in the regulation of structural genes of the capsaicinoid biosynthetic pathway. © 2017 American Society of Plant Biologists. All Rights Reserved.

  8. An R2R3-MYB Transcription Factor Regulates Capsaicinoid Biosynthesis1[OPEN

    Science.gov (United States)

    Arce-Rodríguez, Magda L.

    2017-01-01

    Capsaicinoids are responsible for the hot taste of chili peppers. They are restricted to the genus Capsicum and are synthesized by the acylation of the aromatic compound vanillylamine (derived from the phenylpropanoid pathway) with a branched-chain fatty acid by the catalysis of the putative enzyme capsaicinoid synthase. R2R3-MYB transcription factors have been reported in different species of plants as regulators of structural genes of the phenylpropanoid pathway; therefore, we hypothesized that MYB genes might be involved in the regulation of the biosynthesis of pungent compounds. In this study, an R2R3-MYB transcription factor gene, designated CaMYB31, was isolated and characterized in Capsicum annuum ‘Tampiqueño 74’. Bioinformatic analysis suggested that CaMYB31 could be involved in secondary metabolism, stress and plant hormone responses, and development. CaMYB31 expression analysis from placental tissue of pungent and nonpungent chili pepper fruits showed a positive correlation with the structural genes Ca4H, Comt, Kas, pAmt, and AT3 expression and also with the content of capsaicin and dihydrocapsacin during fruit development. However, CaMYB31 also was expressed in vegetative tissues (leaves, roots, and stems). Moreover, CaMYB31 silencing significantly reduced the expression of capsaicinoid biosynthetic genes and the capsaicinoid content. Additionally, CaMYB31 expression was affected by the plant hormones indoleacetic acid, jasmonic acid, salicylic acid, and gibberellic acid or by wounding, temperature, and light, factors known to affect the production of capsaicinoids. These findings indicate that CaMYB31 is indeed involved in the regulation of structural genes of the capsaicinoid biosynthetic pathway. PMID:28483879

  9. Strong negative self regulation of prokaryotic transcription factors increases the intrinsic noise of protein expression.

    Science.gov (United States)

    Stekel, Dov J; Jenkins, Dafyd J

    2008-01-18

    Many prokaryotic transcription factors repress their own transcription. It is often asserted that such regulation enables a cell to homeostatically maintain protein abundance. We explore the role of negative self regulation of transcription in regulating the variability of protein abundance using a variety of stochastic modeling techniques. We undertake a novel analysis of a classic model for negative self regulation. We demonstrate that, with standard approximations, protein variance relative to its mean should be independent of repressor strength in a physiological range. Consequently, in that range, the coefficient of variation would increase with repressor strength. However, stochastic computer simulations demonstrate that there is a greater increase in noise associated with strong repressors than predicted by theory. The discrepancies between the mathematical analysis and computer simulations arise because with strong repressors the approximation that leads to Michaelis-Menten-like hyperbolic repression terms ceases to be valid. Because we observe that strong negative feedback increases variability and so is unlikely to be a mechanism for noise control, we suggest instead that negative feedback is evolutionarily favoured because it allows the cell to minimize mRNA usage. To test this, we used in silico evolution to demonstrate that while negative feedback can achieve only a modest improvement in protein noise reduction compared with the unregulated system, it can achieve good improvement in protein response times and very substantial improvement in reducing mRNA levels. Strong negative self regulation of transcription may not always be a mechanism for homeostatic control of protein abundance, but instead might be evolutionarily favoured as a mechanism to limit the use of mRNA. The use of hyperbolic terms derived from quasi-steady-state approximation should also be avoided in the analysis of stochastic models with strong repressors.

  10. Strong negative self regulation of Prokaryotic transcription factors increases the intrinsic noise of protein expression

    Directory of Open Access Journals (Sweden)

    Jenkins Dafyd J

    2008-01-01

    Full Text Available Abstract Background Many prokaryotic transcription factors repress their own transcription. It is often asserted that such regulation enables a cell to homeostatically maintain protein abundance. We explore the role of negative self regulation of transcription in regulating the variability of protein abundance using a variety of stochastic modeling techniques. Results We undertake a novel analysis of a classic model for negative self regulation. We demonstrate that, with standard approximations, protein variance relative to its mean should be independent of repressor strength in a physiological range. Consequently, in that range, the coefficient of variation would increase with repressor strength. However, stochastic computer simulations demonstrate that there is a greater increase in noise associated with strong repressors than predicted by theory. The discrepancies between the mathematical analysis and computer simulations arise because with strong repressors the approximation that leads to Michaelis-Menten-like hyperbolic repression terms ceases to be valid. Because we observe that strong negative feedback increases variability and so is unlikely to be a mechanism for noise control, we suggest instead that negative feedback is evolutionarily favoured because it allows the cell to minimize mRNA usage. To test this, we used in silico evolution to demonstrate that while negative feedback can achieve only a modest improvement in protein noise reduction compared with the unregulated system, it can achieve good improvement in protein response times and very substantial improvement in reducing mRNA levels. Conclusion Strong negative self regulation of transcription may not always be a mechanism for homeostatic control of protein abundance, but instead might be evolutionarily favoured as a mechanism to limit the use of mRNA. The use of hyperbolic terms derived from quasi-steady-state approximation should also be avoided in the analysis of stochastic

  11. Engineering the Oryza sativa cell wall with rice NAC transcription factors regulating secondary wall formation

    Directory of Open Access Journals (Sweden)

    Kouki eYoshida

    2013-10-01

    Full Text Available Plant tissues that require structural rigidity synthesize a thick, strong secondary cell wall of lignin, cellulose and hemicelluloses in a complicated bridged structure. Master regulators of secondary wall synthesis were identified in dicots, and orthologs of these regulators have been identified in monocots, but regulation of secondary cell wall formation in monocots has not been extensively studied. Here we demonstrate that the rice transcription factors SECONDARY WALL NAC DOMAIN PROTEINs (SWNs can regulate secondary wall formation in rice (Oryza sativa and are potentially useful for engineering the monocot cell wall. The OsSWN1 promoter is highly active in sclerenchymatous cells of the leaf blade and less active in xylem cells. By contrast, the OsSWN2 promoter is highly active in xylem cells and less active in sclerenchymatous cells. OsSWN2 splicing variants encode two proteins; the shorter protein (OsSWN2S has very low transcriptional activation ability, but the longer protein (OsSWN2L and OsSWN1 have strong transcriptional activation ability. In rice, expression of an OsSWN2S chimeric repressor, driven by the OsSWN2 promoter, resulted in stunted growth and para-wilting (leaf rolling and browning under normal water conditions due to impaired vascular vessels. The same OsSWN2S chimeric repressor, driven by the OsSWN1 promoter, caused a reduction of cell wall thickening in sclerenchymatous cells, a drooping leaf phenotype, reduced lignin and xylose contents and increased digestibility as forage. These data suggest that OsSWNs regulate secondary wall formation in rice and manipulation of OsSWNs may enable improvements in monocotyledonous crops for forage or biofuel applications.

  12. GATA transcription factors as tissue-specific master regulators for induced responses.

    Science.gov (United States)

    Block, Dena Hs; Shapira, Michael

    2015-01-01

    GATA transcription factors play important roles in directing developmental genetic programs and cell differentiation, and are conserved in animals, plants and fungi. C. elegans has 11 GATA-type transcription factors that orchestrate development of the gut, epidermis and vulva. However, the expression of certain GATA proteins persists into adulthood, where their function is less understood. Accumulating evidence demonstrates contributions of 2 terminal differentiation GATA transcription factors, ELT-2 and ELT-3, to epithelial immune responses in the adult intestine and epidermis (hypodermis), respectively. Involvement in other stress responses has also been documented. We recently showed that ELT-2 acted as a tissue-specific master regulator, cooperating with 2 transcription factors activated by the p38 pathway, ATF-7 and SKN-1, to control immune responses in the adult C. elegans intestine. Here, we discuss the broader implications of these findings for understanding the involvement of GATA transcription factors in adult stress responses, and draw parallels between ELT-2 and ELT-3 to speculate that the latter may fulfill similar tissue-specific functions in the epidermis.

  13. Regulation of the MEF2 Family of Transcription Factors by p38†

    OpenAIRE

    Zhao, Ming; New, Liguo; Kravchenko, Vladimir V.; KATO, Yutaka; Gram, Hermann; Di Padova, Franco; Olson, Eric N.; Ulevitch, Richard J.; Han, Jiahuai

    1999-01-01

    Members of the MEF2 family of transcription factors bind as homo- and heterodimers to the MEF2 site found in the promoter regions of numerous muscle-specific, growth- or stress-induced genes. We showed previously that the transactivation activity of MEF2C is stimulated by p38 mitogen-activated protein (MAP) kinase. In this study, we examined the potential role of the p38 MAP kinase pathway in regulating the other MEF2 family members. We found that MEF2A, but not MEF2B or MEF2D, is a substrate...

  14. Key factors regulating the mass delivery of macromolecules to model cell membranes

    DEFF Research Database (Denmark)

    Campbell, Richard A.; Watkins, Erik B.; Jagalski, Vivien

    2014-01-01

    We show that both gravity and electrostatics are key factors regulating interactions between model cell membranes and self-assembled liquid crystalline aggregates of dendrimers and phospholipids. The system is a proxy for the trafficking of reservoirs of therapeutic drugs to cell membranes for slow...... diffusion and continuous delivery. Neutron reflectometry measurements were carried out on supported lipid bilayers of varying charge and on hydrophilic silica surfaces. Translocation of the macromolecule across the membrane and adsorption of the lamellar aggregates occur only when the membrane (1...... of the aggregates to activate endocytosis pathways on specific cell types is discussed in the context of targeted drug delivery applications....

  15. A new role for plant R2R3-MYB transcription factors in cell cycle regulation

    Institute of Scientific and Technical Information of China (English)

    Eleonora Cominelli; Chiara Tonelli

    2009-01-01

    @@ MYB proteins are transcription factors present in all eukaryotes,sharing a common DNA-binding domain that consists of one to three imperfect helix-helix-turn-helix repeats of about 50 amino acids,called RI,R2,and R3 respectively [1].In animals and yeast these proteins represent a small gene family [1].Animal R1R2R3-MYB proteins have been described for their role in cell cycle regulation mainly at the G1/S,but also at the G2/M transition,as firstly demonstrated in Drosophila [2].

  16. ATAF1 transcription factor directly regulates abscisic acid biosynthetic gene NCED3 in Arabidopsis thaliana

    DEFF Research Database (Denmark)

    Jensen, Michael Krogh; Lindemose, Søren; De Masi, Federico

    2013-01-01

    ATAF1, an Arabidopsis thaliana NAC transcription factor, plays important roles in plant adaptation to environmental stress and development. To search for ATAF1 target genes, we used protein binding microarrays and chromatin-immunoprecipitation (ChIP). This identified T[A,C,G]CGT[A,G] and TT[A,C,G...... abscisic acid (ABA) phytohormone biosynthetic gene NCED3. ChIP-qPCR and expression analysis showed that ATAF1 binding to the NCED3 promoter correlated with increased NCED3 expression and ABA hormone levels. These results indicate that ATAF1 regulates ABA biosynthesis....

  17. Transcription factors involved in the regulation of natural killer cell development and function: an update

    Directory of Open Access Journals (Sweden)

    Martha Elia Luevano

    2012-10-01

    Full Text Available Natural Killer (NK cells belong to the innate immune system and are key effectors in the immune response against cancer and infection. Recent studies have contributed to the knowledge of events controlling NK cell fate. The use of knockout mice has enabled the discovery of key transcription factors (TFs essential for NK cell development and function. Yet, unwrapping the downstream targets of these TFs and their influence on NK cells remains a challenge. In this review we discuss the latest TFs described to be involved in the regulation of NK cell development and maturation.

  18. Undifferentiated embryonic cell transcription factor 1 regulates ESC chromatin organization and gene expression

    DEFF Research Database (Denmark)

    Kooistra, Susanne M; van den Boom, Vincent; Thummer, Rajkumar P

    2010-01-01

    Previous reports showed that embryonic stem (ES) cells contain hyperdynamic and globally transcribed chromatin-properties that are important for ES cell pluripotency and differentiation. Here, we demonstrate a role for undifferentiated embryonic cell transcription factor 1 (UTF1) in regulating ES...... cell chromatin structure. Using chromatin immunoprecipitation-on-chip analysis, we identified >1,700 UTF1 target genes that significantly overlap with previously identified Nanog, Oct4, Klf-4, c-Myc, and Rex1 targets. Gene expression profiling showed that UTF1 knock down results in increased expression...... of a large set of genes, including a significant number of UTF1 targets. UTF1 knock down (KD) ES cells are, irrespective of the increased expression of several self-renewal genes, Leukemia inhibitory factor (LIF) dependent. However, UTF1 KD ES cells are perturbed in their differentiation in response...

  19. Stochastic seasonality and nonlinear density-dependent factors regulate population size in an African rodent

    DEFF Research Database (Denmark)

    Leirs, Herwig; Steneth, Nils Chr.; Nichols, James D.

    1997-01-01

    no information on actual demographic rates(9,10). Here we report on both density-dependent and density-independent effects in a murid rodent pest species, the multimammute rat Mastomys natalensis (Smith, 1834), using statistical capture-recapture models, Both effects occur simultaneously, but we also demonstrate......Ecology has long been troubled by the controversy over how populations are regulated(1,2). Some ecologists focus on the role of environmental effects, whereas others argue that density-dependent feedback mechanisms are central(3-6). The relative importance of both processes is still hotly debated......, but clear examples of both processes acting in the same population are rare(7,8). Key-factor analysis (regression of population changes on possible causal factors) and time-series analysis are often used to investigate the presence of density dependence, but such approaches may be biased and provide...

  20. Regulation of endogenous human gene expression by ligand-inducible TALE transcription factors.

    Science.gov (United States)

    Mercer, Andrew C; Gaj, Thomas; Sirk, Shannon J; Lamb, Brian M; Barbas, Carlos F

    2014-10-17

    The construction of increasingly sophisticated synthetic biological circuits is dependent on the development of extensible tools capable of providing specific control of gene expression in eukaryotic cells. Here, we describe a new class of synthetic transcription factors that activate gene expression in response to extracellular chemical stimuli. These inducible activators consist of customizable transcription activator-like effector (TALE) proteins combined with steroid hormone receptor ligand-binding domains. We demonstrate that these ligand-responsive TALE transcription factors allow for tunable and conditional control of gene activation and can be used to regulate the expression of endogenous genes in human cells. Since TALEs can be designed to recognize any contiguous DNA sequence, the conditional gene regulatory system described herein will enable the design of advanced synthetic gene networks.

  1. Voltage-Sensitive Load Controllers for Voltage Regulation and Increased Load Factor in Distribution Systems

    DEFF Research Database (Denmark)

    Douglass, Philip James; Garcia-Valle, Rodrigo; Østergaard, Jacob

    2014-01-01

    consumption which can be mapped to temperature setpoint offsets of thermostat controlled loads. In networks where a lower voltage level corresponds to high system load (and vice versa), this controller acts to regulate voltage and increase the load factor. Simulations are conducted on low- and medium-voltage......This paper presents a novel controller design for controlling appliances based on local measurements of voltage. The controller finds the normalized voltage deviation accounting for the sensitivity of voltage measurements to appliance state. The controller produces a signal indicating desired power...... distribution systems with residential loads including voltage-sensitive water heaters. In low-voltage systems, the results of the simulations show the controller to be effective at reducing the extremes of voltage and increasing the load factor while respecting end-use temperature constraints. In medium-voltage...

  2. Regulation of Transcriptional Networks by PKC Isozymes: Identification of c-Rel as a Key Transcription Factor for PKC-Regulated Genes.

    Directory of Open Access Journals (Sweden)

    Rachana Garg

    Full Text Available Activation of protein kinase C (PKC, a family of serine-threonine kinases widely implicated in cancer progression, has major impact on gene expression. In a recent genome-wide analysis of prostate cancer cells we identified distinctive gene expression profiles controlled by individual PKC isozymes and highlighted a prominent role for PKCδ in transcriptional activation.Here we carried out a thorough bioinformatics analysis to dissect transcriptional networks controlled by PKCα, PKCδ, and PKCε, the main diacylglycerol/phorbol ester PKCs expressed in prostate cancer cells. Despite the remarkable differences in the patterns of transcriptional responsive elements (REs regulated by each PKC, we found that c-Rel represents the most frequent RE in promoters regulated by all three PKCs. In addition, promoters of PKCδ-regulated genes were particularly enriched with REs for CREB, NF-E2, RREB, SRF, Oct-1, Evi-1, and NF-κB. Most notably, by using transcription factor-specific RNAi we were able to identify subsets of PKCδ-regulated genes modulated by c-Rel and CREB. Furthermore, PKCδ-regulated genes condensed under the c-Rel transcriptional regulation display significant functional interconnections with biological processes such as angiogenesis, inflammatory response, and cell motility.Our study identified candidate transcription factors in the promoters of PKC regulated genes, in particular c-Rel was found as a key transcription factor in the control of PKCδ-regulated genes. The deconvolution of PKC-regulated transcriptional networks and their nodes may greatly help in the identification of PKC effectors and have significant therapeutics implications.

  3. Regulacin de la mineralizacin sea por factores inorgnicos y peptdicos Regulation of Bone Mineralization by inorganic and peptide factors

    Directory of Open Access Journals (Sweden)

    A.L Negri

    2011-10-01

    osteoctico perilacunar.Orthotopic mineralization begins with the production of matrix vesicles that are produced by polarized budding of the surface of condrocytes, osteoblasts and odontoblasts. It occurs in two steps: The first one is the formation of hydroxiapatite crystals within the matrix vesicles, followed by the propagation of the hydroxiapatite crystals through the membrane vesicle into the extra cellular matrix. In the regulation of orthotopic mineralization, apart from tissue-specific cells, a great number of enzymes, inorganic and peptide factors participate, that have complex interactions among them. Inorganic pyrophosphate (PPi antagonizes the ability of phosphate (Pi to crystallize with calcium and to form hydroxiapatite, thus suppressing its propagation. For the normal mineralization to continue, an adjusted balance of the extra cellular Pi and PPi levels is needed. Three molecules have been identified that have a central role in the regulation of extra cellular PPi levels: tissue non-specific alkaline phosphatase (TNAP, which hydrolyzes PPi, the nucleotide pyrophosphatase phosphodiesterase 1 (NPP1, which generates PPi from triphosphate nucleosides, and the multiple-steps transmembrane protein ANK which transfers PPi from the intracellular to the extracellular compartment. There are, in turn, two SIBLING proteins called DMP1 and MEPE that regulate mineralization. The expression of DMP1 by the osteocyte is dramatically induced in response to mechanical loading increasing bone mineralization. MEPE protein contains a protease resistant motif called ASARM, which is believed to be the candidate for the mineralization inhibitor (minhibin. Osteopontin is another mineralization inhibitor in its phosphorilated form and its secretion is markedly reduced in knockout mice for NPP1. Present data seem to support the hypothesis that these molecules could be the translators of bone strain and participate in the regulation of mineralization of the perilacunar osteocytic space.

  4. Host genetics and environmental factors regulate ecological succession of the mouse colon tissue-associated microbiota.

    Directory of Open Access Journals (Sweden)

    Philip Smith

    Full Text Available BACKGROUND: The integration of host genetics, environmental triggers and the microbiota is a recognised factor in the pathogenesis of barrier function diseases such as IBD. In order to determine how these factors interact to regulate the host immune response and ecological succession of the colon tissue-associated microbiota, we investigated the temporal interaction between the microbiota and the host following disruption of the colonic epithelial barrier. METHODOLOGY/PRINCIPAL FINDINGS: Oral administration of DSS was applied as a mechanistic model of environmental damage of the colon and the resulting inflammation characterized for various parameters over time in WT and Nod2 KO mice. RESULTS: In WT mice, DSS damage exposed the host to the commensal flora and led to a migration of the tissue-associated bacteria from the epithelium to mucosal and submucosal layers correlating with changes in proinflammatory cytokine profiles and a progressive transition from acute to chronic inflammation of the colon. Tissue-associated bacteria levels peaked at day 21 post-DSS and declined thereafter, correlating with recruitment of innate immune cells and development of the adaptive immune response. Histological parameters, immune cell infiltration and cytokine biomarkers of inflammation were indistinguishable between Nod2 and WT littermates following DSS, however, Nod2 KO mice demonstrated significantly higher tissue-associated bacterial levels in the colon. DSS damage and Nod2 genotype independently regulated the community structure of the colon microbiota. CONCLUSIONS/SIGNIFICANCE: The results of these experiments demonstrate the integration of environmental and genetic factors in the ecological succession of the commensal flora in mammalian tissue. The association of Nod2 genotype (and other host polymorphisms and environmental factors likely combine to influence the ecological succession of the tissue-associated microflora accounting in part for their

  5. Transcription factor veracity: is GBF3 responsible for ABA-regulated expression of Arabidopsis Adh?

    Science.gov (United States)

    Lu, G; Paul, A L; McCarty, D R; Ferl, R J

    1996-01-01

    Assignment of particular transcription factors to specific roles in promoter elements can be problematic, especially in systems such as the G-box, where multiple factors of overlapping specificity exist. In the Arabidopsis alcohol dehydrogenase (Adh) promoter, the G-box regulates expression in response to cold and dehydration, presumably through the action of abscisic acid (ABA), and is bound by a nuclear protein complex in vivo during expression in cell cultures. In this report, we test the conventional wisdom of biochemical approaches used to identify DNA binding proteins and assess their specific interactions by using the G-box and a nearby half G-box element of the Arabidopsis Adh promoter as a model system. Typical in vitro assays demonstrated specific interaction of G-box factor 3 (GBF3) with both the G-box and the half G-box element. Dimethyl sulfate footprint analysis confirmed that the in vitro binding signature of GBF3 essentially matches the footprint signature detected in vivo at the G-box. Because RNA gel blot data indicated that GBF3 is itself induced by ABA, we might have concluded that GBF3 is indeed the GBF responsible in cell cultures for binding to the Adh G-box and is therefore responsible for ABA-regulated expression of Adh. Potential limitations of this conclusion are exposed by the fact that other GBFs bind the G-box with the same signature as GBF3, and subtle differences between in vivo and in vitro footprint signatures indicate that factors other than or in addition to GBF3 interact with the half G-box element. PMID:8672884

  6. Transcription factors, sucrose, and sucrose metabolic genes interact to regulate potato phenylpropanoid metabolism.

    Science.gov (United States)

    Payyavula, Raja S; Singh, Rajesh K; Navarre, Duroy A

    2013-11-01

    Much remains unknown about how transcription factors and sugars regulate phenylpropanoid metabolism in tuber crops like potato (Solanum tuberosum). Based on phylogeny and protein similarity to known regulators of phenylpropanoid metabolism, 15 transcription factors were selected and their expression was compared in white, yellow, red, and purple genotypes with contrasting phenolic and anthocyanin profiles. Red and purple genotypes had increased phenylalanine ammonia lyase (PAL) enzyme activity, markedly higher levels of phenylpropanoids, and elevated expression of most phenylpropanoid structural genes, including a novel anthocyanin O-methyltransferase. The transcription factors Anthocyanin1 (StAN1), basic Helix Loop Helix1 (StbHLH1), and StWD40 were more strongly expressed in red and purple potatoes. Expression of 12 other transcription factors was not associated with phenylpropanoid content, except for StMYB12B, which showed a negative relationship. Increased expression of AN1, bHLH1, and WD40 was also associated with environmentally mediated increases in tuber phenylpropanoids. Treatment of potato plantlets with sucrose induced hydroxycinnamic acids, flavonols, anthocyanins, structural genes, AN1, bHLH1, WD40, and genes encoding the sucrose-hydrolysing enzymes SUSY1, SUSY4, and INV2. Transient expression of StAN1 in tobacco leaves induced bHLH1, structural genes, SUSY1, SUSY4, and INV1, and increased phenylpropanoid amounts. StAN1 infiltration into tobacco leaves decreased sucrose and glucose concentrations. In silico promoter analysis revealed the presence of MYB and bHLH regulatory elements on sucrolytic gene promoters and sucrose-responsive elements on the AN1 promoter. These findings reveal an interesting dynamic between AN1, sucrose, and sucrose metabolic genes in modulating potato phenylpropanoids.

  7. The TRA-1 transcription factor binds TRA-2 to regulate sexual fates in Caenorhabditis elegans

    Science.gov (United States)

    Wang, Shanping; Kimble, Judith

    2001-01-01

    The tra-1 and tra-2 sex-determining genes promote female fates in Caenorhabditis elegans. Classical genetic studies placed tra-1 as the terminal regulator of the pathway with tra-2 acting upstream as a regulator of regulators of tra-1. Here we report the surprising result that the TRA-1 transcription factor binds the intracellular domain of the TRA-2 membrane protein. This binding is dependent on the MX regulatory domain, a region of the TRA-2 intracellular domain shown previously to be critical for the onset of hermaphrodite spermatogenesis. The functional importance of the TRA-1–TRA-2 physical interaction is supported by genetic interactions between tra-1(0) and tra-2(mx) mutations: a reduction of tra-1 gene dose from two copies to one copy enhances the tra-2(mx) feminization phenotype, but has no apparent somatic effect. In Caenorhabditis briggsae, we also find an MX-dependent interaction between Cb-TRA-1 and Cb-TRA-2, but intriguingly, no cross-species interactions are seen. The conservation of the TRA-1– TRA-2 interaction underscores its importance in sex determination. PMID:11250902

  8. Regulation of eukaryotic initiation factor 4AII by MyoD during murine myogenic cell differentiation.

    Directory of Open Access Journals (Sweden)

    Gabriela Galicia-Vázquez

    Full Text Available Gene expression during muscle cell differentiation is tightly regulated at multiple levels, including translation initiation. The PI3K/mTOR signalling pathway exerts control over protein synthesis by regulating assembly of eukaryotic initiation factor (eIF 4F, a heterotrimeric complex that stimulates recruitment of ribosomes to mRNA templates. One of the subunits of eIF4F, eIF4A, supplies essential helicase function during this phase of translation. The presence of two cellular eIF4A isoforms, eIF4AI and eIF4AII, has long thought to impart equivalent functions to eIF4F. However, recent experiments have alluded to distinct activities between them. Herein, we characterize distinct regulatory mechanisms between the eIF4A isoforms during muscle cell differentiation. We find that eIF4AI levels decrease during differentiation whereas eIF4AII levels increase during myofiber formation in a MyoD-dependent manner. This study characterizes a previously undefined mechanism for eIF4AII regulation in differentiation and highlights functional differences between eIF4AI and eIF4AII. Finally, RNAi-mediated alterations in eIF4AI and eIF4AII levels indicate that the myogenic process can tolerate short term reductions in eIF4AI or eIF4AII levels, but not both.

  9. ЕFFECT OF PLANT GROWTH REGULATORS IN THE CONDITIONS OF ANTHROPOGENIC ENVIRONMENTAL FACTORS

    Directory of Open Access Journals (Sweden)

    O. M. Vasilyuk

    2016-08-01

    Full Text Available The paper analyses the general (GА, nM pyruvic acid/ml∙second and specific (SA, nM pyruvic acid /mg second transferase enzyme activity of protein metabolism (Аlanine aminotransferase ALT, EC 2.6.1.2, and Аspartate aminotransferase, AST, EC 2.6.1.1 in Salix alba L. leaves, that planted on the banks of Mokra Sura River (anthropogenic polluted, increased level of salinity and Shpakova River (relatively clean, control which are parts of Dnipro River Basin of Steppe Dnipro Region. We used the plant growth regulator “Kornevin” in order to accelerate rooting and reducing of exogenous pressures on the plant. We registered the Aminotransferase nonspecific reaction towards anthropogenic pressure, which was associated with the formation of non-specific mechanisms of adaptation to support the homeostasis. We revealed the significant differences between experiment and control in index of protein synthesis and metabolism depending on the conditions of growth and development. Protective and leveling effects of growth regulator have been proved. The advisability of using the "Kornevin" as an adaptogene and a protector in variable environmental conditions have been indicated. Salix alba L., increased level of salinity, growth regulators, alaninaminotransferase, aspartataminotransferase, adaptogene, anthropogenic factors

  10. The MYB107 Transcription Factor Positively Regulates Suberin Biosynthesis1[OPEN

    Science.gov (United States)

    Yang, Huijun; Cai, Yuanheng; Kai, Guoyin

    2017-01-01

    Suberin, a lipophilic polymer deposited in the outer integument of the Arabidopsis (Arabidopsis thaliana) seed coat, represents an essential sealing component controlling water and solute movement and protecting seed from pathogenic infection. Although many genes responsible for suberin synthesis are identified, the regulatory components controlling its biosynthesis have not been definitively determined. Here, we show that the Arabidopsis MYB107 transcription factor acts as a positive regulator controlling suberin biosynthetic gene expression in the seed coat. MYB107 coexpresses with suberin biosynthetic genes in a temporal manner during seed development. Disrupting MYB107 particularly suppresses the expression of genes involved in suberin but not cutin biosynthesis, lowers seed coat suberin accumulation, alters suberin lamellar structure, and consequently renders higher seed coat permeability and susceptibility to abiotic stresses. Furthermore, MYB107 directly binds to the promoters of suberin biosynthetic genes, verifying its primary role in regulating their expression. Identifying MYB107 as a positive regulator for seed coat suberin synthesis offers a basis for discovering the potential transcriptional network behind one of the most abundant lipid-based polymers in nature. PMID:27965303

  11. Regulation of a transcription factor network by Cdk1 coordinates late cell cycle gene expression.

    Science.gov (United States)

    Landry, Benjamin D; Mapa, Claudine E; Arsenault, Heather E; Poti, Kristin E; Benanti, Jennifer A

    2014-05-02

    To maintain genome stability, regulators of chromosome segregation must be expressed in coordination with mitotic events. Expression of these late cell cycle genes is regulated by cyclin-dependent kinase (Cdk1), which phosphorylates a network of conserved transcription factors (TFs). However, the effects of Cdk1 phosphorylation on many key TFs are not known. We find that elimination of Cdk1-mediated phosphorylation of four S-phase TFs decreases expression of many late cell cycle genes, delays mitotic progression, and reduces fitness in budding yeast. Blocking phosphorylation impairs degradation of all four TFs. Consequently, phosphorylation-deficient mutants of the repressors Yox1 and Yhp1 exhibit increased promoter occupancy and decreased expression of their target genes. Interestingly, although phosphorylation of the transcriptional activator Hcm1 on its N-terminus promotes its degradation, phosphorylation on its C-terminus is required for its activity, indicating that Cdk1 both activates and inhibits a single TF. We conclude that Cdk1 promotes gene expression by both activating transcriptional activators and inactivating transcriptional repressors. Furthermore, our data suggest that coordinated regulation of the TF network by Cdk1 is necessary for faithful cell division.

  12. Checkpoint Kinases Regulate a Global Network of Transcription Factors in Response to DNA Damage

    Directory of Open Access Journals (Sweden)

    Eric J. Jaehnig

    2013-07-01

    Full Text Available DNA damage activates checkpoint kinases that induce several downstream events, including widespread changes in transcription. However, the specific connections between the checkpoint kinases and downstream transcription factors (TFs are not well understood. Here, we integrate kinase mutant expression profiles, transcriptional regulatory interactions, and phosphoproteomics to map kinases and downstream TFs to transcriptional regulatory networks. Specifically, we investigate the role of the Saccharomyces cerevisiae checkpoint kinases (Mec1, Tel1, Chk1, Rad53, and Dun1 in the transcriptional response to DNA damage caused by methyl methanesulfonate. The result is a global kinase-TF regulatory network in which Mec1 and Tel1 signal through Rad53 to synergistically regulate the expression of more than 600 genes. This network involves at least nine TFs, many of which have Rad53-dependent phosphorylation sites, as regulators of checkpoint-kinase-dependent genes. We also identify a major DNA damage-induced transcriptional network that regulates stress response genes independently of the checkpoint kinases.

  13. The Drosophila Zinc Finger Transcription Factor Ouija Board Controls Ecdysteroid Biosynthesis through Specific Regulation of spookier.

    Directory of Open Access Journals (Sweden)

    Tatsuya Komura-Kawa

    2015-12-01

    Full Text Available Steroid hormones are crucial for many biological events in multicellular organisms. In insects, the principal steroid hormones are ecdysteroids, which play essential roles in regulating molting and metamorphosis. During larval and pupal development, ecdysteroids are synthesized in the prothoracic gland (PG from dietary cholesterol via a series of hydroxylation and oxidation steps. The expression of all but one of the known ecdysteroid biosynthetic enzymes is restricted to the PG, but the transcriptional regulatory networks responsible for generating such exquisite tissue-specific regulation is only beginning to be elucidated. Here, we report identification and characterization of the C2H2-type zinc finger transcription factor Ouija board (Ouib necessary for ecdysteroid production in the PG in the fruit fly Drosophila melanogaster. Expression of ouib is predominantly limited to the PG, and genetic null mutants of ouib result in larval developmental arrest that can be rescued by administrating an active ecdysteroid. Interestingly, ouib mutant animals exhibit a strong reduction in the expression of one ecdysteroid biosynthetic enzyme, spookier. Using a cell culture-based luciferase reporter assay, Ouib protein stimulates transcription of spok by binding to a specific ~15 bp response element in the spok PG enhancer element. Most remarkable, the developmental arrest phenotype of ouib mutants is rescued by over-expression of a functionally-equivalent paralog of spookier. These observations imply that the main biological function of Ouib is to specifically regulate spookier transcription during Drosophila development.

  14. Membrane and integrative nuclear fibroblastic growth factor receptor (FGFR) regulation of FGF-23.

    Science.gov (United States)

    Han, Xiaobin; Xiao, Zhousheng; Quarles, L Darryl

    2015-04-17

    Fibroblastic growth factor receptor 1 (FGFR1) signaling pathways are implicated in the regulation of FGF-23 gene transcription, but the molecular pathways remain poorly defined. We used low molecular weight (LMW, 18 kDa) FGF-2 and high molecular weight (HMW) FGF-2 isoforms, which, respectively, activate cell surface FGF receptors and intranuclear FGFR1, to determine the roles of membrane FGFRs and integrative nuclear FGFR1 signaling (INFS) in the regulation of FGF-23 gene transcription in osteoblasts. We found that LMW-FGF-2 induced NFAT and Ets1 binding to conserved cis-elements in the proximal FGF-23 promoter and stimulated FGF-23 promoter activity through PLCγ/calcineurin/NFAT and MAPK pathways in SaOS-2 and MC3T3-E1 osteoblasts. In contrast, HMW-FGF-2 stimulated FGF-23 promoter activity in osteoblasts through a cAMP-dependent binding of FGFR1 and cAMP-response element-binding protein (CREB) to a conserved cAMP response element (CRE) contiguous with the NFAT binding site in the FGF-23 promoter. Mutagenesis of the NFAT and CRE binding sites, respectively, inhibited the effects of LMW-FGF-2 and HMW-FGF-23 to stimulate FGF-23 promoter activity. FGF-2 activation of both membrane FGFRs and INFS-dependent FGFR1 pathways may provide a means to integrate systemic and local regulation of FGF-23 transcription under diverse physiological and pathological conditions.

  15. CRTR-1, a developmentally regulated transcriptional repressor related to the CP2 family of transcription factors.

    Science.gov (United States)

    Rodda, S; Sharma, S; Scherer, M; Chapman, G; Rathjen, P

    2001-02-02

    CP2-related proteins comprise a family of DNA-binding transcription factors that are generally activators of transcription and expressed ubiquitously. We reported a differential display polymerase chain reaction fragment, Psc2, which was expressed in a regulated fashion in mouse pluripotent cells in vitro and in vivo. Here, we report further characterization of the Psc2 cDNA and function. The Psc2 cDNA contained an open reading frame homologous to CP2 family proteins. Regions implicated in DNA binding and oligomeric complex formation, but not transcription activation, were conserved. Psc2 expression in vivo during embryogenesis and in the adult mouse demonstrated tight spatial and temporal regulation, with the highest levels of expression in the epithelial lining of distal convoluted tubules in embryonic and adult kidneys. Functional analysis demonstrated that PSC2 repressed transcription 2.5-15-fold when bound to a heterologous promoter in ES, 293T, and COS-1 cells. The N-terminal 52 amino acids of PSC2 were shown to be necessary and sufficient for this activity and did not share obvious homology with reported repressor motifs. These results represent the first report of a CP2 family member that is expressed in a developmentally regulated fashion in vivo and that acts as a direct repressor of transcription. Accordingly, the protein has been named CP2-Related Transcriptional Repressor-1 (CRTR-1).

  16. Steroidogenic Factor 1 in the Ventromedial Nucleus of the Hypothalamus Regulates Age-Dependent Obesity

    Science.gov (United States)

    Kinyua, Ann W.; Yang, Dong Joo; Chang, Inik; Kim, Ki Woo

    2016-01-01

    The ventromedial nucleus of the hypothalamus (VMH) is important for the regulation of whole body energy homeostasis and lesions in the VMH are reported to result in massive weight gain. The nuclear receptor steroidogenic factor 1 (SF-1) is a known VMH marker as it is exclusively expressed in the VMH region of the brain. SF-1 plays a critical role not only in the development of VMH but also in its physiological functions. In this study, we generated prenatal VMH-specific SF-1 KO mice and investigated age-dependent energy homeostasis regulation by SF-1. Deletion of SF-1 in the VMH resulted in dysregulated insulin and leptin homeostasis and late onset obesity due to increased food intake under normal chow and high fat diet conditions. In addition, SF-1 ablation was accompanied by a marked reduction in energy expenditure and physical activity and this effect was significantly pronounced in the aged mice. Taken together, our data indicates that SF-1 is a key component in the VMH-mediated regulation of energy homeostasis and implies that SF-1 plays a protective role against metabolic stressors including aging and high fat diet. PMID:27598259

  17. Class I BASIC PENTACYSTEINE factors regulate HOMEOBOX genes involved in meristem size maintenance.

    Science.gov (United States)

    Simonini, Sara; Kater, Martin M

    2014-04-01

    The BASIC PENTACYSTEINE (BCP) family is a poorly characterized plant transcription factor family of GAGA BINDING PROTEINS. In Arabidopsis, there are seven members (BPC1-7) that are broadly expressed, and they can potentially bind more than 3000 Arabidopsis GAGA-repeat-containing genes. To date, BPCs are known to be direct regulators of the INNER NO OUTER (INO), SEEDSTICK (STK), and LEAFY COTYLEDON 2 (LEC2) genes. Because of the high functional redundancy, neither single knockout nor double bpc mutant combinations cause aberrant phenotypes. The bpc1-2 bpc2 bpc3 triple mutant shows several pleiotropic developmental defects, including enlargement of the inflorescence meristem and flowers with supernumerary floral organs. Here, we demonstrated through expression analysis and chromatin immunoprecipitation assays that this phenotype is probably due to deregulation of the expression of the SHOOTMERISTEMLESS (STM) and BREVIPEDICELLUS/KNAT1 (BP) genes, which are both direct targets of BPCs. Moreover, we assigned a role to BPCs in the fine regulation of the cytokinin content in the meristem, as both ISOPENTENYLTRANSFERASE 7 (IPT7) and ARABIDOPSIS RESPONSE REGULATOR 7 (ARR7) genes were shown to be overexpressed in the bpc1-2 bpc2 bpc3 triple mutant.

  18. TCPs, WUSs, and WINDs: families of transcription factors that regulate shoot meristem formation, stem cell maintenance, and somatic cell differentiation.

    Science.gov (United States)

    Ikeda, Miho; Ohme-Takagi, Masaru

    2014-01-01

    In contrast to somatic mammalian cells, which cannot alter their fate, plant cells can dedifferentiate to form totipotent callus cells and regenerate a whole plant, following treatment with specific phytohormones. However, the regulatory mechanisms and key factors that control differentiation-dedifferentiation and cell totipotency have not been completely clarified in plants. Recently, several plant transcription factors that regulate meristem formation and dedifferentiation have been identified and include members of the TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP), WUSCHEL (WUS), and WOUND INDUCED DEDIFFERENTIATION (WIND1) families. WUS and WIND positively control plant cell totipotency, while TCP negatively controls it. Interestingly, TCP is a transcriptional activator that acts as a negative regulator of shoot meristem formation, and WUS is a transcriptional repressor that positively maintains totipotency of the stem cells of the shoot meristem. We describe here the functions of TCP, WUS, and WIND transcription factors in the regulation of differentiation-dedifferentiation by positive and negative transcriptional regulators.

  19. The polyadenylation factor subunit CLEAVAGE AND POLYADENYLATION SPECIFICITY FACTOR30: A key factor of programmed cell death and a regulator of immunity in arabidopsis

    KAUST Repository

    Bruggeman, Quentin

    2014-04-04

    Programmed cell death (PCD) is essential for several aspects of plant life, including development and stress responses. Indeed, incompatible plant-pathogen interactions are well known to induce the hypersensitive response, a localized cell death. Mutational analyses have identified several key PCD components, and we recently identified the mips1 mutant of Arabidopsis (Arabidopsis thaliana), which is deficient for the key enzyme catalyzing the limiting step of myoinositol synthesis. One of the most striking features of mips1 is the light-dependent formation of lesions on leaves due to salicylic acid (SA)-dependent PCD, revealing roles for myoinositol or inositol derivatives in the regulation of PCD. Here, we identified a regulator of plant PCD by screening for mutants that display transcriptomic profiles opposing that of the mips1 mutant. Our screen identified the oxt6 mutant, which has been described previously as being tolerant to oxidative stress. In the oxt6 mutant, a transfer DNA is inserted in the CLEAVAGE AND POLYADENYLATION SPECIFICITY FACTOR30 (CPSF30) gene, which encodes a polyadenylation factor subunit homolog. We show that CPSF30 is required for lesion formation in mips1 via SA-dependent signaling, that the prodeath function of CPSF30 is not mediated by changes in the glutathione status, and that CPSF30 activity is required for Pseudomonas syringae resistance. We also show that the oxt6 mutation suppresses cell death in other lesion-mimic mutants, including lesion-simulating disease1, mitogen-activated protein kinase4, constitutive expressor of pathogenesis-related genes5, and catalase2, suggesting that CPSF30 and, thus, the control of messenger RNA 3′ end processing, through the regulation of SA production, is a key component of plant immune responses. © 2014 American Society of Plant Biologists. All rights reserved.

  20. Identification of Sp1 as a Transcription Activator to Regulate Fibroblast Growth Factor 21 Gene Expression

    Directory of Open Access Journals (Sweden)

    Shuqin Chen

    2017-01-01

    Full Text Available Fibroblast growth factor 21 (FGF21 is a metabolic hormone with multiple beneficial effects on lipid and glucose homeostasis. Previous study demonstrated that FGF21 might be one of the Sp1 target genes. However, the transcriptional role of Sp1 on FGF21 in adipose tissue and liver has not been reported. In this study, we found that the proximal promoter of mouse FGF21 is located between −63 and −20 containing two putative Sp1-binding sites. Sp1 is a mammalian transcription factor involved in the regulation of many genes during physiological and pathological processes. Our study showed that overexpression of Sp1 or suppressing Sp1 expression resulted in increased or reduced FGF21 promoter activity, respectively. Mutation analysis demonstrated that the Sp1-binding site located between −46 and −38 plays a primary role in transcription of FGF21. Electrophoretic mobility shift assay and chromatin immunoprecipitation analysis indicated that Sp1 specifically bound to this region. Furthermore, the binding activity of Sp1 was significantly increased in adipose tissues of HFD-induced obese mouse and liver of DEN-treated mouse. Thus, our results demonstrate that Sp1 positively regulates the basal transcription of FGF21 in the liver and adipose tissue and contributes to the obesity-induced FGF21 upregulation in mouse adipose tissue and hepatic FGF21 upregulation in hepatocarcinogenesis.

  1. Endoglin negatively regulates transforming growth factor beta1-induced profibrotic responses in intestinal fibroblasts.

    LENUS (Irish Health Repository)

    Burke, J P

    2012-02-01

    BACKGROUND: Fibroblasts isolated from strictures in Crohn\\'s disease (CD) exhibit reduced responsiveness to stimulation with transforming growth factor (TGF) beta1. TGF-beta1, acting through the smad pathway, is critical to fibroblast-mediated intestinal fibrosis. The membrane glycoprotein, endoglin, is a negative regulator of TGF-beta1. METHODS: Intestinal fibroblasts were cultured from seromuscular biopsies of patients undergoing intestinal resection for CD strictures or from control patients. Endoglin expression was assessed using confocal microscopy, flow cytometry and western blot. The effect of small interfering (si) RNA-mediated knockdown and plasmid-mediated overexpression of endoglin on fibroblast responsiveness to TGF-beta1 was assessed by examining smad phosphorylation, smad binding element (SBE) promoter activity, connective tissue growth factor (CTGF) expression and ability to contract collagen. RESULTS: Crohn\\'s stricture fibroblasts expressed increased constitutive cell-surface and whole-cell endoglin relative to control cells. Endoglin co-localized with filamentous actin. Fibroblasts treated with siRNA directed against endoglin exhibited enhanced TGF-beta1-mediated smad-3 phosphorylation, and collagen contraction. Cells transfected with an endoglin plasmid did not respond to TGF-beta1 by exhibiting SBE promoter activity or producing CTGF. CONCLUSION: Fibroblasts from strictures in CD express increased constitutive endoglin. Endoglin is a negative regulator of TGF-beta1 signalling in the intestinal fibroblast, modulating smad-3 phosphorylation, SBE promoter activity, CTGF production and collagen contraction.

  2. Rice Homeobox Transcription Factor HOX1a Positively Regulates Gibberellin Responses by Directly Suppressing EL1

    Institute of Scientific and Technical Information of China (English)

    Bi-Qing Wen; Mei-Qing Xing; Hua Zhang Cheng Dai; Hong-Wei Xue

    2011-01-01

    Homeobox transcription factors are involved in various aspects of plant development,including maintenance of the biosynthesis and signaling pathways of different hormones.However,few direct targets of homeobox proteins have been identified.We here show that overexpression of rice homeobox gene HOX1a resulted in enhanced gibberellin (GA) response,indicating a positive effect of HOX1a in GA signaling.HOX1a is induced by GA and encodes a homeobox transcription factor with transcription repression activity.In addition,HOX1a suppresses the transcription of early flowering1 (EL1),a negative regulator of GA signaling,and further electrophoretic mobility shift assay and chromatin immunoprecipitation analysis revealed that HOX1a directly bound to the promoter region of EL1 to suppress its expression and stimulate GA signaling.These results demonstrate that HOX1a functions as a positive regulator of GA signaling by suppressing EL1,providing informative hints on the study of GA signaling.

  3. Nac1 Coordinates a Sub-network of Pluripotency Factors to Regulate Embryonic Stem Cell Differentiation.

    Science.gov (United States)

    Malleshaiah, Mohan; Padi, Megha; Rué, Pau; Quackenbush, John; Martinez-Arias, Alfonso; Gunawardena, Jeremy

    2016-02-01

    Pluripotent cells give rise to distinct cell types during development and are regulated by often self-reinforcing molecular networks. How such networks allow cells to differentiate is less well understood. Here, we use integrative methods to show that external signals induce reorganization of the mouse embryonic stem cell pluripotency network and that a sub-network of four factors, Nac1, Oct4, Tcf3, and Sox2, regulates their differentiation into the alternative mesendodermal and neuroectodermal fates. In the mesendodermal fate, Nac1 and Oct4 were constrained within quantitative windows, whereas Sox2 and Tcf3 were repressed. In contrast, in the neuroectodermal fate, Sox2 and Tcf3 were constrained while Nac1 and Oct4 were repressed. In addition, we show that Nac1 coordinates differentiation by activating Oct4 and inhibiting both Sox2 and Tcf3. Reorganization of progenitor cell networks around shared factors might be a common differentiation strategy and our integrative approach provides a general methodology for delineating such networks.

  4. Transcriptional and post-transcriptional regulation of a NAC1 transcription factor in Medicago truncatula roots.

    Science.gov (United States)

    D'haeseleer, Katrien; Den Herder, Griet; Laffont, Carole; Plet, Julie; Mortier, Virginie; Lelandais-Brière, Christine; De Bodt, Stefanie; De Keyser, Annick; Crespi, Martin; Holsters, Marcelle; Frugier, Florian; Goormachtig, Sofie

    2011-08-01

    • Legume roots develop two types of lateral organs, lateral roots and nodules. Nodules develop as a result of a symbiotic interaction with rhizobia and provide a niche for the bacteria to fix atmospheric nitrogen for the plant. • The Arabidopsis NAC1 transcription factor is involved in lateral root formation, and is regulated post-transcriptionally by miRNA164 and by SINAT5-dependent ubiquitination. We analyzed in Medicago truncatula the role of the closest NAC1 homolog in lateral root formation and in nodulation. • MtNAC1 shows a different expression pattern in response to auxin than its Arabidopsis homolog and no changes in lateral root number or nodulation were observed in plants affected in MtNAC1 expression. In addition, no interaction was found with SINA E3 ligases, suggesting that post-translational regulation of MtNAC1 does not occur in M. truncatula. Similar to what was found in Arabidopsis, a conserved miR164 target site was retrieved in MtNAC1, which reduced protein accumulation of a GFP-miR164 sensor. Furthermore, miR164 and MtNAC1 show an overlapping expression pattern in symbiotic nodules, and overexpression of this miRNA led to a reduction in nodule number. • This work suggests that regulatory pathways controlling a conserved transcription factor are complex and divergent between M. truncatula and Arabidopsis.

  5. Nac1 Coordinates a Sub-network of Pluripotency Factors to Regulate Embryonic Stem Cell Differentiation

    Directory of Open Access Journals (Sweden)

    Mohan Malleshaiah

    2016-02-01

    Full Text Available Pluripotent cells give rise to distinct cell types during development and are regulated by often self-reinforcing molecular networks. How such networks allow cells to differentiate is less well understood. Here, we use integrative methods to show that external signals induce reorganization of the mouse embryonic stem cell pluripotency network and that a sub-network of four factors, Nac1, Oct4, Tcf3, and Sox2, regulates their differentiation into the alternative mesendodermal and neuroectodermal fates. In the mesendodermal fate, Nac1 and Oct4 were constrained within quantitative windows, whereas Sox2 and Tcf3 were repressed. In contrast, in the neuroectodermal fate, Sox2 and Tcf3 were constrained while Nac1 and Oct4 were repressed. In addition, we show that Nac1 coordinates differentiation by activating Oct4 and inhibiting both Sox2 and Tcf3. Reorganization of progenitor cell networks around shared factors might be a common differentiation strategy and our integrative approach provides a general methodology for delineating such networks.

  6. Ethylene response factor 6 is a regulator of reactive oxygen species signaling in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Nasser Sewelam

    Full Text Available Reactive oxygen species (ROS are produced in plant cells in response to diverse biotic and abiotic stresses as well as during normal growth and development. Although a large number of transcription factor (TF genes are up- or down-regulated by ROS, currently very little is known about the functions of these TFs during oxidative stress. In this work, we examined the role of ERF6 (ETHYLENE RESPONSE FACTOR6, an AP2/ERF domain-containing TF, during oxidative stress responses in Arabidopsis. Mutant analyses showed that NADPH oxidase (RbohD and calcium signaling are required for ROS-responsive expression of ERF6. erf6 insertion mutant plants showed reduced growth and increased H2O2 and anthocyanin levels. Expression analyses of selected ROS-responsive genes during oxidative stress identified several differentially expressed genes in the erf6 mutant. In particular, a number of ROS responsive genes, such as ZAT12, HSFs, WRKYs, MAPKs, RBOHs, DHAR1, APX4, and CAT1 were more strongly induced by H2O2 in erf6 plants than in wild-type. In contrast, MDAR3, CAT3, VTC2 and EX1 showed reduced expression levels in the erf6 mutant. Taken together, our results indicate that ERF6 plays an important role as a positive antioxidant regulator during plant growth and in response to biotic and abiotic stresses.

  7. Utrophin up-regulation by an artificial transcription factor in transgenic mice.

    Directory of Open Access Journals (Sweden)

    Elisabetta Mattei

    Full Text Available Duchenne Muscular Dystrophy (DMD is a severe muscle degenerative disease, due to absence of dystrophin. There is currently no effective treatment for DMD. Our aim is to up-regulate the expression level of the dystrophin related gene utrophin in DMD, complementing in this way the lack of dystrophin functions. To this end we designed and engineered several synthetic zinc finger based transcription factors. In particular, we have previously shown that the artificial three zinc finger protein named Jazz, fused with the appropriate effector domain, is able to drive the transcription of a test gene from the utrophin promoter "A". Here we report on the characterization of Vp16-Jazz-transgenic mice that specifically over-express the utrophin gene at the muscular level. A Chromatin Immunoprecipitation assay (ChIP demonstrated the effective access/binding of the Jazz protein to active chromatin in mouse muscle and Vp16-Jazz was shown to be able to up-regulate endogenous utrophin gene expression by immunohistochemistry, western blot analyses and real-time PCR. To our knowledge, this is the first example of a transgenic mouse expressing an artificial gene coding for a zinc finger based transcription factor. The achievement of Vp16-Jazz transgenic mice validates the strategy of transcriptional targeting of endogenous genes and could represent an exclusive animal model for use in drug discovery and therapeutics.

  8. Sulfate as a pivotal factor in regulation of Serratia sp. strain S2B pigment biosynthesis.

    Science.gov (United States)

    Rastegari, Banafsheh; Karbalaei-Heidari, Hamid Reza

    2016-10-01

    In the present work, we investigated the prodiginine family as secondary metabolite members. Bacterial strain S2B, with the ability to produce red pigment, was isolated from the Sarcheshmeh copper mine in Iran. 16S rDNA gene sequencing revealed that the strain was placed in the Serratia genus. Pigment production was optimized using low-cost culture medium and the effects of various physicochemical factors were studied via statistical approaches. Purification of the produced pigment by silica gel column chromatography showed a strong red pigment fraction and a weaker orange band. Mass spectrometry, FT-IR spectroscopy and (1)H NMR analysis revealed that the red pigment was prodigiosin and the orange band was a prodigiosin-like analog, with molecular weights of 323 and 317 Da, respectively. Genotoxicity and cytotoxicity studies confirmed their membership in the prodiginine family. Analysis of the production pattern of the pigments in the presence of different concentrations of ammonium salts revealed the role of sulfate as an important factor in regulation of the pigment biosynthesis pathway. Overall, the data showed that regulation of the pigment biosynthesis pathway in Serratia sp. strain S2B was affected by inorganic micronutrients, particularly the sulfate ions.

  9. Reaction of simple sterile sugar beet hybrids to regulated environmental factors for sugar yield

    Directory of Open Access Journals (Sweden)

    М. О. Корнєєва

    2014-03-01

    Full Text Available Sugar yield, an important indicator, is resulting from interaction of two components: the yield and sugar content, both they are controlled by polygenes, and influenced significantly by environment. A.V. Kilchevskyi and L.V. Hotyliova pointed to the fact that in breeding, contrary to evolution, stabilizing forms are dominated by driving ones, which determine the growth response to regulated factors and decreased resistance to non-regulated environmental factors [1]. A relevant breeding trend is to create the genotypes adequate with certain technologies, so to say «low input variety high input variety» i.e. varieties with low and high energy contribution to technology. From this perspective, selection of stable in their manifestation lines against the analyzing backgrounds has become an important element of the breeding process [2]. Home scientists, such as A.L. Mazmulov and M.S. Hrytsyk have contributed greatly to the development and application of the agro-backgrounds [3, 4].

  10. Serum response factor controls transcriptional network regulating epidermal function and hair follicle morphogenesis.

    Science.gov (United States)

    Lin, Congxing; Hindes, Anna; Burns, Carole J; Koppel, Aaron C; Kiss, Alexi; Yin, Yan; Ma, Liang; Blumenberg, Miroslav; Khnykin, Denis; Jahnsen, Frode L; Crosby, Seth D; Ramanan, Narendrakumar; Efimova, Tatiana

    2013-03-01

    Serum response factor (SRF) is a transcription factor that regulates the expression of growth-related immediate-early, cytoskeletal, and muscle-specific genes to control growth, differentiation, and cytoskeletal integrity in different cell types. To investigate the role for SRF in epidermal development and homeostasis, we conditionally knocked out SRF in epidermal keratinocytes. We report that SRF deletion disrupted epidermal barrier function leading to early postnatal lethality. Mice lacking SRF in epidermis displayed morphogenetic defects, including an eye-open-at-birth phenotype and lack of whiskers. SRF-null skin exhibited abnormal morphology, hyperplasia, aberrant expression of differentiation markers and transcriptional regulators, anomalous actin organization, enhanced inflammation, and retarded hair follicle (HF) development. Transcriptional profiling experiments uncovered profound molecular changes in SRF-null E17.5 epidermis and revealed that many previously identified SRF target CArG box-containing genes were markedly upregulated in SRF-null epidermis, indicating that SRF may function to repress transcription of a subset of its target genes in epidermis. Remarkably, when transplanted onto nude mice, engrafted SRF-null skin lacked hair but displayed normal epidermal architecture with proper expression of differentiation markers, suggesting that although keratinocyte SRF is essential for HF development, a cross-talk between SRF-null keratinocytes and the surrounding microenvironment is likely responsible for the barrier-deficient mutant epidermal phenotype.

  11. Tissue factor expression and methylation regulation in differentiation of embryonic stem cells into trophoblast

    Institute of Scientific and Technical Information of China (English)

    Lin-Xin Liu; Hui Zeng; En-Yi Liu; Fang-Ping Chen

    2014-01-01

    Objective:To explore tissue factor(TF) expression and methylation regulation in differentiation of human embryonic stem cells(hESCs) into trophoblast.Methods:Differentiation of hESCs into trophoblast was induced by bone morphogenetic protein4(BMP4).Expression of gene, protein of TF andDNA methylation at different time points during induction process was detected byRT-PCT,Western blot, flow cytometry andMSP-PCR method.Results:The expression of mRNA, protein level ofTF could be detected during directional differentiation of hESCs to trophoblast cells, semi methylation-semi non methylation expression appeared atTFDNA promoter region, and it showed decreased methylation level and increased non methylation level with formation of trophoblast cell and increased expression ofTF.Conclusions:It shows that during differentiation of hESCs into trophoblast, the differential expression ofTF is related withDNA methylation level, and it is changed with the methylation or non methylated degree.It provids new platform to furtherly explore the regulation mechanisms of specific expression of tissue factor in the process of the embryonic stem cell development.

  12. Alternative splicing of anciently exonized 5S rRNA regulates plant transcription factor TFIIIA.

    Science.gov (United States)

    Fu, Yan; Bannach, Oliver; Chen, Hao; Teune, Jan-Hendrik; Schmitz, Axel; Steger, Gerhard; Xiong, Liming; Barbazuk, W Brad

    2009-05-01

    Identifying conserved alternative splicing (AS) events among evolutionarily distant species can prioritize AS events for functional characterization and help uncover relevant cis- and trans-regulatory factors. A genome-wide search for conserved cassette exon AS events in higher plants revealed the exonization of 5S ribosomal RNA (5S rRNA) within the gene of its own transcription regulator, TFIIIA (transcription factor for polymerase III A). The 5S rRNA-derived exon in TFIIIA gene exists in all representative land plant species but not in green algae and nonplant species, suggesting it is specific to land plants. TFIIIA is essential for RNA polymerase III-based transcription of 5S rRNA in eukaryotes. Integrating comparative genomics and molecular biology revealed that the conserved cassette exon derived from 5S rRNA is coupled with nonsense-mediated mRNA decay. Utilizing multiple independent Arabidopsis overexpressing TFIIIA transgenic lines under osmotic and salt stress, strong accordance between phenotypic and molecular evidence reveals the biological relevance of AS of the exonized 5S rRNA in quantitative autoregulation of TFIIIA homeostasis. Most significantly, this study provides the first evidence of ancient exaptation of 5S rRNA in plants, suggesting a novel gene regulation model mediated by the AS of an anciently exonized noncoding element.

  13. Fibroblast growth factor-regulated palmitoylation of the neural cell adhesion molecule determines neuronal morphogenesis.

    Science.gov (United States)

    Ponimaskin, Evgeni; Dityateva, Galina; Ruonala, Mika O; Fukata, Masaki; Fukata, Yuko; Kobe, Fritz; Wouters, Fred S; Delling, Markus; Bredt, David S; Schachner, Melitta; Dityatev, Alexander

    2008-09-03

    During development of the nervous system, short- and long-range signals cooperate to promote axonal growth, guidance, and target innervation. Particularly, a short-range signal transducer, the neural cell adhesion molecule (NCAM), stimulates neurite outgrowth via mechanisms that require posttranslational modification of NCAM and signaling via receptors to a long-range messenger, the fibroblast growth factor (FGF). In the present study we further characterized a mechanism which regulates the functional interplay between NCAM and FGF receptor(s). We show that activation of FGF receptor(s) by FGF2 leads to palmitoylation of the two major transmembrane NCAM isoforms, NCAM140 and NCAM180, translocation of NCAM to GM1 ganglioside-containing lipid rafts, and stimulation of neurite outgrowth of hippocampal neurons. Ablation of NCAM, mutation of NCAM140 or NCAM180 palmitoylation sites, or pharmacological suppression of NCAM signaling inhibited FGF2-stimulated neurite outgrowth. Of the 23 members of the aspartate-histidine-histidine-cysteine (DHHC) domain containing proteins, DHHC-7 most strongly stimulated palmitoylation of NCAM, and enzyme activity was enhanced by FGF2. Thus, our study uncovers a molecular mechanism by which a growth factor regulates neuronal morphogenesis via activation of palmitoylation, which in turn modifies subcellular location and thus signaling via an adhesion molecule.

  14. Regulation of splicing factors by alternative splicing and NMD is conserved between kingdoms yet evolutionarily flexible.

    Science.gov (United States)

    Lareau, Liana F; Brenner, Steven E

    2015-04-01

    Ultraconserved elements, unusually long regions of perfect sequence identity, are found in genes encoding numerous RNA-binding proteins including arginine-serine rich (SR) splicing factors. Expression of these genes is regulated via alternative splicing of the ultraconserved regions to yield mRNAs that are degraded by nonsense-mediated mRNA decay (NMD), a process termed unproductive splicing (Lareau et al. 2007; Ni et al. 2007). As all human SR genes are affected by alternative splicing and NMD, one might expect this regulation to have originated in an early SR gene and persisted as duplications expanded the SR family. But in fact, unproductive splicing of most human SR genes arose independently (Lareau et al. 2007). This paradox led us to investigate the origin and proliferation of unproductive splicing in SR genes. We demonstrate that unproductive splicing of the splicing factor SRSF5 (SRp40) is conserved among all animals and even observed in fungi; this is a rare example of alternative splicing conserved between kingdoms, yet its effect is to trigger mRNA degradation. As the gene duplicated, the ancient unproductive splicing was lost in paralogs, and distinct unproductive splicing evolved rapidly and repeatedly to take its place. SR genes have consistently employed unproductive splicing, and while it is exceptionally conserved in some of these genes, turnover in specific events among paralogs shows flexible means to the same regulatory end.

  15. Developmentally Regulated Expression of the Nerve Growth Factor Receptor Gene in the Periphery and Brain

    Science.gov (United States)

    Buck, C. R.; Martinez, Humberto J.; Black, Ira B.; Chao, Moses V.

    1987-05-01

    Nerve growth factor (NGF) regulates development and maintenance of function of peripheral sympathetic and sensory neurons. A potential role for the trophic factor in brain has been detected only recently. The ability of a cell to respond to NGF is due, in part, to expression of specific receptors on the cell surface. To study tissue-specific expression of the NGF receptor gene, we have used sensitive cRNA probes for detection of NGF receptor mRNA. Our studies indicate that the receptor gene is selectively and specifically expressed in sympathetic (superior cervical) and sensory (dorsal root) ganglia in the periphery, and by the septum-basal forebrain centrally, in the neonatal rat in vivo. Moreover, examination of tissues from neonatal and adult rats reveals a marked reduction in steady-state NGF receptor mRNA levels in sensory ganglia. In contrast, a 2- to 4-fold increase was observed in the basal forebrain and in the sympathetic ganglia over the same time period. Our observations suggest that NGF receptor mRNA expression is developmentally regulated in specific areas of the nervous system in a differential fashion.

  16. Biogeochemical factors which regulate the formation and fate of sulfide in wetlands

    Science.gov (United States)

    Hines, Mark E.; Lyons, W. Berry; Gaudette, H. E.

    1985-01-01

    Coastal wetland areas occupy a small percentage of the terrestrial environment yet are extremely productive regions which support rapid rates of below ground bacterial activity. Wetlands appear to be significant as biogenic sources of gaseous sulfur, carbon, and nitrogen. These gases are important as tracers of man's activities, and they influence atmospheric chemistry. The interactions among wetland biogeochemical processes regulate the anaerobic production of reduced gases and influence the fate of these volatiles. Therefore, spatial and temporal variations in hydrology, salinity, temperature, and speciation and growth of vegetation affect the type and magnitude of gas emissions thus hindering predictive estimates of gas flux. The research is divided into two major parts, the first is the biogeochemical characterization of a selected tidal wetland area in terms of factors likely to regulate sulfide flux; the second is a direct measurement of gaseous sulfur flux as related to changes in these biogeochemical conditions. Variant factors affecting sulfide flux include the wetlands' tidal range, seasonal salinity, and other hydrological conditions, grass species and plant growth, soil composition, and microbial activity.

  17. Arabidopsis MAP kinase 4 regulates gene expression through transcription factor release in the nucleus.

    Science.gov (United States)

    Qiu, Jin-Long; Fiil, Berthe Katrine; Petersen, Klaus; Nielsen, Henrik Bjørn; Botanga, Christopher J; Thorgrimsen, Stephan; Palma, Kristoffer; Suarez-Rodriguez, Maria Cristina; Sandbech-Clausen, Signe; Lichota, Jacek; Brodersen, Peter; Grasser, Klaus D; Mattsson, Ole; Glazebrook, Jane; Mundy, John; Petersen, Morten

    2008-08-20

    Plant and animal perception of microbes through pathogen surveillance proteins leads to MAP kinase signalling and the expression of defence genes. However, little is known about how plant MAP kinases regulate specific gene expression. We report that, in the absence of pathogens, Arabidopsis MAP kinase 4 (MPK4) exists in nuclear complexes with the WRKY33 transcription factor. This complex depends on the MPK4 substrate MKS1. Challenge with Pseudomonas syringae or flagellin leads to the activation of MPK4 and phosphorylation of MKS1. Subsequently, complexes with MKS1 and WRKY33 are released from MPK4, and WRKY33 targets the promoter of PHYTOALEXIN DEFICIENT3 (PAD3) encoding an enzyme required for the synthesis of antimicrobial camalexin. Hence, wrky33 mutants are impaired in the accumulation of PAD3 mRNA and camalexin production upon infection. That WRKY33 is an effector of MPK4 is further supported by the suppression of PAD3 expression in mpk4-wrky33 double mutant backgrounds. Our data establish direct links between MPK4 and innate immunity and provide an example of how a plant MAP kinase can regulate gene expression by releasing transcription factors in the nucleus upon activation.

  18. Spire, an actin nucleation factor, regulates cell division during Drosophila heart development.

    Directory of Open Access Journals (Sweden)

    Peng Xu

    Full Text Available The Drosophila dorsal vessel is a beneficial model system for studying the regulation of early heart development. Spire (Spir, an actin-nucleation factor, regulates actin dynamics in many developmental processes, such as cell shape determination, intracellular transport, and locomotion. Through protein expression pattern analysis, we demonstrate that the absence of spir function affects cell division in Myocyte enhancer factor 2-, Tinman (Tin-, Even-skipped- and Seven up (Svp-positive heart cells. In addition, genetic interaction analysis shows that spir functionally interacts with Dorsocross, tin, and pannier to properly specify the cardiac fate. Furthermore, through visualization of double heterozygous embryos, we determines that spir cooperates with CycA for heart cell specification and division. Finally, when comparing the spir mutant phenotype with that of a CycA mutant, the results suggest that most Svp-positive progenitors in spir mutant embryos cannot undergo full cell division at cell cycle 15, and that Tin-positive progenitors are arrested at cell cycle 16 as double-nucleated cells. We conclude that Spir plays a crucial role in controlling dorsal vessel formation and has a function in cell division during heart tube morphogenesis.

  19. Accessible chromatin structure permits factors Sp1 and Sp3 to regulate human TGFBI gene expression.

    Science.gov (United States)

    Lee, Jong-Joo; Park, Keunhee; Shin, Myeong Heon; Yang, Wook-Jin; Song, Min-Ji; Park, Joo-Hong; Yong, Tai-Soon; Kim, Eung Kweon; Kim, Hyoung-Pyo

    2011-06-03

    Transforming growth factor beta 1-induced (TGFBI) protein is an extracellular matrix (ECM) protein that is associated with other ECM proteins and functions as a ligand for various types of integrins. In this study, we investigated how human TGFBI expression is regulated in lung and breast cancer cells. We observed that the TGFBI promoter in A549 and MBA-MD-231 cells, which constitutively express TGFBI, existed in an open chromatin conformation associated with transcriptionally permissive histone modifications. Moreover, we found that TGFBI expression required Sp1 transcription elements that can bind transcription factors Sp1 and Sp3 in vitro. Occupancy of the TGFBI promoter by Sp1 and Sp3 in vivo was only observed in TGFBI-expressing cells, indicating that open chromatin conformation might facilitate the binding of Sp1 and Sp3 to the TGFBI promoter region. TGFBI promoter activity was impaired when Sp1 elements were mutated, but was increased when Sp1 or Sp3 factors was overexpressed. Furthermore, Sp1 inhibition in vivo by mithramycin A, as well as knockdown of Sp1 and/or Sp3 expression by short interfering RNA, significantly reduced TGFBI mRNA and protein levels. Thus, our data demonstrated that the expression of TGFBI is well correlated with chromatin conformation at the TGFBI promoter, and that factors Sp1 and Sp3 are the primary determinants for the control of constitutive expression of TGFBI gene. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Yeast mitochondrial RNAP conformational changes are regulated by interactions with the mitochondrial transcription factor.

    Science.gov (United States)

    Drakulic, Srdja; Wang, Liping; Cuéllar, Jorge; Guo, Qing; Velázquez, Gilberto; Martín-Benito, Jaime; Sousa, Rui; Valpuesta, José M

    2014-01-01

    Mitochondrial RNA polymerases (MtRNAPs) are members of the single-subunit RNAP family, the most well-characterized member being the RNAP from T7 bacteriophage. MtRNAPs are, however, functionally distinct in that they depend on one or more transcription factors to recognize and open the promoter and initiate transcription, while the phage RNAPs are capable of performing these tasks alone. Since the transcriptional mechanisms that are conserved in phage and mitochondrial RNAPs have been so effectively characterized in the phage enzymes, outstanding structure-mechanism questions concern those aspects that are distinct in the MtRNAPs, particularly the role of the mitochondrial transcription factor(s). To address these questions we have used both negative staining and cryo-EM to generate three-dimensional reconstructions of yeast MtRNAP initiation complexes with and without the mitochondrial transcription factor (MTF1), and of the elongation complex. Together with biochemical experiments, these data indicate that MTF1 uses multiple mechanisms to drive promoter opening, and that its interactions with the MtRNAP regulate the conformational changes undergone by the latter enzyme as it traverses the template strand.

  1. Regulation of Eukaryotic Initiation Factor 4E and Its Isoform: Implications for Antiviral Strategy in Plants

    Institute of Scientific and Technical Information of China (English)

    Yu-Yang Zhang; Han-Xia Li; Bo Ou-yang; Zhi-Biao Ye

    2006-01-01

    In recent years, biotechnology has permitted regulation of the expression of endogenous plant genes to improve agronomicaiiy important traits. Genetic modification of crops has benefited from emerging knowledge of new genes, especially genes that exhibit novel functions, one of which is eukaryotic initiation factor 4E (elF4E). elF4E is one of the most important translation initiation factors involved in eukaryotic initiation. Recent research has demonstrated that virus resistance mediated by elF4E and its isoform elF (iso)4E occurs in several plant-virus interactions, thus indicating a potential new role for elF4E/elL(iso)4E in resistance strategies against plant viruses. In this review, we briefly describe elF4E activity in plant translation, its potential role, and functions of the elF4E subfamily in plant-virus interactions. Other initiation factors such as elF4G could also play a role in plant resistance against viruses. Finally, the potential for developing elF4E-medlated resistance to plant viruses in the future is discussed. Future research should focus on elucidation of the resistance mechanism and spectrum mediated by elF4E. Knowledge of a particular plant-virus interaction will help to deepen our understanding of elF4E and other eukaryotic initiation factors, and their involvement in virus disease control.

  2. Endothelial-derived tissue factor pathway inhibitor regulates arterial thrombosis but is not required for development or hemostasis.

    NARCIS (Netherlands)

    White, T.A.; Johnson, T.; Zarzhevsky, N.; Tom, C.; Delacroix, S.; Holroyd, E.W.; Maroney, S.A.; Singh, R.; Pan, S.; Fay, W.P.; Deursen, J.M.A. van; Mast, A.E.; Sandhu, G.S.; Simari, R.D.

    2010-01-01

    The antithrombotic surface of endothelium is regulated in a coordinated manner. Tissue factor pathway inhibitor (TFPI) localized at the endothelial cell surface regulates the production of FXa by inhibiting the TF/VIIa complex. Systemic homozygotic deletion of the first Kunitz (K1) domain of TFPI

  3. DMPD: Nuclear factor-kappaB: activation and regulation during toll-like receptorsignaling. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17349209 Nuclear factor-kappaB: activation and regulation during toll-like receptor...signaling. Carmody RJ, Chen YH. Cell Mol Immunol. 2007 Feb;4(1):31-41. (.png) (.svg) (.html) (.csml) Show Nuclear fact...or-kappaB: activation and regulation during toll-like receptorsignaling. PubmedID 17349209 Title Nuclear fact

  4. A MYB transcription factor regulates anthocyanin biosynthesis in mangosteen (Garcinia mangostana L.) fruit during ripening.

    Science.gov (United States)

    Palapol, Yossapol; Ketsa, Saichol; Lin-Wang, Kui; Ferguson, Ian B; Allan, Andrew C

    2009-05-01

    Mangosteen (Garcinia mangostana L.) fruit undergo rapid red colour development, both on the tree and after harvest, resulting in high anthocyanin production in the pericarp. Here, we report the isolation of three full-length mangosteen MYB transcription factors (GmMYB1, GmMYB7 and GmMYB10) and all the anthocyanin biosynthetic pathway genes (GmPal to GmUFGT). Phylogenetic analysis at the protein level of the R2R3-MYB transcription factor family showed GmMYB10 had a high degree of similarity with production of anthocyanin pigment1 in Arabidopsis and as well as sequences from other plant species related to the elevation of anthocyanin pigmentation. In transient transactivation assays, GmMYB10, co-expressed with AtbHLH2, strongly activated the GmDFR and AtDFR promoters. Transcripts of GmMYB10 and GmUFGT were highly abundant with onset of pigmentation and subsequently during red colouration. Our results suggest that GmMYB10 plays an important role in regulating anthocyanin biosynthesis both on the tree and after harvest, while GmUFGT may be a key biosynthetic gene in mangosteen pigmentation. The expression patterns of GmMYB10 and GmUFGT correlated with ethylene production that increased linearly until stage 5 (dark purple) and decreased thereafter. 1-Methycyclopropene (1-MCP) clearly delayed red colouration with resulting down-regulation of GmMYB10. These results suggest that the effect of ethylene on anthocyanin biosynthesis may be via the regulation of GmMYB10 expression.

  5. Kruppel-like factor 4 regulates intestinal epithelial cell morphology and polarity.

    Directory of Open Access Journals (Sweden)

    Tianxin Yu

    Full Text Available Krüppel-like factor 4 (KLF4 is a zinc finger transcription factor that plays a vital role in regulating cell lineage differentiation during development and maintaining epithelial homeostasis in the intestine. In normal intestine, KLF4 is predominantly expressed in the differentiated epithelial cells. It has been identified as a tumor suppressor in colorectal cancer. KLF4 knockout mice demonstrated a decrease in number of goblet cells in the colon, and conditional ablation of KLF4 from the intestinal epithelium led to altered epithelial homeostasis. However, the role of KLF4 in differentiated intestinal cells and colon cancer cells, as well as the mechanism by which it regulates homeostasis and represses tumorigenesis in the intestine is not well understood. In our study, KLF4 was partially depleted in the differentiated intestinal epithelial cells by a tamoxifen-inducible Cre recombinase. We found a significant increase in the number of goblet cells in the KLF4-deleted small intestine, suggesting that KLF4 is not only required for goblet cell differentiation, but also required for maintaining goblet cell numbers through its function in inhibiting cell proliferation. The number and position of Paneth cells also changed. This is consistent with the KLF4 knockout study using villin-Cre [1]. Through immunohistochemistry (IHC staining and statistical analysis, we found that a stem cell and/or tuft cell marker, DCAMKL1, and a proliferation marker, Ki67, are affected by KLF4 depletion, while an enteroendocrine cell marker, neurotensin (NT, was not affected. In addition, we found KLF4 depletion altered the morphology and polarity of the intestinal epithelial cells. Using a three-dimensional (3D intestinal epithelial cyst formation assay, we found that KLF4 is essential for cell polarity and crypt-cyst formation in human colon cancer cells. These findings suggest that, as a tumor suppressor in colorectal cancer, KLF4 affects intestinal epithelial cell

  6. Human mitochondrial transcription factor A functions in both nuclei and mitochondria and regulates cancer cell growth

    Energy Technology Data Exchange (ETDEWEB)

    Han, Bin [Department of Molecular Biology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu (Japan); Department of Urology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu (Japan); Department of Urology, Shengjing Hospital of China Medical University, Shenyang (China); Izumi, Hiroto; Yasuniwa, Yoshihiro; Akiyama, Masaki; Yamaguchi, Takahiro [Department of Molecular Biology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu (Japan); Fujimoto, Naohiro; Matsumoto, Tetsuro [Department of Urology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu (Japan); Wu, Bin [Department of Urology, Shengjing Hospital of China Medical University, Shenyang (China); Tanimoto, Akihide [Department of Pathology, Kagoshima University Graduate School of Medical and Dental Science, Kagoshima (Japan); Sasaguri, Yasuyuki [Pathology and Cell Biology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu (Japan); Kohno, Kimitoshi, E-mail: k-kohno@med.uoeh-u.ac.jp [Department of Molecular Biology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu (Japan)

    2011-04-29

    Highlights: {yields} Mitochondrial transcription factor A (mtTFA) localizes in nuclei and binds tightly to the nuclear chromatin. {yields} mtTFA contains two putative nuclear localization signals (NLS) in the HMG-boxes. {yields} Overexpression of mtTFA enhances the growth of cancer cells, whereas downregulation of mtTFA inhibits their growth by regulating mtTFA target genes, such as baculoviral IAP repeat-containing 5 (BIRC5; also known as survivin). {yields} Knockdown of mtTFA expression induces p21-dependent G1 cell cycle arrest. -- Abstract: Mitochondrial transcription factor A (mtTFA) is one of the high mobility group protein family and is required for both transcription from and maintenance of mitochondrial genomes. However, the roles of mtTFA have not been extensively studied in cancer cells. Here, we firstly reported the nuclear localization of mtTFA. The proportion of nuclear-localized mtTFA varied among different cancer cells. Some mtTFA binds tightly to the nuclear chromatin. DNA microarray and chromatin immunoprecipitation assays showed that mtTFA can regulate the expression of nuclear genes. Overexpression of mtTFA enhanced the growth of cancer cell lines, whereas downregulation of mtTFA inhibited their growth by regulating mtTFA target genes, such as baculoviral IAP repeat-containing 5 (BIRC5; also known as survivin). Knockdown of mtTFA expression induced p21-dependent G1 cell cycle arrest. These results imply that mtTFA functions in both nuclei and mitochondria to promote cell growth.

  7. HBXIP up-regulates ACSL1 through activating transcriptional factor Sp1 in breast cancer.

    Science.gov (United States)

    Wang, Yue; Cai, Xiaoli; Zhang, Shuqin; Cui, Ming; Liu, Fabao; Sun, Baodi; Zhang, Weiying; Zhang, Xiaodong; Ye, Lihong

    2017-03-11

    The oncoprotein hepatitis B X-interacting protein (HBXIP) results in the dysregulation of lipid metabolism to enhance the development of breast cancer. Acyl-CoA synthetase long-chain family member 1 (ACSL1) is required for thioesterification of long-chain fatty acids into their acyl-CoA derivatives. In this study, we present a hypothesis that HBXIP might be involved in the regulation of ACSL1 in breast cancer. Interestingly, we found that the overexpression of HBXIP was able to up-regulate ACSL1 at the levels of mRNA and protein in a dose-dependent manner in breast cancer cells. Conversely, silencing of HBXIP led to the opposite results. Mechanistically, HBXIP as a coactivator interacted with transcriptional factor Sp1 through binding to the promoter of ACSL1 by ChIP assays analysis, leading to the transcription of ACSL1 in breast cancer cells. Immunohistochemistry staining revealed that the positive rate of ACSL1 was 71.4% (35/49) in clinical breast cancer tissues, HBXIP 79.6% (39/49), in which the positive rate of ACSL1 was 76.9% (30/39) in the HBXIP-positive specimens. But, few positive rate of ACSL1 10% (1/10) was observed in normal breast tissues. The mRNA levels of ACSL1 were significantly higher in clinical breast cancer tissues than those in their corresponding peritumor tissues. The mRNA levels of ACSL1 were positively associated with those of HBXIP in clinical breast cancer tissues. Thus, we conclude that the oncoprotein HBXIP is able to up-regulate ACSL1 through activating the transcriptional factor Sp1 in breast cancer.

  8. SELF-REGULATION AS A FACTOR IN PERSONAL-PROFESSIONAL SELF-DEVELOPMENT OF FUTURE SPECIALISTS

    Directory of Open Access Journals (Sweden)

    Zhanna G. Garanina

    2016-09-01

    Full Text Available Introduction: the article considers the problem of personal and professional self-development of future specialists at the stage of higher education and the role of self-regulation in this process. The specifics and the stage of self-regulation process, among which are stages of awareness of the importance of selfdevelopment process, the formation of personal and professional goals, assessment of possible conditions of its achievement, self-programming stages of performing activities, monitoring and evaluation of the achievement of self-development purposes. Materials and Methods: the author used psychodiagnostic methods aimed at identifying the personal and profes¬sional characteristics of students. The correlation and cluster analysis was used for statistical treatment of results. Results: As a result of experimental research on personal and professional self-development of psychology students the factors were identified, which play an important role in achieving self-development purposes in the course of training. Cluster analysis revealed three groups of students with different levels of development of self-regulation, willingness to self-knowledge and self-development, and the level of self-control and self-efficacy. Discussion and Conclusions: the results show that self-regulation of students is related to such characteristics as commitment to self-development, self-attitude, self-efficacy and reflection. Professional and personal self-development of psychology students is quite a meaningful life value, which depends on the awareness of their professional and personal goals as well as on the level of formation of regulatory and reflective qualities that affect the focus and systematic process of personality .

  9. Post-transcriptional regulation of Transforming Growth Factor Beta-1 by microRNA-744.

    Directory of Open Access Journals (Sweden)

    John Martin

    Full Text Available Transforming Growth Factor Beta-1 (TGF-β1 is a pleiotropic cytokine that is of central importance in wound healing, inflammation, and in key pathological processes including cancer and progressive tissue fibrosis. TGF-β1 is post-transcriptionally regulated, but the underlying mechanisms remain incompletely defined. Previously, we have extensively delineated post-transcriptional regulation of TGF-β1 synthesis in the kidney, with evidence for relief of translational repression in proximal tubular cells in the context of diabetic nephropathy. In this study, we have investigated the role of the TGF-β1 3'Untranslated Region (3'UTR. Two different 3'UTR lengths have been reported for TGF-β1, of 543 and 137 nucleotides. Absolute quantification showed that, while both UTR lengths were detectable in various human cell types and in a broad range of tissues, the short form predominated in the kidney and elsewhere. Expression of both forms was up-regulated following auto-induction by TGF-β1, but the short:long UTR ratio remained constant. Incorporation of the short UTR into a luciferase reporter vector significantly reduced reporter protein synthesis without major effect on RNA amount, suggesting post-transcriptional inhibition. In silico approaches identified multiple binding sites for miR-744 located in the proximal TGF-β1 3'UTR. A screen in RNA from human tissues showed widespread miR-744 expression. miR-744 transfection inhibited endogenous TGF-β1 synthesis, while direct targeting of TGF-β1 was shown in separate experiments, in which miR-744 decreased TGF-β1 3'UTR reporter activity. This work identifies miR-744-directed post-transcriptional regulation of TGF-β1 which, given the pleiotropic nature of cellular responses to TGF-β1, is potentially widely significant.

  10. SHORT HYPOCOTYL1 Encodes a SMARCA3-Like Chromatin Remodeling Factor Regulating Elongation1[OPEN

    Science.gov (United States)

    Bo, Kailiang; Behera, Tusar K.; Pandey, Sudhakar; Wen, Changlong; Wang, Yuhui; Simon, Philipp W.; Li, Yuhong

    2016-01-01

    In Arabidopsis (Arabidopsis thaliana), the UVR8-mediated signaling pathway is employed to attain UVB protection and acclimation to deal with low-dosage UVB (LDUVB)-induced stresses. Here, we identified SHORT HYPOCOTYL1 (SH1) in cucumber (Cucumis sativus), which regulates LDUVB-dependent hypocotyl elongation by modulating the UVR8 signaling pathway. We showed that hypocotyl elongation in cucumbers carrying the recessive sh1 allele was LDUVB insensitive and that Sh1 encoded a human SMARCA3-like chromatin remodeling factor. The allele frequency and distribution pattern at this locus among natural populations supported the wild cucumber origin of sh1 for local adaptation, which was under selection during domestication. The cultivated cucumber carries predominantly the Sh1 allele; the sh1 allele is nearly fixed in the semiwild Xishuangbanna cucumber, and the wild cucumber population is largely at Hardy-Weinberg equilibrium for the two alleles. The SH1 protein sequence was highly conserved among eukaryotic organisms, but its regulation of hypocotyl elongation in cucumber seems to be a novel function. While Sh1 expression was inhibited by LDUVB, its transcript abundance was highly correlated with hypocotyl elongation rate and the expression level of cell-elongation-related genes. Expression profiling of key regulators in the UVR8 signaling pathway revealed significant differential expression of CsHY5 between two near isogenic lines of Sh1. Sh1 and CsHY5 acted antagonistically at transcriptional level. A working model was proposed in which Sh1 regulates LDUVB-dependent hypocotyl elongation in cucumber through changing the chromatin states and thus the accessibility of CsHY5 in the UVR8 signaling pathway to promoters of LDUVB-responsive genes for hypocotyl elongation. PMID:27559036

  11. Regulation of a Myb transcription factor by cyclin-dependent kinase 2 in Giardia lamblia.

    Science.gov (United States)

    Cho, Chao-Cheng; Su, Li-Hsin; Huang, Yu-Chang; Pan, Yu-Jiao; Sun, Chin-Hung

    2012-02-03

    The protozoan Giardia lamblia parasitizes the human small intestine to cause diseases. It undergoes differentiation into infectious cysts by responding to intestinal stimulation. How the activated signal transduction pathways relate to encystation stimulation remain largely unknown. During encystation, genes encoding cyst wall proteins (CWPs) are coordinately up-regulated by a Myb2 transcription factor. Because cell differentiation is linked to cell cycle regulation, we tried to understand the role of cell cycle regulators, cyclin-dependent kinases (Cdks), in encystation. We found that the recombinant Myb2 was phosphorylated by Cdk-associated complexes and the levels of phosphorylation increased significantly during encystation. We have identified a putative cdk gene (cdk2) by searching the Giardia genome database. Cdk2 was found to localize in the cytoplasm with higher expression during encystation. Interestingly, overexpression of Cdk2 resulted in a significant increase of the levels of cwp gene expression and cyst formation. In addition, the Cdk2-associated complexes can phosphorylate Myb2 and the levels of phosphorylation increased significantly during encystation. Mutations of important catalytic residues of Cdk2 resulted in a significant decrease of kinase activity and ability of inducing cyst formation. Addition of a Cdk inhibitor, purvalanol A, significantly decreased the Cdk2 kinase activity and the levels of cwp gene expression and cyst formation. Our results suggest that the Cdk2 pathway may be involved in phosphorylation of Myb2, leading to activation of the Myb2 function and up-regulation of cwp genes during encystation. The results provide insights into the use of Cdk inhibitory drugs in disruption of Giardia differentiation into cysts.

  12. Snail transcription factor negatively regulates maspin tumor suppressor in human prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Neal Corey L

    2012-08-01

    Full Text Available Abstract Background Maspin, a putative tumor suppressor that is down-regulated in breast and prostate cancer, has been associated with decreased cell motility. Snail transcription factor is a zinc finger protein that is increased in breast cancer and is associated with increased tumor motility and invasion by induction of epithelial-mesenchymal transition (EMT. We investigated the molecular mechanisms by which Snail increases tumor motility and invasion utilizing prostate cancer cells. Methods Expression levels were analyzed by RT-PCR and western blot analyses. Cell motility and invasion assays were performed, while Snail regulation and binding to maspin promoter was analyzed by luciferase reporter and chromatin immunoprecipitation (ChIP assays. Results Snail protein expression was higher in different prostate cancer cells lines as compared to normal prostate epithelial cells, which correlated inversely with maspin expression. Snail overexpression in 22Rv1 prostate cancer cells inhibited maspin expression and led to increased migration and invasion. Knockdown of Snail in DU145 and C4-2 cancer cells resulted in up-regulation of maspin expression, concomitant with decreased migration. Transfection of Snail into 22Rv1 or LNCaP cells inhibited maspin promoter activity, while stable knockdown of Snail in C4-2 cells increased promoter activity. ChIP analysis showed that Snail is recruited to the maspin promoter in 22Rv1 cells. Conclusions Overall, this is the first report showing that Snail can negatively regulate maspin expression by directly repressing maspin promoter activity, leading to increased cell migration and invasion. Therefore, therapeutic targeting of Snail may be useful to re-induce expression of maspin tumor suppressor and prevent prostate cancer tumor progression.

  13. Deciphering human heat shock transcription factor 1 regulation via post-translational modification in yeast.

    Directory of Open Access Journals (Sweden)

    Liliana Batista-Nascimento

    Full Text Available Heat shock transcription factor 1 (HSF1 plays an important role in the cellular response to proteotoxic stresses. Under normal growth conditions HSF1 is repressed as an inactive monomer in part through post-translation modifications that include protein acetylation, sumoylation and phosphorylation. Upon exposure to stress HSF1 homotrimerizes, accumulates in nucleus, binds DNA, becomes hyper-phosphorylated and activates the expression of stress response genes. While HSF1 and the mechanisms that regulate its activity have been studied for over two decades, our understanding of HSF1 regulation remains incomplete. As previous studies have shown that HSF1 and the heat shock response promoter element (HSE are generally structurally conserved from yeast to metazoans, we have made use of the genetically tractable budding yeast as a facile assay system to further understand the mechanisms that regulate human HSF1 through phosphorylation of serine 303. We show that when human HSF1 is expressed in yeast its phosphorylation at S303 is promoted by the MAP-kinase Slt2 independent of a priming event at S307 previously believed to be a prerequisite. Furthermore, we show that phosphorylation at S303 in yeast and mammalian cells occurs independent of GSK3, the kinase primarily thought to be responsible for S303 phosphorylation. Lastly, while previous studies have suggested that S303 phosphorylation represses HSF1-dependent transactivation, we now show that S303 phosphorylation also represses HSF1 multimerization in both yeast and mammalian cells. Taken together, these studies suggest that yeast cells will be a powerful experimental tool for deciphering aspects of human HSF1 regulation by post-translational modifications.

  14. Altered regulation of brain-derived neurotrophic factor protein in hippocampus following slice preparation.

    Science.gov (United States)

    Danzer, S C; Pan, E; Nef, S; Parada, L F; McNamara, J O

    2004-01-01

    Brain-derived neurotrophic factor (BDNF) and its cognate receptor tyrosine kinase B (TrkB) play important roles in regulating survival, structure, and function of CNS neurons. One method of studying the functions of these molecules has utilized in vitro hippocampal slice preparations. An important caveat to using slices, however, is that slice preparation itself might alter the expression of BDNF, thereby confounding experimental results. To address this concern, BDNF immunoreactivity was examined in rodent slices using two different methods of slice preparation. Rapid and anatomically selective regulation of BDNF content followed slice preparation using both methodologies; however, different patterns of altered BDNF immunoreactivity were observed. First, in cultured slices, BDNF content decreased in the dentate molecular layer and increased in the CA3 pyramidal cell layer and the mossy fiber pathway of the hippocampus after 30 min. Furthermore, an initially "punctate" pattern of BDNF labeling observed in the mossy fiber pathway of control sections changed to homogenous labeling of the pathway in vitro. In contrast to these findings, slices prepared as for acute slice physiology exhibited no change in BDNF content in the molecular layer and mossy fiber pathway 30 min after slicing, but exhibited significant increases in the dentate granule and CA3 pyramidal cell layers. These findings demonstrate that BDNF protein content is altered following slice preparation, that different methods of slice preparation produce different patterns of BDNF regulation, and raise the possibility that BDNF release and TrkB activation may also be regulated. These consequences of hippocampal slice preparation may confound analyses of exogenous or endogenous BDNF on hippocampal neuronal structure or function.

  15. Adiponectin stimulates Wnt inhibitory factor-1 expression through epigenetic regulations involving the transcription factor specificity protein 1.

    Science.gov (United States)

    Liu, Jing; Lam, Janice B B; Chow, Kim H M; Xu, Aimin; Lam, Karen S L; Moon, Randall T; Wang, Yu

    2008-11-01

    Adiponectin (ADN) is an adipokine possessing growth inhibitory activities against various types of cancer cells. Our previous results demonstrated that ADN could impede Wnt/beta-catenin-signaling pathways in MDA-MB-231 human breast carcinoma cells [Wang,Y. et al. (2006) Adiponectin modulates the glycogen synthase kinase-3 beta/beta-catenin signaling pathway and attenuates mammary tumorigenesis of MDA-MB-231 cells in nude mice. Cancer Res., 66, 11462-11470]. Here, we extended our studies to elucidate the effects of ADN on regulating the expressions of Wnt inhibitory factor-1 (WIF1), a Wnt antagonist frequently silenced in human breast tumors. Our results showed that ADN time dependently stimulated WIF1 gene and protein expressions in MDA-MB-231 cells. Overexpression of WIF1 exerted similar inhibitory effects to those of ADN on cell proliferations, nuclear beta-catenin activities, cyclin D1 expressions and serum-induced phosphorylations of Akt and glycogen synthase kinase-3 beta. Blockage of WIF1 activities significantly attenuated the suppressive effects of ADN on MDA-MB-231 cell growth. Furthermore, our in vivo studies showed that both supplementation of recombinant ADN and adenovirus-mediated overexpression of this adipokine substantially enhanced WIF1 expressions in MDA-MB-231 tumors implanted in nude mice. More interestingly, we found that ADN could alleviate methylation of CpG islands located within the proximal promoter region of WIF1, possibly involving the specificity protein 1 (Sp1) transcription factor and its downstream target DNA methyltransferase 1 (DNMT1). Upon ADN treatment, the protein levels of both Sp1 and DNMT1 were significantly decreased. Using silencing RNA approaches, we confirmed that downregulation of Sp1 resulted in an increased expression of WIF1 and decreased methylation of WIF1 promoter. Taken together, these data suggest that ADN might elicit its antitumor activities at least partially through promoting WIF1 expressions.

  16. Growth in Adolescent Self-Regulation and Impact on Sexual Risk-Taking: A Curve-of-Factors Analysis.

    Science.gov (United States)

    Crandall, AliceAnn; Magnusson, Brianna M; Novilla, M Lelinneth B

    2017-06-29

    Adolescent self-regulation is increasingly seen as an important predictor of sexual risk-taking behaviors, but little is understood about how changes in self-regulation affect later sexual risk-taking. Family financial stress may affect the development of self-regulation and later engagement in sexual risk-taking. We examined whether family financial stress influences self-regulation in early adolescence (age 13) and growth in self-regulation throughout adolescence (from age 13-17 years). We then assessed the effects of family financial stress, baseline self-regulation, and the development of self-regulation on adolescent sexual risk-taking behaviors at age 18 years. Using a curve-of-factors model, we examined these relationships in a 6-year longitudinal study of 470 adolescents (52% female) and their parents from a large northwestern city in the United States. Results indicated that family financial stress was negatively associated with baseline self-regulation but not with growth in self-regulation throughout adolescence. Both baseline self-regulation and growth in self-regulation were predictive of decreased likelihood of engaging in sexual risk-taking. Family financial stress was not predictive of later sexual risk-taking. Intervening to support the development of self-regulation in adolescence may be especially protective against later sexual risk-taking.

  17. Expression regulation of zebrafish interferon regulatory factor 9 by promoter analysis.

    Science.gov (United States)

    Shi, Jun; Zhang, Yi-Bing; Zhang, Jian-She; Gui, Jian-Fang

    2013-12-01

    We previously showed that a fish interferon (IFN) regulatory factor 9 (IRF9) homologue, crucian carp Carassius auratus IRF9, displays constitutively nuclear localization and involvement in fish IFN-dependent JAK-STAT signaling; however, little is known about the expression regulation of fish IRF9. Here, we characterized the expression of zebrafish IRF9 by promoter analysis. Zebrafish IRF9 gene promoter contained several putative transcription factor binding sites, including one ISRE (IFN-stimulated response element), one GAS (IFN gamma activation sequence) and three GATEs (IFNγ activated transcriptional element, GATE1/2/3). Further sequence analyses revealed that GAS and GATE motifs existed in all promoters of IRF9 from mammals and fishes. Luciferase assays confirmed that zebrafish IRF9 promoter could be activated by zebrafish IFNφs and zebrafish IFNγ2, as well as transcription factors IRF3, IRF7, and combination of IRF9 and STAT2. Treatment of recombinant crucian carp IFN protein or overexpression of zebrafish IFNγ2 both led to significant increase in crucian carp IRF9 mRNA and protein in cultured fish cells. Comparison of IFN-stimulated promoter activity revealed much more significant induction of zebrafish IRF9 by zebrafish IFNγ2 than by zebrafish IFNφs. Mutation analyses showed that the putative GAS and GATE3 contributed to zebrafish IFNγ2-triggered IRF9 expression, whereas the putative ISRE and the other two GATEs were not functional for induction of zebrafish IRF9. These results together indicated that the expression property of IRF9 might be conserved from fish to mammals and that some not yet identified mechanisms could exist in IRF9 gene transcription regulation in response to IFNs.

  18. COX-2 gene expression in colon cancer tissue related to regulating factors and promoter methylation status

    Directory of Open Access Journals (Sweden)

    Lagerstedt Kristina

    2011-06-01

    Full Text Available Abstract Background Increased cyclooxygenase activity promotes progression of colorectal cancer, but the mechanisms behind COX-2 induction remain elusive. This study was therefore aimed to define external cell signaling and transcription factors relating to high COX-2 expression in colon cancer tissue. Method Tumor and normal colon tissue were collected at primary curative operation in 48 unselected patients. COX-2 expression in tumor and normal colon tissue was quantified including microarray analyses on tumor mRNA accounting for high and low tumor COX-2 expression. Cross hybridization was performed between tumor and normal colon tissue. Methylation status of up-stream COX-2 promoter region was evaluated. Results Tumors with high COX-2 expression displayed large differences in gene expression compared to normal colon. Numerous genes with altered expression appeared in tumors of high COX-2 expression compared to tumors of low COX-2. COX-2 expression in normal colon was increased in patients with tumors of high COX-2 compared to normal colon from patients with tumors of low COX-2. IL1β, IL6 and iNOS transcripts were up-regulated among external cell signaling factors; nine transcription factors (ATF3, C/EBP, c-Fos, Fos-B, JDP2, JunB, c-Maf, NF-κB, TCF4 showed increased expression and 5 (AP-2, CBP, Elk-1, p53, PEA3 were decreased in tumors with high COX-2. The promoter region of COX-2 gene did not show consistent methylation in tumor or normal colon tissue. Conclusions Transcription and external cell signaling factors are altered as covariates to COX-2 expression in colon cancer tissue, but DNA methylation of the COX-2 promoter region was not a significant factor behind COX-2 expression in tumor and normal colon tissue.

  19. Systematic identification of cell cycle regulated transcription factors from microarray time series data

    Directory of Open Access Journals (Sweden)

    Li Lei M

    2008-03-01

    Full Text Available Abstract Background The cell cycle has long been an important model to study the genome-wide transcriptional regulation. Although several methods have been introduced to identify cell cycle regulated genes from microarray data, they can not be directly used to investigate cell cycle regulated transcription factors (CCRTFs, because for many transcription factors (TFs it is their activities instead of expressions that are periodically regulated across the cell cycle. To overcome this problem, it is useful to infer TF activities across the cell cycle by integrating microarray expression data with ChIP-chip data, and then examine the periodicity of the inferred activities. For most species, however, large-scale ChIP-chip data are still not available. Results We propose a two-step method to identify the CCRTFs by integrating microarray cell cycle data with ChIP-chip data or motif discovery data. In S. cerevisiae, we identify 42 CCRTFs, among which 23 have been verified experimentally. The cell cycle related behaviors (e.g. at which cell cycle phase a TF achieves the highest activity predicted by our method are consistent with the well established knowledge about them. We also find that the periodical activity fluctuation of some TFs can be perturbed by the cell synchronization treatment. Moreover, by integrating expression data with in-silico motif discovery data, we identify 8 cell cycle associated regulatory motifs, among which 7 are binding sites for well-known cell cycle related TFs. Conclusion Our method is effective to identify CCRTFs by integrating microarray cell cycle data with TF-gene binding information. In S. cerevisiae, the TF-gene binding information is provided by the systematic ChIP-chip experiments. In other species where systematic ChIP-chip data is not available, in-silico motif discovery and analysis provide us with an alternative method. Therefore, our method is ready to be implemented to the microarray cell cycle data sets from

  20. Vascular endothelial growth factor regulates osteoblast survival – evidence for an autocrine feedback mechanism

    Directory of Open Access Journals (Sweden)

    Street John

    2009-06-01

    Full Text Available Abstract Background Apoptosis of osteoblasts and osteoclasts regulates bone homeostasis. Skeletal injury in humans results in 'angiogenic' responses primarily mediated by vascular endothelial growth factor(VEGF, a protein essential for bone repair in animal models. Osteoblasts release VEGF in response to a number of stimuli and express receptors for VEGF in a differentiation dependent manner. This study investigates the putative role of VEGF in regulating the lifespan of primary human osteoblasts(PHOB in vitro. Methods PHOB were examined for VEGF receptors. Cultures were supplemented with VEGF(0–50 ng/mL, a neutralising antibody to VEGF, mAB VEGF(0.3 ug/mL and Placental Growth Factor (PlGF, an Flt-1 receptor-specific VEGF ligand(0–100 ng/mL to examine their effects on mineralised nodule assay, alkaline phosphatase assay and apoptosis.. The role of the VEGF specific antiapoptotic gene target BCl2 in apoptosis was determined. Results PHOB expressed functional VEGF receptors. VEGF 10 and 25 ng/mL increased nodule formation 2.3- and 3.16-fold and alkaline phosphatase release 2.6 and 4.1-fold respectively while 0.3 ug/mL of mAB VEGF resulted in approx 40% reductions in both. PlGF 50 ng/mL had greater effects on alkaline phosphatase release (103% increase than on nodule formation (57% increase. 10 ng/mL of VEGF inhibited spontaneous and pathological apoptosis by 83.6% and 71% respectively, while PlGF had no significant effect. Pretreatment with mAB VEGF, in the absence of exogenous VEGF resulted in a significant increase in apoptosis (14 vs 3%. VEGF 10 ng/mL increased BCl2 expression 4 fold while mAB VEGF decreased it by over 50%. Conclusion VEGF is a potent regulator of osteoblast life-span in vitro. This autocrine feedback regulates survival of these cells, mediated via a non flt-1 receptor mechanism and expression of BCl2 antiapoptotic gene.

  1. The spatial expression and regulation of transcription factors IDEF1 and IDEF2

    Science.gov (United States)

    Kobayashi, Takanori; Ogo, Yuko; Aung, May Sann; Nozoye, Tomoko; Itai, Reiko Nakanishi; Nakanishi, Hiromi; Yamakawa, Takashi; Nishizawa, Naoko K.

    2010-01-01

    Background and Aims Under conditions of low iron availability, rice plants induce genes involved in iron uptake and utilization. The iron deficiency-responsive cis-acting element binding factors 1 and 2 (IDEF1 and IDEF2) regulate transcriptional response to iron deficiency in rice roots. Clarification of the functions of IDEF1 and IDEF2 could uncover the gene regulation mechanism. Methods Spatial patterns of IDEF1 and IDEF2 expression were analysed by histochemical staining of IDEF1 and IDEF2 promoter-GUS transgenic rice lines. Expression patterns of the target genes of IDEF1 and IDEF2 were analysed using transformants with induced or repressed expression of IDEF1 or IDEF2 grown in iron-rich or in iron-deficient solutions for 1 d. Key Results IDEF1 and IDEF2 were highly expressed in the basal parts of the lateral roots and vascular bundles. IDEF1 and IDEF2 expression was dominant in leaf mesophyll and vascular cells, respectively. These expression patterns were similar under both iron-deficient and iron-sufficient conditions. IDEF1 was strongly expressed in pollen, ovaries, the aleurone layer and embryo. IDEF2 was expressed in pollen, ovaries and the dorsal vascular region of the endosperm. During seed germination, IDEF1 and IDEF2 were expressed in the endosperm and embryo. Expression of IDEF1 target genes was regulated in iron-rich roots similar to early iron-deficiency stages. In addition, the expression patterns of IDEF2 target genes were similar between iron-rich conditions and early or subsequent iron deficiency. Conclusions IDEF1 and IDEF2 are constitutively expressed during both vegetative and reproductive stages. The spatial expression patterns of IDEF1 and IDEF2 overlap with their target genes in restricted cell types, but not in all cells. The spatial expression patterns and gene regulation of IDEF1 and IDEF2 in roots are generally conserved under conditions of iron sufficiency and deficiency, suggesting complicated interactions with unknown factors for

  2. Regulation of rDNA transcription in response to growth factors, nutrients and energy.

    Science.gov (United States)

    Kusnadi, Eric P; Hannan, Katherine M; Hicks, Rodney J; Hannan, Ross D; Pearson, Richard B; Kang, Jian

    2015-02-01

    Exquisite control of ribosome biogenesis is fundamental for the maintenance of cellular growth and proliferation. Importantly, synthesis of ribosomal RNA by RNA polymerase I is a key regulatory step in ribosome biogenesis and a major biosynthetic and energy consuming process. Consequently, ribosomal RNA gene transcription is tightly coupled to the availability of growth factors, nutrients and energy. Thus cells have developed an intricate sensing network to monitor the cellular environment and modulate ribosomal DNA transcription accordingly. Critical controllers in these sensing networks, which mediate growth factor activation of ribosomal DNA transcription, include the PI3K/AKT/mTORC1, RAS/RAF/ERK pathways and MYC transcription factor. mTORC1 also responds to amino acids and energy status, making it a key hub linking all three stimuli to the regulation of ribosomal DNA transcription, although this is achieved via overlapping and distinct mechanisms. This review outlines the current knowledge of how cells respond to environmental cues to control ribosomal RNA synthesis. We also highlight the critical points within this network that are providing new therapeutic opportunities for treating cancers through modulation of RNA polymerase I activity and potential novel imaging strategies.

  3. Iron regulation of the major virulence factors in the AIDS-associated pathogen Cryptococcus neoformans.

    Directory of Open Access Journals (Sweden)

    Won Hee Jung

    2006-11-01

    Full Text Available Iron overload is known to exacerbate many infectious diseases, and conversely, iron withholding is an important defense strategy for mammalian hosts. Iron is a critical cue for Cryptococcus neoformans because the fungus senses iron to regulate elaboration of the polysaccharide capsule that is the major virulence factor during infection. Excess iron exacerbates experimental cryptococcosis and the prevalence of this disease in Sub-Saharan Africa has been associated with nutritional and genetic aspects of iron loading in the background of the HIV/AIDS epidemic. We demonstrate that the iron-responsive transcription factor Cir1 in Cr. neoformans controls the regulon of genes for iron acquisition such that cir1 mutants are "blind" to changes in external iron levels. Cir1 also controls the known major virulence factors of the pathogen including the capsule, the formation of the anti-oxidant melanin in the cell wall, and the ability to grow at host body temperature. Thus, the fungus is remarkably tuned to perceive iron as part of the disease process, as confirmed by the avirulence of the cir1 mutant; this characteristic of the pathogen may provide opportunities for antifungal treatment.

  4. NFAT1 transcription factor regulates cell cycle progression and cyclin E expression in B lymphocytes.

    Science.gov (United States)

    Teixeira, Leonardo K; Carrossini, Nina; Sécca, Cristiane; Kroll, José E; DaCunha, Déborah C; Faget, Douglas V; Carvalho, Lilian D S; de Souza, Sandro J; Viola, João P B

    2016-09-01

    The NFAT family of transcription factors has been primarily related to T cell development, activation, and differentiation. Further studies have shown that these ubiquitous proteins are observed in many cell types inside and outside the immune system, and are involved in several biological processes, including tumor growth, angiogenesis, and invasiveness. However, the specific role of the NFAT1 family member in naive B cell proliferation remains elusive. Here, we demonstrate that NFAT1 transcription factor controls Cyclin E expression, cell proliferation, and tumor growth in vivo. Specifically, we show that inducible expression of NFAT1 inhibits cell cycle progression, reduces colony formation, and controls tumor growth in nude mice. We also demonstrate that NFAT1-deficient naive B lymphocytes show a hyperproliferative phenotype and high levels of Cyclin E1 and E2 upon BCR stimulation when compared to wild-type B lymphocytes. NFAT1 transcription factor directly regulates Cyclin E expression in B cells, inhibiting the G1/S cell cycle phase transition. Bioinformatics analysis indicates that low levels of NFAT1 correlate with high expression of Cyclin E1 in different human cancers, including Diffuse Large B-cell Lymphomas (DLBCL). Together, our results demonstrate a repressor role for NFAT1 in cell cycle progression and Cyclin E expression in B lymphocytes, and suggest a potential function for NFAT1 protein in B cell malignancies.

  5. The Zebrafish moonshine Gene Encodes Transcriptional Intermediary Factor 1γ, an Essential Regulator of Hematopoiesis

    Science.gov (United States)

    Ransom, David G; Bahary, Nathan; Niss, Knut; Traver, David; Burns, Caroline; Trede, Nikolaus S; Paffett-Lugassy, Noelle; Saganic, Walter J; Lim, C. Anthoney; Hersey, Candace; Zhou, Yi; Barut, Bruce A; Lin, Shuo; Kingsley, Paul D; Palis, James; Orkin, Stuart H

    2004-01-01

    Hematopoiesis is precisely orchestrated by lineage-specific DNA-binding proteins that regulate transcription in concert with coactivators and corepressors. Mutations in the zebrafish moonshine (mon) gene specifically disrupt both embryonic and adult hematopoiesis, resulting in severe red blood cell aplasia. We report that mon encodes the zebrafish ortholog of mammalian transcriptional intermediary factor 1γ (TIF1γ) (or TRIM33), a member of the TIF1 family of coactivators and corepressors. During development, hematopoietic progenitor cells in mon mutants fail to express normal levels of hematopoietic transcription factors, including gata1, and undergo apoptosis. Three different mon mutant alleles each encode premature stop codons, and enforced expression of wild-type tif1γ mRNA rescues embryonic hematopoiesis in homozygous mon mutants. Surprisingly, a high level of zygotic tif1γ mRNA expression delineates ventral mesoderm during hematopoietic stem cell and progenitor formation prior to gata1 expression. Transplantation studies reveal that tif1γ functions in a cell-autonomous manner during the differentiation of erythroid precursors. Studies in murine erythroid cell lines demonstrate that Tif1γ protein is localized within novel nuclear foci, and expression decreases during erythroid cell maturation. Our results establish a major role for this transcriptional intermediary factor in the differentiation of hematopoietic cells in vertebrates. PMID:15314655

  6. Regulation of adipogenesis and osteogenesis in mesenchymal stem cells by vascular endothelial growth factor A.

    Science.gov (United States)

    Berendsen, A D; Olsen, B R

    2015-06-01

    Understanding the mechanisms by which bone marrow mesenchymal stem cells (BMSCs) differentiate into bone-forming osteoblasts and marrow adipocytes is crucial to develop strategies for the treatment of several bone diseases. Age-related bone loss resulting in osteopenia and osteoporosis has been associated with reduced numbers of osteoblasts and increased numbers of adipocytes, likely originating from differentiation defects in BMSCs. Although many factors involved in the complex regulation of osteoblast and adipocyte cell lineages have previously been identified, their functional interactions in the context of BMSC differentiation and maintenance of bone homeostasis during ageing are unknown. Recent discoveries have provided important new insights into the mechanisms by which the nuclear envelope protein lamin A and vascular endothelial growth factor A (VEGF) mutually control BMSC fate. Particularly interesting is the finding that VEGF in this context functions as an intracellular protein, unaffected by neutralizing antibodies, and not as a secreted growth factor. These insights may not only facilitate the identification of new targets for treating bone diseases but also lead to improved design of tissue engineering approaches aimed at stimulating bone regeneration and repair. © 2015 The Association for the Publication of the Journal of Internal Medicine.

  7. The zebrafish moonshine gene encodes transcriptional intermediary factor 1gamma, an essential regulator of hematopoiesis.

    Directory of Open Access Journals (Sweden)

    David G Ransom

    2004-08-01

    Full Text Available Hematopoiesis is precisely orchestrated by lineage-specific DNA-binding proteins that regulate transcription in concert with coactivators and corepressors. Mutations in the zebrafish moonshine (mon gene specifically disrupt both embryonic and adult hematopoiesis, resulting in severe red blood cell aplasia. We report that mon encodes the zebrafish ortholog of mammalian transcriptional intermediary factor 1gamma (TIF1gamma (or TRIM33, a member of the TIF1 family of coactivators and corepressors. During development, hematopoietic progenitor cells in mon mutants fail to express normal levels of hematopoietic transcription factors, including gata1, and undergo apoptosis. Three different mon mutant alleles each encode premature stop codons, and enforced expression of wild-type tif1gamma mRNA rescues embryonic hematopoiesis in homozygous mon mutants. Surprisingly, a high level of zygotic tif1gamma mRNA expression delineates ventral mesoderm during hematopoietic stem cell and progenitor formation prior to gata1 expression. Transplantation studies reveal that tif1gamma functions in a cell-autonomous manner during the differentiation of erythroid precursors. Studies in murine erythroid cell lines demonstrate that Tif1gamma protein is localized within novel nuclear foci, and expression decreases during erythroid cell maturation. Our results establish a major role for this transcriptional intermediary factor in the differentiation of hematopoietic cells in vertebrates.

  8. Engineering synthetic TALE and CRISPR/Cas9 transcription factors for regulating gene expression.

    Science.gov (United States)

    Kabadi, Ami M; Gersbach, Charles A

    2014-09-01

    Engineered DNA-binding proteins that can be targeted to specific sites in the genome to manipulate gene expression have enabled many advances in biomedical research. This includes generating tools to study fundamental aspects of gene regulation and the development of a new class of gene therapies that alter the expression of endogenous genes. Designed transcription factors have entered clinical trials for the treatment of human diseases and others are in preclinical development. High-throughput and user-friendly platforms for designing synthetic DNA-binding proteins present innovative methods for deciphering cell biology and designing custom synthetic gene circuits. We review two platforms for designing synthetic transcription factors for manipulating gene expression: Transcription activator-like effectors (TALEs) and the RNA-guided clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 system. We present an overview of each technology and a guide for designing and assembling custom TALE- and CRISPR/Cas9-based transcription factors. We also discuss characteristics of each platform that are best suited for different applications.

  9. Transcriptional regulation of mouse PXR gene: an interplay of transregulatory factors.

    Directory of Open Access Journals (Sweden)

    Sangeeta Kumari

    Full Text Available Pregnane X Receptor (PXR is an important ligand-activated nuclear receptor functioning as a 'master regulator' of expression of phase I, phase II drug metabolizing enzymes, and members of the drug transporters. PXR is primarily expressed in hepatic tissues and to lesser extent in other non-hepatic tissues both in human and in mice. Although its expression profile is well studied but little is known about the regulatory mechanisms that govern PXR gene expression in these cells. In the present study, we have cloned and characterized over 5 kb (-4963 to +54 region lying upstream of mouse PXR transcription start site. Promoter-reporter assays revealed that the proximal promoter region of up to 1 kb is sufficient to support the expression of PXR in the mouse liver cell lines. It was evident that the 500 bp proximal promoter region contains active binding sites for Ets, Tcf, Ikarose and nuclear factor families of transcription factors. Electrophoretic mobility shift assays demonstrated that the minimal region of 134 bp PXR promoter was able to bind Ets-1 and β-catenin proteins. This result was further confirmed by chromatin immunoprecipitation analysis. In summary, the present study identified a promoter region of mouse PXR gene and the transregulatory factors responsible for PXR promoter activity. The results presented herein are expected to provide important cues to gain further insight into the regulatory mechanisms of PXR function.

  10. Expression and Regulation of Corticotropin-Releasing Factor Receptor Type 2 beta in Developing and Mature Mouse Skeletal Muscle

    NARCIS (Netherlands)

    Kuperman, Yael; Issler, Orna; Vaughan, Joan; Bilezikjian, Louise; Vale, Wylie; Chen, Alon

    2011-01-01

    Corticotropin-releasing factor receptor type 2 (CRFR2) is highly expressed in skeletal muscle (SM) tissue where it is suggested to inhibit interactions between insulin signaling pathway components affecting whole-body glucose homeostasis. However, little is known about factors regulating SM CRFR2 ex

  11. Steroidogenic factor 1 directs programs regulating diet-induced thermogenesis and leptin action in the ventral medial hypothalamic nucleus

    Science.gov (United States)

    The transcription factor steroidogenic factor 1 (SF-1) is exclusively expressed in the brain in the ventral medial hypothalamic nucleus (VMH) and is required for the development of this nucleus. However, the physiological importance of transcriptional programs regulated by SF-1 in the VMH is not wel...

  12. Nrf1 and Nrf2 transcription factors regulate androgen receptor transactivation in prostate cancer cells.

    Directory of Open Access Journals (Sweden)

    Michelle A Schultz

    Full Text Available Despite androgen deprivation therapy (ADT, persistent androgen receptor (AR signaling enables outgrowth of castration resistant prostate cancer (CRPC. In prostate cancer (PCa cells, ADT may enhance AR activity through induction of oxidative stress. Herein, we investigated the roles of Nrf1 and Nrf2, transcription factors that regulate antioxidant gene expression, on hormone-mediated AR transactivation using a syngeneic in vitro model of androgen dependent (LNCaP and castration resistant (C4-2B PCa cells. Dihydrotestosterone (DHT stimulated transactivation of the androgen response element (ARE was significantly greater in C4-2B cells than in LNCaP cells. DHT-induced AR transactivation was coupled with higher nuclear translocation of p65-Nrf1 in C4-2B cells, as compared to LNCaP cells. Conversely, DHT stimulation suppressed total Nrf2 levels in C4-2B cells but elevated total Nrf2 levels in LNCaP cells. Interestingly, siRNA mediated silencing of Nrf1 attenuated AR transactivation while p65-Nrf1 overexpression enhanced AR transactivation. Subsequent studies showed that Nrf1 physically interacts with AR and enhances AR's DNA-binding activity, suggesting that the p65-Nrf1 isoform is a potential AR coactivator. In contrast, Nrf2 suppressed AR-mediated transactivation by stimulating the nuclear accumulation of the p120-Nrf1 which suppressed AR transactivation. Quantitative RT-PCR studies further validated the inductive effects of p65-Nrf1 isoform on the androgen regulated genes, PSA and TMPRSS2. Therefore, our findings implicate differential roles of Nrf1 and Nrf2 in regulating AR transactivation in PCa cells. Our findings also indicate that the DHT-stimulated increase in p65-Nrf1 and the simultaneous suppression of both Nrf2 and p120-Nrf1 ultimately facilitates AR transactivation in CRPC cells.

  13. Epidermal growth factor receptor regulates β-catenin location, stability, and transcriptional activity in oral cancer

    Directory of Open Access Journals (Sweden)

    Hung Hsing-Wen

    2010-03-01

    Full Text Available Abstract Background Many cancerous cells accumulate β-catenin in the nucleus. We examined the role of epidermal growth factor receptor (EGFR signaling in the accumulation of β-catenin in the nuclei of oral cancer cells. Results We used two strains of cultured oral cancer cells, one with reduced EGFR expression (OECM1 cells and one with elevated EGFR expression (SAS cells, and measured downstream effects, such as phosphorylation of β-catenin and GSK-3β, association of β-catenin with E-cadherin, and target gene regulation. We also studied the expression of EGFR, β-catenin, and cyclin D1 in 112 samples of oral cancer by immunostaining. Activation of EGFR signaling increased the amount of β-catenin in the nucleus and decreased the amount in the membranes. EGF treatment increased phosphorylation of β-catenin (tyrosine and GSK-3β(Ser-(9, resulting in a loss of β-catenin association with E-cadherin. TOP-FLASH and FOP-FLASH reporter assays demonstrated that the EGFR signal regulates β-catenin transcriptional activity and mediates cyclin D1 expression. Chromatin immunoprecipitation experiments indicated that the EGFR signal affects chromatin architecture at the regulatory element of cyclin D1, and that the CBP, HDAC1, and Suv39h1 histone/chromatin remodeling complex is involved in this process. Immunostaining showed a significant association between EGFR expression and aberrant accumulation of β-catenin in oral cancer. Conclusions EGFR signaling regulates β-catenin localization and stability, target gene expression, and tumor progression in oral cancer. Moreover, our data suggest that aberrant accumulation of β-catenin under EGFR activation is a malignancy marker of oral cancer.

  14. Copy number variants in patients with intellectual disability affect the regulation of ARX transcription factor gene.

    Science.gov (United States)

    Ishibashi, Minaka; Manning, Elizabeth; Shoubridge, Cheryl; Krecsmarik, Monika; Hawkins, Thomas A; Giacomotto, Jean; Zhao, Ting; Mueller, Thomas; Bader, Patricia I; Cheung, Sau W; Stankiewicz, Pawel; Bain, Nicole L; Hackett, Anna; Reddy, Chilamakuri C S; Mechaly, Alejandro S; Peers, Bernard; Wilson, Stephen W; Lenhard, Boris; Bally-Cuif, Laure; Gecz, Jozef; Becker, Thomas S; Rinkwitz, Silke

    2015-11-01

    Protein-coding mutations in the transcription factor-encoding gene ARX cause various forms of intellectual disability (ID) and epilepsy. In contrast, variations in surrounding non-coding sequences are correlated with milder forms of non-syndromic ID and autism and had suggested the importance of ARX gene regulation in the etiology of these disorders. We compile data on several novel and some already identified patients with or without ID that carry duplications of ARX genomic region and consider likely genetic mechanisms underlying the neurodevelopmental defects. We establish the long-range regulatory domain of ARX and identify its brain region-specific autoregulation. We conclude that neurodevelopmental disturbances in the patients may not simply arise from increased dosage due to ARX duplication. This is further exemplified by a small duplication involving a non-functional ARX copy, but with duplicated enhancers. ARX enhancers are located within a 504-kb region and regulate expression specifically in the forebrain in developing and adult zebrafish. Transgenic enhancer-reporter lines were used as in vivo tools to delineate a brain region-specific negative and positive autoregulation of ARX. We find autorepression of ARX in the telencephalon and autoactivation in the ventral thalamus. Fluorescently labeled brain regions in the transgenic lines facilitated the identification of neuronal outgrowth and pathfinding disturbances in the ventral thalamus and telencephalon that occur when arxa dosage is diminished. In summary, we have established a model for how breakpoints in long-range gene regulation alter the expression levels of a target gene brain region-specifically, and how this can cause subtle neuronal phenotypes relating to the etiology of associated neuropsychiatric disease.

  15. Stromal cell-derived factor 1 regulates the actin organization of chondrocytes and chondrocyte hypertrophy.

    Directory of Open Access Journals (Sweden)

    Koichi Murata

    Full Text Available Stromal cell-derived factor 1 (SDF-1/CXCL12/PBSF plays important roles in the biological and physiological functions of haematopoietic and mesenchymal stem cells. This chemokine regulates the formation of multiple organ systems during embryogenesis. However, its roles in skeletal development remain unclear. Here we investigated the roles of SDF-1 in chondrocyte differentiation. We demonstrated that SDF-1 protein was expressed at pre-hypertrophic and hypertrophic chondrocytes in the newly formed endochondral callus of rib fracture as well as in the growth plate of normal mouse tibia by immunohistochemical analysis. Using SDF-1(-/- mouse embryo, we histologically showed that the total length of the whole humeri of SDF-1(-/- mice was significantly shorter than that of wild-type mice, which was contributed mainly by shorter hypertrophic and calcified zones in SDF-1(-/- mice. Actin cytoskeleton of hypertrophic chondrocytes in SDF-1(-/- mouse humeri showed less F-actin and rounder shape than that of wild-type mice. Primary chondrocytes from SDF-1(-/- mice showed the enhanced formation of philopodia and loss of F-actin. The administration of SDF-1 to primary chondrocytes of wild-type mice and SDF-1(-/- mice promoted the formation of actin stress fibers. Organ culture of embryonic metatarsals from SDF-1(-/- mice showed the growth delay, which was recovered by an exogenous administration of SDF-1. mRNA expression of type X collagen in metatarsals and in primary chondrocytes of SDF-1(-/- mouse embryo was down-regulated while the administration of SDF-1 to metatarsals recovered. These data suggests that SDF-1 regulates the actin organization and stimulates bone growth by mediating chondrocyte hypertrophy.

  16. Basic Fibroblast Growth Factor Regulates Persistent ERK Osciliations in Premaligant but not Malignant JB6 Cells

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Thomas J.; Shankaran, Harish; Wiley, H. S.; Opresko, Lee K.; Chrisler, William B.; Quesenberry, Ryan D.

    2010-05-02

    basic fibroblast growth factor (bFGF or FGF2) plays an important role in epidermal wound healing in vivo and is associated with a persistent increased in the extracellular signal-regulated kinase (ERK) pathway in vitro. Here we have examined whether bFGF induces the closure of an experimental scratch wound in JB6 mouse epidermal cells and have explored the regulation of the ERK pathway by bFGF in the context of kinase oscillations. bFGF stimulation is associated with increases in cellular phospho-ERK and phospho-c-Jun levels. In addition, bFGF increases cell proliferation and a change in cell morphology (stellate appearance) in a dose-dependent fashion (0.1 – 100 ng/ml). bFGF treatment also promoted the closure of an experimental scratch wound in vitro. JB6 cells were stably transfected with an ERK1-GFP chimera to follow temporal ERK subcellular distribution patterns. We observe a persistent upregulation of the ERK pathway, as evidenced by a significant increase in nuclear ERK1-GFP levels at time points up to 24 hr after bFGF treatment. Interestingly, at the single cell level, ERK is observed to oscillate between nuclear and cytosolic compartments in response to bFGF treatment. Because this oscillatory behavior is asynchronous in the cell population, it is only clearly resolved at the single cell level. Collectively, data presented here are consistent with an important role for bFGF in wound healing and suggest a more complex regulation of the ERK pathway by bFGF than has previously been appreciated.

  17. The guanine nucleotide exchange factor RIC8 regulates conidial germination through Gα proteins in Neurospora crassa.

    Directory of Open Access Journals (Sweden)

    Carla J Eaton

    Full Text Available Heterotrimeric G protein signaling is essential for normal hyphal growth in the filamentous fungus Neurospora crassa. We have previously demonstrated that the non-receptor guanine nucleotide exchange factor RIC8 acts upstream of the Gα proteins GNA-1 and GNA-3 to regulate hyphal extension. Here we demonstrate that regulation of hyphal extension results at least in part, from an important role in control of asexual spore (conidia germination. Loss of GNA-3 leads to a drastic reduction in conidial germination, which is exacerbated in the absence of GNA-1. Mutation of RIC8 leads to a reduction in germination similar to that in the Δgna-1, Δgna-3 double mutant, suggesting that RIC8 regulates conidial germination through both GNA-1 and GNA-3. Support for a more significant role for GNA-3 is indicated by the observation that expression of a GTPase-deficient, constitutively active gna-3 allele in the Δric8 mutant leads to a significant increase in conidial germination. Localization of the three Gα proteins during conidial germination was probed through analysis of cells expressing fluorescently tagged proteins. Functional TagRFP fusions of each of the three Gα subunits were constructed through insertion of TagRFP in a conserved loop region of the Gα subunits. The results demonstrated that GNA-1 localizes to the plasma membrane and vacuoles, and also to septa throughout conidial germination. GNA-2 and GNA-3 localize to both the plasma membrane and vacuoles during early germination, but are then found in intracellular vacuoles later during hyphal outgrowth.

  18. Identification of metabolism pathways directly regulated by sigma54 factor in Bacillus thuringiensis

    Science.gov (United States)

    Peng, Qi; Wang, Guannan; Liu, Guiming; Zhang, Jie; Song, Fuping

    2015-01-01

    Sigma54 (σ54) regulates nitrogen and carbon utilization in bacteria. Promoters that are σ54-dependent are highly conserved and contain short sequences located at the −24 and −12 positions upstream of the transcription initiation site. σ54 requires regulatory proteins known as bacterial enhancer-binding proteins (bEBPs) to activate gene transcription. We show that σ54 regulates the capacity to grow on various nitrogen sources using a Bacillus thuringiensis HD73 mutant lacking the sigL gene encoding σ54 (ΔsigL). A 2-fold-change cutoff and a false discovery rate cutoff of P < 0.05 were used to analyze the DNA microarray data, which revealed 255 genes that were downregulated and 121 that were upregulated in the ΔsigL mutant relative to the wild-type HD73 strain. The σ54 regulon (stationary phase) was characterized by DNA microarray, bioinformatics, and functional assay; 16 operons containing 47 genes were identified whose promoter regions contain the conserved −12/−24 element and whose transcriptional activities were abolished or reduced in the ΔsigL mutant. Eight σ54-dependent transcriptional bEBPs were found in the Bt HD73 genome, and they regulated nine σ54-dependent promoters. The metabolic pathways activated by σ54 in this process have yet to be identified in Bacillus thuringiensis; nonetheless, the present analysis of the σ54 regulon provides a better understanding of the physiological roles of σ factors in bacteria. PMID:26029175

  19. [Hunger and satiety factors in the regulation of pleasure associated with feeding behavior].

    Science.gov (United States)

    Fetissov, Sergueï O

    2016-01-01

    Feeding is an instinctive behavior accompanied by rewarding feeling of pleasure during obtaining and ingesting food, corresponding to the preparatory and consummatory phases of motivated behavior, respectively. Perception of this emotional state together with alternating feelings of hunger and satiety drives the feeding behavior. Because alterations of feeding behavior including either overeating or anorexia may lead to obesity and cachexia, respectively, understanding the neurochemical mechanisms of regulation of feeding pleasure may help to develop new therapies of these diseases. The dopamine (DA) system of the mesolimbic projections plays a key role in behavioral reward in general and is also involved in regulating feeding-associated pleasure in the forebrain including the nucleus accumbens (NAc) and the lateral hypothalamic area (LHA). It suggests that this DA system can be selectively activated by factors specific to different types of motivated behavior including hunger- and satiety- related hormones. Indeed, central administrations of either orexigenic ghrelin or anorexigenic α-melanocyte-stimulating hormone (α-MSH) increase DA release in the NAc. However, DA has also been shown to inhibit food intake when injected into the LHA, historically known as a « hunger center », indicating DA functional involvement in regulation of both appetite and feeding pleasure. Although both NAc and LHA contain neurons expressing melanocortin receptors, only the LHA receives the α-MSH containing nerve terminals from the α-MSH producing neurons of the hypothalamic arcuate nucleus, the main relay of the peripheral hunger and satiety signals to the brain. A recent study showed that α-MSH in the LHA enhances satiety and inhibits feeding pleasure while potently stimulating DA release in this area during both preparatory and consummatory phases of feeding. It suggests that altered signaling by α-MSH to the DA system in the LHA may be involved in the pathophysiology of

  20. Circadian transcription factor BMAL1 regulates innate immunity against select RNA viruses.

    Science.gov (United States)

    Majumdar, Tanmay; Dhar, Jayeeta; Patel, Sonal; Kondratov, Roman; Barik, Sailen

    2017-02-01

    BMAL1 (brain and muscle ARNT-like protein 1, also known as MOP3 or ARNT3) belongs to the family of the basic helix-loop-helix (bHLH)-PAS domain-containing transcription factors, and is a key component of the molecular oscillator that generates circadian rhythms. Here, we report that BMAL1-deficient cells are significantly more susceptible to infection by two major respiratory viruses of the Paramyxoviridae family, namely RSV and PIV3. Embryonic fibroblasts from Bmal1(-/-) mice produced nearly 10-fold more progeny virus than their wild type controls. These results were supported by animal studies whereby pulmonary infection of RSV produced a more severe disease and morbidity in Bmal1(-/-)mice. These results show that BMAL1 can regulate cellular innate immunity against specific RNA viruses.

  1. Key role of the kidney in the regulation of fibroblast growth factor 23

    DEFF Research Database (Denmark)

    Mace, Maria L; Gravesen, Eva; Hofman-Bang, Jacob

    2015-01-01

    High circulating levels of fibroblast growth factor 23 (FGF23) have been demonstrated in kidney failure, but mechanisms of this are not well understood. Here we examined the impact of the kidney on the early regulation of intact FGF23 in acute uremia as induced by bilateral or unilateral...... nephrectomy (BNX and UNX, respectively) in the rat. BNX induced a significant increase in plasma intact FGF23 levels from 112 to 267 pg/ml within 15 min, which remained stable thereafter. UNX generated intact FGF23 levels between that seen in BNX and sham-operated rats. The intact to C-terminal FGF23 ratio...... was significantly increased in BNX rats. The rapid rise in FGF23 after BNX was independent of parathyroid hormone or FGF receptor signaling. No evidence of early stimulation of FGF23 gene expression in the bone was found. Furthermore, acute severe hyperphosphatemia or hypercalcemia had no impact on intact FGF23...

  2. Regulation of Alternative Splicing in Vivo by Overexpression of Antagonistic Splicing Factors

    Science.gov (United States)

    Caceres, Javier F.; Stamm, Stefan; Helfman, David M.; Krainer, Adrian R.

    1994-09-01

    The opposing effects of SF2/ASF and heterogeneous nuclear ribonucleoprotein (hnRNP) A1 influence alternative splicing in vitro. SF2/ASF or hnRNP A1 complementary DNAs were transiently overexpressed in HeLa cells, and the effect on alternative splicing of several cotransfected reporter genes was measured. Increased expression of SF2/ASF activated proximal 5' splice sites, promoted inclusion of a neuron-specific exon, and prevented abnormal exon skipping. Increased expression of hnRNP A1 activated distal 5' splice sites. Therefore, variations in the intracellular levels of antagonistic splicing factors influence different modes of alternative splicing in vivo and may be a natural mechanism for tissue-specific or developmental regulation of gene expression.

  3. Contact-dependent regulation of a Tannerella forsythia virulence factor, BspA, in biofilms.

    Science.gov (United States)

    Inagaki, Satoru; Kuramitsu, Howard K; Sharma, Ashu

    2005-08-15

    Tannerella forsythia is one of the periodontal organisms implicated in the development of periodontal diseases. The surface associated and secreted protein, BspA (encoded by the bspA gene), of this bacterium is an important virulence factor. The present study was carried out to examine the regulation of the bspA gene during biofilm growth and contact stimuli encountered in interbacterial interactions. The expression levels of the bspA transcript were determined by real-time RT-PCR approach. The levels of bspA transcript were found to be significantly reduced as a result of contact stimulus and in biofilm cells relative to planktonic cells. The results of our study suggest that the likely downregulation of the BspA protein in biofilms and following contact may have implications in pathogenesis as a plausible mechanism of evasion of host immune responses.

  4. Paternal Insulin-like Growth Factor 2 (Igf2 Regulates Stem Cell Activity During Adulthood

    Directory of Open Access Journals (Sweden)

    Vilma Barroca

    2017-02-01

    Full Text Available Insulin-like Growth Factor 2 (IGF2 belongs to the IGF/Insulin pathway, a highly conserved evolutionarily network that regulates growth, aging and lifespan. Igf2 is highly expressed in the embryo and in cancer cells. During mouse development, Igf2 is expressed in all sites where hematopoietic stem cells (HSC successively expand, then its expression drops at weaning and becomes undetectable when adult HSC have reached their niches in bones and start to self-renew. In the present study, we aim to discover the role of IGF2 during adulthood. We show that Igf2 is specifically expressed in adult HSC and we analyze HSC from adult mice deficient in Igf2 transcripts. We demonstrate that Igf2 deficiency avoids the age-related attrition of the HSC pool and that Igf2 is necessary for tissue homeostasis and regeneration. Our study reveals that the expression level of Igf2 is critical to maintain the balance between stem cell self-renewal and differentiation, presumably by regulating the interaction between HSC and their niche. Our data have major clinical interest for transplantation: understanding the changes in adult stem cells and their environments will improve the efficacy of regenerative medicine and impact health- and life-span.

  5. The ETS-5 transcription factor regulates activity states in Caenorhabditis elegans by controlling satiety

    Science.gov (United States)

    Juozaityte, Vaida; Pladevall-Morera, David; Podolska, Agnieszka; Nørgaard, Steffen; Pocock, Roger

    2017-01-01

    Animal behavior is shaped through interplay among genes, the environment, and previous experience. As in mammals, satiety signals induce quiescence in Caenorhabditis elegans. Here we report that the C. elegans transcription factor ETS-5, an ortholog of mammalian FEV/Pet1, controls satiety-induced quiescence. Nutritional status has a major influence on C. elegans behavior. When foraging, food availability controls behavioral state switching between active (roaming) and sedentary (dwelling) states; however, when provided with high-quality food, C. elegans become sated and enter quiescence. We show that ETS-5 acts to promote roaming and inhibit quiescence by setting the internal “satiety quotient” through fat regulation. Acting from the ASG and BAG sensory neurons, we show that ETS-5 functions in a complex network with serotonergic and neuropeptide signaling pathways to control food-regulated behavioral state switching. Taken together, our results identify a neuronal mechanism for controlling intestinal fat stores and organismal behavioral states in C. elegans, and establish a paradigm for the elucidation of obesity-relevant mechanisms. PMID:28193866

  6. Regulation and role of connective tissue growth factor in AngII-induced myocardial fibrosis.

    Science.gov (United States)

    Rosin, Nicole L; Falkenham, Alec; Sopel, Mryanda J; Lee, Timothy D G; Légaré, Jean-Francois

    2013-03-01

    Exposure of rodents to angiotensin II (AngII) is a common model of fibrosis. We have previously shown that cellular infiltration of bone marrow-derived progenitor cells (fibrocytes) occurs before deposition of extracellular matrix and is associated with the production of connective tissue growth factor (CTGF). In the present study, we characterized the role of CTGF in promoting fibrocyte accumulation and regulation after AngII exposure. In animals exposed to AngII using osmotic minipumps (2.0 μg/kg per min), myocardial CTGF mRNA peaked at 6 hours (21-fold; P fibrocyte migration (1 day) into the myocardium or ECM deposition (3 days). CTGF protein expression was evident by day 3 of AngII exposure and seemed to be localized to resident cells. Isolated cardiomyocytes and microvascular endothelial cells responded to AngII with increased CTGF production (2.1-fold and 2.8-fold, respectively; P fibrocytes suggested a role in fibrocyte proliferation (twofold; P fibrocytes or TGF-β mRNA up-regulation. In addition, CTGF contributes to fibrocyte proliferation in the myocardium and enhances fibrocyte differentiation into a myofibroblast phenotype responsible for ECM deposition.

  7. The maize OST1 kinase homolog phosphorylates and regulates the maize SNAC1-type transcription factor.

    Directory of Open Access Journals (Sweden)

    Belmiro Vilela

    Full Text Available The Arabidopsis kinase OPEN STOMATA 1 (OST1 plays a key role in regulating drought stress signalling, particularly stomatal closure. We have identified and investigated the functions of the OST1 ortholog in Z. mays (ZmOST1. Ectopic expression of ZmOST1 in the Arabidopsis ost1 mutant restores the stomatal closure phenotype in response to drought. Furthermore, we have identified the transcription factor, ZmSNAC1, which is directly phosphorylated by ZmOST1 with implications on its localization and protein stability. Interestingly, ZmSNAC1 binds to the ABA-box of ZmOST1, which is conserved in SnRK2s activated by ABA and is part of the contact site for the negative-regulating clade A PP2C phosphatases. Taken together, our results indicate that ZmSNAC1 is a substrate of ZmOST1 and delineate a novel osmotic stress transcriptional pathway in maize.

  8. The transcription factor WIN1/SHN1 regulates Cutin biosynthesis in Arabidopsis thaliana.

    Science.gov (United States)

    Kannangara, Rubini; Branigan, Caroline; Liu, Yan; Penfield, Teresa; Rao, Vijaya; Mouille, Grégory; Höfte, Herman; Pauly, Markus; Riechmann, José Luis; Broun, Pierre

    2007-04-01

    The composition and permeability of the cuticle has a large influence on its ability to protect the plant against various forms of biotic and abiotic stress. WAX INDUCER1 (WIN1) and related transcription factors have recently been shown to trigger wax production, enhance drought tolerance, and modulate cuticular permeability when overexpressed in Arabidopsis thaliana. We found that WIN1 influences the composition of cutin, a polyester that forms the backbone of the cuticle. WIN1 overexpression induces compositional changes and an overall increase in cutin production in vegetative and reproductive organs, while its downregulation has the opposite effect. Changes in cutin composition are preceded by the rapid and coordinated induction of several genes known or likely to be involved in cutin biosynthesis. This transcriptional response is followed after a delay by the induction of genes associated with wax biosynthesis, suggesting that the regulation of cutin and wax production by WIN1 is a two-step process. We demonstrate that at least one of the cutin pathway genes, which encodes long-chain acyl-CoA synthetase LACS2, is likely to be directly targeted by WIN1. Overall, our results suggest that WIN1 modulates cuticle permeability in Arabidopsis by regulating genes encoding cutin pathway enzymes.

  9. Stromal derived factor-1 exerts differential regulation on distinct cortical cell populations in vitro

    Directory of Open Access Journals (Sweden)

    Zeef Leo

    2007-04-01

    Full Text Available Abstract Background Stromal derived factor (SDF-1, an alpha chemokine, is a widely known chemoattractant in the immune system. A growing body of evidence now suggests multiple regulatory roles for SDF-1 in the developing nervous system. Results To investigate the role of SDF-1 signaling in the growth and differentiation of cortical cells, we performed numerous in vitro experiments, including gene chip and quantitative RT-PCR analysis. Using SDF-1 medium and AMD3100, a receptor antagonist, we demonstrate that the chemokine signaling regulates key events during early cortical development. First, SDF-1 signaling maintains cortical progenitors in proliferation, possibly through a mechanism involving connexin 43 mediated intercellular coupling. Second, SDF-1 signaling upregulates the differentiation of cortical GABAergic neurons, independent of sonic signaling pathway. Third, SDF-1 enables the elongation and branching of axons of cortical glutamatergic neurons. Finally, cortical cultures derived from CXCR4-/- mutants show a close parallel to AMD3100 treatment with reduced cell proliferation and differentiation of GABAergic neurons. Conclusion Results from this study show that SDF-1 regulates distinct cortical cell populations in vitro.

  10. Complex SUMO-1 regulation of cardiac transcription factor Nkx2-5.

    Directory of Open Access Journals (Sweden)

    Mauro W Costa

    Full Text Available Reversible post-translational protein modifications such as SUMOylation add complexity to cardiac transcriptional regulation. The homeodomain transcription factor Nkx2-5/Csx is essential for heart specification and morphogenesis. It has been previously suggested that SUMOylation of lysine 51 (K51 of Nkx2-5 is essential for its DNA binding and transcriptional activation. Here, we confirm that SUMOylation strongly enhances Nkx2-5 transcriptional activity and that residue K51 of Nkx2-5 is a SUMOylation target. However, in a range of cultured cell lines we find that a point mutation of K51 to arginine (K51R does not affect Nkx2-5 activity or DNA binding, suggesting the existence of additional Nkx2-5 SUMOylated residues. Using biochemical assays, we demonstrate that Nkx2-5 is SUMOylated on at least one additional site, and this is the predominant site in cardiac cells. The second site is either non-canonical or a "shifting" site, as mutation of predicted consensus sites and indeed every individual lysine in the context of the K51R mutation failed to impair Nkx2-5 transcriptional synergism with SUMO, or its nuclear localization and DNA binding. We also observe SUMOylation of Nkx2-5 cofactors, which may be critical to Nkx2-5 regulation. Our data reveal highly complex regulatory mechanisms driven by SUMOylation to modulate Nkx2-5 activity.

  11. Fibroblast growth factor signaling potentiates VE-cadherin stability at adherens junctions by regulating SHP2.

    Directory of Open Access Journals (Sweden)

    Kunihiko Hatanaka

    Full Text Available BACKGROUND: The fibroblast growth factor (FGF system plays a critical role in the maintenance of vascular integrity via enhancing the stability of VE-cadherin at adherens junctions. However, the precise molecular mechanism is not well understood. In the present study, we aimed to investigate the detailed mechanism of FGF regulation of VE-cadherin function that leads to endothelial junction stabilization. METHODS AND FINDINGS: In vitro studies demonstrated that the loss of FGF signaling disrupts the VE-cadherin-catenin complex at adherens junctions by increasing tyrosine phosphorylation levels of VE-cadherin. Among protein tyrosine phosphatases (PTPs known to be involved in the maintenance of the VE-cadherin complex, suppression of FGF signaling reduces SHP2 expression levels and SHP2/VE-cadherin interaction due to accelerated SHP2 protein degradation. Increased endothelial permeability caused by FGF signaling inhibition was rescued by SHP2 overexpression, indicating the critical role of SHP2 in the maintenance of endothelial junction integrity. CONCLUSIONS: These results identify FGF-dependent maintenance of SHP2 as an important new mechanism controlling the extent of VE-cadherin tyrosine phosphorylation, thereby regulating its presence in adherens junctions and endothelial permeability.

  12. Fibroblast growth factor (Fgf) signaling pathway regulates liver homeostasis in zebrafish.

    Science.gov (United States)

    Tsai, Su-Mei; Liu, Da-Wei; Wang, Wen-Pin

    2013-04-01

    In mammals, fibroblast growth factor (FGF) signaling controls liver specification and regulates the metabolism of lipids, cholesterol, and bile acids. FGF signaling also promotes hepatocyte proliferation, and helps detoxify hepatotoxin during liver regeneration after partial hepatectomy. However, the function of Fgf in zebrafish liver is not yet well understood, specifically for postnatal homeostasis. The current study analyzed the expression of fgf receptors (fgfrs) in the liver of zebrafish. We then investigated the function of Fgf signaling in the zebrafish liver by expressing a dominant-negative Fgf receptor in hepatocytes (lfabp:dnfgfr1-egfp, lf:dnfr). Histological analysis showed that our genetic intervention resulted in a small liver size with defected medial expansion of developing livers in transgenic (Tg) larvae. Morphologically, the liver lobe of lf:dnfr adult fish was shorter than that of control. Ballooning degeneration of hepatocytes was observed in fish as young as 3 months. Further examination revealed the development of hepatic steatosis and cholestasis. In adult Tg fish, we unexpectedly observed increased liver-to-body-weight ratios, with higher percentages of proliferating hepatocytes. Considering all these findings, we concluded that as in mammals, in adult zebrafish the metabolism of lipid and bile acids in the liver are regulated by Fgf signaling. Disruption of the Fgf signal-mediated metabolism might indirectly affect hepatocyte proliferation.

  13. The CKH2/PKL chromatin remodeling factor negatively regulates cytokinin responses in Arabidopsis calli.

    Science.gov (United States)

    Furuta, Kaori; Kubo, Minoru; Sano, Kiyomi; Demura, Taku; Fukuda, Hiroo; Liu, Yao-Guang; Shibata, Daisuke; Kakimoto, Tatsuo

    2011-04-01

    Cytokinins promote cell division and chloroplast development in tissue culture. We previously isolated two mutants of Arabidopsis thaliana, ckh1 (cytokinin-hypersensitive 1) and ckh2, which produce rapidly growing green calli in response to lower levels of cytokinins than those found in the wild type. Here we report that the product of the CKH2 gene is PICKLE, a protein resembling the CHD3 class of SWI/SNF chromatin remodeling factors. We also show that inhibition of histone deacetylase by trichostatin A (TSA) partially substituted for cytokinins, but not for auxin, in the promotion of callus growth, indicating that chromatin remodeling and histone deacetylation are intimately related to cytokinin-induced callus growth. A microarray experiment revealed that either the ckh1 mutation or the ckh2 mutation caused hypersensitivity to cytokinins in terms of gene expression, especially of photosynthesis-related genes. The ckh1 and ckh2 mutations up-regulated nuclear-encoded genes, but not plastid-encoded genes, whereas TSA deregulated both nuclear- and plastid-encoded genes. The ckh1 ckh2 double mutant showed synergistic phenotypes: the callus grew with a green color independently of exogenous cytokinins. A yeast two-hybrid experiment showed protein interaction between CKH1/EER4/AtTAF12b and CKH2/PKL. These results suggest that CKH1/EER4/AtTAF12b and CKH2/PKL may act together on cytokinin-regulated genes.

  14. SAM pointed domain ETS factor (SPDEF) regulates terminal differentiation and maturation of intestinal goblet cells

    Energy Technology Data Exchange (ETDEWEB)

    Noah, Taeko K.; Kazanjian, Avedis [Gastroenterology, Hepatology and Nutrition, Cincinnati Children' s Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, OH (United States); Whitsett, Jeffrey [Developmental Biology, Cincinnati Children' s Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, OH (United States); Neonatology and Pulmonary Biology, Cincinnati Children' s Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, OH (United States); Shroyer, Noah F., E-mail: noah.shroyer@cchmc.org [Gastroenterology, Hepatology and Nutrition, Cincinnati Children' s Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, OH (United States); Developmental Biology, Cincinnati Children' s Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, OH (United States)

    2010-02-01

    Background and Aims: SPDEF (also termed PDEF or PSE) is an ETS family transcription factor that regulates gene expression in the prostate and goblet cell hyperplasia in the lung. Spdef has been reported to be expressed in the intestine. In this paper, we identify an important role for Spdef in regulating intestinal epithelial cell homeostasis and differentiation. Methods: SPDEF expression was inhibited in colon cancer cells to determine its ability to control goblet cell gene activation. The effects of transgenic expression of Spdef on intestinal differentiation and homeostasis were determined. Results: In LS174T colon cancer cells treated with Notch/{gamma}-secretase inhibitor to activate goblet cell gene expression, shRNAs that inhibited SPDEF also repressed expression of goblet cell genes AGR2, MUC2, RETLNB, and SPINK4. Transgenic expression of Spdef caused the expansion of intestinal goblet cells and corresponding reduction in Paneth, enteroendocrine, and absorptive enterocytes. Spdef inhibited proliferation of intestinal crypt cells without induction of apoptosis. Prolonged expression of the Spdef transgene caused a progressive reduction in the number of crypts that expressed Spdef, consistent with its inhibitory effects on cell proliferation. Conclusions: Spdef was sufficient to inhibit proliferation of intestinal progenitors and induce differentiation into goblet cells; SPDEF was required for activation of goblet cell associated genes in vitro. These data support a model in which Spdef promotes terminal differentiation into goblet cells of a common goblet/Paneth progenitor.

  15. Regulation of Serum Response Factor and Adiponectin by PPARγ Agonist Docosahexaenoic Acid

    Directory of Open Access Journals (Sweden)

    Clayton Johnson

    2011-01-01

    Full Text Available Recent studies indicate that significant health benefits involving the regulation of signaling proteins result from the consumption of omega-3 polyunsaturated fatty acids (ω-3 PUFAs. Serum response factor (SRF is involved in transcriptional regulation of muscle growth and differentiation. SRF levels are increased in the aging heart muscle. It has not been examined whether SRF is made by adipocytes and whether SRF secretion by adipocytes is modulated by PPARγ agonist DHA. Adiponectin is made exclusively by adipocytes. We and others have previously reported that PUFAs such as DHA increase adiponectin levels and secretion in adipocytes. Here we show that DHA downregulates SRF with a simultaneous upregulation of adiponectin and that both these responses are reversible by PPARγ antagonist. Furthermore, there appears to be a direct relationship between DHA exposure and increased levels of membrane-associated high-density adiponectin, as well as lower levels of membrane-associated SRF. Thus, we find that the levels of SRF and adiponectin are inversely related in response to treatment with PPARγ agonist DHA. Decreased levels of SRF along with increase in membrane-associated adiponectin could in part mediate the health benefits of DHA.

  16. AUXIN RESPONSE FACTOR 2 Intersects Hormonal Signals in the Regulation of Tomato Fruit Ripening.

    Science.gov (United States)

    Breitel, Dario A; Chappell-Maor, Louise; Meir, Sagit; Panizel, Irina; Puig, Clara Pons; Hao, Yanwei; Yifhar, Tamar; Yasuor, Hagai; Zouine, Mohamed; Bouzayen, Mondher; Granell Richart, Antonio; Rogachev, Ilana; Aharoni, Asaph

    2016-03-01

    The involvement of ethylene in fruit ripening is well documented, though knowledge regarding the crosstalk between ethylene and other hormones in ripening is lacking. We discovered that AUXIN RESPONSE FACTOR 2A (ARF2A), a recognized auxin signaling component, functions in the control of ripening. ARF2A expression is ripening regulated and reduced in the rin, nor and nr ripening mutants. It is also responsive to exogenous application of ethylene, auxin and abscisic acid (ABA). Over-expressing ARF2A in tomato resulted in blotchy ripening in which certain fruit regions turn red and possess accelerated ripening. ARF2A over-expressing fruit displayed early ethylene emission and ethylene signaling inhibition delayed their ripening phenotype, suggesting ethylene dependency. Both green and red fruit regions showed the induction of ethylene signaling components and master regulators of ripening. Comprehensive hormone profiling revealed that altered ARF2A expression in fruit significantly modified abscisates, cytokinins and salicylic acid while gibberellic acid and auxin metabolites were unaffected. Silencing of ARF2A further validated these observations as reducing ARF2A expression let to retarded fruit ripening, parthenocarpy and a disturbed hormonal profile. Finally, we show that ARF2A both homodimerizes and interacts with the ABA STRESS RIPENING (ASR1) protein, suggesting that ASR1 might be linking ABA and ethylene-dependent ripening. These results revealed that ARF2A interconnects signals of ethylene and additional hormones to co-ordinate the capacity of fruit tissue to initiate the complex ripening process.

  17. A novel ethylene responsive factor CitERF13 plays a role in photosynthesis regulation.

    Science.gov (United States)

    Xie, Xiu-Lan; Xia, Xiao-Jian; Kuang, Sheng; Zhang, Xi-Li; Yin, Xue-Ren; Yu, Jing-Quan; Chen, Kun-Song

    2017-03-01

    Ethylene responsive factors (ERFs) act as critical downstream components of the ethylene signalling pathway in regulating plant development and stress responses. However little is known about its role in regulation of photosynthesis. Here, we identified an ethylene-inducible ERF gene in citrus, CitERF13. Transient over-expression of CitERF13 in N. tabacum leaves, resulted in a significant decrease in net photosynthetic rate. Closer examination of photosynthetic activity of PSII and PSI indicated that CitERF13 overexpression led to declines of Fv/Fm, Y(II) and Y(I). However, change in NPQ was less pronounced. CitERF13 overexpression also significantly reduced Vc,max, Jmax and AQY, indicating inhibition of the Calvin cycle. The expression of photosynthesis-related genes was suppressed to a variable extent in leaf blades transiently over-expressing CitERF13. CitERF13 transient overexpression in tobacco or citrus both resulted in a decline of Chlorophyll content and CitERF13 overexpressing tobacco leaf disc was more susceptible to chlorosis in response to MV-mediated oxidative stress. The results suggest that CitERF13 is potentially involved in suppressing photosynthesis through multiple pathways, for instance, inhibiting photochemical activity of photosynthesis, CO2 carboxylation capacity and chlorophyll metabolism. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. A Potential Structural Switch for Regulating DNA-Binding by TEAD Transcription Factors.

    Science.gov (United States)

    Lee, Dong-Sun; Vonrhein, Clemens; Albarado, Diana; Raman, C S; Veeraraghavan, Sudha

    2016-06-19

    TEA domain (TEAD) transcription factors are essential for the normal development of eukaryotes and are the downstream effectors of the Hippo tumor suppressor pathway. Whereas our earlier work established the three-dimensional structure of the highly conserved DNA-binding domain using solution NMR spectroscopy, the structural basis for regulating the DNA-binding activity remains unknown. Here, we present the X-ray crystallographic structure and activity of a TEAD mutant containing a truncated L1 loop, ΔL1 TEAD DBD. Unexpectedly, the three-dimensional structure of the ΔL1 TEAD DBD reveals a helix-swapped homodimer wherein helix 1 is swapped between monomers. Furthermore, each three-helix bundle in the domain-swapped dimer is a structural homolog of MYB-like domains. Our investigations of the DNA-binding activity reveal that although the formation of the three-helix bundle by the ΔL1 TEAD DBD is sufficient for binding to an isolated M-CAT-like DNA element, multimeric forms are deficient for cooperative binding to tandemly duplicated elements, indicating that the L1 loop contributes to the DNA-binding activity of TEAD. These results suggest that switching between monomeric and domain-swapped forms may regulate DNA selectivity of TEAD proteins. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. ERG Cooperates with Androgen Receptor in Regulating Trefoil Factor 3 in Prostate Cancer Disease Progression

    Directory of Open Access Journals (Sweden)

    David S. Rickman

    2010-12-01

    Full Text Available To elucidate the role of ETS gene fusions in castration-resistant prostate cancer (CRPC, we characterized the transcriptome of 54 CRPC tumor samples from men with locally advanced or metastatic disease. Trefoil factor 3 (TFF3 emerged as the most highly differentially regulated gene with respect to ERG rearrangement status and resistance to hormone ablation therapy. Conventional chromatin immunoprecipitation (ChIP-polymerase chain reaction and ChIP followed by DNA sequencing (ChIP-seq revealed direct binding of ERG to ETS binding sites in the TFF3 promoter in ERG-rearranged prostate cancer cell lines. These results were confirmed in ERG-rearranged hormone-naive prostate cancer (HNPC and CRPC tissue samples. Functional studies demonstrated that ERG has an inhibitory effect on TFF3 expression in hormone-naive cancer but not in the castration-resistant state. In addition, we provide evidence suggesting an effect of androgen receptor signaling on ERG-regulated TFF3 expression. Furthermore, TFF3 overexpression enhances ERG-mediated cell invasion in CRPC prostate cancer cells. Taken together, our findings reveal a novel mechanism for enhanced tumor cell aggressiveness resulting from ERG rearrangement in the castration-resistant setting through TFF3 gene expression.

  20. ERG cooperates with androgen receptor in regulating trefoil factor 3 in prostate cancer disease progression.

    Science.gov (United States)

    Rickman, David S; Chen, Ying-Bei; Banerjee, Samprit; Pan, Yihang; Yu, Jindan; Vuong, Terry; Perner, Sven; Lafargue, Christopher J; Mertz, Kirsten D; Setlur, Sunita R; Sircar, Kanishka; Chinnaiyan, Arul M; Bismar, Tarek A; Rubin, Mark A; Demichelis, Francesca

    2010-12-01

    To elucidate the role of ETS gene fusions in castration-resistant prostate cancer (CRPC), we characterized the transcriptome of 54 CRPC tumor samples from men with locally advanced or metastatic disease. Trefoil factor 3 (TFF3) emerged as the most highly differentially regulated gene with respect to ERG rearrangement status and resistance to hormone ablation therapy. Conventional chromatin immunoprecipitation (ChIP)-polymerase chain reaction and ChIP followed by DNA sequencing (ChIP-seq) revealed direct binding of ERG to ETS binding sites in the TFF3 promoter in ERG-rearranged prostate cancer cell lines. These results were confirmed in ERG-rearranged hormone-naive prostate cancer (HNPC) and CRPC tissue samples. Functional studies demonstrated that ERG has an inhibitory effect on TFF3 expression in hormone-naive cancer but not in the castration-resistant state. In addition, we provide evidence suggesting an effect of androgen receptor signaling on ERG-regulated TFF3 expression. Furthermore, TFF3 overexpression enhances ERG-mediated cell invasion in CRPC prostate cancer cells. Taken together, our findings reveal a novel mechanism for enhanced tumor cell aggressiveness resulting from ERG rearrangement in the castration-resistant setting through TFF3 gene expression.

  1. Fibroblast growth factor receptor 4 (FGFR4): a targetable regulator of drug resistance in colorectal cancer.

    Science.gov (United States)

    Turkington, R C; Longley, D B; Allen, W L; Stevenson, L; McLaughlin, K; Dunne, P D; Blayney, J K; Salto-Tellez, M; Van Schaeybroeck, S; Johnston, P G

    2014-02-06

    The discovery of underlying mechanisms of drug resistance, and the development of novel agents to target these pathways, is a priority for patients with advanced colorectal cancer (CRC). We previously undertook a systems biology approach to design a functional genomic screen and identified fibroblast growth factor receptor 4 (FGFR4) as a potential mediator of drug resistance. The aim of this study was to examine the role of FGFR4 in drug resistance using RNAi and the small-molecule inhibitor BGJ398 (Novartis). We found that FGFR4 is highly expressed at the RNA and protein levels in colon cancer tumour tissue compared with normal colonic mucosa and other tumours. Silencing of FGFR4 reduced cell viability in a panel of colon cancer cell lines and increased caspase-dependent apoptosis. A synergistic interaction was also observed between FGFR4 silencing and 5-fluorouracil (5-FU) and oxaliplatin chemotherapy in colon cancer cell lines. Mechanistically, FGFR4 silencing decreased activity of the pro-survival STAT3 transcription factor and expression of the anti-apoptotic protein c-FLIP. Furthermore, silencing of STAT3 resulted in downregulation of c-FLIP protein expression, suggesting that FGFR4 may regulate c-FLIP expression via STAT3. A similar phenotype and downstream pathway changes were observed following FGFR4 silencing in cell lines resistant to 5-FU, oxaliplatin and SN38 and upon exposure of parental cells to the FGFR small-molecule inhibitor BGJ398. Our results indicate that FGFR4 is a targetable regulator of chemo-resistance in CRC, and hence inhibiting FGFR4 in combination with 5-FU and oxaliplatin is a potential therapeutic strategy for this disease.

  2. Transcription Factor CREB3L1 Regulates Vasopressin Gene Expression in the Rat Hypothalamus

    Science.gov (United States)

    Greenwood, Mingkwan; Bordieri, Loredana; Greenwood, Michael P.; Rosso Melo, Mariana; Colombari, Debora S. A.; Colombari, Eduardo; Paton, Julian F. R.

    2014-01-01

    Arginine vasopressin (AVP) is a neurohypophysial hormone regulating hydromineral homeostasis. Here we show that the mRNA encoding cAMP responsive element-binding protein-3 like-1 (CREB3L1), a transcription factor of the CREB/activating transcription factor (ATF) family, increases in expression in parallel with AVP expression in supraoptic nuclei (SONs) and paraventicular nuclei (PVNs) of dehydrated (DH) and salt-loaded (SL) rats, compared with euhydrated (EH) controls. In EH animals, CREB3L1 protein is expressed in glial cells, but only at a low level in SON and PVN neurons, whereas robust upregulation in AVP neurons accompanied DH and SL rats. Concomitantly, CREB3L1 is activated by cleavage, with the N-terminal domain translocating from the Golgi, via the cytosol, to the nucleus. We also show that CREB3L1 mRNA levels correlate with AVP transcription level in SONs and PVNs following sodium depletion, and as a consequence of diurnal rhythm in the suprachiasmatic nucleus. We tested the hypothesis that CREB3L1 activates AVP gene transcription. Both full-length and constitutively active forms of CREB3L1 (CREB3L1CA) induce the expression of rat AVP promoter-luciferase reporter constructs, whereas a dominant-negative mutant reduces expression. Rat AVP promoter deletion constructs revealed that CRE-like and G-box sequences in the region between −170 and −120 bp are important for CREB3L1 actions. Direct binding of CREB3L1 to the AVP promoter was shown by chromatin immunoprecipitation both in vitro and in the SON itself. Injection of a lentiviral vector expressing CREB3L1CA into rat SONs and PVNs resulted in increased AVP biosynthesis. We thus identify CREB3L1 as a regulator of AVP transcription in the rat hypothalamus. PMID:24623760

  3. Differential Regulation of Human Thymosin Beta 15 Isoforms by Transforming Growth Factor Beta 1

    Science.gov (United States)

    Banyard, Jacqueline; Barrows, Courtney; Zetter, Bruce R.

    2009-01-01

    We recently identified an additional isoform of human thymosin beta 15 (also known as NB-thymosin beta, gene name TMSB15A) transcribed from an independent gene, and designated TMSB15B. The purpose of this study was to investigate whether these isoforms were differentially expressed and functional. Our data show that the TMSB15A and TMSB15B isoforms have distinct expression patterns in different tumor cell lines and tissues. TMSB15A was expressed at higher levels in HCT116, DU145, LNCaP and LNCaP-LN3 cancer cells. In MCF-7, SKOV-3, HT1080 and PC-3MLN4 cells, TMSB15A and TMSB15B showed approximately equivalent levels of expression, while TMSB15B was the predominant isoform expressed in PC-3, MDA-MB-231, NCI-H322 and Caco-2 cancer cells. In normal human prostate and prostate cancer tissues, TMSB15A was the predominant isoform expressed. In contrast, normal colon and colon cancer tissue expressed predominantly TMSB15B. The two gene isoforms are also subject to different transcriptional regulation. Treatment of MCF-7 breast cancer cells with transforming growth factor beta 1 repressed TMSB15A expression but had no effect on TMSB15B. siRNA specific to the TMSB15B isoform suppressed cell migration of prostate cancer cells to epidermal growth factor, suggesting a functional role for this second isoform. In summary, our data reveal different expression patterns and regulation of a new thymosin beta 15 gene paralog. This may have important consequences in both tumor and neuronal cell motility. PMID:19296525

  4. Rapamycin regulates connective tissue growth factor expression of lung epithelial cells via phosphoinositide 3-kinase.

    Science.gov (United States)

    Xu, Xuefeng; Wan, Xuan; Geng, Jing; Li, Fei; Yang, Ting; Dai, Huaping

    2013-09-01

    The pathogenesis of idiopathic pulmonary fibrosis (IPF) remains largely unknown. It is believed that IPF is mainly driven by activated alveolar epithelial cells that have a compromised migration capacity, and that also produce substances (such as connective tissue growth factor, CTGF) that contribute to fibroblast activation and matrix protein accumulation. Because the mechanisms regulating these processes are unclear, the aim of this study was to determine the role of rapamycin in regulating epithelial cell migration and CTGF expression. Transformed epithelial cell line A549 and normal human pulmonary alveolar or bronchial epithelial cells were cultured in regular medium or medium containing rapamycin. Real time reverse transcriptase polymerase chain reaction was employed to determine CTGF mRNA expression. Western blotting and an enzyme-linked immunosorbent assay were used for detecting CTGF protein. Wound healing and migration assays were used to determine the cell migration potential. Transforming growth factor (TGF)-β type I receptor (TβRI) inhibitor, SB431542 and phosphoinositide 3-kinase (PI3K) inhibitor, LY294002 were used to determine rapamycin's mechanism of action. It was found that treatment of A549 and normal human alveolar or bronchial epithelial cells with rapamycin significantly promoted basal or TGF-β1 induced CTGF expression. LY294002, not SB431542 attenuated the promotional effect of rapamycin on CTGF expression. Cell mobility was not affected by rapamycin in wound healing and migration assays. These data suggest rapamycin has a profibrotic effect in vitro and underscore the potential of combined therapeutic approach with PI3K and mammalian target of rapamycin inhibitors for the treatment of animal or human lung fibrosis.

  5. Selective regulation of nerve growth factor expression in developing cutaneous tissue by early sensory innervation

    Directory of Open Access Journals (Sweden)

    Vizard Tom N

    2011-04-01

    Full Text Available Abstract Background In the developing vertebrate peripheral nervous system, the survival of sympathetic neurons and the majority of sensory neurons depends on a supply of nerve growth factor (NGF from tissues they innervate. Although neurotrophic theory presupposes, and the available evidence suggests, that the level of NGF expression is completely independent of innervation, the possibility that innervation may regulate the timing or level of NGF expression has not been rigorously investigated in a sufficiently well-characterized developing system. Results To address this important question, we studied the influence of innervation on the regulation of NGF mRNA expression in the embryonic mouse maxillary process in vitro and in vivo. The maxillary process receives its innervation from predominantly NGF-dependent sensory neurons of the trigeminal ganglion and is the most densely innervated cutaneous territory with the highest levels of NGF in the embryo. When early, uninnervated maxillary processes were cultured alone, the level of NGF mRNA rose more slowly than in maxillary processes cultured with attached trigeminal ganglia. In contrast to the positive influence of early innervation on NGF mRNA expression, the levels of brain-derived neurotrophic factor (BDNF mRNA and neurotrophin-3 (NT3 mRNA rose to the same extent in early maxillary processes grown with and without trigeminal ganglia. The level of NGF mRNA, but not BDNF mRNA or NT3 mRNA, was also significantly lower in the maxillary processes of erbB3-/- mice, which have substantially fewer trigeminal neurons than wild-type mice. Conclusions This selective effect of initial innervation on target field NGF mRNA expression provokes a re-evaluation of a key assertion of neurotrophic theory that the level of NGF expression is independent of innervation.

  6. Stromal Expression of Hypoxia Regulated Proteins Is an Adverse Prognostic Factor in Colorectal Carcinomas

    Directory of Open Access Journals (Sweden)

    Arjen H. G. Cleven

    2007-01-01

    Full Text Available Background: Hypoxia modifies the phenotype of tumors in a way that promotes tumor aggressiveness and resistance towards chemotherapy and radiotherapy. However, the expression and influence of hypoxia-regulated proteins on tumor biology are not well characterized in colorectal tumors. We studied the role of protein expression of hypoxia-inducible factor (HIF-1α, HIF-2α, carbonic anhydrase 9 (CA9 and glucose transporter 1 (GLUT1 in patients with colorectal adenocarcinomas. Methods: Expression of HIF-1α, HIF-2α, CA9 and GLUT1 was quantified by immunohistochemistry in 133 colorectal adenocarcinomas. The expression of hypoxia markers was correlated with clinicopathological variables and overall patient survival. Results: Expression of these hypoxia markers was detected in the epithelial compartment of the tumor cells as well as in tumor-associated stromal cells. Although tumor cells frequently showed expression of one or more of the investigated hypoxia markers, no correlation among these markers or with clinical response was found. However, within the tumor stroma, positive correlations between the hypoxia markers HIF-2α, CA9 and GLUT1 were observed. Furthermore expression of HIF-2α and CA9 in tumor-associated stroma were both associated with a significantly reduced overall survival. In the Cox proportional hazard model, stromal HIF-2α expression was an independent prognostic factor for survival. Conclusion: These observations show, that expression of hypoxia regulated proteins in tumor-associated stromal cells, as opposed to their expression in epithelial tumor cells, is associated with poor outcome in colorectal cancer. This study suggests that tumor hypoxia may influence tumor-associated stromal cells in a way that ultimately contributes to patient prognosis.

  7. Cold Plasma Inactivation of Bacterial Biofilms and Reduction of Quorum Sensing Regulated Virulence Factors.

    Directory of Open Access Journals (Sweden)

    Dana Ziuzina

    Full Text Available The main objectives of this work were to investigate the effect of atmospheric cold plasma (ACP against a range of microbial biofilms commonly implicated in foodborne and healthcare associated human infections and against P. aeruginosa quorum sensing (QS-regulated virulence factors, such as pyocyanin, elastase (Las B and biofilm formation capacity post-ACP treatment. The effect of processing factors, namely treatment time and mode of plasma exposure on antimicrobial activity of ACP were also examined. Antibiofilm activity was assessed for E. coli, L. monocytogenes and S. aureus in terms of reduction of culturability and retention of metabolic activity using colony count and XTT assays, respectively. All samples were treated 'inpack' using sealed polypropylene containers with a high voltage dielectric barrier discharge ACP generated at 80 kV for 0, 60, 120 and 300 s and a post treatment storage time of 24 h. According to colony counts, ACP treatment for 60 s reduced populations of E. coli to undetectable levels, whereas 300 s was necessary to significantly reduce populations of L. monocytogenes and S. aureus biofilms. The results obtained from XTT assay indicated possible induction of viable but non culturable state of bacteria. With respect to P. aeruginosa QS-related virulence factors, the production of pyocyanin was significantly inhibited after short treatment times, but reduction of elastase was notable only after 300 s and no reduction in actual biofilm formation was achieved post-ACP treatment. Importantly, reduction of virulence factors was associated with reduction of the cytotoxic effects of the bacterial supernatant on CHO-K1 cells, regardless of mode and duration of treatment. The results of this study point to ACP technology as an effective strategy for inactivation of established biofilms and may play an important role in attenuation of virulence of pathogenic bacteria. Further investigation is warranted to propose direct evidence

  8. The Solanum lycopersicum auxin response factor SlARF2 participates in regulating lateral root formation and flower organ senescence.

    Science.gov (United States)

    Ren, Zhenxin; Liu, Ruiyuan; Gu, Wenting; Dong, Xicun

    2017-03-01

    ARF2 as apleiotropic developmental regulator has been reported in Arabidopsis thaliana and tomato (Solanum lycopersicum). The present study showed SlARF2 transcripts in all tomato plant tissues but with higher accumulation in flowers. During bud-anthesis stages, SlARF2 transcripts showed a dynamic expression pattern in sepal, stamen, ovary and petal. Hormone treatment analysis suggested that SlARF2 transcript accumulation was positively regulated by auxin and gibberellic acid, and negatively regulated by ethylene in tomato seedlings. Phenotypes and molecular analyses of SlARF2-upregulated transgenic tomato indicated that SlARF2 regulated tomato lateral root formation and flower organ senescence may be partially mediated by regulating the gene expression of auxin and ethylene response factors. The data enlarges the functional characterization of SlARF2 in tomato, and broadens our understanding of auxin signaling in regulating plant growth and development. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Baculovirus p35 gene is oppositely regulated by P53 and AP-1 like factors in Spodoptera frugiperda

    Energy Technology Data Exchange (ETDEWEB)

    Mohareer, Krishnaveni [Laboratory of Molecular and Cell Biology, Center for DNA Fingerprinting and Diagnostics, Hyderabad 500001 (India); Institute of Life Sciences, University of Hyderabad Campus, Prof. C.R. Rao Road, Gachibowli, Hyderabad 500046 (India); Sahdev, Sudhir [Laboratory of Molecular and Cell Biology, Center for DNA Fingerprinting and Diagnostics, Hyderabad 500001 (India); Ranbaxy Pharmaceuticals, Gurgaon, New Delhi (India); Hasnain, Seyed E., E-mail: seh@bioschool.iitd.ac.in [Institute of Life Sciences, University of Hyderabad Campus, Prof. C.R. Rao Road, Gachibowli, Hyderabad 500046 (India); Kusuma School of Biological Sciences, IIT Delhi, New Delhi 110016 (India); ILBS, Vasant Kunj, New Delhi (India); King Saud University, Riyadh, KSA (Saudi Arabia)

    2011-11-04

    Highlights: Black-Right-Pointing-Pointer Baculovirus p35 is regulated by both viral and host factors. Black-Right-Pointing-Pointer Baculovirus p35 is negatively regulated by SfP53-like factor. Black-Right-Pointing-Pointer Baculovirus p35 is positively regulated by SfAP-1-like factor. -- Abstract: Baculovirus p35 belongs to the early class of genes of AcMNPV and requires viral factors like Immediate Early protein-1 for its transcription. To investigate the role of host factors in regulating p35 gene expression, the putative transcription factor binding sites were examined in silico and the role of these factors in influencing the transcription of p35 gene was assessed. We focused our studies on AP-1 and P53-like factors, which are activated under oxidative stress conditions. The AP-1 motif is located at -1401 while P53 motif is at -1912 relative to p35 translation start site. The predicted AP-1 and P53 elements formed specific complexes with Spodoptera frugiperda nuclear extracts. Both AP-1 and P53 motif binding proteins were down regulated as a function of AcMNPV infection in Spodoptera cells. To address the question whether during an oxidative outburst, the p35 transcription is enhanced; we investigated the role of these oxidative stress induced host transcription factors in influencing p35 gene transcription. Reporter assays revealed that AP-1 element enhances the transcription of p35 by a factor of two. Interestingly, P53 element appears to repress the transcription of p35 gene.

  10. Arabidopsis Clade I TGA Factors Regulate Apoplastic Defences against the Bacterial Pathogen Pseudomonas syringae through Endoplasmic Reticulum-Based Processes

    OpenAIRE

    Lipu Wang; Pierre R Fobert

    2013-01-01

    During the plant immune response, large-scale transcriptional reprogramming is modulated by numerous transcription (co) factors. The Arabidopsis basic leucine zipper transcription factors TGA1 and TGA4, which comprise the clade I TGA factors, have been shown to positively contribute to disease resistance against virulent strains of the bacterial pathogen Pseudomonas syringae . Despite physically interacting with the key immune regulator, NON-EXPRESSOR OF PATHOGENESIS-RELATED GENES 1 (NPR1), f...

  11. A transcriptional cofactor YAP regulates IFNT expression via transcription factor TEAD in bovine conceptuses.

    Science.gov (United States)

    Kusama, K; Bai, R; Sakurai, T; Bai, H; Ideta, A; Aoyagi, Y; Imakawa, K

    2016-10-01

    Interferon tau (IFNT) is the pregnancy recognition protein in all ruminants, and its expression is restricted to trophoblast cells. Interferon tau production increases as the conceptus elongates; however, its expression is downregulated soon after the initiation of conceptus attachment to the uterine epithelium. Our previous study identified that among 8 bovine IFNT genes, only 2 forms of IFNTs, IFNT2 and IFN-tau-c1, were expressed by the conceptuses during the periattachment period. To characterize whether Hippo signaling including a transcription cofactor yes-associated protein (YAP) was involved in the IFNT regulation, we examined the expression and effects of YAP and/or TEAD in human choriocarcinoma JEG3 and bovine trophoblast CT-1 cells, and in bovine conceptuses obtained from day 17, 20 or 22 pregnant animals (pregnant day 19.5 = day of conceptus attachment to the endometrium). YAP was expressed in bovine conceptuses and transfection of YAP or TEAD4, a transcription factor partner of YAP, expression plasmid increased the luciferase activity of IFNT2 and IFN-tau-c1 reporter plasmids in JEG3 cells. In the presence of YAP expression plasmid, TEAD2 or TEAD4 expression plasmid further upregulated transcriptional activity of IFNT2 or IFN-tau-c1 constructs, which were substantially reduced in the absence of the TEAD-binding site on IFNT2 or IFN-tau-c1 promoter region in JEG3 cells. In CT-1 cells, treatment with TEAD2, TEAD4, or YAP small-interfering RNA downregulated endogenous IFNT expression. It should be noted that TEAD2 and TEAD4 were predominantly localized in the nuclei of trophectoderm of Day 17 conceptuses, but nuclear localization appeared to be lower in those cells of conceptuses on days 20 and 22 of pregnancy. Moreover, the binding of TEAD4 to the TEAD-binding site of the IFN-tau-c1 promoter region in day 17 conceptuses was less in day 20 and 22 conceptuses. Furthermore, the level of YAP phosphorylation increased in day 20 and 22 conceptuses. These

  12. Biphasic regulation of the transcription factor ABORTED MICROSPORES (AMS) is essential for tapetum and pollen development in Arabidopsis.