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Sample records for retinaldehyde represses adipogenesis

  1. E2F repression by C/EBPalpha is required for adipogenesis and granulopoiesis in vivo

    DEFF Research Database (Denmark)

    Porse, B T; Pedersen TA; Xu, X

    2001-01-01

    -dependent transcription and found them to be impaired in their ability to suppress cellular proliferation, and to induce adipocyte differentiation in vitro. Using targeted mutagenesis of the mouse germline, we show that E2F repression-deficient C/EBPalpha alleles failed to support adipocyte and granulocyte...... differentiation in vivo. These results indicate that E2F repression by C/EBPalpha is critical for its ability to induce terminal differentiation, and thus provide genetic evidence that direct cell cycle control by a mammalian lineage-instructive transcription factor couples cellular growth arrest...

  2. Retinaldehyde dehydrogenase 1 deficiency inhibits PPARγ-mediated bone loss and marrow adiposity.

    Science.gov (United States)

    Nallamshetty, Shriram; Le, Phuong T; Wang, Hong; Issacsohn, Maya J; Reeder, David J; Rhee, Eun-Jung; Kiefer, Florian W; Brown, Jonathan D; Rosen, Clifford J; Plutzky, Jorge

    2014-10-01

    PPARγ, a ligand-activated nuclear receptor, regulates fundamental aspects of bone homeostasis and skeletal remodeling. PPARγ-activating anti-diabetic thiazolidinediones in clinical use promote marrow adiposity, bone loss, and skeletal fractures. As such, delineating novel regulatory pathways that modulate the action of PPARγ, and its obligate heterodimeric partner RXR, may have important implications for our understanding and treatment of disorders of low bone mineral density. We present data here establishing retinaldehyde dehydrogenase 1 (Aldh1a1) and its substrate retinaldehyde (Rald) as novel determinants of PPARγ-RXR actions in the skeleton. When compared to wild type (WT) controls, retinaldehyde dehydrogenase-deficient (Aldh1a1(-/-)) mice were protected against bone loss and marrow adiposity induced by either the thiazolidinedione rosiglitazone or a high fat diet, both of which potently activate the PPARγ-RXR complex. Consistent with these results, Rald, which accumulates in vivo in Aldh1a1(-/-) mice, protects against rosiglitazone-mediated inhibition of osteoblastogenesis in vitro. In addition, Rald potently inhibits in vitro adipogenesis and osteoclastogenesis in WT mesenchymal stem cells (MSCs) and hematopoietic stem cells (HSCs) respectively. Primary Aldh1a1(-/-) HSCs also demonstrate impaired osteoclastogenesis in vitro compared to WT controls. Collectively, these findings identify Rald and retinoid metabolism through Aldh1a1 as important novel modulators of PPARγ-RXR transactivation in the marrow niche. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Deficiency of retinaldehyde dehydrogenase 1 induces BMP2 and increases bone mass in vivo.

    Directory of Open Access Journals (Sweden)

    Shriram Nallamshetty

    Full Text Available The effects of retinoids, the structural derivatives of vitamin A (retinol, on post-natal peak bone density acquisition and skeletal remodeling are complex and compartment specific. Emerging data indicates that retinoids, such as all trans retinoic acid (ATRA and its precursor all trans retinaldehyde (Rald, exhibit distinct and divergent transcriptional effects in metabolism. Despite these observations, the role of enzymes that control retinoid metabolism in bone remains undefined. In this study, we examined the skeletal phenotype of mice deficient in retinaldehyde dehydrogenase 1 (Aldh1a1, the enzyme responsible for converting Rald to ATRA in adult animals. Bone densitometry and micro-computed tomography (µCT demonstrated that Aldh1a1-deficient (Aldh1a1(-/- female mice had higher trabecular and cortical bone mass compared to age and sex-matched control C57Bl/6 wild type (WT mice at multiple time points. Histomorphometry confirmed increased cortical bone thickness and demonstrated significantly higher bone marrow adiposity in Aldh1a1(-/- mice. In serum assays, Aldh1a1(-/- mice also had higher serum IGF-1 levels. In vitro, primary Aldh1a1(-/- mesenchymal stem cells (MSCs expressed significantly higher levels of bone morphogenetic protein 2 (BMP2 and demonstrated enhanced osteoblastogenesis and adipogenesis versus WT MSCs. BMP2 was also expressed at higher levels in the femurs and tibias of Aldh1a1(-/- mice with accompanying induction of BMP2-regulated responses, including expression of Runx2 and alkaline phosphatase, and Smad phosphorylation. In vitro, Rald, which accumulates in Aldh1a1(-/- mice, potently induced BMP2 in WT MSCs in a retinoic acid receptor (RAR-dependent manner, suggesting that Rald is involved in the BMP2 increases seen in Aldh1a1 deficiency in vivo. Collectively, these data implicate Aldh1a1 as a novel determinant of cortical bone density and marrow adiposity in the skeleton in vivo through modulation of BMP signaling.

  4. Deficiency of retinaldehyde dehydrogenase 1 induces BMP2 and increases bone mass in vivo.

    Science.gov (United States)

    Nallamshetty, Shriram; Wang, Hong; Rhee, Eun-Jung; Kiefer, Florian W; Brown, Jonathan D; Lotinun, Sutada; Le, Phuong; Baron, Roland; Rosen, Clifford J; Plutzky, Jorge

    2013-01-01

    The effects of retinoids, the structural derivatives of vitamin A (retinol), on post-natal peak bone density acquisition and skeletal remodeling are complex and compartment specific. Emerging data indicates that retinoids, such as all trans retinoic acid (ATRA) and its precursor all trans retinaldehyde (Rald), exhibit distinct and divergent transcriptional effects in metabolism. Despite these observations, the role of enzymes that control retinoid metabolism in bone remains undefined. In this study, we examined the skeletal phenotype of mice deficient in retinaldehyde dehydrogenase 1 (Aldh1a1), the enzyme responsible for converting Rald to ATRA in adult animals. Bone densitometry and micro-computed tomography (µCT) demonstrated that Aldh1a1-deficient (Aldh1a1(-/-) ) female mice had higher trabecular and cortical bone mass compared to age and sex-matched control C57Bl/6 wild type (WT) mice at multiple time points. Histomorphometry confirmed increased cortical bone thickness and demonstrated significantly higher bone marrow adiposity in Aldh1a1(-/-) mice. In serum assays, Aldh1a1(-/-) mice also had higher serum IGF-1 levels. In vitro, primary Aldh1a1(-/-) mesenchymal stem cells (MSCs) expressed significantly higher levels of bone morphogenetic protein 2 (BMP2) and demonstrated enhanced osteoblastogenesis and adipogenesis versus WT MSCs. BMP2 was also expressed at higher levels in the femurs and tibias of Aldh1a1(-/-) mice with accompanying induction of BMP2-regulated responses, including expression of Runx2 and alkaline phosphatase, and Smad phosphorylation. In vitro, Rald, which accumulates in Aldh1a1(-/-) mice, potently induced BMP2 in WT MSCs in a retinoic acid receptor (RAR)-dependent manner, suggesting that Rald is involved in the BMP2 increases seen in Aldh1a1 deficiency in vivo. Collectively, these data implicate Aldh1a1 as a novel determinant of cortical bone density and marrow adiposity in the skeleton in vivo through modulation of BMP signaling.

  5. Photochemistry and stereoselectivity of cellular retinaldehyde-binding protein from bovine retina

    International Nuclear Information System (INIS)

    Saari, J.C.; Bredberg, D.L.

    1987-01-01

    11-cis-Retinaldehyde bound to cellular retinaldehyde-binding protein (CRALBP) is unaffected in bovine eyecup preparations by illumination that bleaches approximately 70% of the rhodopsin. Illumination of retinal homogenates to which CRALBP X [ 3 H]11-cis-retinaldehyde had been added did not result in a reduction of the specific activity of recovered 11-cis-retinaldehyde, ruling out a bleaching regeneration cycle. The quantum efficiency of photoisomerization for CRALBP X 11-cis-retinaldehyde was determined by comparing the rate of photoisomerization of 11-cis-retinaldehyde bound to purified CRALBP and opsin. The low value obtained (0.07), coupled with a low molar extinction coefficient (15,400 M-1 cm-1), results in a photosensitivity only about 4% that of rhodopsin. CRALBP binds 9-cis- and 11-cis-retinaldehyde, producing complexes with absorption maxima at 405 and 425 nm, respectively. No complexes were detected with 13-cis- and all-trans-retinaldehyde. Following incubation of CRALBP X 11-cis-retinol with an equimolar mixture of 9-, 11-, 13-cis-, and all-trans-retinaldehydes, only 11-cis-retinaldehyde and residual 11-cis-retinol are present on the protein following separation from excess retinoids. A similar result is obtained following incubation of CRALBP X 11-cis-retinol with mixtures of 9- and 11-cis-retinaldehyde ranging in composition from 9:1 to 1:9 (9-cis-:11-cis-,mol/mol). The results indicate that CRALBP X 11-cis-retinol is sufficiently stereoselective in its binding properties to warrant consideration as a component of the mechanism for the generation of 11-cis-retinaldehyde in the dark

  6. A deep investigation into the adipogenesis mechanism: Profile of microRNAs regulating adipogenesis by modulating the canonical Wnt/β-catenin signaling pathway

    Directory of Open Access Journals (Sweden)

    Li Jing

    2010-05-01

    Full Text Available Abstract Background MicroRNAs (miRNAs are a large class of tiny non-coding RNAs (~22-24 nt that regulate diverse biological processes at the posttranscriptional level by controlling mRNA stability or translation. As a molecular switch, the canonical Wnt/β-catenin signaling pathway should be suppressed during the adipogenesis; However, activation of this pathway leads to the inhibition of lipid depots formation. The aim of our studies was to identify miRNAs that might be involved in adipogenesis by modulating WNT signaling pathway. Here we established two types of cell model, activation and repression of WNT signaling, and investigated the expression profile of microRNAs using microarray assay. Results The high throughput microarray data revealed 18 miRNAs that might promote adipogenesis by repressing WNT signaling: miR-210, miR-148a, miR-194, miR-322 etc. Meanwhile, we also identified 29 miRNAs that might have negative effect on adipogenesis by activating WNT signaling: miR-344, miR-27 and miR-181 etc. The targets of these miRNAs were also analysed by bioinformatics. To validate the predicted targets and the potential functions of these identified miRNAs, the mimics of miR-210 were transfected into 3T3-L1 cells and enlarged cells with distinct lipid droplets were observed; Meanwhile, transfection with the inhibitor of miR-210 could markedly decrease differentiation-specific factors at the transcription level, which suggested the specific role of miR-210 in promoting adipogenesis. Tcf7l2, the predicted target of miR-210, is a transcription factor triggering the downstream responsive genes of WNT signaling, was blocked at transcription level. Furthermore, the activity of luciferase reporter bearing Tcf7l2 mRNA 3' UTR was decreased after co-transfection with miR-210 in HEK-293FT cells. Last but not least, the protein expression level of β-catenin was increased in the lithium (LiCl treated 3T3-L1 cells after transfection with miR-210. These

  7. Adipogenesis: forces that tip the scales

    DEFF Research Database (Denmark)

    MacDougald, Ormond A; Mandrup, Susanne

    2001-01-01

    The balance of contradictory signals experienced by preadipocytes influences whether these cells undergo adipogenesis. In addition to the endocrine system, these signals originate from the preadipocytes themselves or operate as part of a feedback loop involving mature adipocytes. The factors...

  8. TLE3 Is a Dual-Function Transcriptional Coregulator of Adipogenesis

    DEFF Research Database (Denmark)

    Villanueva, Claudio J; Waki, Hironori; Godio, Cristina

    2011-01-01

    PPARγ and Wnt signaling are central positive and negative regulators of adipogenesis, respectively. Here we identify the groucho family member TLE3 as a transcriptional integrator of the PPARγ and Wnt pathways. TLE3 is a direct target of PPARγ that participates in a feed-forward loop during...... adipocyte differentiation. TLE3 enhances PPARγ activity and functions synergistically with PPARγ on its target promoters to stimulate adipogenesis. At the same time, induction of TLE3 during differentiation provides a mechanism for termination of Wnt signaling. TLE3 antagonizes TCF4 activation by β......-catenin in preadipocytes, thereby inhibiting Wnt target gene expression and reversing β-catenin-dependent repression of adipocyte gene expression. Transgenic expression of TLE3 in adipose tissue in vivo mimics the effects of PPARγ agonist and ameliorates high-fat-diet-induced insulin resistance. Our data suggest that TLE3...

  9. Rasal2 deficiency reduces adipogenesis and occurrence of obesity-related disorders

    Directory of Open Access Journals (Sweden)

    Xiaoqiang Zhu

    2017-06-01

    Full Text Available Objective: Identification of additional regulatory factors involved in the onset of obesity is important to understand the mechanisms underlying this prevailing disease and its associated metabolic disorders and to develop therapeutic strategies. Through isolation and analysis of a mutant, we aimed to uncover the function of a Ras-GAP gene, Rasal2 (Ras protein activator like 2, in the development of obesity and related metabolic disorders and to obtain valuable insights regarding the mechanism underlying the function. Methods: An obesity-based genetic screen was performed to identify an insertional mutation that disrupts the expression of Rasal2 (Rasal2PB/PB mice. Important metabolic parameters, such as fat mass and glucose tolerance, were measured in Rasal2PB/PB mice. The impact of Rasal2 on adipogenesis was evaluated in the mutant mice and in 3T3-L1 preadipocytes treated with Rasal2 siRNA. Ras and ERK activities were then evaluated in Rasal2-deficient preadipocytes or mice, and their functional relationships with Rasal2 on adipogenesis were investigated by employing Ras and MEK inhibitors. Results: Rasal2PB/PB mice showed drastic decrease in Rasal2 expression and a lean phenotype. The mutant mice displayed decreased adiposity and resistance to high-fat diet induced metabolic disorders. Further analysis indicated that Rasal2 deficiency leads to impaired adipogenesis in vivo and in vitro. Moreover, while Rasal2 deficiency resulted in increased activity of both Ras and ERK in preadipocytes, reducing Ras, but not ERK, suppressed the impaired adipogenesis. Conclusions: Rasal2 promotes adipogenesis, which may critically contribute to its role in the development of obesity and related metabolic disorders and may do so by repressing Ras activity in an ERK-independent manner. Keywords: Ras, ERK, Ras-GAP, Glucose tolerance, High-fat diet, Diabetes

  10. Adipogenesis in thyroid eye disease.

    Science.gov (United States)

    Crisp, M; Starkey, K J; Lane, C; Ham, J; Ludgate, M

    2000-10-01

    Adipogenesis contributes to the pathogenesis of thyroid eye disease (TED). Thyrotropin receptor (TSHR) transcripts are present in orbital fat. This study was conducted to determine whether they are expressed as functional protein, and if so, whether this is restricted to TED orbits or to a particular stage in adipocyte differentiation. Samples of fat were obtained from 18 TED-affected orbits and 4 normal orbits, and 9 were obtained from nonorbital locations. Frozen sections were examined by immunocytochemistry using monoclonal antibodies specific for the human TSHR. Samples were disaggregated and the preadipocytes separated from the mature by differential centrifugation and cultured in serum-free or DM and examined for morphologic changes, oil red O and TSHR staining, and TSH-induced cyclic adenosine monophosphate (cAMP) production. Marked immunoreactivity was observed in frozen sections from all three TED samples and faint staining in both normal orbital fat samples. In vitro, 1% to 5% of preadipocytes displayed TSHR immunoreactivity in five of six TED and two of three normal orbital samples and in three of five nonorbital samples. Differentiation, was induced in all 14 orbital samples. Three of four nonorbital samples contained occasional differentiated cells. Fifty percent to 70% of differentiating cells demonstrated receptor immunoreactivity. Two of three TED and four of four nonorbital preadipocytes in DM and/or mature adipocytes displayed a TSH-mediated increase in cAMP. The results indicate that orbital fat TSHR transcripts are expressed as protein, which can be functional. This is not aberrant in TED orbits, although expression may be upregulated. The majority of preadipocytes undergoing differentiation express the receptor, indicating a key role for this population in one mechanism for increasing orbital volume.

  11. Retinaldehyde dehydrogenase 2 as a molecular adjuvant for enhancement of mucosal immunity during DNA vaccination.

    Science.gov (United States)

    Holechek, Susan A; McAfee, Megan S; Nieves, Lizbeth M; Guzman, Vanessa P; Manhas, Kavita; Fouts, Timothy; Bagley, Kenneth; Blattman, Joseph N

    2016-11-04

    In order for vaccines to induce efficacious immune responses against mucosally transmitted pathogens, such as HIV-1, activated lymphocytes must efficiently migrate to and enter targeted mucosal sites. We have previously shown that all-trans retinoic acid (ATRA) can be used as a vaccine adjuvant to enhance mucosal CD8 + T cell responses during vaccination and improve protection against mucosal viral challenge. However, the ATRA formulation is incompatible with most recombinant vaccines, and the teratogenic potential of ATRA at high doses limits its usage in many clinical settings. We hypothesized that increasing in vivo production of retinoic acid (RA) during vaccination with a DNA vector expressing retinaldehyde dehydrogenase 2 (RALDH2), the rate-limiting enzyme in RA biosynthesis, could similarly provide enhanced programming of mucosal homing to T cell responses while avoiding teratogenic effects. Administration of a RALDH2- expressing plasmid during immunization with a HIVgag DNA vaccine resulted in increased systemic and mucosal CD8 + T cell numbers with an increase in both effector and central memory T cells. Moreover, mice that received RALDH2 plasmid during DNA vaccination were more resistant to intravaginal challenge with a recombinant vaccinia virus expressing the same HIVgag antigen (VACVgag). Thus, RALDH2 can be used as an alternative adjuvant to ATRA during DNA vaccination leading to an increase in both systemic and mucosal T cell immunity and better protection from viral infection at mucosal sites. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Repressive Tolerance

    DEFF Research Database (Denmark)

    Pedersen, Morten Jarlbæk

    2017-01-01

    Consultation of organised interests and others when drafting laws is often seen as an important source of both input and output legitimacy. But whereas the input side of the equation stems from the very process of listening to societal actors, output legitimacy can only be strengthened if consult......Consultation of organised interests and others when drafting laws is often seen as an important source of both input and output legitimacy. But whereas the input side of the equation stems from the very process of listening to societal actors, output legitimacy can only be strengthened...... a substantial effect on the substance of laws – shows that there is a great difference in the amenability of different branches of government but that, in general, authorities do not listen much despite a very strong consultation institution and tradition. A suggestion for an explanation could be pointing...... to an administrative culture of repressive tolerance of organised interests: authorities listen but only reacts in a very limited sense. This bears in it the risk of jeopardising the knowledge transfer from societal actors to administrative ditto thus harming the consultation institutions’ potential for strengthening...

  13. Adipogenesis: forces that tip the scales

    DEFF Research Database (Denmark)

    MacDougald, Ormond A; Mandrup, Susanne

    2001-01-01

    factors reviewed include Wnt, transforming growth factor beta, inflammatory cytokines and prostaglandin F(2alpha). Tipping the scales towards or away from adipogenesis has profound implications for human health. In this review, we describe recent contributions to the field and will focus on factors...

  14. Fisetin induces Sirt1 expression while inhibiting early adipogenesis in 3T3-L1 cells.

    Science.gov (United States)

    Kim, Sang Chon; Kim, Yoo Hoon; Son, Sung Wook; Moon, Eun-Yi; Pyo, Suhkneung; Um, Sung Hee

    2015-11-27

    Fisetin (3,7,3',4'-tetrahydroxyflavone) is a naturally found flavonol in many fruits and vegetables and is known to have anti-aging, anti-cancer and anti-viral effects. However, the effects of fisetin on early adipocyte differentiation and the epigenetic regulator controlling adipogenic transcription factors remain unclear. Here, we show that fisetin inhibits lipid accumulation and suppresses the expression of PPARγ in 3T3-L1 cells. Fisetin suppressed early stages of preadipocyte differentiation, and induced expression of Sirt1. Depletion of Sirt1 abolished the inhibitory effects of fisetin on intracellular lipid accumulation and on PPARγ expression. Mechanistically, fisetin facilitated Sirt1-mediated deacetylation of PPARγ and FoxO1, and enhanced the association of Sirt1 with the PPARγ promoter, leading to suppression of PPARγ transcriptional activity, thereby repressing adipogenesis. Lowering Sirt1 levels reversed the effects of fisetin on deacetylation of PPARγ and increased PPARγ transactivation. Collectively, our results suggest the effects of fisetin in increasing Sirt1 expression and in epigenetic control of early adipogenesis. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Novel Wnt Regulator NEL-Like Molecule-1 Antagonizes Adipogenesis and Augments Osteogenesis Induced by Bone Morphogenetic Protein 2

    Science.gov (United States)

    Shen, Jia; James, Aaron W.; Zhang, Xinli; Pang, Shen; Zara, Janette N.; Asatrian, Greg; Chiang, Michael; Lee, Min; Khadarian, Kevork; Nguyen, Alan; Lee, Kevin S.; Siu, Ronald K.; Tetradis, Sotirios; Ting, Kang; Soo, Chia

    2017-01-01

    The differentiation factor NEL-like molecule-1 (NELL-1) has been reported as osteoinductive in multiple in vivo preclinical models. Bone morphogenetic protein (BMP)-2 is used clinically for skeletal repair, but in vivo administration can induce abnormal, adipose-filled, poor-quality bone. We demonstrate that NELL-1 combined with BMP2 significantly optimizes osteogenesis in a rodent femoral segmental defect model by minimizing the formation of BMP2-induced adipose-filled cystlike bone. In vitro studies using the mouse bone marrow stromal cell line M2-10B4 and human primary bone marrow stromal cells have confirmed that NELL-1 enhances BMP2-induced osteogenesis and inhibits BMP2-induced adipogenesis. Importantly, the ability of NELL-1 to direct BMP2-treated cells toward osteogenesis and away from adipogenesis requires intact canonical Wnt signaling. Overall, these studies establish the feasibility of combining NELL-1 with BMP2 to improve clinical bone regeneration and provide mechanistic insight into canonical Wnt pathway activity during NELL-1 and BMP2 osteogenesis. The novel abilities of NELL-1 to stimulate Wnt signaling and to repress adipogenesis may highlight new treatment approaches for bone loss in osteoporosis. PMID:26772960

  16. Dibutyltin Compounds Effects on PPARγ/RXRα Activity, Adipogenesis, and Inflammation in Mammalians Cells

    Directory of Open Access Journals (Sweden)

    Flora A. Milton

    2017-08-01

    that dibutyltins dichloride and dilaurate are also partial RXRα agonists. Furthermore, dibutyltins induce adipogenesis in a PPARγ-dependent manner and repress inflammatory genes in 3T3-L1 and RAW 264.7 cells. Although dibutyltins display some partial PPARγ/RXRα agonistic effects, the translation of cell-based results assays into in vivo effects on inflammation and insulin resistance is not entirely known. Nevertheless, further studies are necessary to address their effects in different periods of life and to elucidate the actions of organostanic compounds in whole-body context.

  17. Salinomycin, a polyether ionophoric antibiotic, inhibits adipogenesis

    International Nuclear Information System (INIS)

    Szkudlarek-Mikho, Maria; Saunders, Rudel A.; Yap, Sook Fan; Ngeow, Yun Fong; Chin, Khew-Voon

    2012-01-01

    Highlights: ► Salinomycin inhibits preadipocyte differentiation into adipocytes. ► Salinomycin inhibits transcriptional regulation of adipogenesis. ► Pharmacological effects of salinomycin suggest toxicity in cancer therapy. -- Abstract: The polyether ionophoric antibiotics including monensin, salinomycin, and narasin, are widely used in veterinary medicine and as food additives and growth promoters in animal husbandry including poultry farming. Their effects on human health, however, are not fully understood. Recent studies showed that salinomycin is a cancer stem cell inhibitor. Since poultry consumption has risen sharply in the last three decades, we asked whether the consumption of meat tainted with growth promoting antibiotics might have effects on adipose cells. We showed in this report that the ionophoric antibiotics inhibit the differentiation of preadipocytes into adipocytes. The block of differentiation is not due to the induction of apoptosis nor the inhibition of cell proliferation. In addition, salinomycin also suppresses the transcriptional activity of the CCAAT/enhancer binding proteins and the peroxisome proliferator-activated receptor γ. These results suggest that the ionophoric antibiotics can be exploited as novel anti-obesity therapeutics and as pharmacological probes for the study of adipose biology. Further, the pharmacological effects of salinomycin could be a harbinger of its toxicity on the adipose tissue and other susceptible target cells in cancer therapy.

  18. Salinomycin, a polyether ionophoric antibiotic, inhibits adipogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Szkudlarek-Mikho, Maria; Saunders, Rudel A. [Department of Medicine, Biochemistry and Cancer Biology, Center for Diabetes and Endocrine Research, College of Medicine, University of Toledo, Toledo, OH 43614 (United States); Yap, Sook Fan [Faculty of Medicine and Health Sciences, Department of Pre-Clinical Sciences, University of Tunku Abdul Rahman (Malaysia); Ngeow, Yun Fong [Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603 (Malaysia); Chin, Khew-Voon, E-mail: khew-voon.chin@utoledo.edu [Department of Medicine, Biochemistry and Cancer Biology, Center for Diabetes and Endocrine Research, College of Medicine, University of Toledo, Toledo, OH 43614 (United States)

    2012-11-30

    Highlights: Black-Right-Pointing-Pointer Salinomycin inhibits preadipocyte differentiation into adipocytes. Black-Right-Pointing-Pointer Salinomycin inhibits transcriptional regulation of adipogenesis. Black-Right-Pointing-Pointer Pharmacological effects of salinomycin suggest toxicity in cancer therapy. -- Abstract: The polyether ionophoric antibiotics including monensin, salinomycin, and narasin, are widely used in veterinary medicine and as food additives and growth promoters in animal husbandry including poultry farming. Their effects on human health, however, are not fully understood. Recent studies showed that salinomycin is a cancer stem cell inhibitor. Since poultry consumption has risen sharply in the last three decades, we asked whether the consumption of meat tainted with growth promoting antibiotics might have effects on adipose cells. We showed in this report that the ionophoric antibiotics inhibit the differentiation of preadipocytes into adipocytes. The block of differentiation is not due to the induction of apoptosis nor the inhibition of cell proliferation. In addition, salinomycin also suppresses the transcriptional activity of the CCAAT/enhancer binding proteins and the peroxisome proliferator-activated receptor {gamma}. These results suggest that the ionophoric antibiotics can be exploited as novel anti-obesity therapeutics and as pharmacological probes for the study of adipose biology. Further, the pharmacological effects of salinomycin could be a harbinger of its toxicity on the adipose tissue and other susceptible target cells in cancer therapy.

  19. Epigenetic developmental programs and adipogenesis: implications for psychotropic induced obesity.

    Science.gov (United States)

    Chase, Kayla; Sharma, Rajiv P

    2013-11-01

    Psychotropic agents are notorious for their ability to increase fat mass in psychiatric patients. The two determinants of fat mass are the production of newly differentiated adipocytes (adipogenesis), and the volume of lipid accumulation. Epigenetic programs have a prominent role in cell fate commitments and differentiation required for adipogenesis. In parallel, epigenetic effects on energy metabolism are well supported by several genetic models. Consequently, a variety of psychotropics, often prescribed in combinations and for long periods, may utilize a common epigenetic effector path causing an increase in adipogenesis or reduction in energy metabolism. In particular, the recent discovery that G protein coupled signaling cascades can directly modify epigenetic regulatory enzymes implicates surface receptor activity by psychotropic medications. The potential therapeutic implications are also suggested by the effects of the clinically approved antidepressant tranylcypromine, also a histone demethylase inhibitor, which has impressive therapeutic effects on metabolism in the obese phenotype.

  20. Racism and Surplus Repression.

    Science.gov (United States)

    Johnson, Howard

    1983-01-01

    Explores the relationship between Herbert Marcuse's theory of "surplus repression" and Freud's theory of the "unconscious" with respect to latent, hidden, covert, or subliminal aspects of racism in the United States. Argues that unconscious racism, manifested in evasion/avoidance, acting out/projection, and attempted…

  1. Obestatin as a regulator of adipocyte metabolism and adipogenesis

    Science.gov (United States)

    Gurriarán-Rodríguez, Uxía; Al-Massadi, Omar; Roca-Rivada, Arturo; Crujeiras, Ana Belén; Gallego, Rosalía; Pardo, Maria; Seoane, Luisa Maria; Pazos, Yolanda; Casanueva, Felipe F; Camiña, Jesús P

    2011-01-01

    Abstract The role of obestatin, a 23-amino-acid peptide encoded by the ghrelin gene, on the control of the metabolism of pre-adipocyte and adipocytes as well as on adipogenesis was determined. For in vitro assays, pre-adipocyte and adipocyte 3T3-L1 cells were used to assess the obestatin effect on cell metabolism and adipogenesis based on the regulation of the key enzymatic nodes, Akt and AMPK and their downstream targets. For in vivo assays, white adipose tissue (WAT) was obtained from male rats under continuous subcutaneous infusion of obestatin. Obestatin activated Akt and its downstream targets, GSK3α/β, mTOR and S6K1, in 3T3-L1 adipocyte cells. Simultaneously, obestatin inactivated AMPK in this cell model. In keeping with this, ACC phosphorylation was also decreased. This fact was confirmed in vivo in white adipose tissue (omental, subcutaneous and gonadal) obtained from male rats under continuous sc infusion of obestatin (24 and 72 hrs). The relevance of obestatin as regulator of adipocyte metabolism was supported by AS160 phosphorylation, GLUT4 translocation and augment of glucose uptake in 3T3-L1 adipocyte cells. In contrast, obestatin failed to modify translocation of fatty acid transporters, FATP1, FATP4 and FAT/CD36, to plasma membrane. Obestatin treatment in combination with IBMX and DEX showed to regulate the expression of C/EBPα, C/EBPβ, C/EBPδ and PPARγ promoting adipogenesis. Remarkable, preproghrelin expression, and thus obestatin expression, increased during adipogenesis being sustained throughout terminal differentiation. Neutralization of endogenous obestatin secreted by 3T3-L1 cells by anti-obestatin antibody decreased adipocyte differentiation. Furthermore, knockdown experiments by preproghrelin siRNA supported that obestatin contributes to adipogenesis. In summary, obestatin promotes adipogenesis in an autocrine/paracrine manner, being a regulator of adipocyte metabolism. These data point to a putative role in the pathogenesis of

  2. Inhibition of adipogenesis and leptin production in 3T3-L1 adipocytes by a derivative of meridianin C

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yu-Kyoung [Department of Molecular Medicine, College of Medicine, Keimyung University, 1095 Dalgubeoldaero, Dalseo-gu, Daegu 704-701 (Korea, Republic of); Lee, Tae-Yoon [Department of Microbiology, College of Medicine, Yeungnam University, 170 Hyunchung-Ro, Nam-gu, Daegu 705-717 (Korea, Republic of); Choi, Jong-Soon [Division of Life Science, Korea Basic Science Institute, 169-148 Gwahakro, Yuseong-gu, Daejeon 305-333 (Korea, Republic of); Hong, Victor Sukbong [Department of Chemistry, College of Natural Sciences, Keimyung University, 1095 Dalgubeoldaero, Dalseo-gu, Daegu 704-701 (Korea, Republic of); Lee, Jinho, E-mail: jinho@gw.kmu.ac.kr [Department of Chemistry, College of Natural Sciences, Keimyung University, 1095 Dalgubeoldaero, Dalseo-gu, Daegu 704-701 (Korea, Republic of); Park, Jong-Wook, E-mail: j303nih@dsmc.or.kr [Department of Immunology, College of Medicine, Keimyung University, 1095 Dalgubeoldaero, Dalseo-gu, Daegu 704-701 (Korea, Republic of); Jang, Byeong-Churl, E-mail: jangbc123@gw.kmu.ac.kr [Department of Molecular Medicine, College of Medicine, Keimyung University, 1095 Dalgubeoldaero, Dalseo-gu, Daegu 704-701 (Korea, Republic of)

    2014-10-03

    Highlights: • Compound 7b, a meridianin C derivative, inhibits adipogenesis. • Compound 7b inhibits C/EBP-α, PPAR-γ, FAS, STAT-3, and STAT-5 in 3T3-L1 adipocytes. • Compound 7b inhibits leptin, but not adiponectin, expression in 3T3-L1 adipocytes. • Compound 7b thus may have therapeutic potential against obesity. - Abstract: Meridianin C, a marine alkaloid, is a potent protein kinase inhibitor and has anti-cancer activity. We have recently developed a series of meridianin C derivatives (compound 7a–7j) and reported their proviral integration Moloney Murine Leukemia Virus (pim) kinases’ inhibitory and anti-proliferative effects on human leukemia cells. Here we investigated the effect of these meridianin C derivatives on adipogenesis. Strikingly, among the derivatives tested, compound 7b most strongly inhibited lipid accumulation during the differentiation of 3T3-L1 preadipocytes into adipocytes. However, meridianin C treatment was largely cytotoxic to 3T3-L1 adipocytes. On mechanistic levels, compound 7b reduced not only the expressions of CCAAT/enhancer-binding protein-α (C/EBP-α), peroxisome proliferator-activated receptor-γ (PPAR-γ), and fatty acid synthase (FAS) but also the phosphorylation levels of signal transducer and activator of transcription-3 (STAT-3) and STAT-5 during adipocyte differentiation. Moreover, compound 7b repressed leptin, but not adiponectin, expression during adipocyte differentiation. Collectively, these findings demonstrate that a meridianin C derivative inhibits adipogenesis by down-regulating expressions and/or phosphorylations of C/EBP-α, PPAR-γ, FAS, STAT-3 and STAT-5.

  3. MAT2B promotes adipogenesis by modulating SAMe levels and activating AKT/ERK pathway during porcine intramuscular preadipocyte differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Cunzhen; Chen, Xiaochang; Wu, Wenjing; Wang, Wusu; Pang, Weijun; Yang, Gongshe, E-mail: gsyang999@hotmail.com

    2016-05-15

    Intramuscular fat (IMF) has been demonstrated as one of the crucial factors of livestock meat quality. The MAT2B protein with MAT2α catalyzes the formation of methyl donor S- adenosylmethionine (SAMe) to mediate cell metabolism including proliferation and apoptosis. However, the regulatory effect of MAT2B on IMF deposition is still unclear. In this study, the effect of MAT2B on adipogenesis and its potential mechanism during porcine intramuscular preadipocyte differentiation was studied. The results showed that overexpression of MAT2B promoted adipogenesis and significantly up-regulated the mRNA and protein levels of adipogenic marker genes including FASN, PPARγ and aP2, consistently, knockdown of MAT2B inhibited lipid accumulation and down-regulated the mRNA and protein levels of the above genes. Furthermore, flow cytometry and EdU-labeling assay indicated that MAT2B regulate adipogenesis was partly due to influence intracellular SAMe levels and further affect cell clonal expansion. Also, increased expression of MAT2B activated the phosphorylations of AKT and ERK1/2, whereas knockdown of MAT2B blocked AKT signaling and repressed the phosphorylation of ERK1/2. Moreover, the inhibitory effect of LY294002 (a specific PI3K inhibitor) on the activities of AKT and ERK1/2 was partially recovered by overexpression of MAT2B in porcine intramuscular adipocytes. Finally, Co-IP experiments showed that MAT2B can directly interact with AKT. Taken together, our findings suggested that MAT2B acted as a positive regulator through modifying SAMe levels as well as activating AKT/ERK signaling pathway to promote porcine intramuscular adipocyte differentiation. - Highlights: • MAT2B up-regulates the expression of adipogenic marker genes and promotes porcine intramuscular preadipocyte differentiation. • MAT2B influences intracellular SAMe levels and further affects cell clonal expansion. • MAT2B interacts with AKT and activates AKT/ERK signaling pathway.

  4. TRP channels in brown and white adipogenesis from human progenitors: new therapeutic targets and the caveats associated with the common antibiotic, streptomycin.

    Science.gov (United States)

    Goralczyk, Anna; van Vijven, Marc; Koch, Mathilde; Badowski, Cedric; Yassin, M Shabeer; Toh, Sue-Anne; Shabbir, Asim; Franco-Obregón, Alfredo; Raghunath, Michael

    2017-08-01

    Transient receptor potential (TRP) channels are polymodal cell sensors responding to diverse stimuli and widely implicated in the developmental programs of numerous tissues. The evidence for an involvement of TRP family members in adipogenesis, however, is scant. We present the first comprehensive expression profile of all known 27 human TRP genes in mesenchymal progenitors cells during white or brown adipogenesis. Using positive trilineage differentiation as an exclusion criterion, TRP polycystic (P)3, and TPR melastatin (M)8 were found to be uniquely adipospecific. Knockdown of TRPP3 repressed the expression of the brown fat signature genes uncoupling protein (UCP)-1 and peroxisome proliferator-activated receptor γ coactivator (PGC)-1α as well as attenuated forskolin-stimulated uncoupled respiration. However, indices of generalized adipogenesis, such as lipid droplet morphology and fatty acid binding protein (FAPB)-4 expression, were not affected, indicating a principal mitochondrial role of TRPP3. Conversely, activating TRPM8 with menthol up-regulated UCP-1 expression and augmented uncoupled respiration predominantly in white adipocytes (browning), whereas streptomycin antagonized TRPM8-mediated calcium entry, downregulated UCP-1 expression, and mitigated uncoupled respiration; menthol was less capable of augmenting uncoupled respiration (thermogenesis) in brown adipocytes. TRPP3 and TRPM8 hence appear to be involved in the priming of mitochondria to perform uncoupled respiration downstream of adenylate cyclase. Our results also underscore the developmental caveats of using antibiotics in adipogenic studies.-Goralczyk, A., van Vijven, M., Koch, M., Badowski, C., Yassin, M. S., Toh, S.-A., Shabbir, A., Franco-Obregón, A., Raghunath, M. TRP channels in brown and white adipogenesis from human progenitors: new therapeutic targets and the caveats associated with the common antibiotic, streptomycin. © FASEB.

  5. New factors controlling the balance between osteoblastogenesis and adipogenesis.

    Science.gov (United States)

    Abdallah, Basem M; Kassem, Moustapha

    2012-02-01

    The majority of conditions associated with bone loss, including aging, are accompanied by increased marrow adiposity possibly due to shifting of the balance between osteoblast and adipocyte differentiation in bone marrow stromal (skeletal) stem cells (MSC). In order to study the relationship between osteoblastogenesis and adipogenesis in bone marrow, we have characterized cellular models of multipotent MSC as well as pre-osteoblastic and pre-adipocytic cell populations. Using these models, we identified two secreted factors in the bone marrow microenviroment: secreted frizzled-related protein 1 (sFRP-1) and delta-like1 (preadipocyte factor 1) (Dlk1/Pref-1). Both exert regulatory effects on osteoblastogenesis and adipogenesis. Our studies suggest a model for lineage fate determination of MSC that is regulated through secreted factors in the bone marrow microenvironment that mediate a cross-talk between lineage committed cell populations in addition to controlling differentiation choices of multipotent MSC. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Scheduled feeding results in adipogenesis and increased acylated ghrelin

    OpenAIRE

    Verbaeys, I.; Tolle, V.; SWENNEN, Quirine; Zizzari, P.; Buyse, J.; Epelbaum, J.; Cokelaere, M.

    2011-01-01

    Ghrelin, known to stimulate adipogenesis, displays an endogenous secretory rhythmicity closely related to meal patterns. Therefore, a chronic imposed feeding schedule might induce modified ghrelin levels and consequently adiposity. Growing Wistar rats were schedule-fed by imposing a particular fixed feeding schedule of 3 meals/day without caloric restriction compared with total daily control intake. After 14 days, their body composition was measured by DEXA and compared with ad libitum-fed co...

  7. Redundant Control of Adipogenesis by Histone Deacetylases 1 and 2*

    OpenAIRE

    Haberland, Michael; Carrer, Michele; Mokalled, Mayssa H.; Montgomery, Rusty L.; Olson, Eric N.

    2010-01-01

    Adipocyte differentiation is a well defined process that is under the control of transcriptional activators and repressors. We show that histone deacetylase (HDAC) inhibitors efficiently block adipocyte differentiation in vitro. This effect is specific to adipogenesis, as another mesenchymal differentiation process, osteoblastogenesis, is enhanced upon HDAC inhibition. Through the systematic genetic deletion of HDAC genes in cultured mesenchymal precursor cells, we show that deletion of HDAC1...

  8. Dexras1 mediates glucocorticoid-associated adipogenesis and diet-induced obesity

    Science.gov (United States)

    Cha, Jiyoung Y.; Kim, Hyo Jung; Yu, Jung Hwan; Xu, Jing; Kim, Daham; Paul, Bindu D.; Choi, Hyeonjin; Kim, Seyun; Lee, Yoo Jeong; Ho, Gary P.; Rao, Feng; Snyder, Solomon H.; Kim, Jae-woo

    2013-01-01

    Adipogenesis, the conversion of precursor cells into adipocytes, is associated with obesity and is mediated by glucocorticoids acting via hitherto poorly characterized mechanisms. Dexras1 is a small G protein of the Ras family discovered on the basis of its marked induction by the synthetic glucocorticoid dexamethasone. We show that Dexras1 mediates adipogenesis and diet-induced obesity. Adipogenic differentiation of 3T3-L1 cells is abolished with Dexras1 depletion, whereas overexpression of Dexras1 elicits adipogenesis. Adipogenesis is markedly reduced in mouse embryonic fibroblasts from Dexras1-deleted mice, whereas adiposity and diet-induced weight gain are diminished in the mutant mice. PMID:24297897

  9. Differential effects of environmental chemicals and food contaminants on adipogenesis, biomarker release and PPARγ activation

    DEFF Research Database (Denmark)

    Taxvig, Camilla; Sørensen, Karin Dreisig; Boberg, Julie

    2012-01-01

    Eleven environmental relevant chemicals were investigated for their ability to affect adipogenesis in vitro, biomarker release from adipocytes and PPARα and γ activation. We found that butylparaben stimulated adipogenesis in 3T3-L1 adipocytes and increased release of leptin, adiponectin and resis...

  10. Effect of salidroside on radiation-induced bone marrow adipogenesis

    International Nuclear Information System (INIS)

    Zhu Jincan; Chen Xiaoyu; Liu Chengcheng; Zhu Aizhen; Liu Shantao; Liu Gexiu

    2014-01-01

    Objective: To investigate the potential and underlying molecular mechanism of salidroside in ameliorating radiation-induced bone marrow adipogenesis and stimulating hematopoiesis. Methods: The female BALB/c mice aged 6-7 weeks were randomly divided into normal control group, radiation group and salidroside group. The radiation group and salidroside group were irradiated with 6.0 Gy of "6"0Co γ-rays. The salidroside group was intraperitoneally injected with 30 mg·kg"-"1·d"-"1 salidroside at 12 h and then every day until 8th d after radiation. The normal control group and radiation group were treated with equal volume of saline as control of salidroside. At 14 d after radiation, the mice weight, peripheral blood count, femur bone marrow histology, and the proportion of adipocyte area were measured, and the expressions of PPAR-γ and FABP4 were detected by q-PCR. Results: After irradiation, the numbers of white blood cells, hemoglobin and platelet in peripheral blood were reduced obviously, and the percentage of adipocyte area was increased significantly. Compared with mice in the radiation group, salidroside inhibited adipogenesis and reduced the proportion of adipocyte area (t = 13.31, P < 0.05) by reducing the expressions of PPAR-γ and FABP4 (t = 8.64, 13.19, P < 0.05). The number of white blood cells was partly recovered at 7 d after irradiation (t = 5.80, P < 0.05). Both white blood cells and hemoglobinin in peripheral blood of the salidroside group were higher than those in the radiation group at 14 d after irradiation. Conclusions: Salidroside could inhibit radiation-induced bone marrow adipogenesis and regulate bone marrow microenvironment, thereby promotes hematopoietic recovery in mice after radiation injury. (authors)

  11. Myostatin Attenuation In Vivo Reduces Adiposity, but Activates Adipogenesis.

    Science.gov (United States)

    Li, Naisi; Yang, Qiyuan; Walker, Ryan G; Thompson, Thomas B; Du, Min; Rodgers, Buel D

    2016-01-01

    A potentially novel approach for treating obesity includes attenuating myostatin as this increases muscle mass and decreases fat mass. Notwithstanding, conflicting studies report that myostatin stimulates or inhibits adipogenesis and it is unknown whether reduced adiposity with myostatin attenuation results from changes in fat deposition or adipogenesis. We therefore quantified changes in the stem, transit amplifying and progenitor cell pool in white adipose tissue (WAT) and brown adipose tissue (BAT) using label-retaining wild-type and mstn(-/-) (Jekyll) mice. Muscle mass was larger in Jekyll mice, WAT and BAT mass was smaller and label induction was equal in all tissues from both wild-type and Jekyll mice. The number of label-retaining cells, however, dissipated quicker in WAT and BAT of Jekyll mice and was only 25% and 17%, respectively, of wild-type cell counts 1 month after induction. Adipose cell density was significantly higher in Jekyll mice and increased over time concomitant with label-retaining cell disappearance, which is consistent with enhanced expansion and differentiation of the stem, transit amplifying and progenitor pool. Stromal vascular cells from Jekyll WAT and BAT differentiated into mature adipocytes at a faster rate than wild-type cells and although Jekyll WAT cells also proliferated quicker in vitro, those from BAT did not. Differentiation marker expression in vitro, however, suggests that mstn(-/-) BAT preadipocytes are far more sensitive to the suppressive effects of myostatin. These results suggest that myostatin attenuation stimulates adipogenesis in vivo and that the reduced adiposity in mstn(-/-) animals results from nutrient partitioning away from fat and in support of muscle.

  12. Technique Selectively Represses Immune System

    Science.gov (United States)

    ... Research Matters December 3, 2012 Technique Selectively Represses Immune System Myelin (green) encases and protects nerve fibers (brown). A new technique prevents the immune system from attacking myelin in a mouse model of ...

  13. A new dermocosmetic containing retinaldehyde, delta-tocopherol glucoside and glycylglycine oleamide for managing naturally aged skin: results from in vitro to clinical studies

    Directory of Open Access Journals (Sweden)

    Rouvrais C

    2017-02-01

    Full Text Available Céline Rouvrais,1,* Daniel Bacqueville,2,* Patrick Bogdanowicz,2,* Marie-José Haure,2 Laure Duprat,2 Christine Coutanceau,3 Nathalie Castex-Rizzi,2 Hélène Duplan,2 Valérie Mengeaud,1 Sandrine Bessou-Touya2 1Clinical Skin Research Center, 2Department of Pharmacology, Pierre Fabre Dermo-Cosmétique, Toulouse, 3Laboratoire Dermatologique Avène, Lavaur, France *These authors contributed equally to this work Introduction: Natural aging of skin tissues, the addition of the cumulative action of the time and radiation exposure result in skin atrophy, wrinkles and degeneration of the extracellular matrix (ECM. The aim of the study was to investigate the beneficial effect of a combination containing retinaldehyde (RAL, delta-tocopherol glucoside (delta-TC and glycylglycine oleamide (GGO and of a dermocosmetic containing the combination. Materials and methods: The protective effect of the combination was assessed through in vitro gene expression of ultraviolet (UV-irradiated fibroblasts. A skin aging assay using UV light on ex vivo skin samples and a clinical study conducted in 36 women aged from 35 to 55 years with a minimum of level 4 to a maximum of level 6 on the crow’s feet photoscale assessed the antiaging effect of the dermocosmetic. Results: When added to UV-irradiated fibroblasts, the combination substantially improved the ECM in activating the elastin fiber production (fibrillin 2, fibulin 1 and 5 and lysyl ­oxidase-like 2 as well as that of proteins involved in the cellular ECM interactions (integrin β1, paxillin and actin a2. An ex vivo photodamaged human skin model showed that the dermocosmetic formulation containing the combination of the active ingredients protected the elastic network against UV-induced alterations including both elastin and fibrillin-rich fibers in the dermis. A daily application of the dermocosmetic for 2 months on naturally aged skin resulted in a statistically significant improvement (p<0.05 of visible

  14. Quercetin inhibits adipogenesis of muscle progenitor cells in vitro

    Directory of Open Access Journals (Sweden)

    Tomoko Funakoshi

    2018-03-01

    Full Text Available Muscle satellite cells are committed myogenic progenitors capable of contributing to myogenesis to maintain adult muscle mass and function. Several experiments have demonstrated that muscle satellite cells can differentiate into adipocytes in vitro, supporting the mesenchymal differentiation potential of these cells. Moreover, muscle satellite cells may be a source of ectopic muscle adipocytes, explaining the lipid accumulation often observed in aged skeletal muscle (sarcopenia and in muscles of patients` with diabetes. Quercetin, a polyphenol, is one of the most abundant flavonoids distributed in edible plants, such as onions and apples, and possesses antioxidant, anticancer, and anti-inflammatory properties. In this study, we examined whether quercetin inhibited the adipogenesis of muscle satellite cells in vitro with primary cells from rat limbs by culture in the presence of quercetin under adipogenic conditions. Morphological observations, Oil Red-O staining results, triglyceride content analysis, and quantitative reverse transcription polymerase chain reaction revealed that quercetin was capable of inhibiting the adipogenic induction of muscle satellite cells into adipocytes in a dose-dependent manner by suppressing the transcript levels of adipogenic markers, such as peroxisome proliferator-activated receptor-γ and fatty acid binding protein 4. Our results suggested that quercetin inhibited the adipogenesis of muscle satellite cells in vitro by suppressing the transcription of adipogenic markers. Keywords: Quercetin, Muscle satellite cell, Differentiation, Intramuscular lipid

  15. T1R3 homomeric sweet taste receptor regulates adipogenesis through Gαs-mediated microtubules disassembly and Rho activation in 3T3-L1 cells.

    Directory of Open Access Journals (Sweden)

    Yosuke Masubuchi

    Full Text Available We previously reported that 3T3-L1 cells express a functional sweet taste receptor possibly as a T1R3 homomer that is coupled to Gs and negatively regulates adipogenesis by a Gαs-mediated but cAMP-independent mechanism. Here, we show that stimulation of this receptor with sucralose or saccharin induced disassembly of the microtubules in 3T3-L1 preadipocytes, which was attenuated by overexpression of the dominant-negative mutant of Gαs (Gαs-G226A. In contrast, overexpression of the constitutively active mutant of Gαs (Gαs-Q227L as well as treatment with cholera toxin or isoproterenol but not with forskolin caused disassembly of the microtubules. Sweetener-induced microtubule disassembly was accompanied by activation of RhoA and Rho-associated kinase (ROCK. This was attenuated with by knockdown of GEF-H1, a microtubule-localized guanine nucleotide exchange factor for Rho GTPase. Furthermore, overexpression of the dominant-negative mutant of RhoA (RhoA-T19N blocked sweetener-induced dephosphorylation of Akt and repression of PPARγ and C/EBPα in the early phase of adipogenic differentiation. These results suggest that the T1R3 homomeric sweet taste receptor negatively regulates adipogenesis through Gαs-mediated microtubule disassembly and consequent activation of the Rho/ROCK pathway.

  16. Translational Repression in Malaria Sporozoites

    Science.gov (United States)

    Turque, Oliver; Tsao, Tiffany; Li, Thomas; Zhang, Min

    2016-01-01

    Malaria is a mosquito-borne infectious disease of humans and other animals. It is caused by the parasitic protozoan, Plasmodium. Sporozoites, the infectious form of malaria parasites, are quiescent when they remain in the salivary glands of the Anopheles mosquito until transmission into a mammalian host. Metamorphosis of the dormant sporozoite to its active form in the liver stage requires transcriptional and translational regulations. Here, we summarize recent advances in the translational repression of gene expression in the malaria sporozoite. In sporozoites, many mRNAs that are required for liver stage development are translationally repressed. Phosphorylation of eukaryotic Initiation Factor 2α (eIF2α) leads to a global translational repression in sporozoites. The eIF2α kinase, known as Upregulated in Infectious Sporozoite 1 (UIS1), is dominant in the sporozoite. The eIF2α phosphatase, UIS2, is translationally repressed by the Pumilio protein Puf2. This translational repression is alleviated when sporozoites are delivered into the mammalian host. PMID:28357358

  17. Translational repression in malaria sporozoites

    Directory of Open Access Journals (Sweden)

    Oliver Turque

    2016-04-01

    Full Text Available Malaria is a mosquito-borne infectious disease of humans and other animals. It is caused by the parasitic protozoan, Plasmodium. Sporozoites, the infectious form of malaria parasites, are quiescent when they remain in the salivary glands of the Anopheles mosquito until transmission into a mammalian host. Metamorphosis of the dormant sporozoite to its active form in the liver stage requires transcriptional and translational regulations. Here, we summarize recent advances in the translational repression of gene expression in the malaria sporozoite. In sporozoites, many mRNAs that are required for liver stage development are translationally repressed. Phosphorylation of eukaryotic Initiation Factor 2α (eIF2α leads to a global translational repression in sporozoites. The eIF2α kinase, known as Upregulated in Infectious Sporozoite 1 (UIS1, is dominant in the sporozoite. The eIF2α phosphatase, UIS2, is translationally repressed by the Pumilio protein Puf2. This translational repression is alleviated when sporozoites are delivered into the mammalian host.

  18. Glucose repression in Saccharomyces cerevisiae.

    Science.gov (United States)

    Kayikci, Ömur; Nielsen, Jens

    2015-09-01

    Glucose is the primary source of energy for the budding yeast Saccharomyces cerevisiae. Although yeast cells can utilize a wide range of carbon sources, presence of glucose suppresses molecular activities involved in the use of alternate carbon sources as well as it represses respiration and gluconeogenesis. This dominant effect of glucose on yeast carbon metabolism is coordinated by several signaling and metabolic interactions that mainly regulate transcriptional activity but are also effective at post-transcriptional and post-translational levels. This review describes effects of glucose repression on yeast carbon metabolism with a focus on roles of the Snf3/Rgt2 glucose-sensing pathway and Snf1 signal transduction in establishment and relief of glucose repression. © FEMS 2015.

  19. The unified theory of repression.

    Science.gov (United States)

    Erdelyi, Matthew Hugh

    2006-10-01

    Repression has become an empirical fact that is at once obvious and problematic. Fragmented clinical and laboratory traditions and disputed terminology have resulted in a Babel of misunderstandings in which false distinctions are imposed (e.g., between repression and suppression) and necessary distinctions not drawn (e.g., between the mechanism and the use to which it is put, defense being just one). "Repression" was introduced by Herbart to designate the (nondefensive) inhibition of ideas by other ideas in their struggle for consciousness. Freud adapted repression to the defensive inhibition of "unbearable" mental contents. Substantial experimental literatures on attentional biases, thought avoidance, interference, and intentional forgetting exist, the oldest prototype being the work of Ebbinghaus, who showed that intentional avoidance of memories results in their progressive forgetting over time. It has now become clear, as clinicians had claimed, that the inaccessible materials are often available and emerge indirectly (e.g., procedurally, implicitly). It is also now established that the Ebbinghaus retention function can be partly reversed, with resulting increases of conscious memory over time (hypermnesia). Freud's clinical experience revealed early on that exclusion from consciousness was effected not just by simple repression (inhibition) but also by a variety of distorting techniques, some deployed to degrade latent contents (denial), all eventually subsumed under the rubric of defense mechanisms ("repression in the widest sense"). Freudian and Bartlettian distortions are essentially the same, even in name, except for motive (cognitive vs. emotional), and experimentally induced false memories and other "memory illusions" are laboratory analogs of self-induced distortions.

  20. Glucose repression in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Kayikci, Omur; Nielsen, Jens

    2015-01-01

    Glucose is the primary source of energy for the budding yeast Saccharomyces cerevisiae. Although yeast cells can utilize a wide range of carbon sources, presence of glucose suppresses molecular activities involved in the use of alternate carbon sources as well as it represses respiration and gluc......Glucose is the primary source of energy for the budding yeast Saccharomyces cerevisiae. Although yeast cells can utilize a wide range of carbon sources, presence of glucose suppresses molecular activities involved in the use of alternate carbon sources as well as it represses respiration...

  1. ADAM 12 protease induces adipogenesis in transgenic mice

    DEFF Research Database (Denmark)

    Kawaguchi, Nobuko; Xu, Xiufeng; Tajima, Rie

    2002-01-01

    ADAM 12 (meltrin-alpha) is a member of the ADAM (a disintegrin and metalloprotease) family. ADAM 12 functions as an active metalloprotease, supports cell adhesion, and has been implicated in myoblast differentiation and fusion. Human ADAM 12 exists in two forms: the prototype membrane-anchored pr......ADAM 12 (meltrin-alpha) is a member of the ADAM (a disintegrin and metalloprotease) family. ADAM 12 functions as an active metalloprotease, supports cell adhesion, and has been implicated in myoblast differentiation and fusion. Human ADAM 12 exists in two forms: the prototype membrane......-anchored protein, ADAM 12-L, and a shorter secreted form, ADAM 12-S. Here we report the occurrence of adipocytes in the skeletal muscle of transgenic mice in which overexpression of either form is driven by the muscle creatine kinase promoter. Cells expressing a marker of early adipogenesis were apparent...

  2. Effect of plasminogen activator inhibitor-1 on adipogenesis in vivo.

    Science.gov (United States)

    Scroyen, Ilse; Jacobs, Frank; Cosemans, Leen; De Geest, Bart; Lijnen, H Roger

    2009-02-01

    To study the functional role of plasminogen activator inhibitor-1 (PAI-1) in obesity, the effect of its overexpression on de novo adipogenesis was evaluated in murine models in vivo. Therefore, 3T3-F442A preadipocytes expressing murine PAI-1 (mPAI-1) or control cells were injected in the back of male NUDE mice, which were fed a high-fat diet (HFD) for four weeks. De novo fat pads that formed from the PAI-1 expressing cells were larger (21 +/- 2.4 mg vs. 14 +/- 1.4 mg; p = 0.017) and showed a higher adipocyte density (373 +/- 28 mm(-2) vs. 301 +/- 12 mm(-2); p = 0.03) as compared to those formed from control cells. In a second model, male NUDE mice were injected in the tail vein with an adenoviral construct expressing mPAI-1 or with the empty vector, and three days later with 3T3-F442A cells. After four weeks of HFD, total body weight and de novo fat pad weight were comparable for both groups. Mild adipocyte hypotrophy was observed in the de novo fat pads of the PAI-1 overexpressing mice (1180 +/- 33 microm(2) vs. 1285 +/- 32 microm(2); p = 0.024), whereas the blood vessel size was significantly smaller than in controls (30 +/- 1.8 microm(2) vs. 63 +/- 3.6 microm(2); p < 0.0001). Thus, the effect of local or systemic PAI-1 (over)expression on adipocyte or blood vessel size and density of de novo formed fat pads appears to be different, and concentration-dependent. Whereas local expression resulted in larger fat pads, systemic overexpression had no effect on de novo adipogenesis, although angiogenesis appeared to be impaired.

  3. Rule of Repression in Chile.

    Science.gov (United States)

    American Indian Journal, 1979

    1979-01-01

    This report on the current condition of the Mapuche Indians of Chile is edited from a document on the "Situation of Human Rights in Chile" and details the repressive and inhumane treatment of the largest indigenous ethnic minority in the country. (Author/RTS)

  4. Hierarchical role for transcription factors and chromatin structure in genome organization along adipogenesis

    DEFF Research Database (Denmark)

    Sarusi Portuguez, Avital; Schwartz, Michal; Siersbaek, Rasmus

    2017-01-01

    The three dimensional folding of mammalian genomes is cell type specific and difficult to alter suggesting that it is an important component of gene regulation. However, given the multitude of chromatin-associating factors, the mechanisms driving the colocalization of active chromosomal domains...... by PPARγ and Lpin1, undergoes orchestrated reorganization during adipogenesis. Coupling the dynamics of genome architecture with multiple chromatin datasets indicated that among all the transcription factors (TFs) tested, RXR is central to genome reorganization at the beginning of adipogenesis...

  5. A new dermocosmetic containing retinaldehyde, delta-tocopherol glucoside and glycylglycine oleamide for managing naturally aged skin: results from in vitro to clinical studies.

    Science.gov (United States)

    Rouvrais, Céline; Bacqueville, Daniel; Bogdanowicz, Patrick; Haure, Marie-José; Duprat, Laure; Coutanceau, Christine; Castex-Rizzi, Nathalie; Duplan, Hélène; Mengeaud, Valérie; Bessou-Touya, Sandrine

    2017-01-01

    Natural aging of skin tissues, the addition of the cumulative action of the time and radiation exposure result in skin atrophy, wrinkles and degeneration of the extracellular matrix (ECM). The aim of the study was to investigate the beneficial effect of a combination containing retinaldehyde (RAL), delta-tocopherol glucoside (delta-TC) and glycylglycine ole-amide (GGO) and of a dermocosmetic containing the combination. The protective effect of the combination was assessed through in vitro gene expression of ultraviolet (UV)-irradiated fibroblasts. A skin aging assay using UV light on ex vivo skin samples and a clinical study conducted in 36 women aged from 35 to 55 years with a minimum of level 4 to a maximum of level 6 on the crow's feet photoscale assessed the antiaging effect of the dermocosmetic. When added to UV-irradiated fibroblasts, the combination substantially improved the ECM in activating the elastin fiber production ( fibrillin 2 , fibulin 1 and 5 and lysyl oxidase-like 2 ) as well as that of proteins involved in the cellular ECM interactions ( integrin b1 , paxillin and actin a2 ). An ex vivo photodamaged human skin model showed that the dermocosmetic formulation containing the combination of the active ingredients protected the elastic network against UV-induced alterations including both elastin and fibrillin-rich fibers in the dermis. A daily application of the dermocosmetic for 2 months on naturally aged skin resulted in a statistically significant improvement ( p care of naturally aged skin in women aged 35-55 years.

  6. Contact with existing adipose tissue is inductive for adipogenesis in matrigel.

    LENUS (Irish Health Repository)

    Kelly, John L

    2006-07-01

    The effect of adipose tissue on inductive adipogenesis within Matrigel (BD Biosciences) was assessed by using a murine chamber model containing a vascular pedicle. Three-chamber configurations that varied in the access to an adipose tissue source were used, including sealed- and open-chamber groups that had no access and limited access, respectively, to the surrounding adipose tissue, and a sealed-chamber group in which adipose tissue was placed as an autograft. All groups showed neovascularization, but varied in the amount of adipogenesis seen in direct relation to their access to preexisting adipose tissue: open chambers showed strong adipogenesis, whereas the sealed chambers had little or no adipose tissue; adipogenesis was restored in the autograft chamber group that contained 2- to 5-mg fat autografts. These showed significantly more adipogenesis than the sealed chambers with no autograft ( p < 0.01). Autografts with 1mg of fat were capable of producing adipogenesis but did so less consistently than the larger autografts. These findings have important implications for adipose tissue engineering strategies and for understanding de novo production of adipose tissue.

  7. Antibiotics detected in urines and adipogenesis in school children.

    Science.gov (United States)

    Wang, Hexing; Wang, Na; Wang, Bin; Fang, Hong; Fu, Chaowei; Tang, Chuanxi; Jiang, Feng; Zhou, Ying; He, Gengsheng; Zhao, Qi; Chen, Yue; Jiang, Qingwu

    2016-01-01

    Although antibiotic use during early life has been demonstrated to be related to the altered adipogenesis in later life, limited data are available for the effect of antibiotic exposure in school children on adiposity from various sources, including from the use or contaminated food or drinking water. To explore the association between the internal exposure of antibiotics from various sources and adipogenesis in school children using the biomonitoring of urinary antibiotics. After 586 school children aged 8-11years were selected from Shanghai in 2013, total urinary concentrations (free and conjugated) of 21 common antibiotics from six categories (macrolides, β-lactams, tetracyclines, fluoroquinolones, sulfonamides, and phenicols), including five human antibiotics (HAs), two antibiotics preferred as HA, four veterinary antibiotics (VAs), and ten antibiotics preferred as VA, were measured by ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. Creatinine-corrected urinary concentrations of antibiotics were used to assess their exposure. Overweight or obesity was determined by the body mass index or waist circumference-based criteria deriving from national data. All 21 antibiotics were found in urines with the overall detection frequency of 79.6%. The multinomial logistic regression analyses showed the significant associations of overweight and obesity with the exposure to VAs and antibiotics preferred as VA, but not with HAs or antibiotics preferred as HA. After adjusted for a number of obesity-relevant variables, the odds ratios (95% confidence interval) of BMI-based obesity risk of tertiles 2 and 3 of urinary concentrations relative to tertile 1 were respectively 2.54 (1.27, 5.07) and 2.92 (1.45, 5.87) for florfenicol, 0.57 (0.12, 2.63) and 3.63 (1.41, 9.32) for trimethoprim, and 3.00 (1.56, 5.76) and 1.99 (0.99, 4.01) for sum of veterinary antibiotics. Similar results were found when the outcome used WC-based obesity

  8. Secoisolariciresinol diglucoside inhibits adipogenesis through the AMPK pathway.

    Science.gov (United States)

    Kang, JongWook; Park, Jinbong; Kim, Hye-Lin; Jung, Yunu; Youn, Dong-Hyun; Lim, Seona; Song, Gahee; Park, Hyewon; Jin, Jong Sik; Kwak, Hyun Jeong; Um, Jae-Young

    2018-02-05

    Flaxseeds are used to treat metabolic diseases such as type 2 diabetes, fatty liver, hyperlipidemia and obesity. Secoisolariciresinol diglucoside (SDG) is a main substance of lignan which belongs to the phytoestrogen family and exists abundantly in flaxseeds. In this study, SDG reduced the body weight and size of adipose tissue, and decreased protein expressions of peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT-enhancer-binding protein α (C/EBPα) in the high fat diet-fed-induced obese mice model. In the vitro study, we examined the anti-adipogenic effect of SDG during differentiation of 3T3-L1 cells into adipocytes. 3T3-L1 preadipocytes were differentiated and treated with various concentrations of SDG. Oil Red O staining was done to measure the quantity of lipid contents. As a result, SDG reduced lipid accumulation and decreased the expressions of adipogenic-related genes such as adipocyte fatty-acid-binding protein 2, adiponectin, and resistin. SDG also decreased the mRNA and protein levels of PPARγ and C/EBPα. Furthermore, phosphorylation levels of AMP-activated protein kinase α (AMPK α) and its upstream activator, liver kinase B1, were significantly increased by SDG in 3T3-L1 cells. These results suggest that SDG inhibits adipogenesis by activating AMPKα, suggesting it could be an attractive therapeutic candidate for the treatment of obesity. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. IS FINANCIAL REPRESSION REALLY BAD?

    Directory of Open Access Journals (Sweden)

    Eun Young OH

    2011-01-01

    Full Text Available This paper examines the relationship between reserve requirements, interest rate taxes, and long-term growth. I present a model which shows that the government might repress the financial sector as this is the easy way of channelling resources to productive sectors. In this endogenous model, I employ the government input in the firm production function. The implications of the model are confirmed in that, an increase in reserve requirements and interest rate controls have two different reverse effects on growth - one is the negative effect on the financial sector. The other is a growth enhancing effect from the effective public spending on the real sectors.

  10. Molecular Regulation of Adipogenesis and Potential Anti-Adipogenic Bioactive Molecules

    Directory of Open Access Journals (Sweden)

    Dorothy Moseti

    2016-01-01

    Full Text Available Adipogenesis is the process by which precursor stem cells differentiate into lipid laden adipocytes. Adipogenesis is regulated by a complex and highly orchestrated gene expression program. In mammalian cells, the peroxisome proliferator-activated receptor γ (PPARγ, and the CCAAT/enhancer binding proteins (C/EBPs such as C/EBPα, β and δ are considered the key early regulators of adipogenesis, while fatty acid binding protein 4 (FABP4, adiponectin, and fatty acid synthase (FAS are responsible for the formation of mature adipocytes. Excess accumulation of lipids in the adipose tissue leads to obesity, which is associated with cardiovascular diseases, type II diabetes and other pathologies. Thus, investigating adipose tissue development and the underlying molecular mechanisms is vital to develop therapeutic agents capable of curbing the increasing incidence of obesity and related pathologies. In this review, we address the process of adipogenic differentiation, key transcription factors and proteins involved, adipogenic regulators and potential anti-adipogenic bioactive molecules.

  11. Isoniazid suppresses antioxidant response element activities and impairs adipogenesis in mouse and human preadipocytes

    International Nuclear Information System (INIS)

    Chen, Yanyan; Xue, Peng; Hou, Yongyong; Zhang, Hao; Zheng, Hongzhi; Zhou, Tong; Qu, Weidong; Teng, Weiping; Zhang, Qiang; Andersen, Melvin E.; Pi, Jingbo

    2013-01-01

    Transcriptional signaling through the antioxidant response element (ARE), orchestrated by the Nuclear factor E2-related factor 2 (Nrf2), is a major cellular defense mechanism against oxidative or electrophilic stress. Here, we reported that isoniazid (INH), a widely used antitubercular drug, displays a substantial inhibitory property against ARE activities in diverse mouse and human cells. In 3T3-L1 preadipocytes, INH concentration-dependently suppressed the ARE-luciferase reporter activity and mRNA expression of various ARE-dependent antioxidant genes under basal and oxidative stressed conditions. In keeping with our previous findings that Nrf2-ARE plays a critical role in adipogenesis by regulating expression of CCAAT/enhancer-binding protein β (C/EBPβ) and peroxisome proliferator-activated receptor γ (PPARγ), suppression of ARE signaling by INH hampered adipogenic differentiation of 3T3-L1 cells and human adipose-derived stem cells (ADSCs). Following adipogenesis induced by hormonal cocktails, INH-treated 3T3-L1 cells and ADSCs displayed significantly reduced levels of lipid accumulation and attenuated expression of C/EBPα and PPARγ. Time-course studies in 3T3-L1 cells revealed that inhibition of adipogenesis by INH occurred in the early stage of terminal adipogenic differentiation, where reduced expression of C/EBPβ and C/EBPδ was observed. To our knowledge, the present study is the first to demonstrate that INH suppresses ARE signaling and interrupts with the transcriptional network of adipogenesis, leading to impaired adipogenic differentiation. The inhibition of ARE signaling may be a potential underlying mechanism by which INH attenuates cellular antioxidant response contributing to various complications. - Highlights: • Isoniazid suppresses ARE-mediated transcriptional activity. • Isoniazid inhibits adipogenesis in preadipocytes. • Isoniazid suppresses adipogenic gene expression during adipogenesis

  12. EDF-1 downregulates the CaM/Cn/NFAT signaling pathway during adipogenesis

    International Nuclear Information System (INIS)

    López-Victorio, Carlos J.; Velez-delValle, Cristina; Beltrán-Langarica, Alicia; Kuri-Harcuch, Walid

    2013-01-01

    Highlights: ► EDF-1 participates early adipogenesis in 3T3F442A cells induced with Staurosporine/Dexamethasone. ► EDF-1 associates with CaM and Cn, most likely inactivating Cn. ► EDF-1/CaM complex seems to prevent NFATc1 activation by Cn. ► EDF-1 regulates the Cn/CaM/NFATc1 pathway during adipogenesis. ► EDF-1 may regulate the activation of Cn through a complex formation with CaM. - Abstract: The endothelial differentiation factor-1 (EDF-1) is a calmodulin binding protein that regulates calmodulin-dependent enzymes. In endothelial cells, this factor can form a protein complex with calmodulin. We analyzed the relationship between this factor and the members of calmodulin/calcineurin/nuclear factor of activated T-cells (NFAT) signaling pathway during adipogenesis of 3T3-F442A cells. We found that the expression of edf1 is upregulated during early adipogenesis, whereas that of calcineurin gene is lowered, suggesting that this pathway should be downregulated to allow for adipogenesis to occur. We also found that EDF-1 associates with calmodulin and calcineurin, most likely inactivating calcineurin. Our results showed that EDF-1 inactivates the calmodulin/calcineurin/NFAT pathway via sequestration of calmodulin, during early adipogenesis, and we propose a mechanism that negatively regulates the activation of calcineurin through a complex formation between EDF-1 and calmodulin. This finding raises the possibility that modulating this pathway might offer some alternatives to regulate adipose biology

  13. Epoxygenase inactivation exacerbates diet and aging-associated metabolic dysfunction resulting from impaired adipogenesis

    Directory of Open Access Journals (Sweden)

    Antoni Olona

    2018-05-01

    Full Text Available Objective: When molecular drivers of healthy adipogenesis are perturbed, this can cause hepatic steatosis. The role of arachidonic acid (AA and its downstream enzymatic cascades, such as cyclooxygenase, in adipogenesis is well established. The exact contribution of the P450 epoxygenase pathway, however, remains to be established. Enzymes belonging to this pathway are mainly encoded by the CYP2J locus which shows extensive allelic expansion in mice. Here we aimed to establish the role of endogenous epoxygenase during adipogenesis under homeostatic and metabolic stress conditions. Methods: We took advantage of the simpler genetic architecture of the Cyp2j locus in the rat and used a Cyp2j4 (orthologue of human CYP2J2 knockout rat in two models of metabolic dysfunction: physiological aging and cafeteria diet (CAF. The phenotyping of Cyp2j4−/− rats under CAF was integrated with proteomics (LC-MS/MS and lipidomics (LC-MS analyses in the liver and the adipose tissue. Results: We report that Cyp2j4 deletion causes adipocyte dysfunction under metabolic challenges. This is characterized by (i down-regulation of white adipose tissue (WAT PPARγ and C/EBPα, (ii adipocyte hypertrophy, (iii extracellular matrix remodeling, and (iv alternative usage of AA pathway. Specifically, in Cyp2j4−/− rats treated with a cafeteria diet, the dysfunctional adipogenesis is accompanied by exacerbated weight gain, hepatic lipid accumulation, and dysregulated gluconeogenesis. Conclusion: These results suggest that AA epoxygenases are essential regulators of healthy adipogenesis. Our results uncover their synergistic role in fine-tuning AA pathway in obesity-mediated hepatic steatosis. Keywords: Adipogenesis, Cytochrome P450 2j4, Cafeteria diet, Aging, Steatosis, Arachidonic acid

  14. EDF-1 downregulates the CaM/Cn/NFAT signaling pathway during adipogenesis

    Energy Technology Data Exchange (ETDEWEB)

    López-Victorio, Carlos J.; Velez-delValle, Cristina; Beltrán-Langarica, Alicia [Department of Cell Biology, Center for Research and Advanced Studies-IPN, Apdo. Postal 14-740, México City 07000 (Mexico); Kuri-Harcuch, Walid, E-mail: walidkuri@gmail.com [Department of Cell Biology, Center for Research and Advanced Studies-IPN, Apdo. Postal 14-740, México City 07000 (Mexico)

    2013-03-01

    Highlights: ► EDF-1 participates early adipogenesis in 3T3F442A cells induced with Staurosporine/Dexamethasone. ► EDF-1 associates with CaM and Cn, most likely inactivating Cn. ► EDF-1/CaM complex seems to prevent NFATc1 activation by Cn. ► EDF-1 regulates the Cn/CaM/NFATc1 pathway during adipogenesis. ► EDF-1 may regulate the activation of Cn through a complex formation with CaM. - Abstract: The endothelial differentiation factor-1 (EDF-1) is a calmodulin binding protein that regulates calmodulin-dependent enzymes. In endothelial cells, this factor can form a protein complex with calmodulin. We analyzed the relationship between this factor and the members of calmodulin/calcineurin/nuclear factor of activated T-cells (NFAT) signaling pathway during adipogenesis of 3T3-F442A cells. We found that the expression of edf1 is upregulated during early adipogenesis, whereas that of calcineurin gene is lowered, suggesting that this pathway should be downregulated to allow for adipogenesis to occur. We also found that EDF-1 associates with calmodulin and calcineurin, most likely inactivating calcineurin. Our results showed that EDF-1 inactivates the calmodulin/calcineurin/NFAT pathway via sequestration of calmodulin, during early adipogenesis, and we propose a mechanism that negatively regulates the activation of calcineurin through a complex formation between EDF-1 and calmodulin. This finding raises the possibility that modulating this pathway might offer some alternatives to regulate adipose biology.

  15. Promotion of adipogenesis by an EP2 receptor agonist via stimulation of angiogenesis in pulmonary emphysema.

    Science.gov (United States)

    Tsuji, Takao; Yamaguchi, Kazuhiro; Kikuchi, Ryota; Itoh, Masayuki; Nakamura, Hiroyuki; Nagai, Atsushi; Aoshiba, Kazutetsu

    2014-08-01

    Body weight loss is a common manifestation in patients with chronic obstructive pulmonary disease (COPD), particularly those with severe emphysema. Adipose angiogenesis is a key mediator of adipogenesis and use of pro-angiogenic agents may serve as a therapeutic option for lean COPD patients. Since angiogenesis is stimulated by PGE2, we examined whether ONO-AE1-259, a selective E-prostanoid (EP) 2 receptor agonist, might promote adipose angiogenesis and adipogenesis in a murine model of elastase-induced pulmonary emphysema (EIE mice). Mice were intratracheally instilled with elastase or saline, followed after 4 weeks by intraperitoneal administration of ONO-AE1-259 for 4 weeks. The subcutaneous adipose tissue (SAT) weight decreased in the EIE mice, whereas in the EIE mice treated with ONO-AE1-259, the SAT weight was largely restored, which was associated with significant increases in SAT adipogenesis, angiogenesis, and VEGF protein production. In contrast, ONO-AE1-259 administration induced no alteration in the weight of the visceral adipose tissue. These results suggest that in EIE mice, ONO-AE1-259 stimulated adipose angiogenesis possibly via VEGF production, and thence, adipogenesis. Our data pave the way for the development of therapeutic interventions for weight loss in emphysema patients, e.g., use of pro-angiogenic agents targeting the adipose tissue vascular component. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Functional characterization of cytochrome P450-derived epoxyeicosatrienoic acids in adipogenesis and obesity.

    Science.gov (United States)

    Zha, Weibin; Edin, Matthew L; Vendrov, Kimberly C; Schuck, Robert N; Lih, Fred B; Jat, Jawahar Lal; Bradbury, J Alyce; DeGraff, Laura M; Hua, Kunjie; Tomer, Kenneth B; Falck, John R; Zeldin, Darryl C; Lee, Craig R

    2014-10-01

    Adipogenesis plays a critical role in the initiation and progression of obesity. Although cytochrome P450 (CYP)-derived epoxyeicosatrienoic acids (EETs) have emerged as a potential therapeutic target for cardiometabolic disease, the functional contribution of EETs to adipogenesis and the pathogenesis of obesity remain poorly understood. Our studies demonstrated that induction of adipogenesis in differentiated 3T3-L1 cells (in vitro) and obesity-associated adipose expansion in high-fat diet (HFD)-fed mice (in vivo) significantly dysregulate the CYP epoxygenase pathway and evoke a marked suppression of adipose-derived EET levels. Subsequent in vitro experiments demonstrated that exogenous EET analog administration elicits potent anti-adipogenic effects via inhibition of the early phase of adipogenesis. Furthermore, EET analog administration to mice significantly mitigated HFD-induced weight gain, adipose tissue expansion, pro-adipogenic gene expression, and glucose intolerance. Collectively, these findings suggest that suppression of EET bioavailability in adipose tissue is a key pathological consequence of obesity, and strategies that promote the protective effects of EETs in adipose tissue offer enormous therapeutic potential for obesity and its downstream pathological consequences. Copyright © 2014 by the American Society for Biochemistry and Molecular Biology, Inc.

  17. Elevated adipogenesis of marrow mesenchymal stem cells during early steroid-associated osteonecrosis development

    Directory of Open Access Journals (Sweden)

    Lee Kwong

    2007-10-01

    Full Text Available Abstract Background Increased bone marrow lipid deposition in steroid-associated osteonecrosis (ON implies that abnormalities in fat metabolism play an important role in ON development. The increase in lipid deposition might be explained by elevated adipogenesis of marrow mesenchymal stem cells (MSCs. However, it remains unclear whether there is a close association between elevated adipogenesis and steroid-associated ON development. Objective The present study was designed to test the hypothesis that there might be a close association between elevated adipogenesis and steroid-associated ON development. Methods ON rabbit model was induced based on our established protocol. Dynamic-MRI was employed for local intra-osseous perfusion evaluation in bilateral femora. Two weeks after induction, bone marrow was harvested for evaluating the ability of adipogenic differentiation of marrow MSCs at both cellular and mRNA level involving adipogenesis-related gene peroxisome proliferator-activated receptor gamma2 (PPARγ2. The bilateral femora were dissected for examining marrow lipid deposition by quantifying fat cell number, fat cell size, lipid deposition area and ON lesions. For investigating association among adipogenesis, lipid deposition and perfusion function with regard to ON occurrence, the rabbits were divided into ON+ (with at least one ON lesion group and ON- (without ON lesion group. For investigating association among adipogenesis, lipid deposition and perfusion function with regard to ON extension, the ON+ rabbits were further divided into sub-single-lesion group (SON group: with one ON lesion and sub-multiple-lesion group (MON group: with more than one ON lesion. Results Local intra-osseous perfusion index was found lower in either ON+ or MON group when compared to either ON- or SON group, whereas the marrow fat cells number and area were much larger in either ON+ or MON group as compared with ON- and SON group. The adipogenic differentiation

  18. Seipin oligomers can interact directly with AGPAT2 and lipin 1, physically scaffolding critical regulators of adipogenesis

    Directory of Open Access Journals (Sweden)

    Md. Mesbah Uddin Talukder

    2015-03-01

    Conclusions: Our study provides the first direct molecular link between seipin and AGPAT2, two proteins whose disruption causes CGL. Moreover, it provides the first example of an interaction between seipin and another protein that causally influences a key aspect of adipogenesis. Together our data suggest that the critical role of seipin in adipogenesis may involve its capacity to juxtapose important regulators of this process in a multi-protein complex.

  19. Molecular mechanism of 9-cis-retinoic acid inhibition of adipogenesis in 3T3-L1 cells

    International Nuclear Information System (INIS)

    Sagara, Chiaki; Takahashi, Katsuhiko; Kagechika, Hiroyuki; Takahashi, Noriko

    2013-01-01

    Highlights: ► We examined the effects of 9-cis-RA on adipogenesis in mouse preadipocyte 3T3-L1. ► 9-cis-RA inhibited lipid accumulation in adipogenetically-induced 3T3-L1 cells. ► A RXR pan-antagonist suppressed the inhibitory effects of 9-cis-RA on adipogenesis. ► This antagonist had no effects on RXRα and PPARγ levels in 9-cis-RA-treated cells. ► 9-cis-RA-induced decrease in both RXRα and PPARγ was independent of RXR activation. -- Abstract: Retinoic acid (RA) signaling is mediated by specific nuclear hormone receptors. Here we examined the effects of 9-cis-RA on adipogenesis in mouse preadipocyte 3T3-L1 cells. 9-cis-RA inhibits the lipid accumulation of adipogenetically induced 3T3-L1 cells. The complex of retinoid X receptor α (RXRα) with peroxisome proliferator-activated receptor γ (PPARγ) is a major transcription factor in the process of adipogenesis, and the levels of these molecules were decreased by 9-cis-RA treatment. A RXR pan-antagonist suppressed 9-cis-RA’s inhibitory effects on adipogenesis, but not on the intracellular levels of both RXRα and PPARγ. These results suggest that 9-cis-RA could inhibit adipogenesis by activating RXR, and decrease both RXR and PPARγs levels in a RXR activation-independent manner

  20. Altered Adipogenesis in Zebrafish Larvae Following High Fat Diet and Chemical Exposure Is Visualised by Stimulated Raman Scattering Microscopy

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    Marjo J. den Broeder

    2017-04-01

    Full Text Available Early life stage exposure to environmental chemicals may play a role in obesity by altering adipogenesis; however, robust in vivo methods to quantify these effects are lacking. The goal of this study was to analyze the effects of developmental exposure to chemicals on adipogenesis in the zebrafish (Danio rerio. We used label-free Stimulated Raman Scattering (SRS microscopy for the first time to image zebrafish adipogenesis at 15 days post fertilization (dpf and compared standard feed conditions (StF to a high fat diet (HFD or high glucose diet (HGD. We also exposed zebrafish embryos to a non-toxic concentration of tributyltin (TBT, 1 nM or Tris(1,3-dichloroisopropylphosphate (TDCiPP, 0.5 µM from 0–6 dpf and reared larvae to 15 dpf under StF. Potential molecular mechanisms of altered adipogenesis were examined by qPCR. Diet-dependent modulation of adipogenesis was observed, with HFD resulting in a threefold increase in larvae with adipocytes, compared to StF and HGD. Developmental exposure to TBT but not TDCiPP significantly increased adipocyte differentiation. The expression of adipogenic genes such as pparda, lxr and lepa was altered in response to HFD or chemicals. This study shows that SRS microscopy can be successfully applied to zebrafish to visualize and quantify adipogenesis, and is a powerful approach for identifying obesogenic chemicals in vivo.

  1. Altered Adipogenesis in Zebrafish Larvae Following High Fat Diet and Chemical Exposure Is Visualised by Stimulated Raman Scattering Microscopy

    Science.gov (United States)

    den Broeder, Marjo J.; Moester, Miriam J. B.; Kamstra, Jorke H.; Cenijn, Peter H.; Davidoiu, Valentina; Kamminga, Leonie M.; Ariese, Freek; de Boer, Johannes F.; Legler, Juliette

    2017-01-01

    Early life stage exposure to environmental chemicals may play a role in obesity by altering adipogenesis; however, robust in vivo methods to quantify these effects are lacking. The goal of this study was to analyze the effects of developmental exposure to chemicals on adipogenesis in the zebrafish (Danio rerio). We used label-free Stimulated Raman Scattering (SRS) microscopy for the first time to image zebrafish adipogenesis at 15 days post fertilization (dpf) and compared standard feed conditions (StF) to a high fat diet (HFD) or high glucose diet (HGD). We also exposed zebrafish embryos to a non-toxic concentration of tributyltin (TBT, 1 nM) or Tris(1,3-dichloroisopropyl)phosphate (TDCiPP, 0.5 µM) from 0–6 dpf and reared larvae to 15 dpf under StF. Potential molecular mechanisms of altered adipogenesis were examined by qPCR. Diet-dependent modulation of adipogenesis was observed, with HFD resulting in a threefold increase in larvae with adipocytes, compared to StF and HGD. Developmental exposure to TBT but not TDCiPP significantly increased adipocyte differentiation. The expression of adipogenic genes such as pparda, lxr and lepa was altered in response to HFD or chemicals. This study shows that SRS microscopy can be successfully applied to zebrafish to visualize and quantify adipogenesis, and is a powerful approach for identifying obesogenic chemicals in vivo. PMID:28441764

  2. Cross talk between insulin and bone morphogenetic protein signaling systems in brown adipogenesis

    DEFF Research Database (Denmark)

    Zhang, Hongbin; Schulz, Tim J; Espinoza, Daniel O

    2010-01-01

    Both insulin and bone morphogenetic protein (BMP) signaling systems are important for adipocyte differentiation. Analysis of gene expression in BMP7-treated fibroblasts revealed a coordinated change in insulin signaling components by BMP7. To further investigate the cross talk between insulin...... BMP7's suppressive effect on pref-1 transcription. Together, these data suggest cross talk between the insulin and BMP signaling systems by which BMP7 can rescue brown adipogenesis in cells with insulin resistance....

  3. Dexras1 links glucocorticoids to insulin-like growth factor-1 signaling in adipogenesis

    Science.gov (United States)

    Kim, Hyo Jung; Cha, Jiyoung Y.; Seok, Jo Woon; Choi, Yoonjeong; Yoon, Bo Kyung; Choi, Hyeonjin; Yu, Jung Hwan; Song, Su Jin; Kim, Ara; Lee, Hyemin; Kim, Daeun; Han, Ji Yoon; Kim, Jae-woo

    2016-01-01

    Glucocorticoids are associated with obesity, but the underlying mechanism by which they function remains poorly understood. Previously, we showed that small G protein Dexras1 is expressed by glucocorticoids and leads to adipocyte differentiation. In this study, we explored the mechanism by which Dexras1 mediates adipogenesis and show a link to the insulin-like growth factor-1 (IGF-1) signaling pathway. Without Dexras1, the activation of MAPK and subsequent phosphorylation of CCAAT/enhancer binding protein β (C/EBPβ) is abolished, thereby inhibiting mitotic clonal expansion and further adipocyte differentiation. Dexras1 translocates to the plasma membrane upon insulin or IGF-1 treatment, for which the unique C-terminal domain (amino acids 223–276) is essential. Dexras1-dependent MAPK activation is selectively involved in the IGF-1 signaling, because another Ras protein, H-ras localized to the plasma membrane independently of insulin treatment. Moreover, neither epidermal growth factor nor other cell types shows Dexras1-dependent MAPK activation, indicating the importance of Dexras1 in IGF-1 signaling in adipogenesis. Dexras1 interacts with Shc and Raf, indicating that Dexras1-induced activation of MAPK is largely dependent on the Shc-Grb2-Raf complex. These results suggest that Dexras1 is a critical mediator of the IGF-1 signal to activate MAPK, linking glucocorticoid signaling to IGF-1 signaling in adipogenesis. PMID:27345868

  4. Ginkgolide C Suppresses Adipogenesis in 3T3-L1 Adipocytes via the AMPK Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Chian-Jiun Liou

    2015-01-01

    Full Text Available Ginkgolide C, isolated from Ginkgo biloba leaves, is a flavone reported to have multiple biological functions, from decreased platelet aggregation to ameliorating Alzheimer disease. The study aim was to evaluate the antiadipogenic effect of ginkgolide C in 3T3-L1 adipocytes. Ginkgolide C was used to treat differentiated 3T3-L1 cells. Cell supernatant was collected to assay glycerol release, and cells were lysed to measure protein and gene expression related to adipogenesis and lipolysis by western blot and real-time PCR, respectively. Ginkgolide C significantly suppressed lipid accumulation in differentiated adipocytes. It also decreased adipogenesis-related transcription factor expression, including peroxisome proliferator-activated receptor and CCAAT/enhancer-binding protein. Furthermore, ginkgolide C enhanced adipose triglyceride lipase and hormone-sensitive lipase production for lipolysis and increased phosphorylation of AMP-activated protein kinase (AMPK, resulting in decreased activity of acetyl-CoA carboxylase for fatty acid synthesis. In coculture with an AMPK inhibitor (compound C, ginkgolide C also improved activation of sirtuin 1 and phosphorylation of AMPK in differentiated 3T3-L1 cells. The results suggest that ginkgolide C is an effective flavone for increasing lipolysis and inhibiting adipogenesis in adipocytes through the activated AMPK pathway.

  5. A new synthetic matrix metalloproteinase inhibitor reduces human mesenchymal stem cell adipogenesis.

    Directory of Open Access Journals (Sweden)

    Dale B Bosco

    Full Text Available Development of adipose tissue requires the differentiation of less specialized cells, such as human mesenchymal stem cells (hMSCs, into adipocytes. Since matrix metalloproteinases (MMPs play critical roles in the cell differentiation process, we conducted investigations to determine if a novel mercaptosulfonamide-based MMP inhibitor (MMPI, YHJ-7-52, could affect hMSC adipogenic differentiation and lipid accumulation. Enzyme inhibition assays, adipogenic differentiation experiments, and quantitative PCR methods were employed to characterize this inhibitor and determine its effect upon adipogenesis. YHJ-7-52 reduced lipid accumulation in differentiated cells by comparable amounts as a potent hydroxamate MMPI, GM6001. However, YHJ-7-82, a non-inhibitory structural analog of YHJ-7-52, in which the zinc-binding thiol group is replaced by a hydroxyl group, had no effect on adipogenesis. The two MMPIs (YHJ-7-52 and GM6001 were also as effective in reducing lipid accumulation in differentiated cells as T0070907, an antagonist of peroxisome-proliferator activated receptor gamma (PPAR-gamma, at a similar concentration. PPAR-gamma is a typical adipogenic marker and a key regulatory protein for the transition of preadiopocyte to adipocyte. Moreover, MMP inhibition was able to suppress lipid accumulation in cells co-treated with Troglitazone, a PPAR-gamma agonist. Our results indicate that MMP inhibitors may be used as molecular tools for adipogenesis and obesity treatment research.

  6. The H3K27 demethylase, Utx, regulates adipogenesis in a differentiation stage-dependent manner.

    Directory of Open Access Journals (Sweden)

    Kazushige Ota

    Full Text Available Understanding the molecular mechanisms that drive adipogenesis is important in developing new treatments for obesity and diabetes. Epigenetic regulations determine the capacity of adipogenesis. In this study, we examined the role of a histone H3 lysine 27 demethylase, the ubiquitously transcribed tetratricopeptide repeat protein on the X chromosome (Utx, in the differentiation of mouse embryonic stem cells (mESCs to adipocytes. Using gene trapping, we examined Utx-deficient male mESCs to determine whether loss of Utx would enhance or inhibit the differentiation of mESCs to adipocytes. Utx-deficient mESCs showed diminished potential to differentiate to adipocytes compared to that of controls. In contrast, Utx-deficient preadipocytes showed enhanced differentiation to adipocytes. Microarray analyses indicated that the β-catenin/c-Myc signaling pathway was differentially regulated in Utx-deficient cells during adipocyte differentiation. Therefore, our data suggest that Utx governs adipogenesis by regulating c-Myc in a differentiation stage-specific manner and that targeting the Utx signaling pathway could be beneficial for the treatment of obesity, diabetes, and congenital utx-deficiency disorders.

  7. Cysteine dioxygenase type 1 promotes adipogenesis via interaction with peroxisome proliferator-activated receptor gamma

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Peng; Chen, Yi; Ji, Ning; Lin, Yunfeng; Yuan, Quan; Ye, Ling; Chen, Qianming, E-mail: qmchen@scu.edu.cn

    2015-02-27

    Mammalian cysteine dioxygenase type 1 (CDO1) is an essential enzyme for taurine biosynthesis and the biodegradation of toxic cysteine. As previously suggested, Cdo1 may be a marker of liposarcoma progression and adipogenic differentiation, but the role of Cdo1 in adipogenesis has yet been reported. In this study, we found that the expression of Cdo1 is dramatically elevated during adipogenic differentiation of 3T3-L1 pre-adipocytes and mouse bone marrow-derived mesenchymal stem cells (mBMSCs). Conversely, knockdown of Cdo1 inhibited expression of adipogenic specific genes and lipid droplet formation in 3T3-L1 cells and mBMSCs. Mechanistically, we found Cdo1 interacted with Pparγ in response to adipogenic stimulus. Further, depletion of Cdo1 reduced the recruitment of Pparγ to the promoters of C/EBPα and Fabp4. Collectively, our finding indicates that Cdo1 may be a co-activator of Pparγ in adipogenesis, and may contribute to the development of disease associated with excessive adipose tissue. - Highlights: • Cdo1expression is highly up-regulated during adipogenic differentiation of 3T3-L1 and mBMSCs. • Depletion of Cdo1 inhibited expression of adipogenic specific genes and lipid droplet formation. • Cdo1interacts with Pparγ during adipogenesis. • Knockdown of Cdo1 inhibited Pparγ binding to the promoters of C/EBPα and Fabp4.

  8. Gene-chip studies of adipogenesis-regulated microRNAs in mouse primary adipocytes and human obesity

    Directory of Open Access Journals (Sweden)

    Gallagher Iain J

    2011-03-01

    Full Text Available Abstract Background Adipose tissue abundance relies partly on the factors that regulate adipogenesis, i.e. proliferation and differentiation of adipocytes. While components of the transcriptional program that initiates adipogenesis is well-known, the importance of microRNAs in adipogenesis is less well studied. We thus set out to investigate whether miRNAs would be actively modulated during adipogenesis and obesity. Methods Several models exist to study adipogenesis in vitro, of which the cell line 3T3-L1 is the most well known, albeit not the most physiologically appropriate. Thus, as an alternative, we produced EXIQON microarray of brown and white primary murine adipocytes (prior to and following differentiation to yield global profiles of miRNAs. Results We found 65 miRNAs regulated during in vitro adipogenesis in primary adipocytes. We evaluated the similarity of our responses to those found in non-primary cell models, through literature data-mining. When comparing primary adipocyte profiles, with those of cell lines reported in the literature, we found a high degree of difference in 'adipogenesis' regulated miRNAs suggesting that the model systems may not be accurately representing adipogenesis. The expression of 10 adipogenesis-regulated miRNAs were studied using real-time qPCR and then we selected 5 miRNAs, that showed robust expression, were profiled in subcutaneous adipose tissue obtained from 20 humans with a range of body mass indices (BMI, range = 21-48, and all samples have U133+2 Affymetrix profiles provided. Of the miRNAs tested, mir-21 was robustly expressed in human adipose tissue and positively correlated with BMI (R2 = 0.49, p Conclusion In conclusion, we provide a preliminary analysis of miRNAs associated with primary cell in vitro adipogenesis and demonstrate that the inflammation-associated miRNA, mir-21 is up-regulated in subcutaneous adipose tissue in human obesity. Further, we provide a novel transcriptomics database of

  9. Vanadate impedes adipogenesis in mesenchymal stem cells derived from different depots within bone.

    Directory of Open Access Journals (Sweden)

    Frans Alexander Jacobs

    2016-08-01

    Full Text Available Glucocorticoid induced osteoporosis (GIO is associated with an increase in bone marrow adiposity which skews the differentiation of mesenchymal stem cell (MSC progenitors away from osteoblastogenesis and towards adipogenesis. We have previously found that vanadate, a non-specific protein tyrosine phosphatase inhibitor, prevents GIO in rats, but it was unclear whether vanadate directly influenced adipogenesis in bone-derived MSCs. For the present study, we investigated the effect of vanadate on adipogenesis in primary rat MSCs derived from bone marrow (bmMSCs and from the proximal end of the femur (pfMSCs. By passage 3 after isolation, both cell populations expressed the MSC cell surface markers CD90 and CD106, but not the haematopoietic marker CD45. However, although variable, expression of the fibroblast marker CD26 was higher in pfMSCs than in bmMSCs. Differentiation studies using osteogenic and adipogenic induction media (OM and AM, respectively demonstrated that pfMSCs rapidly accumulated lipid droplets within 1 week of exposure to AM, while bmMSCs isolated from the same femur only formed lipid droplets after 3 weeks of AM treatment. Conversely, pfMSCs exposed to OM produced mineralized extracellular matrix (ECM after 3 weeks, compared to 1 week for OM-treated bmMSCs. Vanadate (10 µM added to AM resulted in a significant reduction in AM-induced intracellular lipid accumulation and expression of adipogenic gene markers (PPARγ2, aP2, adipsin in both pfMSCs and bmMSCs. Pharmacological concentrations of glucocorticoids (1 µM alone did not induce lipid accumulation in either bmMSCs or pfMSCs, but resulted in significant cell death in pfMSCs. Our findings demonstrate the existence of at least two fundamentally different MSC depots within the femur, and highlights the presence of MSCs capable of rapid adipogenesis within the proximal femur, an area prone to osteoporotic fractures. In addition, our results suggest that the increased bone marrow

  10. Identification of new genes involved in human adipogenesis and fat storage.

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    Jörn Söhle

    Full Text Available Since the worldwide increase in obesity represents a growing challenge for health care systems, new approaches are needed to effectively treat obesity and its associated diseases. One prerequisite for advances in this field is the identification of genes involved in adipogenesis and/or lipid storage. To provide a systematic analysis of genes that regulate adipose tissue biology and to establish a target-oriented compound screening, we performed a high throughput siRNA screen with primary (preadipocytes, using a druggable siRNA library targeting 7,784 human genes. The primary screen showed that 459 genes affected adipogenesis and/or lipid accumulation after knock-down. Out of these hits, 333 could be validated in a secondary screen using independent siRNAs and 110 genes were further regulated on the gene expression level during adipogenesis. Assuming that these genes are involved in neutral lipid storage and/or adipocyte differentiation, we performed InCell-Western analysis for the most striking hits to distinguish between the two phenotypes. Beside well known regulators of adipogenesis and neutral lipid storage (i.e. PPARγ, RXR, Perilipin A the screening revealed a large number of genes which have not been previously described in the context of fatty tissue biology such as axonemal dyneins. Five out of ten axonemal dyneins were identified in our screen and quantitative RT-PCR-analysis revealed that these genes are expressed in preadipocytes and/or maturing adipocytes. Finally, to show that the genes identified in our screen are per se druggable we performed a proof of principle experiment using an antagonist for HTR2B. The results showed a very similar phenotype compared to knock-down experiments proofing the "druggability". Thus, we identified new adipogenesis-associated genes and those involved in neutral lipid storage. Moreover, by using a druggable siRNA library the screen data provides a very attractive starting point to identify anti

  11. Mitosis-associated repression in development.

    Science.gov (United States)

    Esposito, Emilia; Lim, Bomyi; Guessous, Ghita; Falahati, Hanieh; Levine, Michael

    2016-07-01

    Transcriptional repression is a pervasive feature of animal development. Here, we employ live-imaging methods to visualize the Snail repressor, which establishes the boundary between the presumptive mesoderm and neurogenic ectoderm of early Drosophila embryos. Snail target enhancers were attached to an MS2 reporter gene, permitting detection of nascent transcripts in living embryos. The transgenes exhibit initially broad patterns of transcription but are refined by repression in the mesoderm following mitosis. These observations reveal a correlation between mitotic silencing and Snail repression. We propose that mitosis and other inherent discontinuities in transcription boost the activities of sequence-specific repressors, such as Snail. © 2016 Esposito et al.; Published by Cold Spring Harbor Laboratory Press.

  12. Literature, Advertising and Return of the Repressed

    Directory of Open Access Journals (Sweden)

    Francesco Ghelli

    2013-06-01

    Full Text Available Since I have faced with the hypothesis elaborated by Francesco Orlando, according to which literature is a form of return of the repressed, I wondered what – in our era of deregulation, end of censorship and taboos – could occupy the place of the repressed. One of the most influential sociologists, Zygmunt Bauman, has outlined the epochal passage from “the uneasiness in civilization” to today's “uneasiness of freedom”. The problem of desire today would not be a clash with a limit, but an indefinite freedom that is likely to turn into lost, loss of intensity and meaning.

  13. Kojyl cinnamate ester derivatives promote adiponectin production during adipogenesis in human adipose tissue-derived mesenchymal stem cells.

    Science.gov (United States)

    Rho, Ho Sik; Hong, Soo Hyun; Park, Jongho; Jung, Hyo-Il; Park, Young-Ho; Lee, John Hwan; Shin, Song Seok; Noh, Minsoo

    2014-05-01

    The subcutaneous fat tissue mass gradually decreases with age, and its regulation is a strategy to develop anti-aging compounds to ameliorate the photo-aging of human skin. The adipogenesis of human adipose tissue-mesenchymal stem cells (hAT-MSCs) can be used as a model to discover novel anti-aging compounds. Cinnamomum cassia methanol extracts were identified as adipogenesis-promoting agents by natural product library screening. Cinnamates, the major chemical components of Cinnamomum cassia extracts, promoted adipogenesis in hAT-MSCs. We synthesized kojyl cinnamate ester derivatives to improve the pharmacological activity of cinnamates. Structure-activity studies of kojyl cinnamate derivatives showed that both the α,β-unsaturated carbonyl ester group and the kojic acid moiety play core roles in promoting adiponectin production during adipogenesis in hAT-MSCs. We conclude that kojyl cinnamate ester derivatives provide novel pharmacophores that can regulate adipogenesis in hAT-MSCs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Political Repression in U.S. History

    NARCIS (Netherlands)

    van Minnen, C.A.

    2009-01-01

    The authors of the essays in this book amass considerable historical evidence illustrating various forms of political repression and its relationship with democracy in the United States, from the late-eighteenth century to the present. They discuss efforts, made mostly but not only by government

  15. Nitrogen Catabolite Repression in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Hofman-Bang, H Jacob Peider

    1999-01-01

    In Saccharomyces cerevisiae the expression of all known nitrogen catabolite pathways are regulated by four regulators known as Gln3, Gat1, Da180, and Deh1. This is known as nitrogen catabolite repression (NCR). They bind to motifs in the promoter region to the consensus sequence S' GATAA 3'. Gln3...

  16. Catabolite repression of enzyme synthesis does not prevent sporulation.

    OpenAIRE

    Lopez, J M; Uratani-Wong, B; Freese, E

    1980-01-01

    In the presence of excess glucose, a decrease of guanine nucleotides in Bacillus subtilis initiated sporulation but did not prevent catabolite repression of three enzymes. Therefore, the ultimate mechanism(s) repressing enzyme synthesis differs from that suppressing sporulation.

  17. Curcumin inhibits adipogenesis induced by benzyl butyl phthalate in 3T3-L1 cells.

    Science.gov (United States)

    Sakuma, Satoru; Sumida, Maki; Endoh, Yukiko; Kurita, Ayaka; Yamaguchi, Ayana; Watanabe, Tomoki; Kohda, Tetsuya; Tsukiyama, Yui; Fujimoto, Yohko

    2017-08-15

    Phthalates are a group of endocrine disrupting chemicals and may have contributed to the recent global obesity health crisis. Increased adipogenesis via the peroxisome proliferator-activated receptor γ (PPARγ)-CCAAT-enhancer binding protein α (C/EBPα) pathway could be one critical mechanism responsible for phthalate-induced weight gain. On the other hand, curcumin has been shown to inhibit adipogenesis in cells and animal models. The present study was undertaken to evaluate, for the first time, whether curcumin could reduce adipogenesis induced by benzyl butyl phthalate (BBP) via downregulation of the PPARγ-C/EBPα pathway. 3T3-L1 preadipocytes were differentiated by treating them with insulin, dexamethasone, and 3-isobutyl-1-methylxanthine in the presence of BBP, with or without curcumin. Cells that were grown in the presence of BBP alone showed a significant increase in triacylglycerol (TG) levels. In addition, the number of Oil Red O-stained cells and the mRNA expression levels of PPARγ, C/EBPα, adiponectin, and tumor necrosis factor-α (TNFα) were significantly increased. However, treatment with BBP in combination with curcumin resulted in major reductions in TG levels, the numbers of Oil Red O-stained cells, and the mRNA expression levels of the four proteins. These results suggest that curcumin might be an inhibitor of BBP-induced weight gain and inflammation via stimulation of adipocyte differentiation and TNFα generation. Curcumin may, therefore, be a potential medication for preventing the harmful effects of phthalates. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. An in vitro approach for prioritization and evaluation of chemical effects on glucocorticoid receptor mediated adipogenesis.

    Science.gov (United States)

    Hartman, Jessica K; Beames, Tyler; Parks, Bethany; Doheny, Daniel; Song, Gina; Efremenko, Alina; Yoon, Miyoung; Foley, Briana; Deisenroth, Chad; McMullen, Patrick D; Clewell, Rebecca A

    2018-05-18

    Rising obesity rates worldwide have socio-economic ramifications. While genetics, diet, and lack of exercise are major contributors to obesity, environmental factors may enhance susceptibility through disruption of hormone homeostasis and metabolic processes. The obesogen hypothesis contends that chemical exposure early in development may enhance adipocyte differentiation, thereby increasing the number of adipocytes and predisposing for obesity and metabolic disease. We previously developed a primary human adipose stem cell (hASC) assay to evaluate the effect of environmental chemicals on PPARG-dependent adipogenesis. Here, the assay was modified to determine the effects of chemicals on the glucocorticoid receptor (GR) pathway. In differentiation cocktail lacking the glucocorticoid agonist dexamethasone (DEX), hASCs do not differentiate into adipocytes. In the presence of GR agonists, adipocyte maturation was observed using phenotypic makers for lipid accumulation, adipokine secretion, and expression of key genes. To evaluate the role of environmental compounds on adipocyte differentiation, progenitor cells were treated with 19 prioritized compounds previously identified by ToxPi as having GR-dependent bioactivity, and multiplexed assays were used to confirm a GR-dependent mode of action. Five chemicals were found to be strong agonists. The assay was also modified to evaluate GR-antagonists, and 8/10 of the hypothesized antagonists inhibited adipogenesis. The in vitro bioactivity data was put into context with extrapolated human steady state concentrations (Css) and clinical exposure data (Cmax). These data support using a human adipose-derived stem cell differentiation assay to test the potential of chemicals to alter human GR-dependent adipogenesis. Copyright © 2017. Published by Elsevier Inc.

  19. Interleukin-6 induces impairment in human subcutaneous adipogenesis in obesity-associated insulin resistance.

    Science.gov (United States)

    Almuraikhy, Shamma; Kafienah, Wael; Bashah, Moataz; Diboun, Ilhame; Jaganjac, Morana; Al-Khelaifi, Fatima; Abdesselem, Houari; Mazloum, Nayef A; Alsayrafi, Mohammed; Mohamed-Ali, Vidya; Elrayess, Mohamed A

    2016-11-01

    A subset of obese individuals remains insulin sensitive by mechanisms as yet unclear. The hypothesis that maintenance of normal subcutaneous (SC) adipogenesis accounts, at least partially, for this protective phenotype and whether it can be abrogated by chronic exposure to IL-6 was investigated. Adipose tissue biopsies were collected from insulin-sensitive (IS) and insulin-resistant (IR) individuals undergoing weight-reduction surgery. Adipocyte size, pre-adipocyte proportion of stromal vascular fraction (SVF)-derived cells, adipogenic capacity and gene expression profiles of isolated pre-adipocytes were determined, along with local in vitro IL-6 secretion. Adipogenic capacity was further assessed in response to exogenous IL-6 application. Despite being equally obese, IR individuals had significantly lower plasma leptin and adiponectin levels and higher IL-6 levels compared with age-matched IS counterparts. Elevated systemic IL-6 in IR individuals was associated with hyperplasia of adipose tissue-derived SVF cells, despite higher frequency of hypertrophied adipocytes. SC pre-adipocytes from these tissues exhibited lower adipogenic capacity accompanied by downregulation of PPARγ (also known as PPARG) and CEBPα (also known as CEBPA) and upregulation of GATA3 expression. Impaired adipogenesis in IR individuals was further associated with increased adipose secretion of IL-6. Treatment of IS-derived SC pre-adipocytes with IL-6 reduced their adipogenic capacity to levels of the IR group. Obesity-associated insulin resistance is marked by impaired SC adipogenesis, mediated, at least in a subset of individuals, by elevated local levels of IL-6. Understanding the molecular mechanisms underlying reduced adipogenic capacity in IR individuals could help target appropriate therapeutic strategies aimed at those at greatest risk of insulin resistance and type 2 diabetes mellitus.

  20. IGFBP4 Is Required for Adipogenesis and Influences the Distribution of Adipose Depots.

    Science.gov (United States)

    Maridas, David E; DeMambro, Victoria E; Le, Phuong T; Mohan, Subburaman; Rosen, Clifford J

    2017-10-01

    Insulinlike growth factor (IGF) I induces adipogenesis in vitro. IGF-binding protein 4 (IGFBP4) is highly expressed in adipocytes and osteoblasts and is inhibitory of IGFs in vitro. We previously reported that Igfbp4 null mice (Igfbp4-/-) had decreased fat proportions at 8 and 16 weeks of age. However, the mechanism leading to the reduced adiposity remains unknown. The purpose of this study was to elucidate how IGFBP4 mediates adipose tissue development in vivo. Our results showed that inguinal and gonadal white adipose tissue (gWAT) from Igfbp4-/- mice had decreased weights and Pparγ expression. Cultures of primary bone marrow stromal cells (BMSCs) and ear mesenchymal stem cells (eMSCs) from mutant mice showed reduced adipogenesis. Both BMSCs and eMSC had a strong induction of Igfbp4 expression during adipogenesis. Furthermore, the increase in phosphorylated Akt (p-Akt), a downstream target of IGF-I signaling, in wild-type cells, was blunted in mutant eMSCs. On a high-fat diet (HFD) there were sexual differences in adipocyte expansion of Igfbp4-/- mice. Mutant males gained weight by expanding their white fat depots. However, Igfbp4-/- female mice were protected against diet-induced obesity. Ovariectomized Igfbp4-/- female mice gained weight in a manner similar to that seen in ovariectomized controls. Thus, Igfbp4 is required for inguinal fat expansion in female mice but not in male mice. However, gWAT expansion, which is prevented by estrogen during HFD, does not require Igfbp4. Copyright © 2017 Endocrine Society.

  1. The skeletal cell-derived molecule sclerostin drives bone marrow adipogenesis.

    Science.gov (United States)

    Fairfield, Heather; Falank, Carolyne; Harris, Elizabeth; Demambro, Victoria; McDonald, Michelle; Pettitt, Jessica A; Mohanty, Sindhu T; Croucher, Peter; Kramer, Ina; Kneissel, Michaela; Rosen, Clifford J; Reagan, Michaela R

    2018-02-01

    The bone marrow niche is a dynamic and complex microenvironment that can both regulate, and be regulated by the bone matrix. Within the bone marrow (BM), mesenchymal stromal cell (MSC) precursors reside in a multi-potent state and retain the capacity to differentiate down osteoblastic, adipogenic, or chondrogenic lineages in response to numerous biochemical cues. These signals can be altered in various pathological states including, but not limited to, osteoporotic-induced fracture, systemic adiposity, and the presence of bone-homing cancers. Herein we provide evidence that signals from the bone matrix (osteocytes) determine marrow adiposity by regulating adipogenesis in the bone marrow. Specifically, we found that physiologically relevant levels of Sclerostin (SOST), which is a Wnt-inhibitory molecule secreted from bone matrix-embedded osteocytes, can induce adipogenesis in 3T3-L1 cells, mouse ear- and BM-derived MSCs, and human BM-derived MSCs. We demonstrate that the mechanism of SOST induction of adipogenesis is through inhibition of Wnt signaling in pre-adipocytes. We also demonstrate that a decrease of sclerostin in vivo, via both genetic and pharmaceutical methods, significantly decreases bone marrow adipose tissue (BMAT) formation. Overall, this work demonstrates a direct role for SOST in regulating fate determination of BM-adipocyte progenitors. This provides a novel mechanism for which BMAT is governed by the local bone microenvironment, which may prove relevant in the pathogenesis of certain diseases involving marrow adipose. Importantly, with anti-sclerostin therapy at the forefront of osteoporosis treatment and a greater recognition of the role of BMAT in disease, these data are likely to have important clinical implications. © 2017 Wiley Periodicals, Inc.

  2. Transcriptional profiling of human femoral mesenchymal stem cells in osteoporosis and its association with adipogenesis.

    Science.gov (United States)

    Choi, Yong Jun; Song, Insun; Jin, Yilan; Jin, Hyun-Seok; Ji, Hyung Min; Jeong, Seon-Yong; Won, Ye-Yeon; Chung, Yoon-Sok

    2017-10-20

    Genetic alterations are major contributing factors in the development of osteoporosis. Osteoblasts and adipocytes share a common origin, mesenchymal stem cells (MSCs), and their genetic determinants might be important in the relationship between osteoporosis and obesity. In the present study, we aimed to isolate differentially expressed genes (DEGs) in osteoporosis and normal controls using human MSCs, and elucidate the common pathways and genes related to osteoporosis and adipogenesis. Human MSCs were obtained from the bone marrow of femurs from postmenopausal women during orthopedic surgeries. RNA sequencing (RNA-seq) was carried out using next-generation sequencing (NGS) technology. DEGs were identified using RNA-seq data. Ingenuity pathway analysis (IPA) was used to elucidate the common pathway related to osteoporosis and adipogenesis. Candidate genes for the common pathway were validated with other independent osteoporosis and obese subjects using RT-PCR (reverse transcription-polymerase chain reaction) analysis. Fifty-three DEGs were identified between postmenopausal osteoporosis patients and normal bone mineral density (BMD) controls. Most of the genetic changes were related to the differentiation of cells. The nuclear receptor subfamily 4 group A (NR4A) family was identified as possible common genes related to osteogenesis and adipogenesis. The expression level of the mRNA of NR4A1 was significantly higher in osteoporosis patients than in controls (p=0.018). The expression level of the mRNA of NR4A2 was significantly higher in obese patients than in controls (p=0.041). Some genetic changes in MSCs are involved in the pathophysiology of osteoporosis. The NR4A family might comprise common genes related to osteoporosis and obesity. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Regulation of brown fat adipogenesis by protein tyrosine phosphatase 1B.

    Directory of Open Access Journals (Sweden)

    Kosuke Matsuo

    2011-01-01

    Full Text Available Protein-tyrosine phosphatase 1B (PTP1B is a physiological regulator of insulin signaling and energy balance, but its role in brown fat adipogenesis requires additional investigation.To precisely determine the role of PTP1B in adipogenesis, we established preadipocyte cell lines from wild type and PTP1B knockout (KO mice. In addition, we reconstituted KO cells with wild type, substrate-trapping (D/A and sumoylation-resistant (K/R PTP1B mutants, then characterized differentiation and signaling in these cells. KO, D/A- and WT-reconstituted cells fully differentiated into mature adipocytes with KO and D/A cells exhibiting a trend for enhanced differentiation. In contrast, K/R cells exhibited marked attenuation in differentiation and lipid accumulation compared with WT cells. Expression of adipogenic markers PPARγ, C/EBPα, C/EBPδ, and PGC1α mirrored the differentiation pattern. In addition, the differentiation deficit in K/R cells could be reversed completely by the PPARγ activator troglitazone. PTP1B deficiency enhanced insulin receptor (IR and insulin receptor substrate 1 (IRS1 tyrosyl phosphorylation, while K/R cells exhibited attenuated insulin-induced IR and IRS1 phosphorylation and glucose uptake compared with WT cells. In addition, substrate-trapping studies revealed that IRS1 is a substrate for PTP1B in brown adipocytes. Moreover, KO, D/A and K/R cells exhibited elevated AMPK and ACC phosphorylation compared with WT cells.These data indicate that PTP1B is a modulator of brown fat adipogenesis and suggest that adipocyte differentiation requires regulated expression of PTP1B.

  4. Enrichment of Adipose-Derived Stromal Cells for BMPR1A Facilitates Enhanced Adipogenesis.

    Science.gov (United States)

    Zielins, Elizabeth R; Paik, Kevin; Ransom, Ryan C; Brett, Elizabeth A; Blackshear, Charles P; Luan, Anna; Walmsley, Graham G; Atashroo, David A; Senarath-Yapa, Kshemendra; Momeni, Arash; Rennert, Robert; Sorkin, Michael; Seo, Eun Young; Chan, Charles K; Gurtner, Geoffrey C; Longaker, Michael T; Wan, Derrick C

    2016-02-01

    Reconstruction of soft tissue defects has traditionally relied on the use of grafts and flaps, which may be associated with variable resorption and/or significant donor site morbidity. Cell-based strategies employing adipose-derived stromal cells (ASCs), found within the stromal vascular fraction (SVF) of adipose tissue, may offer an alternative strategy for soft tissue reconstruction. In this study, we investigated the potential of a bone morphogenetic protein receptor type 1A (BMPR1A)(+) subpopulation of ASCs to enhance de novo adipogenesis. Human lipoaspirate was enzymatically digested to isolate SVF and magnetic-activated cell separation was utilized to obtain BMPR1A(+) and BMPR1A(-) cells. These cells, along with unenriched cells, were expanded in culture and evaluated for adipogenic gene expression and in vitro adipocyte formation. Cells from each group were also labeled with a green fluorescent protein (GFP) lentivirus and transplanted into the inguinal fat pads, an adipogenic niche, of immunocompromised mice to determine their potential for de novo adipogenesis. Confocal microscopy along with staining of lipid droplets and vasculature was performed to evaluate the formation of mature adipocytes by transplanted cells. In comparison to BMPR1A(-) and unenriched ASCs, BMPR1A(+) cells demonstrated significantly enhanced adipogenesis when cultured in an adipogenic differentiation medium, as evidenced by increased staining with Oil Red O and increased expression of peroxisome proliferator-activating receptor gamma (PPAR-γ) and fatty acid-binding protein 4 (FABP4). BMPR1A(+) cells also formed significantly more adipocytes in vivo, as demonstrated by quantification of GFP+ adipocytes. Minimal formation of mature adipocytes was appreciated by BMPR1A(-) cells. BMPR1A(+) ASCs show an enhanced ability for adipogenesis in vitro, as shown by gene expression and histological staining. Furthermore, within an adipogenic niche, BMPR1A(+) cells possessed an increased capacity

  5. MicroRNA Regulation of Brown Adipogenesis and Thermogenic Energy Expenditure

    DEFF Research Database (Denmark)

    Shamsi, Farnaz; Zhang, Hongbin; Tseng, Yu-Hua

    2017-01-01

    Obesity, diabetes, and associated metabolic diseases have become global epidemics. Obesity results from excess accumulation of white fat, while brown and its related beige fat function to dissipate energy as heat, thus counteracting obesity and its related metabolic disorders. Understanding...... attracted a great deal of research interests in exploring their roles in physiological and pathophysiological conditions. This review focuses on the recent advances of regulating brown adipogenesis and energy metabolism by miRNAs, aiming to delineate the regulatory principles of miRNAs on this unique aspect...... of energy homeostasis....

  6. Ursolic acid inhibits adipogenesis in 3T3-L1 adipocytes through LKB1/AMPK pathway.

    Directory of Open Access Journals (Sweden)

    Yonghan He

    Full Text Available BACKGROUND: Ursolic acid (UA is a triterpenoid compound with multiple biological functions. This compound has recently been reported to possess an anti-obesity effect; however, the mechanisms are less understood. OBJECTIVE: As adipogenesis plays a critical role in obesity, the present study was conducted to investigate the effect of UA on adipogenesis and mechanisms of action in 3T3-L1 preadipocytes. METHODS AND RESULTS: The 3T3-L1 preadipocytes were induced to differentiate in the presence or absence of UA for 6 days. The cells were determined for proliferation, differentiation, fat accumulation as well as the protein expressions of molecular targets that regulate or are involved in fatty acid synthesis and oxidation. The results demonstrated that ursolic acid at concentrations ranging from 2.5 µM to 10 µM dose-dependently attenuated adipogenesis, accompanied by reduced protein expression of CCAAT element binding protein β (C/EBPβ, peroxisome proliferator-activated receptor γ (PPARγ, CCAAT element binding protein α (C/EBPα and sterol regulatory element binding protein 1c (SREBP-1c, respectively. Ursolic acid increased the phosphorylation of acetyl-CoA carboxylase (ACC and protein expression of carnitine palmitoyltransferase 1 (CPT1, but decreased protein expression of fatty acid synthase (FAS and fatty acid-binding protein 4 (FABP4. Ursolic acid increased the phosphorylation of AMP-activated protein kinase (AMPK and protein expression of (silent mating type information regulation 2, homolog 1 (Sirt1. Further studies demonstrated that the anti-adipogenic effect of UA was reversed by the AMPK siRNA, but not by the Sirt1 inhibitor nicotinamide. Liver kinase B1 (LKB1, the upstream kinase of AMPK, was upregulated by UA. When LKB1 was silenced with siRNA or the inhibitor radicicol, the effect of UA on AMPK activation was diminished. CONCLUSIONS: Ursolic acid inhibited 3T3-L1 preadipocyte differentiation and adipogenesis through the LKB1/AMPK

  7. PFOS induces adipogenesis and glucose uptake in association with activation of Nrf2 signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jialin [Institute of Biochemistry and Molecular Biology, College of Life and Health Sciences, Northeastern University, Shenyang 110819 (China); Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881 (United States); Shimpi, Prajakta; Armstrong, Laura; Salter, Deanna [Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881 (United States); Slitt, Angela L., E-mail: aslitt@uri.edu [Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881 (United States)

    2016-01-01

    PFOS is a chemical of nearly ubiquitous exposure in humans. Recent studies have associated PFOS exposure to adipose tissue-related effects. The present study was to determine whether PFOS alters the process of adipogenesis and regulates insulin-stimulated glucose uptake in mouse and human preadipocytes. In murine-derived 3T3-L1 preadipocytes, PFOS enhanced hormone-induced differentiation to adipocytes and adipogenic gene expression, increased insulin-stimulated glucose uptake at concentrations ranging from 10 to 100 μM, and enhanced Glucose transporter type 4 and Insulin receptor substrate-1 expression. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2), NAD(P)H dehydrogenase, quinone 1 and Glutamate-cysteine ligase, catalytic subunit were significantly induced in 3T3-L1 cells treated with PFOS, along with a robust induction of Antioxidant Response Element (ARE) reporter in mouse embryonic fibroblasts isolated from ARE-hPAP transgenic mice by PFOS treatment. Chromatin immunoprecipitation assays further illustrated that PFOS increased Nrf2 binding to ARE sites in mouse Nqo1 promoter, suggesting that PFOS activated Nrf2 signaling in murine-derived preadipocytes. Additionally, PFOS administration in mice (100 μg/kg/day) induced adipogenic gene expression and activated Nrf2 signaling in epididymal white adipose tissue. Moreover, the treatment on human visceral preadipocytes illustrated that PFOS (5 and 50 μM) promoted adipogenesis and increased cellular lipid accumulation. It was observed that PFOS increased Nrf2 binding to ARE sites in association with Nrf2 signaling activation, induction of Peroxisome proliferator-activated receptor γ and CCAAT/enhancer-binding protein α expression, and increased adipogenesis. This study points to a potential role of PFOS in dysregulation of adipose tissue expandability, and warrants further investigations on the adverse effects of persistent pollutants on human health. - Highlights: • PFOS induces adipogenesis in association

  8. Plasticizers used in food-contact materials affect adipogenesis in 3T3-L1 cells.

    Science.gov (United States)

    Pomatto, Valentina; Cottone, Erika; Cocci, Paolo; Mozzicafreddo, Matteo; Mosconi, Gilberto; Nelson, Erik Russel; Palermo, Francesco Alessandro; Bovolin, Patrizia

    2018-04-01

    Recent studies suggest that exposure to some plasticizers, such as Bisphenol A (BPA), play a role in endocrine/metabolic dispruption and can affect lipid accumulation in adipocytes. Here, we investigated the adipogenic activity and nuclear receptor interactions of four plasticizers approved for the manufacturing of food-contact materials (FCMs) and currently considered safer alternatives. Differentiating 3T3-L1 mouse preadipocytes were exposed to scalar concentrations (0.01-25 μM) of DiNP (Di-iso-nonyl-phthalate), DiDP (Di-iso-decyl-phthalate), DEGDB (Diethylene glycol dibenzoate), or TMCP (Tri-m-cresyl phosphate). Rosiglitazone, a well-known pro-adipogenic peroxisome proliferator activated receptor gamma (PPARγ) agonist, and the plasticizer BPA were included as reference compounds. All concentrations of plasticizers were able to enhance lipid accumulation, with TMCP being the most effective one. Accordingly, when comparing in silico the ligand binding efficiencies to the nuclear receptors PPARγ and retinoid-X-receptor-alpha (RXRα), TMPC displayed the highest affinity to both receptors. Differently from BPA, the four plasticizers were most effective in enhancing lipid accumulation when added in the mid-late phase of differentiation, thus suggesting the involvement of different intracellular signalling pathways. In line with this, TMCP, DiDP, DiNP and DEGDB were able to activate PPARγ in transient transfection assays, while previous studies demonstrated that BPA acts mainly through other nuclear receptors. qRT-PCR studies showed that all plasticizers were able to increase the expression of CCAAT/enhancer binding protein β (Cebpβ) in the early steps of adipogenesis, and the adipogenesis master gene Pparγ2 in the middle phase, with very similar efficacy to that of Rosiglitazone. In addition, TMCP was able to modulate the expression of both Fatty Acid Binding Protein 4/Adipocyte Protein 2 (Fabp4/Ap2) and Lipoprotein Lipase (Lpl) transcripts in the late phase

  9. Synergistic Effects of a Mixture of Glycosaminoglycans to Inhibit Adipogenesis and Enhance Chondrocyte Features in Multipotent Cells

    Directory of Open Access Journals (Sweden)

    Petar D. Petrov

    2015-11-01

    Full Text Available Background/Aims: Multipotent mesenchymal stem cells affect homeostasis of adipose and joint tissues. Factors influencing their differentiation fate are of interest for both obesity and joint problems. We studied the impact of a mixture of glycosaminoglycans (GAGs (hyaluronic acid: dermatan sulfate 1:0.25, w/w used in an oral supplement for joint discomfort (Oralvisc™ on the differentiation fate of multipotent cells. Methods: Primary mouse embryo fibroblasts (MEFs were used as a model system. Post-confluent monolayer MEF cultures non-stimulated or hormonally stimulated to adipogenesis were chronically exposed to the GAGs mixture, its individual components or vehicle. The appearance of lipid laden cells, lipid accumulation and expression of selected genes at the mRNA and protein level was assessed. Results: Exposure to the GAGs mixture synergistically suppressed spontaneous adipogenesis and induced the expression of cartilage extracellular matrix proteins, aggrecan core protein, decorin and cartilage oligomeric matrix protein. Hormonally-induced adipogenesis in the presence of the GAGs mixture resulted in decreased adipogenic differentiation, down-regulation of adipogenic/lipogenic factors and genes for insulin resistance-related adipokines (resistin and retinol binding protein 4, and up-regulation of oxidative metabolism-related genes. Adipogenesis in the presence of dermatan sulfate, the minor component of the mixture, was not impaired but resulted in smaller lipid droplets and the induction of a more complete brown adipocyte-related transcriptional program in the cells in the adipose state. Conclusions: The Oralvisc™ GAGs mixture can tip the adipogenic/chondrogenic fate balance of multipotent cells away from adipogenesis while favoring chondrocyte related gene expression. The mixture and its dermatan sulfate component also have modulatory effects of interest on hormonally-induced adipogenesis and on metabolic and secretory capabilities of

  10. Combined metformin and insulin treatment reverses metabolically impaired omental adipogenesis and accumulation of 4-hydroxynonenal in obese diabetic patients

    Directory of Open Access Journals (Sweden)

    Morana Jaganjac

    2017-08-01

    Full Text Available Objective: Obesity-associated impaired fat accumulation in the visceral adipose tissue can lead to ectopic fat deposition and increased risk of insulin resistance and type 2 diabetes mellitus (T2DM. This study investigated whether impaired adipogenesis of omental (OM adipose tissues and elevated 4-hydroxynonenal (4-HNE accumulation contribute to this process, and if combined metformin and insulin treatment in T2DM patients could rescue this phenotype. Methods: OM adipose tissues were obtained from forty clinically well characterized obese individuals during weight reduction surgery. Levels of 4-HNE protein adducts, adipocyte size and number of macrophages were determined within these tissues by immunohistochemistry. Adipogenic capacity and gene expression profiles were assessed in preadipocytes derived from these tissues in relation to insulin resistance and in response to 4-HNE, metformin or combined metformin and insulin treatment. Results: Preadipocytes isolated from insulin resistant (IR and T2DM individuals exhibited lower adipogenesis, marked by upregulation of anti-adipogenic genes, compared to preadipocytes derived from insulin sensitive (IS individuals. Impaired adipogenesis was also associated with increased 4-HNE levels, smaller adipocytes and greater macrophage presence in the adipose tissues. Within the T2DM group, preadipocytes from combined metformin and insulin treated subset showed better in vitro adipogenesis compared to metformin alone, which was associated with less presence of macrophages and 4-HNE in the adipose tissues. Treatment of preadipocytes in vitro with 4-HNE reduced their adipogenesis and increased proliferation, even in the presence of metformin, which was partially rescued by the presence of insulin. Conclusion: This study reveals involvement of 4-HNE in the impaired OM adipogenesis-associated with insulin resistance and T2DM and provides a proof of concept that this impairment can be reversed by the synergistic

  11. RNAi and heterochromatin repress centromeric meiotic recombination

    DEFF Research Database (Denmark)

    Ellermeier, Chad; Higuchi, Emily C; Phadnis, Naina

    2010-01-01

    During meiosis, the formation of viable haploid gametes from diploid precursors requires that each homologous chromosome pair be properly segregated to produce an exact haploid set of chromosomes. Genetic recombination, which provides a physical connection between homologous chromosomes, is essen......During meiosis, the formation of viable haploid gametes from diploid precursors requires that each homologous chromosome pair be properly segregated to produce an exact haploid set of chromosomes. Genetic recombination, which provides a physical connection between homologous chromosomes....... Surprisingly, one mutant derepressed for recombination in the heterochromatic mating-type region during meiosis and several mutants derepressed for centromeric gene expression during mitotic growth are not derepressed for centromeric recombination during meiosis. These results reveal a complex relation between...... types of repression by heterochromatin. Our results also reveal a previously undemonstrated role for RNAi and heterochromatin in the repression of meiotic centromeric recombination and, potentially, in the prevention of birth defects by maintenance of proper chromosome segregation during meiosis....

  12. Cancer, acute stress disorder, and repressive coping

    DEFF Research Database (Denmark)

    Pedersen, Anette Fischer; Zachariae, Robert

    2010-01-01

    The purpose of this study was to investigate the association between repressive coping style and Acute Stress Disorder (ASD) in a sample of cancer patients. A total of 112 cancer patients recently diagnosed with cancer participated in the study. ASD was assessed by the Stanford Acute Stress...... Reaction Questionnaire, and repressive coping was assessed by a combination of scores from the Marlowe-Crowne Social Desirability Scale, and the Bendig version of the Taylor Manifest Anxiety Scale. Significantly fewer patients classified as "repressors" were diagnosed with ASD compared to patients...... classified as "non-repressors". However, further investigations revealed that the lower incidence of ASD in repressors apparently was caused by a low score on anxiety and not by an interaction effect between anxiety and defensiveness. Future studies have to investigate whether different psychological...

  13. Nuclear AXIN2 represses MYC gene expression

    Energy Technology Data Exchange (ETDEWEB)

    Rennoll, Sherri A.; Konsavage, Wesley M.; Yochum, Gregory S., E-mail: gsy3@psu.edu

    2014-01-03

    Highlights: •AXIN2 localizes to cytoplasmic and nuclear compartments in colorectal cancer cells. •Nuclear AXIN2 represses the activity of Wnt-responsive luciferase reporters. •β-Catenin bridges AXIN2 to TCF transcription factors. •AXIN2 binds the MYC promoter and represses MYC gene expression. -- Abstract: The β-catenin transcriptional coactivator is the key mediator of the canonical Wnt signaling pathway. In the absence of Wnt, β-catenin associates with a cytosolic and multi-protein destruction complex where it is phosphorylated and targeted for proteasomal degradation. In the presence of Wnt, the destruction complex is inactivated and β-catenin translocates into the nucleus. In the nucleus, β-catenin binds T-cell factor (TCF) transcription factors to activate expression of c-MYC (MYC) and Axis inhibition protein 2 (AXIN2). AXIN2 is a member of the destruction complex and, thus, serves in a negative feedback loop to control Wnt/β-catenin signaling. AXIN2 is also present in the nucleus, but its function within this compartment is unknown. Here, we demonstrate that AXIN2 localizes to the nuclei of epithelial cells within normal and colonic tumor tissues as well as colorectal cancer cell lines. In the nucleus, AXIN2 represses expression of Wnt/β-catenin-responsive luciferase reporters and forms a complex with β-catenin and TCF. We demonstrate that AXIN2 co-occupies β-catenin/TCF complexes at the MYC promoter region. When constitutively localized to the nucleus, AXIN2 alters the chromatin structure at the MYC promoter and directly represses MYC gene expression. These findings suggest that nuclear AXIN2 functions as a rheostat to control MYC expression in response to Wnt/β-catenin signaling.

  14. Nuclear AXIN2 represses MYC gene expression

    International Nuclear Information System (INIS)

    Rennoll, Sherri A.; Konsavage, Wesley M.; Yochum, Gregory S.

    2014-01-01

    Highlights: •AXIN2 localizes to cytoplasmic and nuclear compartments in colorectal cancer cells. •Nuclear AXIN2 represses the activity of Wnt-responsive luciferase reporters. •β-Catenin bridges AXIN2 to TCF transcription factors. •AXIN2 binds the MYC promoter and represses MYC gene expression. -- Abstract: The β-catenin transcriptional coactivator is the key mediator of the canonical Wnt signaling pathway. In the absence of Wnt, β-catenin associates with a cytosolic and multi-protein destruction complex where it is phosphorylated and targeted for proteasomal degradation. In the presence of Wnt, the destruction complex is inactivated and β-catenin translocates into the nucleus. In the nucleus, β-catenin binds T-cell factor (TCF) transcription factors to activate expression of c-MYC (MYC) and Axis inhibition protein 2 (AXIN2). AXIN2 is a member of the destruction complex and, thus, serves in a negative feedback loop to control Wnt/β-catenin signaling. AXIN2 is also present in the nucleus, but its function within this compartment is unknown. Here, we demonstrate that AXIN2 localizes to the nuclei of epithelial cells within normal and colonic tumor tissues as well as colorectal cancer cell lines. In the nucleus, AXIN2 represses expression of Wnt/β-catenin-responsive luciferase reporters and forms a complex with β-catenin and TCF. We demonstrate that AXIN2 co-occupies β-catenin/TCF complexes at the MYC promoter region. When constitutively localized to the nucleus, AXIN2 alters the chromatin structure at the MYC promoter and directly represses MYC gene expression. These findings suggest that nuclear AXIN2 functions as a rheostat to control MYC expression in response to Wnt/β-catenin signaling

  15. Enhancement of adipogenesis and fibrogenesis in skeletal muscle of Wagyu compared with Angus cattle.

    Science.gov (United States)

    Duarte, M S; Paulino, P V R; Das, A K; Wei, S; Serão, N V L; Fu, X; Harris, S M; Dodson, M V; Du, M

    2013-06-01

    Intramuscular fat and collagen content are major factors affecting beef quality, but mechanisms regulating intramuscular adipose and connective tissue deposition are far from clear. Japanese Wagyu cattle are well known for their extremely high marbling. The objective of this study was to evaluate intramuscular fat (IMF) and collagen deposition in the muscle of Wagyu compared with Angus cattle. Animals were managed under the same condition and slaughtered at an averaging 585 ± 12.1 kg of BW. Samples of sternomandibularis muscle were collected from Wagyu (n = 3) and Angus (n = 3) for molecular and histological investigations of adipogenesis and fibrogenesis. With exception of C/EBPβ (P = 0.2864), the expression of the adipogenic markers C/EBPα (P = 0.008), PPARγ (P = 0.028), and zip finger protein 423 (Zfp423; P = 0.047) in Wagyu were greater than in Angus muscle, which was consistent with greater IMF deposition in Wagyu (P Angus cattle. These results clearly show that both IMF and collagen contents are enhanced in Wagyu cattle and more adipogenic cells are detected in Wagyu muscle, indicating intramuscular adipogenesis is enhanced in Wagyu compared with Angus muscle.

  16. The role of innate immunity in the regulation of brown and beige adipogenesis.

    Science.gov (United States)

    Alexaki, Vasileia Ismini; Chavakis, Triantafyllos

    2016-03-01

    The adipose tissue (AT) is multifunctional, acting as an endocrine tissue and participating in the regulation of the organism's homeostasis. Metabolic, endocrine and inflammatory mechanisms are tightly intertwined within the AT, regulating its function. Disruption of the equilibrium among these mechanisms leads to pathologies, the most common being obesity-related insulin resistance. Two types of AT exist, the white and the brown AT. Traditionally the white AT (WAT) was thought to store energy in the form of lipids, while the brown AT (BAT) was known to mediate heat generation. Recently, the 'brite' or 'beige' AT was identified, which is localized predominantly in subcutaneous WAT, but shares functional features with the BAT and is capable of heat production. The major stimulus triggering beige and brown adipogenesis is cold exposure and catecholamine signalling. However, several further signals and mechanisms exist, which can orchestrate and fine-tune beige and brown AT function. Immune cells and inflammation have emerged as regulators of beige and brown AT function. The present review will focus on the recently identified crosstalk between innate immunity and the regulation of beige and brown adipogenesis.

  17. Polyphenolic extract from Hibiscus sabdariffa reduces body fat by inhibiting hepatic lipogenesis and preadipocyte adipogenesis.

    Science.gov (United States)

    Kao, Erl-Shyh; Yang, Mon-Yuan; Hung, Chia-Hung; Huang, Chien-Ning; Wang, Chau-Jong

    2016-01-01

    Diets high in fat lead to excess lipid accumulation in adipose tissue, which is a crucial factor in the development of obesity, hepatitis, and hyperlipidemia. In this study, we investigated the anti-obesity effect of Hibiscus sabdariffa extract (HSE) in vivo. Hamsters fed a high-fat diet (HFD) develop symptoms of obesity, which were determined based on body weight changes and changes in plasma and serum triglycerides, free fatty acid concentrations, total cholesterol levels, LDL-C levels, HDL-C levels, and adipocyte tissue weight. HFD-fed hamsters were used to investigate the effects of HSE on symptoms of obesity such as adipogenesis and fatty liver, loss of blood glucose regulation, and serum ion imbalance. Interestingly, HSE treatment effectively reduced the effects of the HFD in hamsters in a dose-dependent manner. Further, after inducing maturation of preadipocytes, Hibiscus sabdariffa polyphenolic extract (HPE) was shown to suppress the adipogenesis of adipocytes. However, HPE does not affect the viability of preadipocytes. Therefore, both HSE and HPE are effective and viable treatment strategies for preventing the development and treating the symptoms of obesity.

  18. Naringenin Inhibits Adipogenesis and Reduces Insulin Sensitivity and Adiponectin Expression in Adipocytes

    Directory of Open Access Journals (Sweden)

    Allison J. Richard

    2013-01-01

    Full Text Available Adipose tissue development and function are widely studied to examine the relationship between obesity and the metabolic syndrome. It is well documented that the inability of adipose tissue to properly increase its lipid storage capacity during the obese state can lead to metabolic dysfunction. In a blind screen of 425 botanicals, we identified naringenin as an inhibitor of adipocyte differentiation. Naringenin is one of the most abundant citrus flavonoids, and recent studies have demonstrated antihyperlipidemic capabilities. These studies have largely focused on the effects of naringenin on the liver. Our biochemical studies clearly demonstrate that naringenin inhibits adipogenesis and impairs mature fat cell function. Naringenin specifically inhibited adipogenesis in a dose-dependent fashion as judged by examining lipid accumulation and induction of adipocyte marker protein expression. In mature 3T3-L1 adipocytes, naringenin reduced the ability of insulin to induce IRS-1 tyrosine phosphorylation and substantially inhibited insulin-stimulated glucose uptake in a dose-dependent manner and over a time frame of 1.5 to 24 hours. Exposure to naringenin also inhibited adiponectin protein expression in mature murine and human adipocytes. Our studies have revealed that naringenin may have a negative impact on adipocyte-related diseases by limiting differentiation of preadipocytes, by significantly inducing insulin resistance, and by decreasing adiponectin expression in mature fat cells.

  19. Overexpressed human heme Oxygenase-1 decreases adipogenesis in pigs and porcine adipose-derived stem cells.

    Science.gov (United States)

    Park, Eun Jung; Koo, Ok Jae; Lee, Byeong Chun

    2015-11-27

    Adipose-derived mesenchymal stem cells (ADSC) are multipotent, which means they are able to differentiate into several lineages in vivo and in vitro under proper conditions. This indicates it is possible to determine the direction of differentiation of ADSC by controlling the microenvironment. Heme oxygenase 1 (HO-1), a type of antioxidant enzyme, attenuates adipogenicity and obesity. We produced transgenic pigs overexpressing human HO-1 (hHO-1-Tg), and found that these animals have little fatty tissue when autopsied. To determine whether overexpressed human HO-1 suppresses adipogenesis in pigs, we analyzed body weight increases of hHO-1-Tg pigs and wild type (WT) pigs of the same strain, and induced adipogenic differentiation of ADSC derived from WT and hHO-1-Tg pigs. The hHO-1-Tg pigs had lower body weights than WT pigs from 16 weeks of age until they died. In addition, hHO-1-Tg ADSC showed reduced adipogenic differentiation and expression of adipogenic molecular markers such as PPARγ and C/EBPα compared to WT ADSC. These results suggest that HO-1 overexpression reduces adipogenesis both in vivo and in vitro, which could support identification of therapeutic targets of obesity and related metabolic diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Corticosteroid Receptors, Their Chaperones and Cochaperones: How Do They Modulate Adipogenesis?

    Directory of Open Access Journals (Sweden)

    Judith Toneatto

    2014-11-01

    Full Text Available It is well known that glucocorticoids and mineralocorticoids are part of the list of hormones that control adipogenesis as well as different aspects of the physiology of the adipose tissue. Their actions are mediated through their binding to the glucocorticoid and the mineralocorticoid receptors (GR and MR, respectively, in complex with heat shock proteins (Hsps and high molecular weight immunophilins (IMMs. Albeit many aspects of the molecular mechanism of the corticosteroid receptors are not fully elucidated yet, it was not until recently that the first evidences of the functional importance of Hsps and IMMs in the process of adipocyte differentiation have been described. Hsp90 and the high molecular weight IMM FKBP51 modulate GR and MR activity at multiple levels, that is, hormone binding affinity, their subcellular distribution, and the transcriptional status, among other aspects of the NR function. Interestingly, it has recently been described that Hsp90 and FKBP51 also participate in the control of PPARγ, a key transcription factor in the control of adipogenesis and the maintenance of the adipocyte phenotype. In addition, novel roles have been uncovered for FKBP51 in the organization of the nuclear architecture through its participation in the reorganization of the nuclear lamina and the control of the subnuclear distribution of GR. Thus, the aim of this review is to integrate and discuss the actual understanding of the role of corticosteroid receptors, their chaperones and cochaperones, in the process of adipocyte differentiation.

  1. Oxidative stress accumulates in adipose tissue during aging and inhibits adipogenesis.

    Science.gov (United States)

    Findeisen, Hannes M; Pearson, Kevin J; Gizard, Florence; Zhao, Yue; Qing, Hua; Jones, Karrie L; Cohn, Dianne; Heywood, Elizabeth B; de Cabo, Rafael; Bruemmer, Dennis

    2011-04-14

    Aging constitutes a major independent risk factor for the development of type 2 diabetes and is accompanied by insulin resistance and adipose tissue dysfunction. One of the most important factors implicitly linked to aging and age-related chronic diseases is the accumulation of oxidative stress. However, the effect of increased oxidative stress on adipose tissue biology remains elusive. In this study, we demonstrate that aging in mice results in a loss of fat mass and the accumulation of oxidative stress in adipose tissue. In vitro, increased oxidative stress through glutathione depletion inhibits preadipocyte differentiation. This inhibition of adipogenesis is at least in part the result of reduced cell proliferation and an inhibition of G(1)→S-phase transition during the initial mitotic clonal expansion of the adipocyte differentiation process. While phosphorylation of the retinoblastoma protein (Rb) by cyclin/cdk complexes remains unaffected, oxidative stress decreases the expression of S-phase genes downstream of Rb. This silencing of S phase gene expression by increased oxidative stress is mediated through a transcriptional mechanism involving the inhibition of E2F recruitment and transactivation of its target promoters. Collectively, these data demonstrate a previously unrecognized role of oxidative stress in the regulation of adipogenesis which may contribute to age-associated adipose tissue dysfunction.

  2. Structurally-diverse, PPARγ-activating environmental toxicants induce adipogenesis and suppress osteogenesis in bone marrow mesenchymal stromal cells

    International Nuclear Information System (INIS)

    Watt, James; Schlezinger, Jennifer J.

    2015-01-01

    Environmental obesogens are a newly recognized category of endocrine disrupting chemicals that have been implicated in contributing to the rising rates of obesity in the United States. While obesity is typically regarded as an increase in visceral fat, adipocyte accumulation in the bone has been linked to increased fracture risk, lower bone density, and osteoporosis. Exposure to environmental toxicants that activate peroxisome proliferator activated receptor γ (PPARγ), a critical regulator of the balance of differentiation between adipogenesis and osteogenesis, may contribute to the increasing prevalence of osteoporosis. However, induction of adipogenesis and suppression of osteogenesis are separable activities of PPARγ, and ligands may selectively alter these activities. It currently is unknown whether suppression of osteogenesis is a common toxic endpoint of environmental PPARγ ligands. Using a primary mouse bone marrow culture model, we tested the hypothesis that environmental toxicants acting as PPARγ agonists divert the differentiation pathway of bone marrow-derived multipotent mesenchymal stromal cells towards adipogenesis and away from osteogenesis. The toxicants tested included the organotins tributyltin and triphenyltin, a ubiquitous phthalate metabolite (mono-(2-ethylhexyl) phthalate, MEHP), and two brominated flame retardants (tetrabromobisphenol-a, TBBPA, and mono-(2-ethylhexyl) tetrabromophthalate, METBP). All of the compounds activated PPARγ1 and 2. All compounds increased adipogenesis (lipid accumulation, Fabp4 expression) and suppressed osteogenesis (alkaline phosphatase activity, Osx expression) in mouse primary bone marrow cultures, but with different potencies and efficacies. Despite structural dissimilarities, there was a strong negative correlation between efficacies to induce adipogenesis and suppress osteogenesis, with the organotins being distinct in their exceptional ability to suppress osteogenesis. As human exposure to a mixture of

  3. A Growth Model of Inflation, Tax Evasion and Financial Repression

    OpenAIRE

    Roubini, Nouriel; Sala-i-Martin, Xavier

    1992-01-01

    In this paper we study the effects of policies of financial repression on long term growth and try to explain why optimizing governments might want to repress the financial sector. We also explain why inflation may be negatively related to growth, even though it does not affect growth directly. We argue that the main reason why governments repress the financial sector is that this sector is the source of "easy" resources for the public budget The source of revenue stemming from this intervent...

  4. DeltaFosB induces osteosclerosis and decreases adipogenesis by two independent cell-autonomous mechanisms

    DEFF Research Database (Denmark)

    Kveiborg, Marie; Sabatakos, George; Chiusaroli, Riccardo

    2004-01-01

    establishes that the skeletal phenotype is cell autonomous to the osteoblast lineage and independent of adipocyte formation. It also strongly suggests that the decreased fat phenotype of NSE-DeltaFosB mice is independent of the changes in the osteoblast lineage. In vitro, overexpression of Delta......Osteoblasts and adipocytes may develop from common bone marrow mesenchymal precursors. Transgenic mice overexpressing DeltaFosB, an AP-1 transcription factor, under the control of the neuron-specific enolase (NSE) promoter show both markedly increased bone formation and decreased adipogenesis...... of DeltaFosB on adipocyte differentiation appears to occur at early stages of stem cell commitment, affecting C/EBPbeta functions. It is concluded that the changes in osteoblast and adipocyte differentiation in DeltaFosB transgenic mice result from independent cell-autonomous mechanisms....

  5. Lithium Chloride Modulates Adipogenesis and Osteogenesis of Human Bone Marrow-Derived Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Linjun Tang

    2015-08-01

    Full Text Available Background/Aims: Lithium chloride (LiCl has long been used as a psychiatric medication; however, its role in the differentiation of bone marrow-derived mesenchymal stem cells (BMSCs remains largely unknown. The aim of this study is to explore the effect of LiCl on the differentiation of BMSCs. Methods: The roles of LiCl in osteogenic and adipogenic processes were observed using alizarin red staining and oil red O staining, respectively. The effects of LiCl on the Wnt and Hedgehog (Hh pathways were investigated. Results: Our data showed that LiCl effectively promoted osteogenesis and inhibited adipogenesis by simultaneously affecting the Wnt and Hh pathways. Conclusion: These results suggest that LiCl influences the differentiation of BMSCs directly through the Wnt and Hh pathways and thus may be a candidate drug for the treatment of osteoporosis.

  6. HMGA2 promotes adipogenesis by activating C/EBPβ-mediated expression of PPARγ

    Energy Technology Data Exchange (ETDEWEB)

    Xi, Yang; Shen, Wanjing; Ma, Lili; Zhao, Ming; Zheng, Jiachen [Diabetes Center, and Zhejiang Provincial Key Laboratory of Pathophysiology, Institute of Biochemistry and Molecular Biology, School of Medicine, Ningbo University, Ningbo 315211 (China); Bu, Shizhong, E-mail: bushizhong@nbu.edu.cn [Diabetes Center, and Zhejiang Provincial Key Laboratory of Pathophysiology, Institute of Biochemistry and Molecular Biology, School of Medicine, Ningbo University, Ningbo 315211 (China); Hino, Shinjiro [Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, 860-0811 (Japan); Nakao, Mitsuyoshi, E-mail: mnakao@gpo.kumamoto-u.ac.jp [Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, 860-0811 (Japan); Core Research for Evolutional Science and Technology (CREST), Japan Agency for Medical Research and Development, Tokyo (Japan)

    2016-04-15

    Adipogenesis is orchestrated by a highly ordered network of transcription factors including peroxisome-proliferator activated receptor-gamma (PPARγ) and CCAAT-enhancer binding protein (C/EBP) family proteins. High mobility group protein AT-hook 2 (HMGA2), an architectural transcription factor, has been reported to play an essential role in preadipocyte proliferation, and its overexpression has been implicated in obesity in mice and humans. However, the direct role of HMGA2 in regulating the gene expression program during adipogenesis is not known. Here, we demonstrate that HMGA2 is required for C/EBPβ-mediated expression of PPARγ, and thus promotes adipogenic differentiation. We observed a transient but marked increase of Hmga2 transcript at an early phase of differentiation of mouse 3T3-L1 preadipocytes. Importantly, Hmga2 knockdown greatly impaired adipocyte formation, while its overexpression promoted the formation of mature adipocytes. We found that HMGA2 colocalized with C/EBPβ in the nucleus and was required for the recruitment of C/EBPβ to its binding element at the Pparγ2 promoter. Accordingly, HMGA2 and C/EBPβ cooperatively enhanced the Pparγ2 promoter activity. Our results indicate that HMGA2 is an essential constituent of the adipogenic transcription factor network, and thus its function may be affected during the course of obesity. - Highlights: • Overexpression of HMGA2 has been implicated in obesity in mice and humans. • HMGA2 is required for adipocyte formation. • HMGA2 colocalizes with C/EBPβ and is required for C/EBPβ recruitment to Pparγ2 promoter. • HMGA2 and C/EBPβ cooperatively enhance the Pparγ2 promoter activity.

  7. HMGA2 promotes adipogenesis by activating C/EBPβ-mediated expression of PPARγ

    International Nuclear Information System (INIS)

    Xi, Yang; Shen, Wanjing; Ma, Lili; Zhao, Ming; Zheng, Jiachen; Bu, Shizhong; Hino, Shinjiro; Nakao, Mitsuyoshi

    2016-01-01

    Adipogenesis is orchestrated by a highly ordered network of transcription factors including peroxisome-proliferator activated receptor-gamma (PPARγ) and CCAAT-enhancer binding protein (C/EBP) family proteins. High mobility group protein AT-hook 2 (HMGA2), an architectural transcription factor, has been reported to play an essential role in preadipocyte proliferation, and its overexpression has been implicated in obesity in mice and humans. However, the direct role of HMGA2 in regulating the gene expression program during adipogenesis is not known. Here, we demonstrate that HMGA2 is required for C/EBPβ-mediated expression of PPARγ, and thus promotes adipogenic differentiation. We observed a transient but marked increase of Hmga2 transcript at an early phase of differentiation of mouse 3T3-L1 preadipocytes. Importantly, Hmga2 knockdown greatly impaired adipocyte formation, while its overexpression promoted the formation of mature adipocytes. We found that HMGA2 colocalized with C/EBPβ in the nucleus and was required for the recruitment of C/EBPβ to its binding element at the Pparγ2 promoter. Accordingly, HMGA2 and C/EBPβ cooperatively enhanced the Pparγ2 promoter activity. Our results indicate that HMGA2 is an essential constituent of the adipogenic transcription factor network, and thus its function may be affected during the course of obesity. - Highlights: • Overexpression of HMGA2 has been implicated in obesity in mice and humans. • HMGA2 is required for adipocyte formation. • HMGA2 colocalizes with C/EBPβ and is required for C/EBPβ recruitment to Pparγ2 promoter. • HMGA2 and C/EBPβ cooperatively enhance the Pparγ2 promoter activity.

  8. Effects of oral florfenicol and azithromycin on gut microbiota and adipogenesis in mice.

    Directory of Open Access Journals (Sweden)

    Rui Li

    Full Text Available Certain antibiotics detected in urine are associated with childhood obesity. In the current experimental study, we investigated two representative antibiotics detected in urine, florfenicol and azithromycin, for their early effects on adipogenesis, gut microbiota, short-chain fatty acids (SCFAs, and bile acids in mice. Thirty C57BL/6 mice aged four weeks were randomly divided into three groups (florfenicol, azithromycin and control. The two experimental groups were administered florfenicol or azithromycin at 5 mg/kg/day for four weeks. Body weight was measured weekly. The composition of the gut microbiota, body fat, SCFAs, and bile acids in colon contents were measured at the end of the experiment. The composition of the gut microbiota was determined by sequencing the bacterial 16S rRNA gene. The concentration of SCFAs and bile acids was determined using gas chromatography and liquid chromatography coupled to tandem mass spectrometry, respectively. The composition of the gut microbiota indicated that the two antibiotics altered the gut microbiota composition and decreased its richness and diversity. At the phylum level, the ratio of Firmicutes/Bacteroidetes increased significantly in the antibiotic groups. At the genus level, there were declines in Christensenella, Gordonibacter and Anaerotruncus in the florfenicol group, in Lactobacillus in the azithromycin group, and in Alistipes, Desulfovibrio, Parasutterella and Rikenella in both the antibiotic groups. The decrease in Rikenella in the azithromycin group was particularly noticeable. The concentration of SCFAs and secondary bile acids decreased in the colon, but the concentration of primary bile acids increased. These findings indicated that florfenicol and azithromycin increased adipogenesis and altered gut microbiota composition, SCFA production, and bile acid metabolism, suggesting that exposure to antibiotics might be one risk factor for childhood obesity. More studies are needed to

  9. Differential repression of arylsulphatase synthesis in Aspergillus oryzae.

    Science.gov (United States)

    Burns, G R; Wynn, C H

    1977-09-15

    1. The activities of the three arylsulphatases (arylsulphate sulphohydrolase, EC 3.1.6.1) of Aspergillus oryzae produced under a variety of repressing and non-repressing conditions were determined. 2. These enzymes exhibit different sensitivities to repression by inorganic sulphate. 3. Arylsulphatase I, but not arylsulphatases II and III, exhibits a transient de-repression in the early growth phase in sulphate media. 4. When the fungus is cultured in repressing media and subsequently transferred to non-repressing media, the synthesis of the three enzymes is non-co-ordinate. 5. Growth of the fungus in media containing choline O-sulphate or tyrosine O-sulphate as the sole source of sulphur results in complete de-repression of arylsulphatase I, But the synthesis of arylsulphatases II and III is essentially fully repressed. 6. The marked similarities between the repression characteristics of arylsulphatases II and III, contrasted with those of arylsulphatase I, indicate that the genetic locus of arylsulphatase I is distinct from that of arylsulphatases II and III, suggesting that there are distinct physiological roles for the enzyme.

  10. Lactobacillus plantarum LG42 Isolated from Gajami Sik-Hae Inhibits Adipogenesis in 3T3-L1 Adipocyte

    Directory of Open Access Journals (Sweden)

    Jeong-Eun Park

    2013-01-01

    Full Text Available We investigated whether lactic acid bacteria isolated from gajami sik-hae (GLAB are capable of reducing the intracellular lipid accumulation by downregulating the expression of adipogenesis-related genes in differentiated 3T3-L1 cells. The GLAB, Lactobacillus plantarum LG42, significantly decreased the intracellular triglyceride storage and the glycerol-3-phosphate dehydrogenase (GPDH activity in a dose-dependent manner. mRNA expression of transcription factors like peroxisome proliferator-activated receptor (PPAR γ and CCAAT/enhancer-binding protein (C/EBP α involved in adipogenesis was markedly decreased by the GLAB treatment. Moreover, the GLAB also decreased the expression level of adipogenic markers like adipocyte fatty acid binding protein (aP2, leptin, GPDH, and fatty acid translocase (CD36 significantly. These results suggest that the GLAB inhibits lipid accumulation in the differentiated adipocyte through downregulating the expression of adipogenic transcription factors and other specific genes involved in lipid metabolism.

  11. Inhibition of the acetyl lysine-binding pocket of bromodomain and extraterminal domain proteins interferes with adipogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Goupille, Olivier [CEA, Institute of Emerging Diseases and Innovative Therapies (IMETI), Fontenay-aux-Roses and Université Paris-Saclay, UMR-E 007 (France); Penglong, Tipparat [CEA, Institute of Emerging Diseases and Innovative Therapies (IMETI), Fontenay-aux-Roses and Université Paris-Saclay, UMR-E 007 (France); Thalassemia Research Center, Mahidol University (Thailand); Kadri, Zahra; Granger-Locatelli, Marine [CEA, Institute of Emerging Diseases and Innovative Therapies (IMETI), Fontenay-aux-Roses and Université Paris-Saclay, UMR-E 007 (France); Fucharoen, Suthat [Thalassemia Research Center, Mahidol University (Thailand); Maouche-Chrétien, Leila [CEA, Institute of Emerging Diseases and Innovative Therapies (IMETI), Fontenay-aux-Roses and Université Paris-Saclay, UMR-E 007 (France); INSERM, Paris (France); Prost, Stéphane [CEA, Institute of Emerging Diseases and Innovative Therapies (IMETI), Fontenay-aux-Roses and Université Paris-Saclay, UMR-E 007 (France); Leboulch, Philippe [CEA, Institute of Emerging Diseases and Innovative Therapies (IMETI), Fontenay-aux-Roses and Université Paris-Saclay, UMR-E 007 (France); Thalassemia Research Center, Mahidol University (Thailand); Chrétien, Stany, E-mail: stany.chretien@cea.fr [CEA, Institute of Emerging Diseases and Innovative Therapies (IMETI), Fontenay-aux-Roses and Université Paris-Saclay, UMR-E 007 (France); INSERM, Paris (France)

    2016-04-15

    The bromodomain and extraterminal (BET) domain family proteins are epigenetic modulators involved in the reading of acetylated lysine residues. The first BET protein inhibitor to be identified, (+)-JQ1, a thienotriazolo-1, 4-diazapine, binds selectively to the acetyl lysine-binding pocket of BET proteins. We evaluated the impact on adipogenesis of this druggable targeting of chromatin epigenetic readers, by investigating the physiological consequences of epigenetic modifications through targeting proteins binding to chromatin. JQ1 significantly inhibited the differentiation of 3T3-L1 preadipocytes into white and brown adipocytes by down-regulating the expression of genes involved in adipogenesis, particularly those encoding the peroxisome proliferator-activated receptor (PPAR-γ), the CCAAT/enhancer-binding protein (C/EBPα) and, STAT5A and B. The expression of a constitutively activated STAT5B mutant did not prevent inhibition by JQ1. Thus, the association of BET/STAT5 is required for adipogenesis but STAT5 transcription activity is not the only target of JQ1. Treatment with JQ1 did not lead to the conversion of white adipose tissue into brown adipose tissue (BAT). BET protein inhibition thus interferes with generation of adipose tissue from progenitors, confirming the importance of the connections between epigenetic mechanisms and specific adipogenic transcription factors. - Highlights: • JQ1 prevented the differentiation of 3T3-L1 preadipocytes into white adipocytes. • JQ1 affected clonal cell expansion and abolished lipid accumulation. • JQ1 prevented the differentiation of 3T3-L1 preadipocytes into brown adipocytes. • JQ1 treatment did not lead to the conversion of white adipose tissue into brown adipose tissue. • JQ1 decreased STAT5 expression, but STAT5B{sup ca} expression did not restore adipogenesis.

  12. Inhibition of the acetyl lysine-binding pocket of bromodomain and extraterminal domain proteins interferes with adipogenesis

    International Nuclear Information System (INIS)

    Goupille, Olivier; Penglong, Tipparat; Kadri, Zahra; Granger-Locatelli, Marine; Fucharoen, Suthat; Maouche-Chrétien, Leila; Prost, Stéphane; Leboulch, Philippe; Chrétien, Stany

    2016-01-01

    The bromodomain and extraterminal (BET) domain family proteins are epigenetic modulators involved in the reading of acetylated lysine residues. The first BET protein inhibitor to be identified, (+)-JQ1, a thienotriazolo-1, 4-diazapine, binds selectively to the acetyl lysine-binding pocket of BET proteins. We evaluated the impact on adipogenesis of this druggable targeting of chromatin epigenetic readers, by investigating the physiological consequences of epigenetic modifications through targeting proteins binding to chromatin. JQ1 significantly inhibited the differentiation of 3T3-L1 preadipocytes into white and brown adipocytes by down-regulating the expression of genes involved in adipogenesis, particularly those encoding the peroxisome proliferator-activated receptor (PPAR-γ), the CCAAT/enhancer-binding protein (C/EBPα) and, STAT5A and B. The expression of a constitutively activated STAT5B mutant did not prevent inhibition by JQ1. Thus, the association of BET/STAT5 is required for adipogenesis but STAT5 transcription activity is not the only target of JQ1. Treatment with JQ1 did not lead to the conversion of white adipose tissue into brown adipose tissue (BAT). BET protein inhibition thus interferes with generation of adipose tissue from progenitors, confirming the importance of the connections between epigenetic mechanisms and specific adipogenic transcription factors. - Highlights: • JQ1 prevented the differentiation of 3T3-L1 preadipocytes into white adipocytes. • JQ1 affected clonal cell expansion and abolished lipid accumulation. • JQ1 prevented the differentiation of 3T3-L1 preadipocytes into brown adipocytes. • JQ1 treatment did not lead to the conversion of white adipose tissue into brown adipose tissue. • JQ1 decreased STAT5 expression, but STAT5B"c"a expression did not restore adipogenesis.

  13. Silencing of RB1 and RB2/P130 during adipogenesis of bone marrow stromal cells results in dysregulated differentiation

    OpenAIRE

    Capasso, Stefania; Alessio, Nicola; Di Bernardo, Giovanni; Cipollaro, Marilena; Melone, Mariarosa A. B.; Peluso, Gianfranco; Giordano, Antonio; Galderisi, Umberto

    2014-01-01

    Bone marrow adipose tissue (BMAT) is different from fat found elsewhere in the body, and only recently have some of its functions been investigated. BMAT may regulate bone marrow stem cell niche and plays a role in energy storage and thermogenesis. BMAT may be involved also in obesity and osteoporosis onset. Given the paramount functions of BMAT, we decided to better clarify the human bone marrow adipogenesis by analyzing the role of the retinoblastoma gene family, which are key players in ce...

  14. Silencing of RB1 and RB2/P130 during adipogenesis of bone marrow stromal cells results in dysregulated differentiation.

    Science.gov (United States)

    Capasso, Stefania; Alessio, Nicola; Di Bernardo, Giovanni; Cipollaro, Marilena; Melone, Mariarosa Ab; Peluso, Gianfranco; Giordano, Antonio; Galderisi, Umberto

    2014-01-01

    Bone marrow adipose tissue (BMAT) is different from fat found elsewhere in the body, and only recently have some of its functions been investigated. BMAT may regulate bone marrow stem cell niche and plays a role in energy storage and thermogenesis. BMAT may be involved also in obesity and osteoporosis onset. Given the paramount functions of BMAT, we decided to better clarify the human bone marrow adipogenesis by analyzing the role of the retinoblastoma gene family, which are key players in cell cycle regulation. Our data provide evidence that the inactivation of RB1 or RB2/P130 in uncommitted bone marrow stromal cells (BMSC) facilitates the first steps of adipogenesis. In cultures with silenced RB1 or RB2/P130, we observed an increase of clones with adipogenic potential and a higher percentage of cells accumulating lipid droplets. Nevertheless, the absence of RB1 or RB2/P130 impaired the terminal adipocyte differentiation and gave rise to dysregulated adipose cells, with alteration in lipid uptake and release. For the first time, we evidenced that RB2/P130 plays a role in bone marrow adipogenesis. Our data suggest that while the inactivation of retinoblastoma proteins may delay the onset of last cell division and allow more BMSC to be committed to adipocyte, it did not allow a permanent cell cycle exit, which is a prerequisite for adipocyte terminal maturation.

  15. Stable expression of lipocalin-type prostaglandin D synthase in cultured preadipocytes impairs adipogenesis program independently of endogenous prostanoids

    Energy Technology Data Exchange (ETDEWEB)

    Hossain, Mohammad Salim; Chowdhury, Abu Asad; Rahman, Mohammad Sharifur [Department of Life Science and Biotechnology, Shimane University, 1060 Nishikawatsu-cho, Matsue, Shimane 690-8504 (Japan); Nishimura, Kohji [Department of Molecular and Functional Genomics, Center for Integrated Research in Science, Shimane University, 1060 Nishikawatsu-cho, Matsue, Shimane 690-8504 (Japan); Jisaka, Mitsuo; Nagaya, Tsutomu [Department of Life Science and Biotechnology, Shimane University, 1060 Nishikawatsu-cho, Matsue, Shimane 690-8504 (Japan); Shono, Fumiaki [Department of Clinical Pharmacy, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, 180 Yamashiro-cho, Tokushima-shi, Tokushima 770-8514 (Japan); Yokota, Kazushige, E-mail: yokotaka@life.shimane-u.ac.jp [Department of Life Science and Biotechnology, Shimane University, 1060 Nishikawatsu-cho, Matsue, Shimane 690-8504 (Japan)

    2012-02-15

    Lipocalin-type prostaglandin D synthase (L-PGDS) expressed preferentially in adipocytes is responsible for the synthesis of PGD{sub 2} and its non-enzymatic dehydration products, PGJ{sub 2} series, serving as pro-adipogenic factors. However, the role of L-PGDS in the regulation of adipogenesis is complex because of the occurrence of several derivatives from PGD{sub 2} and their distinct receptor subtypes as well as other functions such as a transporter of lipophilic molecules. To manipulate the expression levels of L-PGDS in cultured adipocytes, cultured preadipogenic 3T3-L1 cells were transfected stably with a mammalian expression vector having cDNA encoding murine L-PGDS oriented in the sense direction. The isolated cloned stable transfectants with L-PGDS expressed higher levels of the transcript and protein levels of L-PGDS, and synthesized PGD{sub 2} from exogenous arachidonic acid at significantly higher levels. By contrast, the synthesis of PGE{sub 2} remained unchanged, indicating no influence on the reactions of cyclooxygenase (COX) and PGE synthase. Furthermore, the ability of those transfectants to synthesize {Delta}{sup 12}-PGJ{sub 2} increased more greatly during the maturation phase. The sustained expression of L-PGDS in cultured stable transfectants hampered the storage of fats during the maturation phase of adipocytes, which was accompanied by the reduced gene expression of adipocyte-specific markers reflecting the down-regulation of the adipogenesis program. The suppressed adipogenesis was not rescued by either exogenous aspirin or peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) agonists including troglitazone and {Delta}{sup 12}-PGJ{sub 2}. Taken together, the results indicate the negative regulation of the adipogenesis program by the enhanced expression of L-PGDS through a cellular mechanism involving the interference of the PPAR{gamma} signaling pathway without the contribution of endogenous pro-adipogenic prostanoids

  16. Phosphorylation at tyrosine 114 of Proliferating Cell Nuclear Antigen (PCNA) is required for adipogenesis in response to high fat diet

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Yuan-Hung; Ho, Po-Chun; Chen, Min-Shan; Hugo, Eric; Ben-Jonathan, Nira [Department of Cancer Biology, University of Cincinnati College of Medicine, 3125 Eden Avenue, Cincinnati, OH 45267-0521 (United States); Department of Environmental Health, University of Cincinnati College of Medicine, 3223 Eden Avenue, Kettering Laboratory, Cincinnati, OH 45267-0056 (United States); Wang, Shao-Chun, E-mail: shao-chun.wang@uc.edu [Department of Cancer Biology, University of Cincinnati College of Medicine, 3125 Eden Avenue, Cincinnati, OH 45267-0521 (United States); Department of Environmental Health, University of Cincinnati College of Medicine, 3223 Eden Avenue, Kettering Laboratory, Cincinnati, OH 45267-0056 (United States)

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer Proliferating Cell Nuclear Antigen (PCNA) is phosphorylated at Y114. Black-Right-Pointing-Pointer Phospho-Y114 of PCNA is not required for cell proliferation for normal growth. Black-Right-Pointing-Pointer MCE during adipogenesis is abolished in the lack of the phosphorylation. Black-Right-Pointing-Pointer Homozygous Y114F mice are resistant to high fat diet induced obesity. Black-Right-Pointing-Pointer Our results shed light on the interface between proliferation and differentiation. -- Abstract: Clonal proliferation is an obligatory component of adipogenesis. Although several cell cycle regulators are known to participate in the transition between pre-adipocyte proliferation and terminal adipocyte differentiation, how the core DNA synthesis machinery is coordinately regulated in adipogenesis remains elusive. PCNA (Proliferating Cell Nuclear Antigen) is an indispensable component for DNA synthesis during proliferation. Here we show that PCNA is subject to phosphorylation at the highly conserved tyrosine residue 114 (Y114). Replacing the Y114 residue with phenylalanine (Y114F), which is structurally similar to tyrosine but cannot be phosphorylated, does not affect normal animal development. However, when challenged with high fat diet, mice carrying homozygous Y114F alleles (PCNA{sup F/F}) are resistant to adipose tissue enlargement in comparison to wild-type (WT) mice. Mouse embryonic fibroblasts (MEFs) harboring WT or Y114F mutant PCNA proliferate at similar rates. However, when subjected to adipogenesis induction in culture, PCNA{sup F/F} MEFs are not able to re-enter the cell cycle and fail to form mature adipocytes, while WT MEFs undergo mitotic clonal expansion in response to the adipogenic stimulation, accompanied by enhanced Y114 phosphorylation of PCNA, and differentiate to mature adipocytes. Consistent with the function of Y114 phosphorylation in clonal proliferation in adipogenesis, fat tissues isolated from WT

  17. Effect of Nelumbo nucifera Petal Extracts on Lipase, Adipogenesis, Adipolysis, and Central Receptors of Obesity

    Directory of Open Access Journals (Sweden)

    Chandrasekaran Chinampudur Velusami

    2013-01-01

    Full Text Available N. nucifera is one among the important medicinal plants assessed for its antiobesity action in various preclinical models. The present study was aimed at investigating the antiobesity effect of methanol and successive water extracts of petals of N. nucifera by studying its effect on adipogenesis, adipolysis, lipase, serotonin (5-HT2C, cannabinoid (CNR2, melanocyte concentrating hormone (MCHR1, and melanocortin (MC4R receptors. Both methanol and successive water extracts of N. nucifera petals had an effect on inhibition of lipid storage in adipocytes and on increasing lipolysis. N. nucifera petal methanol extract exhibited the concentration-dependent inhibitory effect on lipase activity with an IC50 value of 47 µg/mL. N. nucifera petal extracts showed evident agonist and antagonist activity towards 5-HT2C and CNR2 receptors, respectively, while it showed no effect towards MCHR1 and MC4R receptors. Overall, methanol extract of N. nucifera petals showed better activity than successive water extract.

  18. Pituitary adenylate cyclase activating peptide (PACAP participates in adipogenesis by activating ERK signaling pathway.

    Directory of Open Access Journals (Sweden)

    Tatjana Arsenijevic

    Full Text Available Pituitary adenylate cyclase activating peptide (PACAP belongs to the secretin/glucagon/vasoactive intestinal peptide (VIP family. Its action can be mediated by three different receptor subtypes: PAC1, which has exclusive affinity for PACAP, and VPAC1 and VPAC2 which have equal affinity for PACAP and VIP. We showed that all three receptors are expressed in 3T3-L1 cells throughout their differentiation into adipocytes. We established the activity of these receptors by cAMP accumulation upon induction by PACAP. Together with insulin and dexamethasone, PACAP induced adipogenesis in 3T3-L1 cell line. PACAP increased cAMP production within 15 min upon stimulation and targeted the expression and phosphorylation of MAPK (ERK1/2, strengthened by the ERK1/2 phosphorylation being partially or completely abolished by different combinations of PACAP receptors antagonists. We therefore speculate that ERK1/2 activation is crucial for the activation of CCAAT/enhancer- binding protein β (C/EBPβ.

  19. The LXCXE Retinoblastoma Protein-Binding Motif of FOG-2 Regulates Adipogenesis.

    Science.gov (United States)

    Goupille, Olivier; Penglong, Tipparat; Kadri, Zahra; Granger-Locatelli, Marine; Denis, Raphaël; Luquet, Serge; Badoual, Cécile; Fucharoen, Suthat; Maouche-Chrétien, Leila; Leboulch, Philippe; Chrétien, Stany

    2017-12-19

    GATA transcription factors and their FOG cofactors play a key role in tissue-specific development and differentiation, from worms to humans. Mammals have six GATA and two FOG factors. We recently demonstrated that interactions between retinoblastoma protein (pRb) and GATA-1 are crucial for erythroid proliferation and differentiation. We show here that the LXCXE pRb-binding site of FOG-2 is involved in adipogenesis. Unlike GATA-1, which inhibits cell division, FOG-2 promotes proliferation. Mice with a knockin of a Fog2 gene bearing a mutated LXCXE pRb-binding site are resistant to obesity and display higher rates of white-to-brown fat conversion. Thus, each component of the GATA/FOG complex (GATA-1 and FOG-2) is involved in pRb/E2F regulation, but these molecules have markedly different roles in the control of tissue homeostasis. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  20. Repressive coping and alexithymia in idiopathic environmental intolerance

    DEFF Research Database (Denmark)

    Skovbjerg, Sine; Zachariae, Robert; Rasmussen, Alice

    2010-01-01

    To examine if the non-expression of negative emotions (i.e., repressive coping) and differences in the ability to process and regulate emotions (i.e., alexithymia) is associated with idiopathic environmental intolerance (IEI).......To examine if the non-expression of negative emotions (i.e., repressive coping) and differences in the ability to process and regulate emotions (i.e., alexithymia) is associated with idiopathic environmental intolerance (IEI)....

  1. Dose- and type-dependent effects of long-chain fatty acids on adipogenesis and lipogenesis of bovine adipocytes.

    Science.gov (United States)

    Yanting, Chen; Yang, Q Y; Ma, G L; Du, M; Harrison, J H; Block, E

    2018-02-01

    Differentiation and lipid metabolism of adipocytes have a great influence on milk performance, health, and feed efficiency of dairy cows. The effects of dietary long-chain fatty acids (FA) on adipogenesis and lipogenesis of dairy cows are often confounded by other nutritional and physiological factors in vivo. Therefore, this study used an in vitro approach to study the effect of dose and type of long-chain FA on adipogenesis and lipogenesis of bovine adipocytes. Stromal vascular cells were isolated from adipose tissue of dairy cows and induced into mature adipocytes in the presence of various long-chain FA including myristic, palmitic, stearic, oleic, or linoleic acid. When concentrations of myristic, palmitic, and oleic acids in adipogenic mediums were 150 and 200 μM, the induced mature adipocytes had greater lipid content compared with other concentrations of FA. In addition, mature adipocytes induced at 100 μM stearic acid and 300 μM linoleic acid had the greatest content of lipid than at other concentrations. High concentrations of saturated FA were more toxic for cells than the same concentration of unsaturated FA during the induction. When commitment stage was solely treated with FA, the number of differentiated mature adipocytes was greater for oleic and linoleic acids than other FA. When the maturation stage was treated with FA, the number of mature adipocytes was not affected, but the lipid content in adipocytes was affected and ranked oleic > linoleic > myristic > stearic > palmitic. In summary, this study showed that adipogenesis and lipogenesis of bovine adipocytes were differentially affected by long-chain FA, with unsaturated FA more effective than saturated FA. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  2. Kirenol inhibits adipogenesis through activation of the Wnt/β-catenin signaling pathway in 3T3-L1 adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mi-Bo [Department of Biomaterials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Song, Youngwoo; Kim, Changhee [Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Hwang, Jae-Kwan, E-mail: jkhwang@yonsei.ac.kr [Department of Biomaterials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2014-03-07

    Highlights: • Kirenol inhibits the adipogenic transcription factors and lipogenic enzymes. • Kirenol stimulates the Wnt/β-catenin signaling pathway components. • Kirenol inhibits adipogenesis through activation of the Wnt/β-catenin signaling pathway. - Abstract: Kirenol, a natural diterpenoid compound, has been reported to possess anti-oxidant, anti-inflammatory, anti-allergic, and anti-arthritic activities; however, its anti-adipogenic effect remains to be studied. The present study evaluated the effect of kirenol on anti-adipogenesis through the activation of the Wnt/β-catenin signaling pathway. Kirenol prevented intracellular lipid accumulation by down-regulating key adipogenesis transcription factors [peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer binding proteins α (C/EBPα), and sterol regulatory element binding protein-1c (SREBP-1c)] and lipid biosynthesis-related enzymes [fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC)], as well as adipocytokines (adiponectin and leptin). Kirenol effectively activated the Wnt/β-catenin signaling pathway, in which kirenol up-regulated the expression of low density lipoprotein receptor related protein 6 (LRP6), disheveled 2 (DVL2), β-catenin, and cyclin D1 (CCND1), while it inactivated glycogen synthase kinase 3β (GSK3β) by increasing its phosphorylation. Kirenol down-regulated the expression levels of PPARγ and C/EBPα, which were up-regulated by siRNA knockdown of β-catenin. Overall, kirenol is capable of inhibiting the differentiation and lipogenesis of 3T3-L1 adipocytes through the activation of the Wnt/β-catenin signaling pathway, suggesting its potential as natural anti-obesity agent.

  3. Novel polysome messages and changes in translational activity appear after induction of adipogenesis in 3T3-L1 cells

    Directory of Open Access Journals (Sweden)

    Fromm-Dornieden Carolin

    2012-03-01

    Full Text Available Abstract Background Control of translation allows for rapid adaptation of the cell to stimuli, rather than the slower transcriptional control. We presume that translational control is an essential process in the control of adipogenesis, especially in the first hours after hormonal stimulation. 3T3-L1 preadipocytes were cultured to confluency and adipogenesis was induced by standard protocols using a hormonal cocktail. Cells were harvested before and 6 hours after hormonal induction. mRNAs attached to ribosomes (polysomal mRNAs were separated from unbound mRNAs by velocity sedimentation. Pools of polysomal and unbound mRNA fractions were analyzed by microarray analysis. Changes in relative abundance in unbound and polysomal mRNA pools were calculated to detect putative changes in translational activity. Changes of expression levels of selected genes were verified by qPCR and Western blotting. Results We identified 43 genes that shifted towards the polysomal fraction (up-regulated and 2 genes that shifted towards free mRNA fraction (down-regulated. Interestingly, we found Ghrelin to be down-regulated. Up-regulated genes comprise factors that are nucleic acid binding (eIF4B, HSF1, IRF6, MYC, POLR2a, RPL18, RPL27a, RPL6, RPL7a, RPS18, RPSa, TSC22d3, form part of ribosomes (RPL18, RPL27a, RPL6, RPL7a, RPS18, RPSa, act on the regulation of translation (eIF4B or transcription (HSF1, IRF6, MYC, TSC22d3. Others act as chaperones (BAG3, HSPA8, HSP90ab1 or in other metabolic or signals transducing processes. Conclusions We conclude that a moderate reorganisation of the functionality of the ribosomal machinery and translational activity are very important steps for growth and gene expression control in the initial phase of adipogenesis.

  4. Regulation of adipogenesis by nucelar receptor PPARγ is modulated by the histone demethylase JMJD2C

    Directory of Open Access Journals (Sweden)

    Lizcano Fernando

    2011-01-01

    Full Text Available A potential strategy to combat obesity and its associated complications involves modifying gene expression in adipose cells to reduce lipid accumulation. The nuclear receptor Peroxisome Proliferator-activated receptor gamma (PPARγ is the master regulator of adipose cell differentiation and its functional activation is currently used as a therapeutic approach for Diabetes Mellitus type 2. However, total activation of PPARγ induces undesirable secondary effects that might be set with a partial activation. A group of proteins that produce histone demethylation has been shown to modify the transcriptional activity of nuclear receptors. Here we describe the repressive action of the jumonji domain containing 2C/lysine demethylase 4 C (JMJD2C/KDM4C on PPARγ transcriptional activation. JMJD2C significantly reduced the rosiglitazone stimulated PPARγ activation. This effect was mainly observed in experiments performed using the Tudor domains that may interact with histone deacetylase class 1 (HDAC and this interaction probably reduces the mediated activation of PPARγ. Trichostatin A, a HDAC inhibitor, reduces the repressive effect of JMJD2C. When JMJD2C was over-expressed in 3T3-L1 cells, a reduction of differentiation was observed with the Tudor domain. In summary, we herein describe JMJD2C-mediated reduction of PPARgamma transcriptional activation as well as preadipocyte differentiation. This novel action of JMJD2C might have an important role in new therapeutic approaches to treat obesity and its complications.

  5. Modulation of adipogenesis and glucose uptake by Curcuma longa extract in 3T3L1 and L6 cell lines - An in vitro study

    Directory of Open Access Journals (Sweden)

    A. Prathapan

    2012-05-01

    Full Text Available Objective: To evaluate the effects of ethyl acetate extract of Curcuma longa against modulation of glucose uptake and adipogenesis in cell line models. Methods: We used 3T3L1 and L6 cells to investigate cytotoxicity, glucose uptake with 2-NBDG as probe and adipogenesis. All the analysis was done with flowcytometry. Results: The results showed that the extract did not possess any significant glucose uptake activity but it exhibited significant adipocyte differentiation potential. Conclusions: Ethyl acetate extract of Curcuma longa exhibits significant antiadipogenesis and can be used as an effective drug for the treatment of obesity and other associated complications.

  6. The role of mitochondria in carbon catabolite repression in yeast.

    Science.gov (United States)

    Haussmann, P; Zimmermann, F K

    1976-10-18

    The role of mitochondria in carbon catabolite repression in Saccharomyces cerevisiae was investigated by comparing normal, respiratory competent (RHO) strains with their mitochondrially inherited, respiratory deficient mutant derivatives (rho). Formation of maltase and invertase was used as an indicator system for the effect of carbon catabolite repression on carbon catabolic reactions. Fermentation rates for glucose, maltose and sucrose were the same in RHO and rho strains. Specific activities of maltase and invertase were usually higher in the rho-mutants. A very pronounced difference in invertase levels was observed when cells were grown on maltose; rho-mutants had around 30 times more invertase than their RHO parent strains. The fact that rho-mutants were much less sensitive to carbon catabolite repression of invertase synthesis than their RHO parents was used to search for the mitochondrial factor(s) or function(s) involved in carbon catabolite repression. A possible metabolic influence of mitochondria on this system of regulation was tested after growth of RHO strains under anaerobic conditions (no respiration nor oxidative phosphorylation), in the presence of KCN (respiration inhibited), dinitrophenol (uncoupling of oxidative phosphorylation) and of both inhibitors anaerobic conditions and dinitrophenol had no effect on the extent of invertase repression. KCN reduced the degree of repression but not to the level found in rho-mutants. A combination of both inhibitors gave the same results as with KCN alone. Erythromycin and chloramphenicol were used as specific inhibitors of mitochondrial protein synthesis. Erythromycin prevented the formation of mitochondrial respiratory systems but did not induce rho-mutants under the conditions used. However, repression of invertase was as strong as in the absence of the inhibitor. Chloramphenicol led only to a slight reduction of the respiratory systems and did not affect invertase levels. A combination of both

  7. Coculture with BJ fibroblast cells inhibits the adipogenesis and lipogenesis in 3T3-L1 cells

    International Nuclear Information System (INIS)

    Jeong, Hyun Jeong; Park, Sahng Wook; Kim, Hojeong; Park, Sang-Kyu; Yoon, Dojun

    2010-01-01

    Mouse or human fibroblasts are commonly used as feeder cells to prevent differentiation in stem or primary cell culture. In the present study, we addressed whether fibroblasts can affect the differentiation of adipocytes. We found that the differentiation of 3T3-L1 preadipocytes was strongly suppressed when the cells were cocultured with human fibroblast (BJ) cells. BrdU incorporation analysis indicated that mitotic clonal expansion, an early event required for 3T3-L1 cell adipogenesis, was not affected by BJ cells. The 3T3-L1 cell expression levels of peroxisome proliferator-activated receptor γ2, CCAAT/enhancer-binding protein alpha (C/EBPα), sterol regulatory element binding protein-1c, and Krueppel-like factor 15, but not those of C/EBPβ or C/EBPδ, were decreased by coculture with BJ cells. When mature 3T3-L1 adipocytes were cocultured with BJ cells, their lipid contents were significantly reduced, with decreased fatty acid synthase expression and increased phosphorylated form of acetyl-CoA carboxylase 1. Our data indicate that coculture with BJ fibroblast cells inhibits the adipogenesis of 3T3-L1 preadipocytes and decreases the lipogenesis of mature 3T3-L1 adipocytes.

  8. Bee Venom Suppresses the Differentiation of Preadipocytes and High Fat Diet-Induced Obesity by Inhibiting Adipogenesis.

    Science.gov (United States)

    Cheon, Se-Yun; Chung, Kyung-Sook; Roh, Seong-Soo; Cha, Yun-Yeop; An, Hyo-Jin

    2017-12-24

    Bee venom (BV) has been widely used in the treatment of certain immune-related diseases. It has been used for pain relief and in the treatment of chronic inflammatory diseases. Despite its extensive use, there is little documented evidence to demonstrate its medicinal utility against obesity. In this study, we demonstrated the inhibitory effects of BV on adipocyte differentiation in 3T3-L1 cells and on a high fat diet (HFD)-induced obesity mouse model through the inhibition of adipogenesis. BV inhibited lipid accumulation, visualized by Oil Red O staining, without cytotoxicity in the 3T3-L1 cells. Male C57BL/6 mice were fed either a HFD or a control diet for 8 weeks, and BV (0.1 mg/kg or 1 mg/kg) or saline was injected during the last 4 weeks. BV-treated mice showed a reduced body weight gain. BV was shown to inhibit adipogenesis by downregulating the expression of the transcription factors CCAAT/enhancer-binding proteins (C/EBPs) and the peroxisome proliferator-activated receptor gamma (PPARγ), using RT-qPCR and Western blotting. BV induced the phosphorylation of AMP-activated kinase (AMPK) and acetyl-CoA carboxylase (ACC) in the cell line and in obese mice. These findings demonstrate that BV mediates anti-obesity/differentiation effects by suppressing obesity-related transcription factors.

  9. Overexpression of Akt1 enhances adipogenesis and leads to lipoma formation in zebrafish.

    Directory of Open Access Journals (Sweden)

    Che-Yu Chu

    Full Text Available BACKGROUND: Obesity is a complex, multifactorial disorder influenced by the interaction of genetic, epigenetic, and environmental factors. Obesity increases the risk of contracting many chronic diseases or metabolic syndrome. Researchers have established several mammalian models of obesity to study its underlying mechanism. However, a lower vertebrate model for conveniently performing drug screening against obesity remains elusive. The specific aim of this study was to create a zebrafish obesity model by over expressing the insulin signaling hub of the Akt1 gene. METHODOLOGY/PRINCIPAL FINDINGS: Skin oncogenic transformation screening shows that a stable zebrafish transgenic of Tg(krt4Hsa.myrAkt1(cy18 displays severely obese phenotypes at the adult stage. In Tg(krt4:Hsa.myrAkt1(cy18, the expression of exogenous human constitutively active Akt1 (myrAkt1 can activate endogenous downstream targets of mTOR, GSK-3α/β, and 70S6K. During the embryonic to larval transitory phase, the specific over expression of myrAkt1 in skin can promote hypertrophic and hyperplastic growth. From 21 hour post-fertilization (hpf onwards, myrAkt1 transgene was ectopically expressed in several mesenchymal derived tissues. This may be the result of the integration position effect. Tg(krt4:Hsa.myrAkt1(cy18 caused a rapid increase of body weight, hyperplastic growth of adipocytes, abnormal accumulation of fat tissues, and blood glucose intolerance at the adult stage. Real-time RT-PCR analysis showed the majority of key genes on regulating adipogenesis, adipocytokine, and inflammation are highly upregulated in Tg(krt4:Hsa.myrAkt1(cy18. In contrast, the myogenesis- and skeletogenesis-related gene transcripts are significantly downregulated in Tg(krt4:Hsa.myrAkt1(cy18, suggesting that excess adipocyte differentiation occurs at the expense of other mesenchymal derived tissues. CONCLUSION/SIGNIFICANCE: Collectively, the findings of this study provide direct evidence that Akt1

  10. Suppression and repression: A theoretical discussion illustrated by a movie

    Directory of Open Access Journals (Sweden)

    Maria Lucia de Souza Campos Paiva

    2012-02-01

    Full Text Available The first translations of Freud's work into Portuguese have presented problems because they were not translated from the German language. More than a hundred years after the beginning of Psychoanalysis, there are still many discussions on Freud's metapsychology and a considerable difficulty in obtaining a consensus on the translation of some concepts. This paper refers back to Freud's concepts of primal repression, repression and suppression. In order to discuss such concepts, we have made use of a film, co-produced by Germans and Argentineans, which is named "The Song in me" (Das Lied in mir, released to the public in 2011 and directed by Florian Micoud Cossen. Through this motion picture, the following of Freud's concepts are analyzed, and the differentiation between them is discussed: suppression and repression, as well as the importance of their precise translation.

  11. The transcription factor DREAM represses A20 and mediates inflammation

    OpenAIRE

    Tiruppathi, Chinnaswamy; Soni, Dheeraj; Wang, Dong-Mei; Xue, Jiaping; Singh, Vandana; Thippegowda, Prabhakar B.; Cheppudira, Bopaiah P.; Mishra, Rakesh K.; DebRoy, Auditi; Qian, Zhijian; Bachmaier, Kurt; Zhao, Youyang; Christman, John W.; Vogel, Stephen M.; Ma, Averil

    2014-01-01

    Here we show that the transcription-repressor DREAM binds to the A20 promoter to repress the expression of A20, the deubiquitinase suppressing inflammatory NF-κB signaling. DREAM-deficient (Dream−/− ) mice displayed persistent and unchecked A20 expression in response to endotoxin. DREAM functioned by transcriptionally repressing A20 through binding to downstream regulatory elements (DREs). In contrast, USF1 binding to the DRE-associated E-box domain activated A20 expression in response to inf...

  12. Extremadura: Behind the material traces of Franco’s repression

    OpenAIRE

    Muñoz Encinar, Laura; Chaves Palacios, Julián

    2014-01-01

    After the failed coup d’état of July 17th, 1936 and after the start of the Spanish Civil War that followed it, rebels carried out a repressive strategy based on the execution of thousands of people as a key tool of social control. The socialization of fear and terror through humiliation, killing and disappearance would become the main strategy employed throughout the war and the post-war period. In this context, perpetrators would exercise repressive practices on victims and their bodies. As ...

  13. Mechanisms of transcriptional repression by histone lysine methylation

    DEFF Research Database (Denmark)

    Hublitz, Philip; Albert, Mareike; Peters, Antoine H F M

    2009-01-01

    . In this report, we review the recent literature to deduce mechanisms underlying Polycomb and H3K9 methylation mediated repression, and describe the functional interplay with activating H3K4 methylation. We summarize recent data that indicate a close relationship between GC density of promoter sequences......, transcription factor binding and the antagonizing activities of distinct epigenetic regulators such as histone methyltransferases (HMTs) and histone demethylases (HDMs). Subsequently, we compare chromatin signatures associated with different types of transcriptional outcomes from stable repression to highly...

  14. Polycomb complexes act redundantly to repress genomic repeats and genes

    DEFF Research Database (Denmark)

    Leeb, Martin; Pasini, Diego; Novatchkova, Maria

    2010-01-01

    Polycomb complexes establish chromatin modifications for maintaining gene repression and are essential for embryonic development in mice. Here we use pluripotent embryonic stem (ES) cells to demonstrate an unexpected redundancy between Polycomb-repressive complex 1 (PRC1) and PRC2 during...... the formation of differentiated cells. ES cells lacking the function of either PRC1 or PRC2 can differentiate into cells of the three germ layers, whereas simultaneous loss of PRC1 and PRC2 abrogates differentiation. On the molecular level, the differentiation defect is caused by the derepression of a set...

  15. TRP channels in brown and white adipogenesis from human progenitors : new therapeutic targets and the caveats associated with the common antibiotic, streptomycin

    NARCIS (Netherlands)

    Goralczyk, A.; van Vijven, M.; Koch, M.; Badowski, C.; Yassin, M.S.; Toh, S.A.; Shabbir, A.; Franco-Obregón, A.; Raghunath, M.

    2017-01-01

    Transient receptor potential (TRP) channels are polymodal cell sensors responding to diverse stimuli and widely implicated in the developmental programs of numerous tissues. The evidence for an involvement of TRP family members in adipogenesis, however, is scant. We present the first comprehensive

  16. The environmental obesogen tributyltin chloride acts via peroxisome proliferator activated receptor gamma to induce adipogenesis in murine 3T3-L1 preadipocytes

    Science.gov (United States)

    Li, Xia; Ycaza, John; Blumberg, Bruce

    2012-01-01

    Obesogens are chemicals that predispose exposed individuals to weight gain and obesity by increasing the number of fat cells, storage of fats into existing cells, altering metabolic rates, or disturbing the regulation of appetite and satiety. Tributyltin exposure causes differentiation of multipotent stromal stem cells (MSCs) into adipocytes; prenatal TBT exposure leads to epigenetic changes in the stem cell compartment that favor the production of adipocytes at the expense of bone, in vivo. While it is known that TBT acts through peroxisome proliferator activated receptor gamma to induce adipogenesis in MSCs, the data in 3T3-L1 preadipocytes are controversial. Here we show that TBT can activate the RXR-PPARγ heterodimer even in the presence of the PPARγ antagonist GW9662. We found that GW9662 has a ten-fold shorter half-life in cell culture than do PPARγ activators such as rosiglitazone (ROSI), accounting for previous observations that GW9662 did not inhibit TBT-mediated adipogenesis. When the culture conditions are adjusted to compensate for the short half-life of GW-9662, we found that TBT induces adipogenesis, triglyceride storage and the expression of adipogenic marker genes in 3T3-L1 cells in a PPARγ-dependent manner. Our results are broadly applicable to the study of obesogen action and indicate that ligand stability is an important consideration in the design and interpretation of adipogenesis assays. PMID:21397693

  17. Metals of Deep Ocean Water Increase the Anti-Adipogenesis Effect of Monascus-Fermented Product via Modulating the Monascin and Ankaflavin Production.

    Science.gov (United States)

    Lung, Tzu-Ying; Liao, Li-Ya; Wang, Jyh-Jye; Wei, Bai-Luh; Huang, Ping-Yi; Lee, Chun-Lin

    2016-05-27

    Deep ocean water (DOW) obtained from a depth of more than 200 m includes abundant nutrients and minerals. DOW was proven to positively increase monascin (MS) and ankaflavin (AK) production and the anti-adipogenesis effect of Monascus-fermented red mold dioscorea (RMD). However, the influences that the major metals in DOW have on Monascus secondary metabolite biosynthesis and anti-adipogenesis remain unknown. Therefore, the major metals in DOW were used as the culture water to produce RMD. The secondary metabolites production and anti-adipogenesis effect of RMD cultured with various individual metal waters were investigated. In the results, the addition of water with Mg, Ca, Zn, and Fe increased MS and AK production and inhibited mycotoxin citrinin (CT). However, the positive influence may be contributed to the regulation of pigment biosynthesis. Furthermore, in the results of cell testing, higher lipogenesis inhibition was seen in the treatments of various ethanol extracts of RMD cultured with water containing Mg, K, Zn, and Fe than in those of RMD cultured with ultra-pure water. In conclusion, various individual metals resulted in different effects on MS and AK productions as well as the anti-adipogenesis effect of RMD, but the specific metals contained in DOW may cause synergistic or comprehensive effects that increase the significantly positive influence.

  18. Coffee extract inhibits adipogenesis in 3T3-L1 preadipocyes by interrupting insulin signaling through the downregulation of IRS1.

    Directory of Open Access Journals (Sweden)

    Chihiro Maki

    Full Text Available Although epidemiological data have indicated that a strong negative association exists between coffee consumption and the prevalence of obesity-associated diseases, the molecular mechanisms by which coffee intake prevents obesity-associated diseases has not yet been elucidated. In this study, we found that coffee intake significantly suppressed high-fat diet (HFD-induced metabolic alternations such as increases in body weight and the accumulation of adipose tissue, and up-regulation of glucose, free fatty acid, total cholesterol and insulin levels in the blood. We also found that coffee extract significantly inhibited adipogenesis in 3T3-L1 preadipocytes. In the early phase of adipogenesis, 3T3-L1 cells treated with coffee extract displayed the retardation of cell cycle entry into the G2/M phase called as mitotic clonal expansion (MCE. Coffee extract also inhibited the activation of CCAAT/enhancer-binding protein β (C/EBPβ by preventing its phosphorylation by ERK. Furthermore, the coffee extract suppressed the adipogenesis-related events such as MCE and C/EBPβ activation through the down-regulation of insulin receptor substrate 1 (IRS1. The stability of the IRS1 protein was markedly decreased by the treatment with coffee extract due to proteasomal degradation. These results have revealed an anti-adipogenic function for coffee intake and identified IRS1 as a novel target for coffee extract in adipogenesis.

  19. The influence of thiazolidinediones on adipogenesis in vitro and in vivo: potential modifiers of intramuscular adipose tissue deposition in meat animals.

    Science.gov (United States)

    Hausman, G J; Poulos, S P; Pringle, T D; Azain, M J

    2008-04-01

    Thiazolidinediones (TZD) are insulin sensitizing agents currently used for the treatment of type 2 diabetes and are widely used as adipogenic agents because they are ligands of peroxisome proliferator-activated receptor gamma (PPARgamma), a key adipogenic transcription factor. In vivo and in vitro studies of TZD as potential modifiers of intramuscular or marbling adipogenesis are reviewed. Thiazolidinedione-induced adipogenesis has been reported in numerous cell culture systems, including rodent, human, bovine, and porcine adipose tissue stromal-vascular (S-V) cell cultures. Studies of porcine S-V cell cultures derived from semitendinosus muscle show that TZD can potentially modify intramuscular or marbling adipogenesis. Preadipocyte recruitment was TZD-dependent in muscle S-V cultures but TZD-independent in adipose S-V cultures. There appear to be differences between adipocytes in muscle and subcutaneous adipose tissue, reminiscent of differences observed in adipocytes from different adipose tissue depots. Troglitazone, a TZD, induces marbling adipogenesis without inhibiting myogenesis when cells are grown on laminin precoated culture dishes. Additionally, troglitazone treatment does not increase lipid content in porcine adipose tissue or muscle S-V cell cultures. Thiazolidinedione treatment increases lipid content of muscle in rodents and humans; however, rosiglitazone treatment for 49 d in pigs did not influence muscle lipid content and meat quality, but several significant changes in muscle fatty acid composition were observed. Although timing of treatment with TZD needs to be optimized, evidence suggests these compounds may enhance marbling deposition in swine.

  20. Space microgravity drives transdifferentiation of human bone marrow-derived mesenchymal stem cells from osteogenesis to adipogenesis.

    Science.gov (United States)

    Zhang, Cui; Li, Liang; Jiang, Yuanda; Wang, Cuicui; Geng, Baoming; Wang, Yanqiu; Chen, Jianling; Liu, Fei; Qiu, Peng; Zhai, Guangjie; Chen, Ping; Quan, Renfu; Wang, Jinfu

    2018-03-13

    Bone formation is linked with osteogenic differentiation of mesenchymal stem cells (MSCs) in the bone marrow. Microgravity in spaceflight is known to reduce bone formation. In this study, we used a real microgravity environment of the SJ-10 Recoverable Scientific Satellite to examine the effects of space microgravity on the osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hMSCs). hMSCs were induced toward osteogenic differentiation for 2 and 7 d in a cell culture device mounted on the SJ-10 Satellite. The satellite returned to Earth after going through space experiments in orbit for 12 d, and cell samples were harvested and analyzed for differentiation potentials. The results showed that space microgravity inhibited osteogenic differentiation and resulted in adipogenic differentiation, even under osteogenic induction conditions. Under space microgravity, the expression of 10 genes specific for osteogenesis decreased, including collagen family members, alkaline phosphatase ( ALP), and runt-related transcription factor 2 ( RUNX2), whereas the expression of 4 genes specific for adipogenesis increased, including adipsin ( CFD), leptin ( LEP), CCAAT/enhancer binding protein β ( CEBPB), and peroxisome proliferator-activated receptor-γ ( PPARG). In the analysis of signaling pathways specific for osteogenesis, we found that the expression and activity of RUNX2 was inhibited, expression of bone morphogenetic protein-2 ( BMP2) and activity of SMAD1/5/9 were decreased, and activity of focal adhesion kinase (FAK) and ERK-1/2 declined significantly under space microgravity. These data indicate that space microgravity plays a dual role by decreasing RUNX2 expression and activity through the BMP2/SMAD and integrin/FAK/ERK pathways. In addition, we found that space microgravity increased p38 MAPK and protein kinase B (AKT) activities, which are important for the promotion of adipogenic differentiation of hMSCs. Space microgravity significantly

  1. miRNA-dependent translational repression in the Drosophila ovary.

    Directory of Open Access Journals (Sweden)

    John Reich

    Full Text Available The Drosophila ovary is a tissue rich in post-transcriptional regulation of gene expression. Many of the regulatory factors are proteins identified via genetic screens. The more recent discovery of microRNAs, which in other animals and tissues appear to regulate translation of a large fraction of all mRNAs, raised the possibility that they too might act during oogenesis. However, there has been no direct demonstration of microRNA-dependent translational repression in the ovary.Here, quantitative analyses of transcript and protein levels of transgenes with or without synthetic miR-312 binding sites show that the binding sites do confer translational repression. This effect is dependent on the ability of the cells to produce microRNAs. By comparison with microRNA-dependent translational repression in other cell types, the regulated mRNAs and the protein factors that mediate repression were expected to be enriched in sponge bodies, subcellular structures with extensive similarities to the P bodies found in other cells. However, no such enrichment was observed.Our results reveal the variety of post-transcriptional regulatory mechanisms that operate in the Drosophila ovary, and have implications for the mechanisms of miRNA-dependent translational control used in the ovary.

  2. Repressive coping and alexithymia in ideopathic environmental intolerance

    DEFF Research Database (Denmark)

    Skovbjerg, Sine; Zachariae, Robert; Rasmussen, Alice

    2010-01-01

    participated in a general population-based study and reported symptoms of environmental intolerance (n = 787) and patients with IEI (n = 237). The participants completed questionnaires assessing IEI, namely, a measure of repressive coping combining scores on the Marlowe–Crowne Social Desirability Scale (MCSDS...

  3. Financial repression, money growth, and seignorage: The Polish experience

    NARCIS (Netherlands)

    Aarle, B. van; Budina, N.

    1997-01-01

    Financial Repression, Money Growth and Seignorage: The Polish Experience. — A small analytical framework is developed to analyze the relation between reserve requirements, base money growth and seignorage revenues. From the analysis, the authors can derive of steady-state seignorage revenues as a

  4. CcpA-dependent carbon catabolite repression in bacteria

    NARCIS (Netherlands)

    Warner, JB; Lolkema, JS; Warner, Jessica B.

    2003-01-01

    Carbon catabolite repression (CCR) by transcriptional regulators follows different mechanisms in gram-positive and gram-negative bacteria. In gram-positive bacteria, CcpA-dependent CCR is mediated by phosphorylation of the phosphoenolpyruvate:sugar phosphotransferase system intermediate HPr at a

  5. Financial repression and high public debt in Europe

    NARCIS (Netherlands)

    van Riet, Ad

    2018-01-01

    The sharp rise in public debt-to-GDP ratios in the aftermath of the global financial crisis of 2008 posed serious challenges for fiscal policy in euro area countries. This thesis examines whether and to what extent modern financial repression has been applied in Europe to address these challenges.

  6. Repression of competition favours cooperation : experimental evidence from bacteria

    NARCIS (Netherlands)

    Kümmerli, Rolf; van den Berg, Piet; Griffin, Ashleigh S; West, Stuart A; Gardner, Andy

    Repression of competition (RC) within social groups has been suggested as a key mechanism driving the evolution of cooperation, because it aligns the individual's proximate interest with the interest of the group. Despite its enormous potential for explaining cooperation across all levels of

  7. Repressive Tolerance and the Practice of Adult Education

    Science.gov (United States)

    Brookfield, Stephen D.

    2014-01-01

    Herbert Marcuse's concept of repressive tolerance argues that behind the justification of tolerance lies the possibility of ideological domination. Tolerance allows intolerable practices to go unchallenged and flattens discussion to assume all viewpoints have equal validity. When alternative, dissenting views are inserted into the curriculum…

  8. The Perils of Repressive Tolerance in Music Education Curriculum

    Science.gov (United States)

    Perrine, William M.

    2017-01-01

    In recent years, philosophers of music education have called for a greater degree of political engagement by music education practitioners. Using Marcuse's discussion of "repressive tolerance" as a conceptual framework, I argue that a politicized curriculum in music education works against the liberal ideas of free speech and a free…

  9. Peroxisome proliferator-activated receptor gamma recruits the positive transcription elongation factor b complex to activate transcription and promote adipogenesis

    DEFF Research Database (Denmark)

    Iankova, Irena; Petersen, Rasmus K; Annicotte, Jean-Sébastien

    2006-01-01

    Positive transcription elongation factor b (P-TEFb) phosphorylates the C-terminal domain of RNA polymerase II, facilitating transcriptional elongation. In addition to its participation in general transcription, P-TEFb is recruited to specific promoters by some transcription factors such as c......-Myc or MyoD. The P-TEFb complex is composed of a cyclin-dependent kinase (cdk9) subunit and a regulatory partner (cyclin T1, cyclin T2, or cyclin K). Because cdk9 has been shown to participate in differentiation processes, such as muscle cell differentiation, we studied a possible role of cdk9...... with and phosphorylation of peroxisome proliferator-activated receptor gamma (PPARgamma), which is the master regulator of this process, on the promoter of PPARgamma target genes. PPARgamma-cdk9 interaction results in increased transcriptional activity of PPARgamma and therefore increased adipogenesis....

  10. State Repression and its Effects on Civil Conflict, Socio-Economic Outcomes, and Leadership Tenure

    Science.gov (United States)

    feedback loop: how citizens respond peacefully or violently influences the type of repression rulers employ. How rulers use repression influences how and...whether citizens protest. Moreover, how rulers respond to their citizens may influence leadership duration. Obviously, the relationship among repression...US (and allied) officials may want policy options to influence rulers who are becoming increasingly repressive (as in Turkey and Egypt) or leaders who

  11. Myostatin inhibits myogenesis and promotes adipogenesis in C3H 10T(1/2) mesenchymal multipotent cells.

    Science.gov (United States)

    Artaza, Jorge N; Bhasin, Shalender; Magee, Thomas R; Reisz-Porszasz, Suzanne; Shen, Ruoquin; Groome, Nigel P; Meerasahib, Mohamed Fareez; Fareez, Meerasaluh M; Gonzalez-Cadavid, Nestor F

    2005-08-01

    Inactivating mutations of the mammalian myostatin gene are associated with increased muscle mass and decreased fat mass; conversely, myostatin transgenic mice that overexpress myostatin in the skeletal muscle have decreased muscle mass and increased fat mass. We investigated the effects of recombinant myostatin protein and antimyostatin antibody on myogenic and adipogenic differentiation of mesenchymal multipotent cells. Accordingly, 10T(1/2) cells were incubated with 5'-azacytidine for 3 d to induce differentiation and then treated with a recombinant protein for myostatin (Mst) carboxy terminal 113 amino acids or a polyclonal anti-Mst antibody for 3, 7, and 14 d. Cells were also cotransfected with a Mst cDNA plasmid expressing the full-length 375-amino acid protein (pcDNA-Mst375) and the silencer RNAs for either Mst (pSil-Mst) or a random sequence (pSil-RS) for 3 or 7 d, and Mst expression was determined. Adipogenesis was evaluated by quantitative image analysis of fat cells before and after oil-red-O staining, immunocytochemistry of adiponectin, and Western blot for CCAAT/enhancer binding protein-alpha. Myogenesis was estimated by quantitative image analysis-immunocytochemistry for MyoD (Myo differentiation protein), myogenin, and myosin heavy chain type II, or by Western blot for myogenin. 5'-Azacytidine-mediated differentiation induced endogenous full-length Mst expression. Recombinant Mst carboxy terminal 113 amino acids inhibited both early and late markers of myogenesis and stimulated both early and late markers of adipogenesis, whereas the antibody against Mst exerted the reverse effects. Myogenin levels at 7 d after transfection of pcDNA-Mst375 were reduced as expected and elevated by pSil-Mst, which blocked efficiently Mst375 expression. In conclusion, myostatin promotes the differentiation of multipotent mesenchymal cells into the adipogenic lineage and inhibits myogenesis.

  12. PROBLEM OF CRIMINAL REPRESSION, APPLIED OUTSIDE OF CRIMINAL LIABILITY

    Directory of Open Access Journals (Sweden)

    Vitaly Stepashin

    2017-01-01

    Full Text Available УДК 343.2A new institute of repressive measures applied outside the criminal liability in criminal law (including as a condition for exemption from criminal liability is forming now in Russian legislation. The author concludes that the provisions of the criminal law on monetary compensation and a court fine should be deleted because of the following reasons. 1 By their nature, and monetary compensation and a court fine, not being a formal punishment (and, therefore, a form of realization of criminal responsibility is a monetary penalty, i.e., penalty-punishment. Moreover, the rules of court fine destination identical rules of criminal sentencing. 2 Quantitatively court fine may exceed the minimum limits of criminal punish-ment in the form of fines. The dimensions of monetary compensation in the order of hours. Pt. 2, Art. 76.1 of the Criminal Code and at all close to the maximum values of fine-punishment. 3 Exemption from criminal liability requires states to refrain from prosecuting the person alleged to have committed a crime, which means that the nonuse of criminal repression. Regulatory standards analyzed, on the other hand, require mandatory use of repression, ie, virtually no exemption from criminal liability does not occur at all. 4 The use of a quasi-penalty in the form of monetary compensation and court fines are not an exemption from criminal responsibility, but on the contrary, the use of criminal repression (of responsibility, and in a simplified manner. 5 Contrary to the requirements of the Constitution and the Criminal Code of criminal repression is applied to persons whose guilt has not been established in the commission of a crime. Thus, in criminal law introduced a presumption of guilt. 6 Customization repression (in fact – of criminal responsibility in the application of the judicial penalty is substantially limited, and the application of monetary compensation is excluded at all, contrary to the requirement that the rough

  13. Polycomb group protein-mediated repression of transcription

    DEFF Research Database (Denmark)

    Morey, Lluís; Helin, Kristian

    2010-01-01

    The polycomb group (PcG) proteins are essential for the normal development of multicellular organisms. They form multi-protein complexes that work as transcriptional repressors of several thousand genes controlling differentiation pathways during development. How the PcG proteins work as transcri......The polycomb group (PcG) proteins are essential for the normal development of multicellular organisms. They form multi-protein complexes that work as transcriptional repressors of several thousand genes controlling differentiation pathways during development. How the PcG proteins work...... as transcriptional repressors is incompletely understood, but involves post-translational modifications of histones by two major PcG protein complexes: polycomb repressive complex 1 and polycomb repressive complex 2....

  14. Drosophila DNA-Binding Proteins in Polycomb Repression

    Directory of Open Access Journals (Sweden)

    Maksim Erokhin

    2018-01-01

    Full Text Available The formation of individual gene expression patterns in different cell types is required during differentiation and development of multicellular organisms. Polycomb group (PcG proteins are key epigenetic regulators responsible for gene repression, and dysregulation of their activities leads to developmental abnormalities and diseases. PcG proteins were first identified in Drosophila, which still remains the most convenient system for studying PcG-dependent repression. In the Drosophila genome, these proteins bind to DNA regions called Polycomb response elements (PREs. A major role in the recruitment of PcG proteins to PREs is played by DNA-binding factors, several of which have been characterized in detail. However, current knowledge is insufficient for comprehensively describing the mechanism of this process. In this review, we summarize and discuss the available data on the role of DNA-binding proteins in PcG recruitment to chromatin.

  15. Political Repressions in USSR (Against Speculations, Perversion and Mystifications

    Directory of Open Access Journals (Sweden)

    Viktor N. Zemskov

    2012-12-01

    Full Text Available In the article the great numbers of political repressions, which were exaggerated by authors: R.A. Medvedev, A.I. Solzhenitsyn, O.G. Shatunovskoy, A.V. Antonov-Ovseenko in 80-90s are criticized. The author characterizes figures given in tens and even in hundreds of millions of victims as a statistical charlatanism.After checking up the KGB archives, and documents of division responsible for NKVD-MVD special settlements, the author spills the light on real numbers of political repressions in USSR. In his view, the total number of political victims does not exceed 2, 6 million people. This number implies over 800 thousand of death sentenced for political reasons, around 600 thousand political prisoners who died in labor camps, and about 1, 2 million people died in exile (including ‘Kulak Exile’ and during transportation (deported ethnic groups and others.

  16. Repressive effects of resveratrol on androgen receptor transcriptional activity.

    Directory of Open Access Journals (Sweden)

    Wen-feng Shi

    2009-10-01

    Full Text Available The chemopreventive effects of resveratrol (RSV on prostate cancer have been well established; the androgen receptor (AR plays pivotal roles in prostatic tumorigenesis. However, the exact underlying molecular mechanisms about the effects of RSV on AR have not been fully elucidated. A model system is needed to determine whether and how RSV represses AR transcriptional activity.The AR cDNA was first cloned into the retroviral vector pOZ-N and then integrated into the genome of AR-negative HeLa cells to generate the AR(+ cells. The constitutively expressed AR was characterized by monitoring hormone-stimulated nuclear translocation, DNA binding, and transcriptional activation, with the AR(- cells serving as controls. AR(+ cells were treated with RSV, and both AR protein levels and AR transcriptional activity were measured simultaneously. Chromatin immunoprecipitation (ChIP assays were used to detect the effects of RSV on the recruitment of AR to its cognate element (ARE.AR in the AR (+ stable cell line functions in a manner similar to that of endogenously expressed AR. Using this model system we clearly demonstrated that RSV represses AR transcriptional activity independently of any effects on AR protein levels. However, neither the hormone-mediated nucleus translocation nor the AR/ARE interaction was affected by RSV treatment.We demonstrated unambiguously that RSV regulates AR target gene expression, at least in part, by repressing AR transcriptional activity. Repressive effects of RSV on AR activity result from mechanisms other than the affects of AR nuclear translocation or DNA binding.

  17. A molecular doorstop ensures a trickle through translational repression.

    Science.gov (United States)

    Brook, Matthew; Smith, Richard W P; Gray, Nicola K

    2012-03-30

    Switching mRNA translation off and on is central to regulated gene expression, but what mechanisms moderate the extent of switch-off? Yao et al. describe how basal expression from interferon-gamma-induced transcripts is maintained during mRNA-specific translational repression. This antagonistic mechanism utilizes a truncated RNA-binding factor generated by a unique alternative polyadenylation event. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Revisiting the Master-Signifier, or, Mandela and Repression.

    Science.gov (United States)

    Hook, Derek; Vanheule, Stijn

    2015-01-01

    The concept of the master-signifier has been subject to a variety of applications in Lacanian forms of political discourse theory and ideology critique. While there is much to be commended in literature of this sort, it often neglects salient issues pertaining to the role of master signifiers in the clinical domain of (individual) psychical economy. The popularity of the concept of the master (or "empty") signifier in political discourse analysis has thus proved a double-edged sword. On the one hand it demonstrates how crucial psychical processes are performed via the operations of the signifier, extending thus the Lacanian thesis that identification is the outcome of linguistic and symbolic as opposed to merely psychological processes. On the other, the use of the master signifier concept within the political realm to track discursive formations tends to distance the term from the dynamics of the unconscious and operation of repression. Accordingly, this paper revisits the master signifier concept, and does so within the socio-political domain, yet while paying particular attention to the functioning of unconscious processes of fantasy and repression. More specifically, it investigates how Nelson Mandela operates as a master signifier in contemporary South Africa, as a vital means of knitting together diverse elements of post-apartheid society, enabling the fantasy of the post-apartheid nation, and holding at bay a whole series of repressed and negated undercurrents.

  19. Revisiting the master-signifier, or, Mandela and repression

    Directory of Open Access Journals (Sweden)

    Derek eHook

    2016-01-01

    Full Text Available The concept of the master-signifier has been subject to a variety of applications in Lacanian forms of political discourse theory and ideology critique. While there is much to be commended in literature of this sort, it often neglects salient issues pertaining to the role of master signifiers in the clinical domain of (individual psychical economy. The popularity of the concept of the master (or ‘empty’ signifier in political discourse analysis has thus proved a double-edged sword. On the one hand it demonstrates how crucial psychical processes are performed via the operations of the signifier, extending thus the Lacanian thesis that identification is as much the outcome of linguistic and symbolic as opposed to merely psychological processes. On the other, the use of the master signifier concept within the political realm to track discursive formations tends to distance the term from the dynamics of the unconscious and operation of repression. Accordingly, this paper revisits the master signifier concept, and does so within the socio-political domain, yet while paying particular attention to the functioning of unconscious processes of fantasy and repression. More specifically, it investigates how Nelson Mandela operates as a master signifier in contemporary South Africa, as a vital means of knitting together diverse elements of post-apartheid society, enabling the fantasy of the post-apartheid nation, and holding at bay a whole series of repressed and negated undercurrents.

  20. Heterologous expression of C. elegans fat-1 decreases the n-6/n-3 fatty acid ratio and inhibits adipogenesis in 3T3-L1 cells

    International Nuclear Information System (INIS)

    An, Lei; Pang, Yun-Wei; Gao, Hong-Mei; Tao, Li; Miao, Kai; Wu, Zhong-Hong

    2012-01-01

    Highlights: ► Expression of C. elegans fat-1 reduces the n-6/n-3 PUFA ratio in 3T3-L1 cells. ► fat-1 inhibits the proliferation and differentiation of 3T3-L1 preadipocytes. ► fat-1 reduces lipid deposition in 3T3-L1 adipocytes. ► The lower n-6/n-3 ratio induces apoptosis in 3T3-L1 adipocytes. -- Abstract: In general, a diet enriched in polyunsaturated fatty acids (PUFAs) inhibits the development of obesity and decreases adipose tissue. The specific impacts of n-3 and n-6 PUFAs on adipogenesis, however, have not been definitively determined. Traditional in vivo and in vitro supplementation studies have yielded inconsistent or even contradictory results, which likely reflect insufficiently controlled experimental systems. Caenorhabditiselegans fat-1 gene encodes an n-3 fatty acid desaturase, and its heterologous expression represents an effective method both for altering the n-6/n-3 PUFA ratio and for evaluating the biological effects of n-3 and n-6 PUFAs. We sought to determine whether a reduced n-6/n-3 ratio could influence adipogenesis in 3T3-L1 cells. Lentivirus-mediated introduction of the fat-1 gene into 3T3-L1 preadipocytes significantly reduced the n-6/n-3 ratio and inhibited preadipocyte proliferation and differentiation. In mature adipocytes, fat-1 expression reduced lipid deposition, as measured by Oil Red O staining, and induced apoptosis. Our results indicate that a reduced n-6/n-3 ratio inhibits adipogenesis through several mechanisms and that n-3 PUFAs more effectively inhibit adipogenesis (but not lipogenesis) than do n-6 PUFAs.

  1. Wnt6, Wnt10a and Wnt10b inhibit adipogenesis and stimulate osteoblastogenesis through a β-catenin-dependent mechanism

    OpenAIRE

    Cawthorn, William P.; Bree, Adam J.; Yao, Yao; Du, Baowen; Hemati, Nahid; Martinez-Santibañez, Gabriel; MacDougald, Ormond A.

    2011-01-01

    Wnt10b is an established regulator of mesenchymal stem cell (MSC) fate that inhibits adipogenesis and stimulates osteoblastogenesis, thereby impacting bone mass in vivo. However, downstream mechanisms through which Wnt10b exerts these effects are poorly understood. Moreover, whether other endogenous Wnt ligands also modulate MSC fate remains to be fully addressed. In this study, we identify Wnt6 and Wnt10a as additional Wnt family members that, like Wnt10b, are downregulated during developmen...

  2. Heterologous expression of C. elegans fat-1 decreases the n-6/n-3 fatty acid ratio and inhibits adipogenesis in 3T3-L1 cells

    Energy Technology Data Exchange (ETDEWEB)

    An, Lei, E-mail: anleim@yahoo.com.cn [Ministry of Agriculture Key Laboratory of Animal Genetics, Breeding and Reproduction, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing 100193 (China); Pang, Yun-Wei, E-mail: yunweipang@126.com [Ministry of Agriculture Key Laboratory of Animal Genetics, Breeding and Reproduction, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing 100193 (China); Gao, Hong-Mei, E-mail: Gaohongmei_123@yahoo.cn [Ministry of Agriculture Key Laboratory of Animal Genetics, Breeding and Reproduction, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing 100193 (China); Research Unit for Animal Life Sciences, Animal Resource Science Center, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Ibaraki-Iwama 319-0206 (Japan); Tao, Li, E-mail: Eunice8023@yahoo.cn [Ministry of Agriculture Key Laboratory of Animal Genetics, Breeding and Reproduction, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing 100193 (China); College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin 130118 (China); Miao, Kai, E-mail: miaokai7@163.com [Ministry of Agriculture Key Laboratory of Animal Genetics, Breeding and Reproduction, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing 100193 (China); Wu, Zhong-Hong, E-mail: wuzhh@cau.edu.cn [Ministry of Agriculture Key Laboratory of Animal Genetics, Breeding and Reproduction, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing 100193 (China); and others

    2012-11-23

    Highlights: Black-Right-Pointing-Pointer Expression of C. elegans fat-1 reduces the n-6/n-3 PUFA ratio in 3T3-L1 cells. Black-Right-Pointing-Pointer fat-1 inhibits the proliferation and differentiation of 3T3-L1 preadipocytes. Black-Right-Pointing-Pointer fat-1 reduces lipid deposition in 3T3-L1 adipocytes. Black-Right-Pointing-Pointer The lower n-6/n-3 ratio induces apoptosis in 3T3-L1 adipocytes. -- Abstract: In general, a diet enriched in polyunsaturated fatty acids (PUFAs) inhibits the development of obesity and decreases adipose tissue. The specific impacts of n-3 and n-6 PUFAs on adipogenesis, however, have not been definitively determined. Traditional in vivo and in vitro supplementation studies have yielded inconsistent or even contradictory results, which likely reflect insufficiently controlled experimental systems. Caenorhabditiselegans fat-1 gene encodes an n-3 fatty acid desaturase, and its heterologous expression represents an effective method both for altering the n-6/n-3 PUFA ratio and for evaluating the biological effects of n-3 and n-6 PUFAs. We sought to determine whether a reduced n-6/n-3 ratio could influence adipogenesis in 3T3-L1 cells. Lentivirus-mediated introduction of the fat-1 gene into 3T3-L1 preadipocytes significantly reduced the n-6/n-3 ratio and inhibited preadipocyte proliferation and differentiation. In mature adipocytes, fat-1 expression reduced lipid deposition, as measured by Oil Red O staining, and induced apoptosis. Our results indicate that a reduced n-6/n-3 ratio inhibits adipogenesis through several mechanisms and that n-3 PUFAs more effectively inhibit adipogenesis (but not lipogenesis) than do n-6 PUFAs.

  3. PI3K/Akt is involved in brown adipogenesis mediated by growth differentiation factor-5 in association with activation of the Smad pathway

    Energy Technology Data Exchange (ETDEWEB)

    Hinoi, Eiichi; Iezaki, Takashi; Fujita, Hiroyuki; Watanabe, Takumi; Odaka, Yoshiaki; Ozaki, Kakeru; Yoneda, Yukio, E-mail: yyoneda@p.kanazawa-u.ac.jp

    2014-07-18

    Highlights: • Akt is preferentially phosphorylated in BAT and sWAT of aP2-GDF5 mice. • PI3K/Akt signaling is involved in GDF5-induced brown adipogenesis. • PI3K/Akt signaling regulates GDF5-induced Smad5 phosphorylation. - Abstract: We have previously demonstrated promotion by growth differentiation factor-5 (GDF5) of brown adipogenesis for systemic energy expenditure through a mechanism relevant to activating the bone morphological protein (BMP) receptor/mothers against decapentaplegic homolog (Smad)/peroxisome proliferator-activated receptor gamma co-activator 1α (PGC-1α) pathway. Here, we show the involvement of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway in brown adipogenesis mediated by GDF5. Overexpression of GDF5 in cells expressing adipocyte protein-2 markedly accelerated the phosphorylation of Smad1/5/8 and Akt in white and brown adipose tissues. In brown adipose tissue from heterozygous GDF5{sup Rgsc451} mutant mice expressing a dominant-negative (DN) GDF5 under obesogenic conditions, the basal phosphorylation of Smad1/5/8 and Akt was significantly attenuated. Exposure to GDF5 not only promoted the phosphorylation of both Smad1/5/8 and Akt in cultured brown pre-adipocytes, but also up-regulated Pgc1a and uncoupling protein-1 expression in a manner sensitive to the PI3K/Akt inhibitor Ly294002 as well as retroviral infection with DN-Akt. GDF5 drastically promoted BMP-responsive luciferase reporter activity in a Ly294002-sensitive fashion. Both Ly294002 and DN-Akt markedly inhibited phosphorylation of Smad5 in the nuclei of brown pre-adipocytes. These results suggest that PI3K/Akt signals play a role in the GDF5-mediated brown adipogenesis through a mechanism related to activation of the Smad pathway.

  4. Adipogenesis stimulates the nuclear localization of EWS with an increase in its O-GlcNAc glycosylation in 3T3-L1 cells

    International Nuclear Information System (INIS)

    Li, Qiang; Kamemura, Kazuo

    2014-01-01

    Highlights: • The majority of EWS localizes stably in the cytosol in 3T3-L1 preadipocytes. • Adipogenic stimuli induce the nuclear localization of EWS. • Adipogenesis promotes O-GlcNAcylation of EWS. • O-GlcNAcylation stimulates the recruitment of EWS to the nuclear periphery. - Abstract: Although the Ewing sarcoma (EWS) proto-oncoprotein is found in the nucleus and cytosol and is associated with the cell membrane, the regulatory mechanisms of its subcellular localization are still unclear. Here we found that adipogenic stimuli induce the nuclear localization of EWS in 3T3-L1 cells. Tyrosine phosphorylation in the C-terminal PY-nuclear localization signal of EWS was negative throughout adipogenesis. Instead, an adipogenesis-dependent increase in O-linked β-N-acetylglucosamine (O-GlcNAc) glycosylation of EWS was observed. Pharmacological inactivation of O-GlcNAcase in preadipocytes promoted perinuclear localization of EWS. Our findings suggest that the nuclear localization of EWS is partly regulated by the glycosylation

  5. Milk Fat Globule Membrane Attenuates High-Fat Diet-Induced Obesity by Inhibiting Adipogenesis and Increasing Uncoupling Protein 1 Expression in White Adipose Tissue of Mice

    Directory of Open Access Journals (Sweden)

    Tiange Li

    2018-03-01

    Full Text Available Milk fat globule membrane (MFGM, a protein-lipid complex surrounding the fat globules in milk, has many health benefits. The aim of the current study was to investigate whether MFGM could prevent obesity through inhibiting adipogenesis and promoting brown remodeling of white adipose tissue (WAT in mice fed with high-fat diet. C57BL/6 mice were fed a normal diet (ND, high-fat diet (HFD, HFD plus MFGM at 100 mg/kg BW, 200 mg/kg BW or 400 mg/kg BW for 8 weeks. Results showed that MFGM suppressed body weight gain induced by HFD, reduced white adipose tissue (WAT mass accompanied with the decrease in adipocyte sizes. MFGM was found to have partially improved serum lipid profiles, as well as to have suppressed HFD-induced adipogenesis as shown by reduced expression of peroxisome proliferators-activator receptor-γ (PPARγ, CCAAT/enhancer-binding protein-α (C/EBPα and sterol regulatory element-binding protein-1c (SREBP-1c. MFGM also markedly increased the phosphorylation of AMP-activated protein kinase (AMPK and acetyl-CoA carboxylase (ACC, showing activation of AMPK pathway. Moreover, MFGM promoted browning of inguinal WAT by upregulation the protein expression of uncoupling protein 1 (UCP1 in HFD mice. Taken together, these findings provide evidence that MFGM may protect against diet-induced adiposity by suppressing adipogenesis and promoting brown-like transformation in WAT.

  6. Traditional Korean Herbal Formula Samsoeum Attenuates Adipogenesis by Regulating the Phosphorylation of ERK1/2 in 3T3-L1 Cells

    Directory of Open Access Journals (Sweden)

    Soo-Jin Jeong

    2015-01-01

    Full Text Available Adipogenesis is the cell differentiation process from preadipocytes into adipocytes and the critical action in the development of obesity. In the present study, we conducted in vitro analyses to investigate the inhibitory effects of Samsoeum (SSE, a traditional herbal decoction. SSE had no significant cytotoxic effect against either the undifferentiated or differentiated 3T3-L1 cells. Oil Red O staining results showed that SSE significantly inhibited fat accumulation in adipocytes. SSE treatment consistently reduced the intracellular triglyceride content in the cells. SSE significantly inactivated glycerol-3-phosphate dehydrogenase (GPDH, a major link between carbohydrate and lipid metabolisms in 3T3-L1 adipocytes, and markedly inhibited the production of leptin, an important adipokine, in differentiated cells. SSE markedly suppressed the mRNA expression of the adipogenesis-related genes peroxisome proliferator-activated receptor-gamma (PPAR-γ, CCAAT/enhancer binding protein-alpha (C/EBP-α, fatty acid synthase (FAS, lipoprotein lipase (LPL, and fatty acid binding protein 4 (FABP4. Importantly, SSE increased the phosphorylation of ERK1/2, but not p38 MAPK and JNK, in adipose cells. Overall, our results indicate that SSE exerts antiadipogenic activity and modulates expressions of adipogenesis-related genes and ERK1/2 activation in adipocytes.

  7. In vitro and in vivo enhancement of adipogenesis by Italian ryegrass (Lolium multiflorum in 3T3-L1 cells and mice.

    Directory of Open Access Journals (Sweden)

    Mariadhas Valan Arasu

    Full Text Available Adipogenesis is very much important in improving the quality of meat in animals. The aim of the present study was to investigate the in vitro and in vivo adipogenesis regulation properties of Lolium multiflorum on 3T3-L1 pre-adipocytes and mice. Chemical composition of petroleum ether extract of L. multiflorum (PET-LM confirmed the presence of fatty acids, such as α-linolenic acid, docosahexaenoic acid, oleic acid, docosatetraenoic acid, and caprylic acid, as the major compounds. PET-LM treatment increased viability, lipid accumulation, lipolysis, cell cycle progression, and DNA synthesis in the cells. PET-LM treatment also augmented peroxysome proliferator activated receptor (PPAR-γ2, CCAAT/enhancer binding protein-α, adiponectin, adipocyte binding protein, glucose transporter-4, fatty acid synthase, and sterol regulatory element binding protein-1 expression at mRNA and protein levels in differentiated adipocytes. In addition, mice administered with 200 mg/kg body weight PET-LM for 8 weeks showed greater body weight than control mice. These findings suggest that PET-LM facilitates adipogenesis by stimulating PPARγ-mediated signaling cascades in adipocytes which could be useful for quality meat development in animals.

  8. Acetate alters expression of genes involved in beige adipogenesis in 3T3-L1 cells and obese KK-Ay mice

    Science.gov (United States)

    Hanatani, Satoko; Motoshima, Hiroyuki; Takaki, Yuki; Kawasaki, Shuji; Igata, Motoyuki; Matsumura, Takeshi; Kondo, Tatsuya; Senokuchi, Takafumi; Ishii, Norio; Kawashima, Junji; Kukidome, Daisuke; Shimoda, Seiya; Nishikawa, Takeshi; Araki, Eiichi

    2016-01-01

    The induction of beige adipogenesis within white adipose tissue, known as “browning”, has received attention as a novel potential anti-obesity strategy. The expression of some characteristic genes including PR domain containing 16 is induced during the browning process. Although acetate has been reported to suppress weight gain in both rodents and humans, its potential effects on beige adipogenesis in white adipose tissue have not been fully characterized. We examined the effects of acetate treatment on 3T3-L1 cells and in obese diabetic KK-Ay mice. The mRNA expression levels of genes involved in beige adipocyte differentiation and genes selectively expressed in beige adipocytes were significantly elevated in both 3T3-L1 cells incubated with 1.0 mM acetate and the visceral white adipose tissue from mice treated with 0.6% acetate for 16 weeks. In KK-Ay mice, acetate reduced the food efficiency ratio and increased the whole-body oxygen consumption rate. Additionally, reduction of adipocyte size and uncoupling protein 1-positive adipocytes and interstitial areas with multilocular adipocytes appeared in the visceral white adipose tissue of acetate-treated mice, suggesting that acetate induced initial changes of “browning”. In conclusion, acetate alters the expression of genes involved in beige adipogenesis and might represent a potential therapeutic agent to combat obesity. PMID:27895388

  9. Andrographolide inhibits adipogenesis of 3T3-L1 cells by suppressing C/EBPβ expression and activation

    International Nuclear Information System (INIS)

    Chen, Ching-Chu; Chuang, Wei-Ting; Lin, Ai-Hsuan; Tsai, Chia-Wen; Huang, Chin-Shiu; Chen, Yun-Ting; Chen, Haw-Wen; Lii, Chong-Kuei

    2016-01-01

    Andrographolide, a diterpenoid, is the most abundant terpenoid in Andrographis paniculata, a popular Chinese herbal medicine. Andrographolide displays diverse biological activities including hypoglycemia, hypolipidemia, anti-inflammation, and anti-tumorigenesis. Recent evidence indicates that andrographolide displays anti-obesity property by inhibiting lipogenic gene expression, however, the underlying mechanisms remain to be elucidated. In this study, the effects of andrographolide on transcription factor cascade and mitotic clonal expansion in 3T3-L1 preadipocyte differentiation into adipocyte were determined. Andrographolide dose-dependently (0–15 μM) inhibited CCAAT/enhancer-binding protein α (C/EBPα) and C/EBPβ mRNA and protein expression as well as peroxisome proliferator-activated receptor γ (PPARγ) protein level during the adipogenesis of 3T3-L1 cells. Concomitantly, fatty acid synthase and stearoyl-CoA desaturase expression and lipid accumulation were attenuated by andrographolide. Oil-red O staining further showed that the first 48 h after the initiation of differentiation was critical for andrographolide inhibition of adipocyte formation. Andrographolide inhibited the phosphorylation of PKA and the activation of cAMP response element-binding protein (CREB) in response to a differentiation cocktail, which led to attenuated C/EBPβ expression. In addition, ERK and GSK3β-dependent C/EBPβ phosphorylation was attenuated by andrographolide. Moreover, andrographolide suppressed cyclin A, cyclin E, and CDK2 expression and impaired the progression of mitotic clonal expansion (MCE) by arresting the cell cycle at the Go/G1 phase. Taken together, these results indicate that andrographolide has a potent anti-obesity action by inhibiting PKA-CREB-mediated C/EBPβ expression as well as C/EBPβ transcriptional activity, which halts MCE progression and attenuates C/EBPα and PPARγ expression. - Highlights: • Andrographolide is a diterpenoid phytochemical.

  10. Andrographolide inhibits adipogenesis of 3T3-L1 cells by suppressing C/EBPβ expression and activation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ching-Chu [Division of Endocrinology and Metabolism, Department of Medicine, China Medical University Hospital, Taichung, Taiwan (China); Division of Endocrinology and Metabolism, Department of Chinese Medicine, China Medical University, China Medical University, Taichung, Taiwan (China); Chuang, Wei-Ting; Lin, Ai-Hsuan; Tsai, Chia-Wen [Department of Nutrition, China Medical University, Taichung, Taiwan (China); Huang, Chin-Shiu [Department of Health and Nutrition Biotechnology, Asia University, Taichung, Taiwan (China); Department of Medical Research, China Medical University Hospital, Taichung, Taiwan (China); Chen, Yun-Ting [Department of Nutrition, China Medical University, Taichung, Taiwan (China); Chen, Haw-Wen, E-mail: chenhw@mail.cmu.edu.tw [Department of Nutrition, China Medical University, Taichung, Taiwan (China); Lii, Chong-Kuei, E-mail: cklii@mail.cmu.edu.tw [Department of Nutrition, China Medical University, Taichung, Taiwan (China); Department of Health and Nutrition Biotechnology, Asia University, Taichung, Taiwan (China)

    2016-09-15

    Andrographolide, a diterpenoid, is the most abundant terpenoid in Andrographis paniculata, a popular Chinese herbal medicine. Andrographolide displays diverse biological activities including hypoglycemia, hypolipidemia, anti-inflammation, and anti-tumorigenesis. Recent evidence indicates that andrographolide displays anti-obesity property by inhibiting lipogenic gene expression, however, the underlying mechanisms remain to be elucidated. In this study, the effects of andrographolide on transcription factor cascade and mitotic clonal expansion in 3T3-L1 preadipocyte differentiation into adipocyte were determined. Andrographolide dose-dependently (0–15 μM) inhibited CCAAT/enhancer-binding protein α (C/EBPα) and C/EBPβ mRNA and protein expression as well as peroxisome proliferator-activated receptor γ (PPARγ) protein level during the adipogenesis of 3T3-L1 cells. Concomitantly, fatty acid synthase and stearoyl-CoA desaturase expression and lipid accumulation were attenuated by andrographolide. Oil-red O staining further showed that the first 48 h after the initiation of differentiation was critical for andrographolide inhibition of adipocyte formation. Andrographolide inhibited the phosphorylation of PKA and the activation of cAMP response element-binding protein (CREB) in response to a differentiation cocktail, which led to attenuated C/EBPβ expression. In addition, ERK and GSK3β-dependent C/EBPβ phosphorylation was attenuated by andrographolide. Moreover, andrographolide suppressed cyclin A, cyclin E, and CDK2 expression and impaired the progression of mitotic clonal expansion (MCE) by arresting the cell cycle at the Go/G1 phase. Taken together, these results indicate that andrographolide has a potent anti-obesity action by inhibiting PKA-CREB-mediated C/EBPβ expression as well as C/EBPβ transcriptional activity, which halts MCE progression and attenuates C/EBPα and PPARγ expression. - Highlights: • Andrographolide is a diterpenoid phytochemical.

  11. Repression of death consciousness and the psychedelic trip

    Directory of Open Access Journals (Sweden)

    Varsha Dutta

    2012-01-01

    Full Text Available Death is our most repressed consciousness, it inheres our condition as the primordial fear. Perhaps it was necessary that this angst be repressed in man or he would be hurled against the dark forces of nature. Modern ethos was built on this edifice, where the ′denial of death′ while ′embracing one′s symbolic immortality′ would be worshipped, so this ideology simply overturned and repressed looking into the morass of the inevitable when it finally announced itself. Once this slowly pieced its way into all of life, ′death′ would soon become a terminology in medicine too and assert its position, by giving a push to those directly dealing with the dying to shy away from its emotional and spiritual affliction. The need to put off death and prolong one′s life would become ever more urgent. Research using psychedelics on the terminally ill which had begun in the 1950s and 1960s would coerce into another realm and alter the face of medicine; but the aggression with which it forced itself in the 1960s would soon be politically maimed, and what remained would be sporadic outpours that trickled its way from European labs and underground boot camps. Now, with the curtain rising, the question has etched itself again, about the use of psychedelic drugs in medicine, particularly psychedelic psychotherapy with the terminally ill. This study is an attempt to philosophically explore death anxiety from its existential context and how something that is innate in our condition cannot be therapeutically cured. Psychedelic use was immutably linked with ancient cultures and only recently has it seen its scientific revival, from which a scientific culture grew around psychedelic therapy. How much of what was threaded in the ritual and spiritual mores can be extricated and be interpreted in our own mechanized language of medicine is the question that nudges many.

  12. Arctigenin Inhibits Adipogenesis by Inducing AMPK Activation and Reduces Weight Gain in High-Fat Diet-Induced Obese Mice.

    Science.gov (United States)

    Han, Yo-Han; Kee, Ji-Ye; Park, Jinbong; Kim, Hye-Lin; Jeong, Mi-Young; Kim, Dae-Seung; Jeon, Yong-Deok; Jung, Yunu; Youn, Dong-Hyun; Kang, JongWook; So, Hong-Seob; Park, Raekil; Lee, Jong-Hyun; Shin, Soyoung; Kim, Su-Jin; Um, Jae-Young; Hong, Seung-Heon

    2016-09-01

    Although arctigenin (ARC) has been reported to have some pharmacological effects such as anti-inflammation, anti-cancer, and antioxidant, there have been no reports on the anti-obesity effect of ARC. The aim of this study is to investigate whether ARC has an anti-obesity effect and mediates the AMP-activated protein kinase (AMPK) pathway. We investigated the anti-adipogenic effect of ARC using 3T3-L1 pre-adipocytes and human adipose tissue-derived mesenchymal stem cells (hAMSCs). In high-fat diet (HFD)-induced obese mice, whether ARC can inhibit weight gain was investigated. We found that ARC reduced weight gain, fat pad weight, and triglycerides in HFD-induced obese mice. ARC also inhibited the expression of peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer-binding protein alpha (C/EBPα) in in vitro and in vivo. Furthermore, ARC induced the AMPK activation resulting in down-modulation of adipogenesis-related factors including PPARγ, C/EBPα, fatty acid synthase, adipocyte fatty acid-binding protein, and lipoprotein lipase. This study demonstrates that ARC can reduce key adipogenic factors by activating the AMPK in vitro and in vivo and suggests a therapeutic implication of ARC for obesity treatment. J. Cell. Biochem. 117: 2067-2077, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  13. Inhibition of Protein Farnesylation Arrests Adipogenesis and Affects PPARγ Expression and Activation in Differentiating Mesenchymal Stem Cells

    Science.gov (United States)

    Rivas, Daniel; Akter, Rahima; Duque, Gustavo

    2007-01-01

    Protein farnesylation is required for the activation of multiple proteins involved in cell differentiation and function. In white adipose tissue protein, farnesylation has shown to be essential for the successful differentiation of preadipocytes into adipocytes. We hypothesize that protein farnesylation is required for PPARγ2 expression and activation, and therefore for the differentiation of human mesenchymal stem cells (MSCs) into adipocytes. MSCs were plated and induced to differentiate into adipocytes for three weeks. Differentiating cells were treated with either an inhibitor of farnesylation (FTI-277) or vehicle alone. The effect of inhibition of farnesylation in differentiating adipocytes was determined by oil red O staining. Cell survival was quantified using MTS Formazan. Additionally, nuclear extracts were obtained and prelamin A, chaperon protein HDJ-2, PPARγ, and SREBP-1 were determined by western blot. Finally, DNA binding PPARγ activity was determined using an ELISA-based PPARγ activation quantification method. Treatment with an inhibitor of farnesylation (FTI-277) arrests adipogenesis without affecting cell survival. This effect was concomitant with lower levels of PPARγ expression and activity. Finally, accumulation of prelamin A induced an increased proportion of mature SREBP-1 which is known to affect PPARγ activity. In summary, inhibition of protein farnesylation arrests the adipogenic differentiation of MSCs and affects PPARγ expression and activity. PMID:18274630

  14. Central Role of the PPARγ Gene Network in Coordinating Beef Cattle Intramuscular Adipogenesis in Response to Weaning Age and Nutrition.

    Science.gov (United States)

    Moisá, Sonia J; Shike, Daniel W; Faulkner, Dan B; Meteer, William T; Keisler, Duane; Loor, Juan J

    2014-01-01

    Adipogenic/lipogenic transcriptional networks regulating intramuscular fat deposition (IMF) in response to weaning age and dietary starch level were studied. The longissimus muscle (LM) of beef steers on an early weaning (141 days age) plus high-starch diet (EWS) or a normal weaning (NW, 222 days age) plus starch creep-feed diet (CFS) was biopsied at 0 (EW), 25, 50, 96 (NW), 167, and 222 (pre-slaughter) days. Expression patterns of 35 target genes were studied. From NW through slaughter, all steers received the same high-starch diet. In EWS steers the expression of PPARG, other adipogenic (CEBPA, ZFP423) and lipogenic (THRSP, SREBF1, INSIG1) activators, and several enzymes (FASN, SCD, ELOVL6, PCK1, DGAT2) that participate in the process of IMF increased gradually to a peak between 96 and 167 days on treatment. Steers in NW did not achieve similar expression levels even by 222 days on treatment, suggesting a blunted response even when fed a high-starch diet after weaning. High-starch feeding at an early age (EWS) triggers precocious and sustained adipogenesis, resulting in greater marbling.

  15. Theobromine suppresses adipogenesis through enhancement of CCAAT-enhancer-binding protein β degradation by adenosine receptor A1.

    Science.gov (United States)

    Mitani, Takakazu; Watanabe, Shun; Yoshioka, Yasukiyo; Katayama, Shigeru; Nakamura, Soichiro; Ashida, Hitoshi

    2017-12-01

    Theobromine, a methylxanthine derived from cacao beans, reportedly has various health-promoting properties but molecular mechanism by which effects of theobromine on adipocyte differentiation and adipogenesis remains unclear. In this study, we aimed to clarify the molecular mechanisms of the anti-adipogenic effect of theobromine in vitro and in vivo. ICR mice (4week-old) were administered with theobromine (0.1g/kg) for 7days. Theobromine administration attenuated gains in body and epididymal adipose tissue weights in mice and suppressed expression of adipogenic-associated genes in mouse adipose tissue. In 3T3-L1 preadipocytes, theobromine caused degradation of C/EBPβ protein by the ubiquitin-proteasome pathway. Pull down assay showed that theobromine selectively interacts with adenosine receptor A1 (AR1), and AR1 knockdown inhibited theobromine-induced C/EBPβ degradation. Theobromine increased sumoylation of C/EBPβ at Lys133. Expression of the small ubiquitin-like modifier (SUMO)-specific protease 2 (SENP2) gene, coding for a desumoylation enzyme, was suppressed by theobromine. In vivo knockdown studies showed that AR1 knockdown in mice attenuated the anti-adipogenic effects of theobromine in younger mice. Theobromine suppresses adipocyte differentiation and induced C/EBPβ degradation by increasing its sumoylation. Furthermore, the inhibition of AR1 signaling is important for theobromine-induced C/EBPβ degradation. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Effect of high hydrostatic pressure extract of fresh ginseng on adipogenesis in 3T3-L1 adipocytes.

    Science.gov (United States)

    Lee, Mak-Soon; Jung, Sunyoon; Oh, Soojung; Shin, Yoonjin; Kim, Chong-Tai; Kim, In-Hwan; Kim, Yangha

    2015-09-01

    Red ginseng is produced by steaming and drying fresh ginseng. Through this processing, chemical compounds are modified, and then biological activities are changed. In the food-processing industry, high hydrostatic pressure (HHP) has become an alternative to heat processing to make maximum use of bioactive compounds in food materials. This study comparatively investigated the anti-adipogenic effects of water extract of red ginseng (WRG) and high hydrostatic pressure extract of fresh ginseng (HPG) in 3T3-L1 adipocytes. Both WRG and HPG inhibited the accumulation of intracellular lipids and triglycerides, and the activity of glycerol-3-phosphate dehydrogenase (GPDH), a key enzyme in triglyceride biosynthesis. Intracellular lipid content and GPDH activity were significantly lower in the HPG group compared to the WRG group. In addition, mRNA expression of adipogenic genes, including CEBP-α, SREBP-1c and aP2, were lower in HPG-treated cells compared to WRG-treated cells. HPG significantly increased the activity of AMPK, and WRG did not. Results suggested that HPG may have superior beneficial effects on the inhibition of adipogenesis compared with WRG. The anti-adipogenic effects of HPG were partially associated with the inhibition of GPDH activity, suppression of adipogenic gene expression and activation of AMPK in 3T3-L1 adipocytes. © 2014 Society of Chemical Industry.

  17. Blood-Brain Glucose Transfer: Repression in Chronic Hyperglycemia

    Science.gov (United States)

    Gjedde, Albert; Crone, Christian

    1981-10-01

    Diabetic patients with increased plasma glucose concentrations may develop cerebral symptoms of hypoglycemia when their plasma glucose is rapidly lowered to normal concentrations. The symptoms may indicate insufficient transport of glucose from blood to brain. In rats with chronic hyperglycemia the maximum glucose transport capacity of the blood-brain barrier decreased from 400 to 290 micromoles per 100 grams per minute. When plasma glucose was lowered to normal values, the glucose transport rate into brain was 20 percent below normal. This suggests that repressive changes of the glucose transport mechanism occur in brain endothelial cells in response to increased plasma glucose.

  18. ATF3 represses PPARγ expression and inhibits adipocyte differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Min-Kyung; Jung, Myeong Ho, E-mail: jung0603@pusan.ac.kr

    2014-11-07

    Highlights: • ATF3 decrease the expression of PPARγ and its target gene in 3T3-L1 adipocytes. • ATF3 represses the promoter activity of PPARγ2 gene. • ATF/CRE (−1537/−1530) is critical for ATF3-mediated downregulation of PPARγ. • ATF3 binds to the promoter region containing the ATF/CRE. • ER stress inhibits adipocyte differentiation through downregulation of PPARγ by ATF3. - Abstract: Activating transcription factor 3 (ATF3) is a stress-adaptive transcription factor that mediates cellular stress response signaling. We previously reported that ATF3 represses CCAAT/enhancer binding protein α (C/EBPα) expression and inhibits 3T3-L1 adipocyte differentiation. In this study, we explored potential role of ATF3 in negatively regulating peroxisome proliferator activated receptor-γ (PPARγ). ATF3 decreased the expression of PPARγ and its target gene in 3T3-L1 adipocytes. ATF3 also repressed the activity of −2.6 Kb promoter of mouse PPARγ2. Overexpression of PPARγ significantly prevented the ATF3-mediated inhibition of 3T3-L1 differentiation. Transfection studies with 5′ deleted-reporters showed that ATF3 repressed the activity of −2037 bp promoter, whereas it did not affect the activity of −1458 bp promoter, suggesting that ATF3 responsive element is located between the −2037 and −1458. An electrophoretic mobility shift assay and chromatin immunoprecipitation assay demonstrated that ATF3 binds to ATF/CRE site (5′-TGACGTTT-3′) between −1537 and −1530. Mutation of the ATF/CRE site abrogated ATF3-mediated transrepression of the PPARγ2 promoter. Treatment with thapsigargin, endoplasmic reticulum (ER) stress inducer, increased ATF3 expression, whereas it decreased PPARγ expression. ATF3 knockdown significantly blocked the thapsigargin-mediated downregulation of PPARγ expression. Furthermore, overexpression of PPARγ prevented inhibition of 3T3-L1 differentiation by thapsigargin. Collectively, these results suggest that ATF3-mediated

  19. REST represses a subset of the pancreatic endocrine differentiation program

    DEFF Research Database (Denmark)

    Martin, David; Kim, Yung-Hae; Sever, Dror

    2015-01-01

    in neurons and in endocrine cells, which is necessary for their normal function. During development, REST represses a subset of genes in the neuronal differentiation program and Rest is down-regulated as neurons differentiate. Here, we investigate the role of REST in the differentiation of pancreatic...... endocrine cells, which are molecularly close to neurons. We show that Rest is widely expressed in pancreas progenitors and that it is down-regulated in differentiated endocrine cells. Sustained expression of REST in Pdx1(+) progenitors impairs the differentiation of endocrine-committed Neurog3...

  20. How social media matter: Repression and the diffusion of the Occupy Wall Street movement.

    Science.gov (United States)

    Suh, Chan S; Vasi, Ion Bogdan; Chang, Paul Y

    2017-07-01

    This study explores the role played by social media in reshaping the repression-mobilization relationship. Drawing on the case of the Occupy Wall Street movement, we examine the impact of Facebook and Twitter on the spatial diffusion of protests during a period of heightened state repression. Results from event history analyses suggest that the effects of repression on protest diffusion are contingent on the presence of social media accounts supporting the movement. We find that state repression at earlier protest sites encouraged activists to create Facebook and Twitter accounts in their own cities, which then served as important vehicles for the initiation of new Occupy protests. Moreover, results suggest that repression incidents can directly facilitate future protests in cities that already have Occupy Facebook accounts. This study highlights the potential of social media to both mediate and moderate the influence of repression on the diffusion of contemporary movements. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Eukaryotic translation initiator protein 1A isoform, CCS-3, enhances the transcriptional repression of p21CIP1 by proto-oncogene FBI-1 (Pokemon/ZBTB7A).

    Science.gov (United States)

    Choi, Won-Il; Kim, Youngsoo; Kim, Yuri; Yu, Mi-young; Park, Jungeun; Lee, Choong-Eun; Jeon, Bu-Nam; Koh, Dong-In; Hur, Man-Wook

    2009-01-01

    FBI-1, a member of the POK (POZ and Kruppel) family of transcription factors, plays a role in differentiation, oncogenesis, and adipogenesis. eEF1A is a eukaryotic translation elongation factor involved in several cellular processes including embryogenesis, oncogenic transformation, cell proliferation, and cytoskeletal organization. CCS-3, a potential cervical cancer suppressor, is an isoform of eEF1A. We found that eEF1A forms a complex with FBI-1 by co-immunoprecipitation, SDS-PAGE, and MALDI-TOF Mass analysis of the immunoprecipitate. GST fusion protein pull-downs showed that FBI-1 directly interacts with eEF1A and CCS-3 via the zinc finger and POZ-domain of FBI-1. FBI-1 co-localizes with either eEF1A or CCS-3 at the nuclear periplasm. CCS-3 enhances transcriptional repression of the p21CIP1 gene (hereafter referred to as p21) by FBI-1. The POZ-domain of FBI-1 interacts with the co-repressors, SMRT and BCoR. We found that CCS-3 also interacts with the co-repressors independently. The molecular interaction between the co-repressors and CCS-3 at the POZ-domain of FBI-1 appears to enhance FBI-1 mediated transcriptional repression. Our data suggest that CCS-3 may be important in cell differentiation, tumorigenesis, and oncogenesis by interacting with the proto-oncogene FBI-1 and transcriptional co-repressors. Copyright 2009 S. Karger AG, Basel.

  2. The Efficiency of Repressive Anti-Corruption Measures in Conditions of High-Level Corruption

    OpenAIRE

    Abramov Fedir V.

    2017-01-01

    The article is aimed at determining the efficiency of repressive anti-corruption measures in conditions of high-level corruption. It is shown that the formal rules regulating the use of repressive methods of countering corruption are characterized by a significant level of the target inefficiency of formal rules. Resulting from ignorance as to the causes of both occurence and spread of corruption – the inefficiency of the current formal rules – repressive anti-corruption measures are fundamen...

  3. Transcription and replication result in distinct epigenetic marks following repression of early gene expression

    OpenAIRE

    Kallestad, Les; Woods, Emily; Christensen, Kendra; Gefroh, Amanda; Balakrishnan, Lata; Milavetz, Barry

    2013-01-01

    Simian Virus 40 (SV40) early transcription is repressed when the product of early transcription, T-antigen, binds to its cognate regulatory sequence, Site I, in the promoter of the SV40 minichromosome. Because SV40 minichromosomes undergo replication and transcription potentially repression could occur during active transcription or during DNA replication. Since repression is frequently epigenetically marked by the introduction of specific forms of methylated histone H3, we characterized th...

  4. Mechanism of ultraviolet light induced catabolite repression of L-arabinose isomerase

    Energy Technology Data Exchange (ETDEWEB)

    Bhatnagar, D; Bhattacharya, A K [Banaras Hindu Univ. (India). Inst. of Medical Sciences

    1982-12-01

    An attempt has been made to find out how U.V. irradiation of E.coli B/r cells causes catabolite repression to inhibit L-arabinose isomerase synthesis. The results presented show that U.V. irradiation leads to a lowering of the cellular cyclic AMP level and of the cyclic AMP binding activity. Unlike catabolite repression by glucose, no small molecular weight compound is involved in U.V. light induced inhibition of the binding activity. It is therefore concluded that the mechanism of catabolite repression induced by U.V. appears to be different from that of the catabolite repression by glucose.

  5. DNA residence time is a regulatory factor of transcription repression

    Science.gov (United States)

    Clauß, Karen; Popp, Achim P.; Schulze, Lena; Hettich, Johannes; Reisser, Matthias; Escoter Torres, Laura; Uhlenhaut, N. Henriette

    2017-01-01

    Abstract Transcription comprises a highly regulated sequence of intrinsically stochastic processes, resulting in bursts of transcription intermitted by quiescence. In transcription activation or repression, a transcription factor binds dynamically to DNA, with a residence time unique to each factor. Whether the DNA residence time is important in the transcription process is unclear. Here, we designed a series of transcription repressors differing in their DNA residence time by utilizing the modular DNA binding domain of transcription activator-like effectors (TALEs) and varying the number of nucleotide-recognizing repeat domains. We characterized the DNA residence times of our repressors in living cells using single molecule tracking. The residence times depended non-linearly on the number of repeat domains and differed by more than a factor of six. The factors provoked a residence time-dependent decrease in transcript level of the glucocorticoid receptor-activated gene SGK1. Down regulation of transcription was due to a lower burst frequency in the presence of long binding repressors and is in accordance with a model of competitive inhibition of endogenous activator binding. Our single molecule experiments reveal transcription factor DNA residence time as a regulatory factor controlling transcription repression and establish TALE-DNA binding domains as tools for the temporal dissection of transcription regulation. PMID:28977492

  6. Andrographolide inhibits adipogenesis of 3T3-L1 cells by suppressing C/EBPβ expression and activation.

    Science.gov (United States)

    Chen, Ching-Chu; Chuang, Wei-Ting; Lin, Ai-Hsuan; Tsai, Chia-Wen; Huang, Chin-Shiu; Chen, Yun-Ting; Chen, Haw-Wen; Lii, Chong-Kuei

    2016-09-15

    Andrographolide, a diterpenoid, is the most abundant terpenoid in Andrographis paniculata, a popular Chinese herbal medicine. Andrographolide displays diverse biological activities including hypoglycemia, hypolipidemia, anti-inflammation, and anti-tumorigenesis. Recent evidence indicates that andrographolide displays anti-obesity property by inhibiting lipogenic gene expression, however, the underlying mechanisms remain to be elucidated. In this study, the effects of andrographolide on transcription factor cascade and mitotic clonal expansion in 3T3-L1 preadipocyte differentiation into adipocyte were determined. Andrographolide dose-dependently (0-15μM) inhibited CCAAT/enhancer-binding protein α (C/EBPα) and C/EBPβ mRNA and protein expression as well as peroxisome proliferator-activated receptor γ (PPARγ) protein level during the adipogenesis of 3T3-L1 cells. Concomitantly, fatty acid synthase and stearoyl-CoA desaturase expression and lipid accumulation were attenuated by andrographolide. Oil-red O staining further showed that the first 48h after the initiation of differentiation was critical for andrographolide inhibition of adipocyte formation. Andrographolide inhibited the phosphorylation of PKA and the activation of cAMP response element-binding protein (CREB) in response to a differentiation cocktail, which led to attenuated C/EBPβ expression. In addition, ERK and GSK3β-dependent C/EBPβ phosphorylation was attenuated by andrographolide. Moreover, andrographolide suppressed cyclin A, cyclin E, and CDK2 expression and impaired the progression of mitotic clonal expansion (MCE) by arresting the cell cycle at the Go/G1 phase. Taken together, these results indicate that andrographolide has a potent anti-obesity action by inhibiting PKA-CREB-mediated C/EBPβ expression as well as C/EBPβ transcriptional activity, which halts MCE progression and attenuates C/EBPα and PPARγ expression. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Increased adipogenesis in cultured embryonic chondrocytes and in adult bone marrow of dominant negative Erg transgenic mice.

    Directory of Open Access Journals (Sweden)

    Sébastien Flajollet

    Full Text Available In monolayer culture, primary articular chondrocytes have an intrinsic tendency to lose their phenotype during expansion. The molecular events underlying this chondrocyte dedifferentiation are still largely unknown. Several transcription factors are important for chondrocyte differentiation. The Ets transcription factor family may be involved in skeletal development. One family member, the Erg gene, is mainly expressed during cartilage formation. To further investigate the potential role of Erg in the maintenance of the chondrocyte phenotype, we isolated and cultured chondrocytes from the rib cartilage of embryos of transgenic mice that express a dominant negative form of Erg (DN-Erg during cartilage formation. DN-Erg expression in chondrocytes cultured for up to 20 days did not affect the early dedifferentiation usually observed in cultured chondrocytes. However, lipid droplets accumulated in DN-Erg chondrocytes, suggesting adipocyte emergence. Transcriptomic analysis using a DNA microarray, validated by quantitative RT-PCR, revealed strong differential gene expression, with a decrease in chondrogenesis-related markers and an increase in adipogenesis-related gene expression in cultured DN-Erg chondrocytes. These results indicate that Erg is involved in either maintaining the chondrogenic phenotype in vitro or in cell fate orientation. Along with the in vitro studies, we compared adipocyte presence in wild-type and transgenic mice skeletons. Histological investigations revealed an increase in the number of adipocytes in the bone marrow of adult DN-Erg mice even though no adipocytes were detected in embryonic cartilage or bone. These findings suggest that the Ets transcription factor family may contribute to the homeostatic balance in skeleton cell plasticity.

  8. Radicicol, a heat shock protein 90 inhibitor, inhibits differentiation and adipogenesis in 3T3-L1 preadipocytes

    Energy Technology Data Exchange (ETDEWEB)

    He, Yonghan [Department of Nutrition and Food Hygiene, Public Health College, Harbin Medical University, 157 Baojian Road, Harbin 150081 (China); Aquatic and Crop Resource Development, Life Sciences Branch, National Research Council Canada, Charlottetown, PE, Canada C1A 4P3 (Canada); State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223 (China); Li, Ying [Department of Nutrition and Food Hygiene, Public Health College, Harbin Medical University, 157 Baojian Road, Harbin 150081 (China); Zhang, Shuocheng [Aquatic and Crop Resource Development, Life Sciences Branch, National Research Council Canada, Charlottetown, PE, Canada C1A 4P3 (Canada); Perry, Ben [Aquatic and Crop Resource Development, Life Sciences Branch, National Research Council Canada, Charlottetown, PE, Canada C1A 4P3 (Canada); Department of Biomedical Sciences, University of Prince Edward Island, 550 University Avenue, Charlottetown, PE, Canada C1A 4P3 (Canada); Zhao, Tiantian [Aquatic and Crop Resource Development, Life Sciences Branch, National Research Council Canada, Charlottetown, PE, Canada C1A 4P3 (Canada); Department of Psychology, University of Toronto, 1265 Military Trail, Toronto, ON, Canada M1C 1A4 (Canada); Wang, Yanwen, E-mail: yanwen.wang@nrc.ca [Aquatic and Crop Resource Development, Life Sciences Branch, National Research Council Canada, Charlottetown, PE, Canada C1A 4P3 (Canada); Department of Biomedical Sciences, University of Prince Edward Island, 550 University Avenue, Charlottetown, PE, Canada C1A 4P3 (Canada); Sun, Changhao, E-mail: sun2002changhao@yahoo.com [Department of Nutrition and Food Hygiene, Public Health College, Harbin Medical University, 157 Baojian Road, Harbin 150081 (China)

    2013-06-28

    Highlights: •Radicicol suppressed intracellular fat accumulation in 3T3-L1 adipocytes. •Radicicol inhibited the expression of FAS and FABP4. •Radicicol blocked cell cycle at the G1-S phase during cell differentiation. •Radicicol inhibited the PDK1/Akt pathway in adipocyte differentiation. -- Abstract: Heat shock protein 90 (Hsp90) is involved in various cellular processes, such as cell proliferation, differentiation and apoptosis. As adipocyte differentiation plays a critical role in obesity development, the present study investigated the effect of an Hsp90 inhibitor radicicol on the differentiation of 3T3-L1 preadipocytes and potential mechanisms. The cells were treated with different concentrations of radicicol during the first 8 days of cell differentiation. Adipogenesis, the expression of adipogenic transcriptional factors, differentiation makers and cell cycle were determined. It was found that radicicol dose-dependently decreased intracellular fat accumulation through down-regulating the expression of peroxisome proliferator-activated receptor γ (PPAR{sub γ}) and CCAAT element binding protein α (C/EBP{sub α}), fatty acid synthase (FAS) and fatty acid-binding protein 4 (FABP4). Flow cytometry analysis revealed that radicicol blocked cell cycle at G1-S phase. Radicicol redcued the phosphorylation of Akt while showing no effect on β-catenin expression. Radicicol decreased the phosphorylation of phosphoinositide-dependent kinase 1 (PDK1). The results suggest that radicicol inhibited 3T3-L1 preadipocyte differentiation through affecting the PDK1/Akt pathway and subsequent inhibition of mitotic clonal expansion and the expression/activity of adipogenic transcriptional factors and their downstream adipogenic proteins.

  9. Radicicol, a heat shock protein 90 inhibitor, inhibits differentiation and adipogenesis in 3T3-L1 preadipocytes

    International Nuclear Information System (INIS)

    He, Yonghan; Li, Ying; Zhang, Shuocheng; Perry, Ben; Zhao, Tiantian; Wang, Yanwen; Sun, Changhao

    2013-01-01

    Highlights: •Radicicol suppressed intracellular fat accumulation in 3T3-L1 adipocytes. •Radicicol inhibited the expression of FAS and FABP4. •Radicicol blocked cell cycle at the G1-S phase during cell differentiation. •Radicicol inhibited the PDK1/Akt pathway in adipocyte differentiation. -- Abstract: Heat shock protein 90 (Hsp90) is involved in various cellular processes, such as cell proliferation, differentiation and apoptosis. As adipocyte differentiation plays a critical role in obesity development, the present study investigated the effect of an Hsp90 inhibitor radicicol on the differentiation of 3T3-L1 preadipocytes and potential mechanisms. The cells were treated with different concentrations of radicicol during the first 8 days of cell differentiation. Adipogenesis, the expression of adipogenic transcriptional factors, differentiation makers and cell cycle were determined. It was found that radicicol dose-dependently decreased intracellular fat accumulation through down-regulating the expression of peroxisome proliferator-activated receptor γ (PPAR γ ) and CCAAT element binding protein α (C/EBP α ), fatty acid synthase (FAS) and fatty acid-binding protein 4 (FABP4). Flow cytometry analysis revealed that radicicol blocked cell cycle at G1-S phase. Radicicol redcued the phosphorylation of Akt while showing no effect on β-catenin expression. Radicicol decreased the phosphorylation of phosphoinositide-dependent kinase 1 (PDK1). The results suggest that radicicol inhibited 3T3-L1 preadipocyte differentiation through affecting the PDK1/Akt pathway and subsequent inhibition of mitotic clonal expansion and the expression/activity of adipogenic transcriptional factors and their downstream adipogenic proteins

  10. Kaempferol slows intervertebral disc degeneration by modifying LPS-induced osteogenesis/adipogenesis imbalance and inflammation response in BMSCs.

    Science.gov (United States)

    Zhu, Jun; Tang, Haoyu; Zhang, Zhenhua; Zhang, Yong; Qiu, Chengfeng; Zhang, Ling; Huang, Pinge; Li, Feng

    2017-02-01

    Intervertebral disc (IVD) degeneration is a common disease that represents a significant cause of socio-economic problems. Bone marrow-derived mesenchymal stem cells (BMSCs) are a potential autologous stem cell source for the nucleus pulposus regeneration. Kaempferol has been reported to exert protective effects against both osteoporosis and obesity. This study explored the effect of kaempferol on BMSCs differentiation and inflammation. The results demonstrated that kaempferol did not show any cytotoxicity at concentrations of 20, 60 and 100μM. Kaempferol enhanced cell viability by counteracting the lipopolysaccharide (LPS)-induced cell apoptosis and increasing cell proliferation. Western blot analysis of mitosis-associated nuclear antigen (Ki67) and proliferation cell nuclear antigen (PCNA) further confirmed the increased effect of kaempferol on LPS-induced decreased viability of BMSCs. Besides, kaempferol elevated LPS-induced reduced level of chondrogenic markers (SOX-9, Collagen II and Aggrecan), decreased the level of matrix-degrading enzymes, i.e., matrix metalloprotease (MMP)-3 and MMP-13, suggesting the osteogenesis of BMSC under kaempferol treatment. On the other hand, kaempferol enhanced LPS-induced decreased expression of lipid catabolism-related genes, i.e., carnitine palmitoyl transferase-1 (CPT-1). Kaempferol also suppressed the expression of lipid anabolism-related genes, i.e., peroxisome proliferators-activated receptor-γ (PPAR-γ). The Oil red O staining further convinced the inhibition effect of kaempferol on BMSCs adipogenesis. In addition, kaempferol alleviated inflammatory by reducing the level of pro-inflammatory cytokines (i.e., interleukin (IL)-6) and increasing anti-inflammatory cytokine (IL-10) via inhibiting the nucleus translocation of nuclear transcription factor (NF)-κB p65. Taken together, our research indicated that kaempferol may serve as a novel target for treatment of IVD degeneration. Copyright © 2016 Elsevier B.V. All rights

  11. Chrysophanic Acid Suppresses Adipogenesis and Induces Thermogenesis by Activating AMP-activated Protein Kinase Alpha in vivo and in vitro

    Directory of Open Access Journals (Sweden)

    Hara Lim

    2016-12-01

    Full Text Available Chrysophanic acid (CA is a member of the anthraquinone family abundant in rhubarb, a widely used herb for obesity treatment in Traditional Korean Medicine. Though several studies have indicated numerous features of CA, no study has yet reported the effect of CA on obesity. In this study, we tried to identify the anti-obesity effects of CA. By using 3T3-L1 adipocytes and primary cultured brown adipocytes as in vitro models, high-fat diet (HFD-induced obese mice, and zebrafish as in vivo models, we determined the anti-obesity effects of CA. CA reduced weight gain in HFD-induced obese mice. They also decreased lipid accumulation and the expressions of adipogenesis factors including peroxisome proliferator-activated receptor gamma (PPARγ and CCAAT/enhancer-binding protein alpha (C/EBPα in 3T3-L1 adipocytes. In addition, uncoupling protein 1 (UCP1 and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α, the brown fat specific thermogenic genes, were up-regulated in brown adipocytes by CA treatment. Furthermore, when co-treated with Compound C, the AMP-activated protein kinase (AMPK inhibitor, CA was able to restore the activation of AMPKα in both types of adipocytes, indicating the multi-controlling effect of CA was partially via the AMPKα pathway. Given all together, these results indicate that CA can ameliorate obesity by controlling the adipogenic and thermogenic pathway at the same time. On these bases we suggest the new potential of CA as an anti-obese pharmacotherapy.

  12. Kaempferol suppresses lipid accumulation by inhibiting early adipogenesis in 3T3-L1 cells and zebrafish.

    Science.gov (United States)

    Lee, Yeon-Joo; Choi, Hyeon-Son; Seo, Min-Jung; Jeon, Hui-Jeon; Kim, Kui-Jin; Lee, Boo-Yong

    2015-08-01

    Kaempferol is a flavonoid present in Kaempferia galanga and Opuntia ficus indica var. saboten. Recent studies have suggested that it has anti-oxidant, anti-inflammatory, anti-cancer, and anti-obesity effects. In this study, we focused on the anti-adipogenic effects of kaempferol during adipocyte differentiation. The results showed that kaempferol inhibits lipid accumulation in adipocytes and zebrafish. Oil Red O and Nile Red staining showed that the number of intracellular lipid droplets decreased in adipocytes and zebrafish treated with kaempferol. LPAATθ (lysophosphatidic acid acyltransferase), lipin1, and DGAT1 (triglyceride synthetic enzymes) and FASN and SREBP-1C (fatty acid synthetic proteins) showed decreased expression levels in the presence of kaempferol. In addition, treatment of kaempferol showed an inhibitory activity on cell cycle progression. Kaempferol delayed cell cycle progression from the S to G2/M phase through the regulation of cyclins in a dose-dependent manner. Kaempferol blocked the phosphorylation of AKT (protein kinase B) and mammalian target of rapamycin (mTOR) signaling pathway during the early stages of adipogenesis. In addition, kaempferol down-regulated pro-early adipogenic factors such as CCAAT-enhancer binding proteins β (C/EBPβ), and Krüppel-like factors (KLFs) 4 and 5, while anti-early adipogenic factors, such as KLF2 and pref-1(preadipocyte factor-1), were upregulated. These kaempferol-mediated regulations of early adipogenic factors resulted in the attenuation of late adipogenic factors such as C/EBPα and peroxisome proliferator-activated receptor γ (PPARγ). These results were supported in zebrafish based on the decrease in lipid accumulation and expression of adipogenic factors. Our results indicated that kaempferol might have an anti-obesity effect by regulating lipid metabolism.

  13. Interference of transcription across H-NS binding sites and repression by H-NS.

    Science.gov (United States)

    Rangarajan, Aathmaja Anandhi; Schnetz, Karin

    2018-05-01

    Nucleoid-associated protein H-NS represses transcription by forming extended DNA-H-NS complexes. Repression by H-NS operates mostly at the level of transcription initiation. Less is known about how DNA-H-NS complexes interfere with transcription elongation. In vitro H-NS has been shown to enhance RNA polymerase pausing and to promote Rho-dependent termination, while in vivo inhibition of Rho resulted in a decrease of the genome occupancy by H-NS. Here we show that transcription directed across H-NS binding regions relieves H-NS (and H-NS/StpA) mediated repression of promoters in these regions. Further, we observed a correlation of transcription across the H-NS-bound region and de-repression. The data suggest that the transcribing RNA polymerase is able to remodel the H-NS complex and/or dislodge H-NS from the DNA and thus relieve repression. Such an interference of transcription and H-NS mediated repression may imply that poorly transcribed AT-rich loci are prone to be repressed by H-NS, while efficiently transcribed loci escape repression. © 2018 John Wiley & Sons Ltd.

  14. miR-200b mediates post-transcriptional repression of ZFHX1B

    DEFF Research Database (Denmark)

    Christoffersen, Nanna Rønbjerg; Silahtaroglu, Asli; Ørom, Ulf Lupo Andersson

    2007-01-01

    of E-cadherin. We show that Zfhx1b and miR-200b are regionally coexpressed in the adult mouse brain and that miR-200b represses the expression of Zfhx1b via multiple sequence elements present in the 3'-untranslated region. Overexpression of miR-200b leads to repression of endogenous ZFHX1B...

  15. Induction and catabolite repression of α-glucosidase synthesis in protoplasts of Saccharomyces carlsbergensis

    NARCIS (Netherlands)

    Wijk, R. van; Ouwehand, J.; Bos, T. van den; Koningsberger, V.V.

    1969-01-01

    1. 1. Kinetic data on the repression, the derepression and the induction of α-glucosidase synthesis in protoplasts of Saccharomyces carlsbergensis suggested that some site other than the stereospecific site for the induction by maltose was involved in the repression by glucose. 2. 2. A study of the

  16. A Hexose Transporter Homologue Controls Glucose Repression in the Methylotrophic Yeast Hansenula polymorpha

    NARCIS (Netherlands)

    Stasyk, Oleh V.; Stasyk, Olena G.; Komduur, Janet; Veenhuis, Marten; Cregg, James M.; Sibirny, Andrei A.

    2004-01-01

    Peroxisome biogenesis and synthesis of peroxisomal enzymes in the methylotrophic yeast Hansenula polymorpha are under the strict control of glucose repression. We identified an H. polymorpha glucose catabolite repression gene (HpGCR1) that encodes a hexose transporter homologue. Deficiency in GCR1

  17. cAMP/PKA regulates osteogenesis, adipogenesis and ratio of RANKL/OPG mRNA expression in mesenchymal stem cells by suppressing leptin.

    Directory of Open Access Journals (Sweden)

    Der-Chih Yang

    Full Text Available BACKGROUND: Mesenchymal stem cells (MSCs are a pluripotent cell type that can differentiate into adipocytes, osteoblasts and other cells. The reciprocal relationship between adipogenesis and osteogenesis was previously demonstrated; however, the mechanisms remain largely unknown. METHODS AND FINDINGS: We report that activation of PKA by 3-isobutyl-1 methyl xanthine (IBMX and forskolin enhances adipogenesis, the gene expression of PPARgamma2 and LPL, and downregulates the gene expression of Runx2 and osteopontin, markers of osteogenesis. PKA activation also decreases the ratio of Receptor Activator of the NF-kappaB Ligand to Osteoprotegerin (RANKL/OPG gene expression - the key factors of osteoclastogenesis. All these effects are mediated by the cAMP/PKA/CREB pathway by suppressing leptin, and may contribute to PKA stimulators-induced in vivo bone loss in developing zebrafish. CONCLUSIONS: Using MSCs, the center of a newly proposed bone metabolic unit, we identified cAMP/PKA signaling, one of the many signaling pathways that regulate bone homeostasis via controlling cyto-differentiation of MSCs and altering RANKL/OPG gene expression.

  18. Zanthoxylum piperitum DC ethanol extract suppresses fat accumulation in adipocytes and high fat diet-induced obese mice by regulating adipogenesis.

    Science.gov (United States)

    Gwon, So Young; Ahn, Ji Yun; Kim, Tae Wan; Ha, Tae Youl

    2012-01-01

    This study was conducted to determine the anti-obesity effects of Zanthoxylum piperitum DC fruit ethanol extract (ZPE) in 3T3-L1 adipocytes and obese mice fed a high-fat diet. We evaluated the influence of the addition of ZPE to a high-fat diet on body weight, adipose tissue weight, serum and hepatic lipids in C57BL/6 mice. In addition, adipogenic gene expression was determined by Western blot and real-time reverse transcription-PCR analysis. We assessed the effect of ZPE on 3T3-L1 preadipocyte differentiation. ZPE reduced weight gain, white adipose tissue mass, and serum triglyceride and cholesterol levels (pZPE decreased lipid accumulation and PPARγ, C/EBPα, SREBP-1, and FAS protein and mRNA levels in the liver. ZPE inhibited in vitro adipocyte differentiation in a dose-dependent manner and significantly attenuated adipogenic transcription factors, such as PPARγ, C/EBPα, and SREBP-1 in 3T3L1 cells. These findings suggest that Z. piperitum DC exerts an anti-obesity effect by inhibiting adipogenesis through the downregulation of genes involved in the adipogenesis pathway.

  19. Theobromine inhibits differentiation of 3T3-L1 cells during the early stage of adipogenesis via AMPK and MAPK signaling pathways.

    Science.gov (United States)

    Jang, Yeon Jeong; Koo, Hyun Jung; Sohn, Eun-Hwa; Kang, Se Chan; Rhee, Dong-Kwon; Pyo, Suhkneung

    2015-07-01

    Obesity is characterized by hypertrophy and/or by the differentiation or adipogenesis of pre-existing adipocytes. In this study, we investigated the inhibitory effects of theobromine, a type of alkaloid in cocoa, on adipocyte differentiation of 3T3-L1 preadipocytes and its mechanisms of action. Theobromine inhibited the accumulation of lipid droplets, the expression of PPARγ and C/EBPα, and the mRNA expression of aP2 and leptin. The inhibition of adipogenic differentiation by theobromine occurred primarily in the early stages of differentiation. In addition, theobromine arrested the cell cycle at the G0/G1 phase and regulated the expressions of CDK2, p27, and p21. Theobromine treatment increased AMPK phosphorylation and knockdown of AMPKα1/α2 prevented the ability of theobromine to inhibit PPARγ expression in the differentiating 3T3-L1 cells. Theobromine reduced the phosphorylation of ERK and JNK. Moreover, the secretion and the mRNA level of TNF-α and IL-6 were inhibited by theobromine treatment. These data suggest that theobromine inhibits adipocyte differentiation during the early stages of adipogenesis by regulating the expression of PPARγ and C/EBPα through the AMPK and ERK/JNK signaling pathways in 3T3-L1 preadipocytes.

  20. Extremadura: Behind the material traces of Franco’s repression

    Directory of Open Access Journals (Sweden)

    Muñoz Encinar, Laura

    2014-12-01

    Full Text Available After the failed coup d’état of July 17th, 1936 and after the start of the Spanish Civil War that followed it, rebels carried out a repressive strategy based on the execution of thousands of people as a key tool of social control. The socialization of fear and terror through humiliation, killing and disappearance would become the main strategy employed throughout the war and the post-war period. In this context, perpetrators would exercise repressive practices on victims and their bodies. As a result, countless mass graves were opened in order to hide the bodies of victims. In the region of Extremadura, these mass graves have been investigated through the application of archeology and physical anthropology as disciplines of research and historical knowledge production. The exhumations, have given us a diachronic point of view of the repressive strategies developed, associated with different contexts between 1936 and 1946. Analyses of mass executions linked to rebels’ occupation of territories in this region, systematic rearguard killings in occupied areas, elimination procedures carried out in concentration camps and prisons and the fight against the armed guerrilla during the dictatorship, are the main contributions of this article.Tras el fracaso del golpe de Estado del 17 de julio de 1936 y el inicio de la Guerra Civil en España, se llevó a cabo, por parte de los sublevados, una estrategia represiva basada en la ejecución de miles de personas como principal herramienta de control social. La socialización del miedo y el terror a través de las vejaciones, ejecuciones y desapariciones será la principal estrategia utilizada, donde el uso de las víctimas y los cuerpos formará también parte de las prácticas represivas ideadas por los perpetradores. Como consecuencia, se abrieron incontables fosas comunes con el objetivo de ocultar los cadáveres de los represaliados. Estas fosas han sido investigadas en la Comunidad Autónoma de

  1. Role of sugar uptake and metabolic intermediates on catabolite repression in Bacillus subtilis.

    Science.gov (United States)

    Lopez, J M; Thoms, B

    1977-01-01

    Many phosphorylated intermediates exert catabolite repression on the enzyme acetoin dehydrogenase in Bacillus subtilis. This was shown with strains that are blocked at different positions in central metabolism when they receive sugars that cannot be metabolized past enzymatic block(s). In the case of sorbitol, transport events were not involved in catabolite repression, for this sugar cannot repress acetoin dehydrogenase in a strain lacking sorbitol dehydrogenase but otherwise able to take up sorbitol. The presence of glucose did not markedly influence the uptake of acetoin. PMID:401492

  2. THE DYNAMICS OF REPRESSIVE HABITUS LAWS: ETHNOGRAPHIC CASE STUDY IN UNWIMA

    Directory of Open Access Journals (Sweden)

    Teddy Asmara

    2015-01-01

    Full Text Available This research describes repressive legal habitus Unwima community by focusing on the issue of why they create a legal cognition such manner and how to empower them in the public domain when facing a lawsuit in court and examination process in higher education office. The results of the research with ethnographic methods and interpretative analysis, First, that repressive legal habitus is a part of the neo-feudalistic thinking in education management. Second, the empowerment of repressive legal habitus in the public domain potentially generate a legal behavior of impulsive that tends to a manipulative, coercive, veiled, and other immorality practices.

  3. Andrei Sakharov Prize Talk: Supporting Repressed Scientists: Continuing Efforts

    Science.gov (United States)

    Birman, Joseph L.

    2010-02-01

    Some years ago, Max Perutz asked ``By What Right Do We Scientists Invoke Human Rights?" My presentation will start with mentioning actions of the international community which relate to this question. Such action as the creation in 1919 of the International Research Council, and continuing on to the present with the UN sanctioned International Council of Scientific Unions [ICSU], and other Committees such as those formed by APS, CCS, NYAS, AAAS which give support to repressed scientists around the world now. My own work has attempted to combine my individual initiatives with work as a member and officer of these groups. Together with like minded colleagues who are deeply affected when colleagues are discharged from their positions, exiled, imprisoned and subject to brutal treatment, often after mock ``trials", we react. On visits in 1968 to conferences in Budapest, and then in 1969 to Moscow, Tallin and Leningrad I became personally and deeply touched by the lives of colleagues who were seriously constrained by living under dictatorships. I could move freely into and out of their countries,speak openly about my work or any other matter. They could not, under penalty of possibly serious punishment. Yet, I felt these people were like my extended family. If my grandparents had not left Eastern Europe for the USA in the late 189Os our situations could have been reversed. A little later in the 197O's, ``refusenik" and ``dissident" scientists in the USSR needed support. Colleagues like Andrei Sakharov, Naum Meiman, Mark Azbel, Yakov Alpert, Yuri Orlov and others were being punished for exercising their rights under the UN sanctioned international protocals on ``Universality of Science and Free Circulation of Scientists". Their own governments [which signed these agreements] ignored the very protections they had supported. On frequent trips to the USSR during the 7Os,and 8Os I also seized the opportunity for ``individual initiative" to help these colleagues. I asked for

  4. Repression of CC16 by cigarette smoke (CS exposure.

    Directory of Open Access Journals (Sweden)

    Lingxiang Zhu

    Full Text Available Club (Clara Cell Secretory Protein (CCSP, or CC16 is produced mainly by non-ciliated airway epithelial cells including bronchiolar club cells and the change of its expression has been shown to associate with the progress and severity of Chronic Obstructive Pulmonary Disease (COPD. In an animal model, the lack of CC16 renders the animal susceptible to the tumorigenic effect of a major CS carcinogen. A recent population-based Tucson Epidemiological Study of Airway Obstructive Diseases (TESAOD has indicated that the low serum CC16 concentration is closely linked with the smoke-related mortality, particularly that driven by the lung cancer. However, the study of CC16 expression in well-defined smoke exposure models has been lacking, and there is no experimental support for the potential causal link between CC16 and CS-induced pathophysiological changes in the lung. In the present study, we have found that airway CC16 expression was significantly repressed in COPD patients, in monkey CS exposure model, and in CS-induced mouse model of COPD. Additionally, the lack of CC16 exacerbated airway inflammation and alveolar loss in the mouse model. Therefore, CC16 may play an important protective role in CS-related diseases.

  5. Promoter DNA hypermethylation and gene repression in undifferentiated Arabidopsis cells.

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    María Berdasco

    Full Text Available Maintaining and acquiring the pluripotent cell state in plants is critical to tissue regeneration and vegetative multiplication. Histone-based epigenetic mechanisms are important for regulating this undifferentiated state. Here we report the use of genetic and pharmacological experimental approaches to show that Arabidopsis cell suspensions and calluses specifically repress some genes as a result of promoter DNA hypermethylation. We found that promoters of the MAPK12, GSTU10 and BXL1 genes become hypermethylated in callus cells and that hypermethylation also affects the TTG1, GSTF5, SUVH8, fimbrin and CCD7 genes in cell suspensions. Promoter hypermethylation in undifferentiated cells was associated with histone hypoacetylation and primarily occurred at CpG sites. Accordingly, we found that the process specifically depends on MET1 and DRM2 methyltransferases, as demonstrated with DNA methyltransferase mutants. Our results suggest that promoter DNA methylation may be another important epigenetic mechanism for the establishment and/or maintenance of the undifferentiated state in plant cells.

  6. Repression of the albumin gene in Novikoff hepatoma cells

    International Nuclear Information System (INIS)

    Capetanaki, Y.G.; Flytzanis, C.N.; Alonso, A.

    1982-01-01

    Novikoff hepatoma cells have lost their capacity to synthesize albumin. As a first approach to study the mechanisms underlying this event, in vitro translation in a reticulocyte system was performed using total polyadenylated mRNA from rat liver and Novikoff hepatoma cells. Immunoprecipitation of the in vitro translation products with albumin-specific antibody revealed a total lack of albumin synthesis in Novikoff hepatoma, suggesting the absence of functional albumin mRNA in these cells. Titration experiments using as probe albumin cDNA cloned in pBR322 plasmid demonstrated the absence of albumin-specific sequences in both polysomal and nuclear polyadenylated and total RNA from Novikoff cells. This albumin recombinant plasmid was obtained by screening a rat liver cDNA library with albumin [/sup 32/P]cDNA reverse transcribed from immuno-precipitated mRNA. The presence of an albumin-specific gene insert was documented with translation assays as well as by restriction mapping. Repression of the albumin gene at the transcriptional level was further demonstrated by RNA blotting experiments using the cloned albumin cDNA probe. Genomic DNA blots using the cloned albumin cDNA as probe did not reveal any large-scale deletions, insertions, or rearrangements in the albumin gene, suggesting that the processes involved in the suppression of albumin mRNA synthesis do not involve extensive genomic rearrangements

  7. Fecal fermentation products of common bean-derived fiber inhibit C/EBP alpha and PPAR gamma expression and lipid accumulation but stimulate PPAR delta and UCP2 expression in the adipogenesis of 3T3-L1 cells

    Science.gov (United States)

    Background: Clinical and animal studies have suggested efficacies of common bean (Phaseolus vulgaris) consumption on weight loss. Fermentation of common bean-derived dietary fiber by gut microbiota is proposed to modulate obesity; however, the mechanism by which the adipogenesis is inhibited is uncl...

  8. Spirulina maxima Extract Reduces Obesity through Suppression of Adipogenesis and Activation of Browning in 3T3-L1 Cells and High-Fat Diet-Induced Obese Mice.

    Science.gov (United States)

    Seo, Young-Jin; Kim, Kui-Jin; Choi, Jia; Koh, Eun-Jeong; Lee, Boo-Yong

    2018-06-01

    Obesity predisposes animals towards the metabolic syndrome and diseases such as type 2 diabetes, atherosclerosis, and cardiovascular disease. Spirulina maxima is a microalga with anti-oxidant, anti-cancer, and neuroprotective activities, but the anti-obesity effect of Spirulina maxima 70% ethanol extract (SM70EE) has not yet been fully established. We investigated the effect of SM70EE on adipogenesis, lipogenesis, and browning using in vitro and in vivo obesity models. SM70EE treatment reduced lipid droplet accumulation by the oil red O staining method and downregulated the adipogenic proteins C/EBPα, PPARγ, and aP2, and the lipogenic proteins SREBP1, ACC, FAS, LPAATβ, Lipin1, and DGAT1 by western blot analysis. In addition, the index components of SM70EE, chlorophyll a, and C-phycocyanin, reduced adipogenesis and lipogenesis protein levels in 3T3-L1 and C3H10T1/2 cells. High-fat diet (HFD)-fed mice administered with SM70EE demonstrated smaller adipose depots and lower blood lipid concentrations than control HFD-fed mice. The lower body mass gain in treated SM70EE-administrated mice was associated with lower protein expression of adipogenesis factors and higher expression of AMPKα-induced adipose browning proteins PRDM16, PGC1α, and UCP1. SM70EE administration ameliorates obesity, likely by reducing adipogenesis and activating the thermogenic program, in 3T3-L1 cells and HFD-induced obese mice.

  9. The contentious fans: the impact of repression, media coverage, grievances and aggressive play on supporters’ violence

    NARCIS (Netherlands)

    Braun, R.; Vliegenthart, R.

    2008-01-01

    This article poses the question of which macro-sociological explanations best predict the level of soccer supporters’ violence. By conceptualizing supporters’ violence as a form of contentious violence, four possible explanations are proposed: repression, media attention, unemployment and aggressive

  10. Combination of Garcinia cambogia Extract and Pear Pomace Extract Additively Suppresses Adipogenesis and Enhances Lipolysis in 3T3-L1 Cells.

    Science.gov (United States)

    Sharma, Kushal; Kang, Siwon; Gong, Dalseong; Oh, Sung-Hwa; Park, Eun-Young; Oak, Min-Ho; Yi, Eunyoung

    2018-01-01

    Inhibition of adipogenesis has been a therapeutic target for reducing obesity and obesity-related disorders such as diabetes, hypertension, atherosclerosis, and cancer. For decades, anti-adipogenic potential of many herbal extracts has been investigated. One example is Garcinia cambogia extract (GE) containing (-)-hydroxycitric acid as an active ingredient. GE is currently marketed as a weight loss supplement, used alone or with other ingredients. Pear pomace extract (PE), another natural product, has been also shown to have anti-adipogenic activity in a recent report. It was tested if the mixture of PE and GE (MIX) would produce more effective anti-adipogenic activity than PE or GE alone. Differentiation of 3T3-L1 preadipocyte was induced by adding insulin, dexamethasone, and isobutylmethylxanthine and lipid accumulation was measured by Oil Red O staining. Cellular markers for adipogenesis and lipolysis such as CCAAT/enhancer binding protein (C/EBP-α), peroxisome proliferator-activated receptor gamma (PPAR-γ), fatty acid synthase (FAS), and hormone-sensitive lipase (HSL) was measured using immunocytochemistry. MIX, compared to PE or GE alone, showed greater inhibition of lipid accumulation. Furthermore, MIX reduced the expression of adipogenesis-related factors C/EBP-α, PPAR-γ, and FAS more than PE or GE alone did. In contrast, the expression of HSL the enzyme required for lipolysis was further enhanced in MIX-treated adipocytes compared to the PE or GE alone treated groups. Anti-adipogenic effect of PE and GE appears synergistic, and the MIX may be a useful therapeutic combination for the treatment of obesity and obesity-related diseases. PE and GE efficiently inhibited adipocyte differentiation by suppressing the expression of adipogenic transcription factor CEBP-α and PPAR-γ.PE and GE significantly decreased the expression of adipogenic enzyme FAS.PE and GE increased the expression of lipid degrading enzyme HSL.Mixture of PE and GE exhibited additive or

  11. Mutual repression enhances the steepness and precision of gene expression boundaries.

    Directory of Open Access Journals (Sweden)

    Thomas R Sokolowski

    Full Text Available Embryonic development is driven by spatial patterns of gene expression that determine the fate of each cell in the embryo. While gene expression is often highly erratic, embryonic development is usually exceedingly precise. In particular, gene expression boundaries are robust not only against intra-embryonic fluctuations such as noise in gene expression and protein diffusion, but also against embryo-to-embryo variations in the morphogen gradients, which provide positional information to the differentiating cells. How development is robust against intra- and inter-embryonic variations is not understood. A common motif in the gene regulation networks that control embryonic development is mutual repression between pairs of genes. To assess the role of mutual repression in the robust formation of gene expression patterns, we have performed large-scale stochastic simulations of a minimal model of two mutually repressing gap genes in Drosophila, hunchback (hb and knirps (kni. Our model includes not only mutual repression between hb and kni, but also the stochastic and cooperative activation of hb by the anterior morphogen Bicoid (Bcd and of kni by the posterior morphogen Caudal (Cad, as well as the diffusion of Hb and Kni between neighboring nuclei. Our analysis reveals that mutual repression can markedly increase the steepness and precision of the gap gene expression boundaries. In contrast to other mechanisms such as spatial averaging and cooperative gene activation, mutual repression thus allows for gene-expression boundaries that are both steep and precise. Moreover, mutual repression dramatically enhances their robustness against embryo-to-embryo variations in the morphogen levels. Finally, our simulations reveal that diffusion of the gap proteins plays a critical role not only in reducing the width of the gap gene expression boundaries via the mechanism of spatial averaging, but also in repairing patterning errors that could arise because of the

  12. Acetate repression of methane oxidation by supplemental Methylocella silvestris in a peat soil microcosm.

    Science.gov (United States)

    Rahman, M Tanvir; Crombie, Andrew; Moussard, Hélène; Chen, Yin; Murrell, J Colin

    2011-06-01

    Methylocella spp. are facultative methanotrophs that grow on methane and multicarbon substrates, such as acetate. Acetate represses transcription of methane monooxygenase of Methylocella silvestris in laboratory culture. DNA stable-isotope probing (DNA-SIP) using (13)C-methane and (12)C-acetate, carried out with Methylocella-spiked peat soil, showed that acetate also repressed methane oxidation by Methylocella in environmental samples.

  13. Acetate Repression of Methane Oxidation by Supplemental Methylocella silvestris in a Peat Soil Microcosm ▿ †

    Science.gov (United States)

    Rahman, M. Tanvir; Crombie, Andrew; Moussard, Hélène; Chen, Yin; Murrell, J. Colin

    2011-01-01

    Methylocella spp. are facultative methanotrophs that grow on methane and multicarbon substrates, such as acetate. Acetate represses transcription of methane monooxygenase of Methylocella silvestris in laboratory culture. DNA stable-isotope probing (DNA-SIP) using 13C-methane and 12C-acetate, carried out with Methylocella-spiked peat soil, showed that acetate also repressed methane oxidation by Methylocella in environmental samples. PMID:21515721

  14. Acetate Repression of Methane Oxidation by Supplemental Methylocella silvestris in a Peat Soil Microcosm ▿ †

    OpenAIRE

    Rahman, M. Tanvir; Crombie, Andrew; Moussard, Hélène; Chen, Yin; Murrell, J. Colin

    2011-01-01

    Methylocella spp. are facultative methanotrophs that grow on methane and multicarbon substrates, such as acetate. Acetate represses transcription of methane monooxygenase of Methylocella silvestris in laboratory culture. DNA stable-isotope probing (DNA-SIP) using 13C-methane and 12C-acetate, carried out with Methylocella-spiked peat soil, showed that acetate also repressed methane oxidation by Methylocella in environmental samples.

  15. Repressive histone methylation regulates cardiac myocyte cell cycle exit.

    Science.gov (United States)

    El-Nachef, Danny; Oyama, Kyohei; Wu, Yun-Yu; Freeman, Miles; Zhang, Yiqiang; Robb MacLellan, W

    2018-05-22

    Mammalian cardiac myocytes (CMs) stop proliferating soon after birth and subsequent heart growth comes from hypertrophy, limiting the adult heart's regenerative potential after injury. The molecular events that mediate CM cell cycle exit are poorly understood. To determine the epigenetic mechanisms limiting CM cycling in adult CMs (ACMs) and whether trimethylation of lysine 9 of histone H3 (H3K9me3), a histone modification associated with repressed chromatin, is required for the silencing of cell cycle genes, we developed a transgenic mouse model where H3K9me3 is specifically removed in CMs by overexpression of histone demethylase, KDM4D. Although H3K9me3 is found across the genome, its loss in CMs preferentially disrupts cell cycle gene silencing. KDM4D binds directly to cell cycle genes and reduces H3K9me3 levels at these promotors. Loss of H3K9me3 preferentially leads to increased cell cycle gene expression resulting in enhanced CM cycling. Heart mass was increased in KDM4D overexpressing mice by postnatal day 14 (P14) and continued to increase until 9-weeks of age. ACM number, but not size, was significantly increased in KDM4D expressing hearts, suggesting CM hyperplasia accounts for the increased heart mass. Inducing KDM4D after normal development specifically in ACMs resulted in increased cell cycle gene expression and cycling. We demonstrated that H3K9me3 is required for CM cell cycle exit and terminal differentiation in ACMs. Depletion of H3K9me3 in adult hearts prevents and reverses permanent cell cycle exit and allows hyperplastic growth in adult hearts in vivo. Copyright © 2017. Published by Elsevier Ltd.

  16. A single cis element maintains repression of the key developmental regulator Gata2.

    Directory of Open Access Journals (Sweden)

    Jonathan W Snow

    2010-09-01

    Full Text Available In development, lineage-restricted transcription factors simultaneously promote differentiation while repressing alternative fates. Molecular dissection of this process has been challenging as transcription factor loci are regulated by many trans-acting factors functioning through dispersed cis elements. It is not understood whether these elements function collectively to confer transcriptional regulation, or individually to control specific aspects of activation or repression, such as initiation versus maintenance. Here, we have analyzed cis element regulation of the critical hematopoietic factor Gata2, which is expressed in early precursors and repressed as GATA-1 levels rise during terminal differentiation. We engineered mice lacking a single cis element -1.8 kb upstream of the Gata2 transcriptional start site. Although Gata2 is normally repressed in late-stage erythroblasts, the -1.8 kb mutation unexpectedly resulted in reactivated Gata2 transcription, blocked differentiation, and an aberrant lineage-specific gene expression pattern. Our findings demonstrate that the -1.8 kb site selectively maintains repression, confers a specific histone modification pattern and expels RNA Polymerase II from the locus. These studies reveal how an individual cis element establishes a normal developmental program via regulating specific steps in the mechanism by which a critical transcription factor is repressed.

  17. Purple corn silk: A potential anti-obesity agent with inhibition on adipogenesis and induction on lipolysis and apoptosis in adipocytes.

    Science.gov (United States)

    Chaiittianan, Rungsiri; Sutthanut, Khaetthareeya; Rattanathongkom, Ariya

    2017-04-06

    Corn silk or the stigma of Zea mays L. has traditionally been used in weight loss stimulation and treatment of cystitis, urinary infections and obesity. Purple corn silk, rich of polyphenolic substances, was reported on anti-diabetic and anti-obesity effect in animal studies. However, scientific evidence on mechanisms and targets of action of purple corn silk related to adipocyte life cycle has been limited. To determine phytochemical compositions and investigate anti-obesity potential of the purple corn silk focusing on interruption of adipocyte life cycle; effect on pre-adipocyte proliferation, adipogenesis, adipocyte lipolysis, and apoptosis. The ethanolic purple corn silk extract (PCS) was prepared and investigated for phytochemical compositions by LC/MS/MS technique and anti-obesity potential using murine 3T3-L1 cell line. Using methyl thiazole tetrazolium (MTT) assay, the effects on pre-adipocytes and adipocyte viability and on pre-adipocytes proliferation at 24-, 48-, and 72-h incubation period were evaluated. In addition, anti-adipogenesis via inhibition on adipocyte differentiation and reduction of total lipid accumulation was evaluated using Oil Red O staining and spectrophotometric methods, respectively. The lipolysis effect was determined by measurement of glycerol released content using glycerol test kit after 48-h treatment of PCS to adipocytes. Apoptosis inductive effect was done by using 2-(4-Amidinophenyl)-6-indolecarbamidine dihydrochloride (DAPI) staining method. The polyphenols including anthocyanins, quercetin and phenolic acids and derivatives were found as the major chemical compositions of the PCS. With multiple-stages interruption on the adipocyte life cycle, anti-obesity effect of PCS was interestingly demonstrated. When compared to the control, the PCS at concentration range between 250-1000 μg/mL showed anti-adipogenesis effect as expressing of significant inhibition on pre-adipocyte proliferation at all incubation period (43.52±5

  18. Anti-obesity effect of extract from fermented Curcuma longa L. through regulation of adipogenesis and lipolysis pathway in high-fat diet-induced obese rats

    Science.gov (United States)

    Kim, Ji Hye; Kim, Ok-Kyung; Yoon, Ho-Geun; Park, Jeongjin; You, Yanghee; Kim, Kyungmi; Lee, Yoo-Hyun; Choi, Kyung-Chul; Lee, Jeongmin; Jun, Woojin

    2016-01-01

    Background Even though Curcuma longa L. possesses various biological activities, it has strong flavor and taste, which decrease consumer palatability and limit industrial applications in food. Objective The present study investigates the effects of C. longa L. fermented with Aspergillus oryzae supplementation in 60% high-fat diet-induced obese rats measured by the activation of adipogenesis and lipolysis. Design Rats were divided into four groups (n=6 per group) after 1 week of acclimatization: a normal diet group comprised rats fed the AIN76A rodent diet; a high-fat diet-induced obese group with rats fed a 60% high-fat diet; a Garcinia cambogia treated group (positive control) with rats fed a 60% high-fat diet with G. cambogia 500 g/kg body weight (b.w.)/day; and an fermented C. longa L. 50% ethanolic extract treated group (FCE50) with rats fed a 60% high-fat diet with FCE50 500 g/kg b.w./day. Each group received the appropriate vehicle or sample daily by gastric intubation for 12 weeks. Results We found that FCE50 administration suppressed b.w. gain and reduced white adipose tissue weight, serum triglyceride (TG), and cholesterol in high-fat diet-induced obese rats. These results can be associated with the suppression of adipocyte differentiation and lipogenesis with a decrease in the mRNA expressions of fatty acid synthase, acetyl-CoA carboxylase, adipocyte protein 2, and lipoprotein lipase induced by FCE50 administration. In addition, FCE50 increased lipolysis and β-oxidation by up-regulating the expression of lipases such as adipose triglyceride lipase, hormone-sensitive lipase, adiponectin, and AMP-activated protein kinase. Conclusions These results suggest that FCE50 can be a candidate for the prevention of obesity via suppressing adipogenesis and promoting lipolysis. PMID:26822962

  19. Effects of arecoline on adipogenesis, lipolysis, and glucose uptake of adipocytes-A possible role of betel-quid chewing in metabolic syndrome

    International Nuclear Information System (INIS)

    Hsu, Hsin-Fen; Tsou, Tsui-Chun; Chao, How-Ran; Shy, Cherng-Gueih; Kuo, Ya-Ting; Tsai, Feng-Yuan; Yeh, Szu-Ching; Ko, Ying-Chin

    2010-01-01

    To investigate the possible involvement of betel-quid chewing in adipocyte dysfunction, we determined the effects of arecoline, a major alkaloid in areca nuts, on adipogenic differentiation (adipogenesis), lipolysis, and glucose uptake by fat cells. Using mouse 3T3-L1 preadipocytes, we showed that arecoline inhibited adipogenesis as determined by oil droplet formation and adipogenic marker gene expression. The effects of arecoline on lipolysis of differentiated 3T3-L1 adipocytes were determined by the glycerol release assay, indicating that arecoline induced lipolysis in an adenylyl cyclase-dependent manner. The diabetogenic effects of arecoline on differentiated 3T3-L1 adipocytes were evaluated by the glucose uptake assay, revealing that ≥ 300 μM arecoline significantly attenuated insulin-induced glucose uptake; however, no marked effect on basal glucose uptake was detected. Moreover, using 94 subjects that were randomly selected from a health check-up, we determined the association of betel-quid chewing with hyperlipidemia and its related risk factors. Hyperlipidemia frequency and serum triglyceride levels of betel-quid chewers were significantly higher than those of non-betel-quid chewers. In this study, we demonstrated that arecoline inhibits adipogenic differentiation, induces adenylyl cyclase-dependent lipolysis, and interferes with insulin-induced glucose uptake. Arecoline-induced fat cell dysfunction may lead to hyperlipidemia and hyperglycemia/insulin-resistance. These findings provide the first in vitro evidence of betel-quid chewing modulation of adipose cell metabolism that could contribute to the explanation of the association of this habit with metabolic syndrome disorders.

  20. The fruits of Gleditsia sinensis Lam. inhibits adipogenesis through modulation of mitotic clonal expansion and STAT3 activation in 3T3-L1 cells.

    Science.gov (United States)

    Lee, Ji-Hye; Go, Younghoon; Lee, Bonggi; Hwang, Youn-Hwan; Park, Kwang Il; Cho, Won-Kyung; Ma, Jin Yeul

    2018-08-10

    Gleditsia sinensis Lam. (G. sinensis) has been used in Oriental medicine for tumor, thrombosis, inflammation-related disease, and obesity. The pharmacological inhibitory effects of fruits of G. sinensis (GFE) on hyperlipidemia have been reported, but its inhibitory effects on adipogenesis and underlying mechanisms have not been elucidated. Herein we evaluated the anti-adipogenic effects of GFE and described the underlying mechanisms. The effects of ethanol extracts of GFE on adipocyte differentiation were examined in 3T3-L1 cells using biochemical and molecular analyses. During the differentiation of 3T3-L1 cells, GFE significantly reduced lipid accumulation and downregulated master adipogenic transcription factors, including CCAAT/enhancer-binding protein-α and peroxisome proliferator-activated receptor-γ, at mRNA and protein levels. These changes led to the suppression of several adipogenic-specific genes and proteins, including fatty acid synthase, sterol regulatory element-binding protein 1, stearoyl-CoA desaturase-1, and acetyl CoA carboxylase. However, the inhibitory effects of GFE on lipogenesis were only shown when GFE is treated in the early stage of adipogenesis within the first two days of differentiation. As a potential mechanism, during the early stages of differentiation, GFE inhibited cell proliferation by a decrease in the expression of DNA synthesis-related proteins and increased p27 expression and suppressed signal transducer and activator of transcription 3 (STAT3) activation induced in a differentiation medium. GFE inhibits lipogenesis by negative regulation of adipogenic transcription factors, which is associated with GFE-mediated cell cycle arrest and STAT3 inhibition. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. De-repression of RaRF-mediated RAR repression by adenovirus E1A in the nucleolus.

    Science.gov (United States)

    Um, Soo-Jong; Youn, Hye Sook; Kim, Eun-Joo

    2014-02-21

    Transcriptional activity of the retinoic acid receptor (RAR) is regulated by diverse binding partners, including classical corepressors and coactivators, in response to its ligand retinoic acid (RA). Recently, we identified a novel corepressor of RAR called the retinoic acid resistance factor (RaRF) (manuscript submitted). Here, we report how adenovirus E1A stimulates RAR activity by associating with RaRF. Based on immunoprecipitation (IP) assays, E1A interacts with RaRF through the conserved region 2 (CR2), which is also responsible for pRb binding. The first coiled-coil domain of RaRF was sufficient for this interaction. An in vitro glutathione-S-transferase (GST) pull-down assay was used to confirm the direct interaction between E1A and RaRF. Further fluorescence microscopy indicated that E1A and RaRF were located in the nucleoplasm and nucleolus, respectively. However, RaRF overexpression promoted nucleolar translocation of E1A from the nucleoplasm. Both the RA-dependent interaction of RAR with RaRF and RAR translocation to the nucleolus were disrupted by E1A. RaRF-mediated RAR repression was impaired by wild-type E1A, but not by the RaRF binding-defective E1A mutant. Taken together, our data suggest that E1A is sequestered to the nucleolus by RaRF through a specific interaction, thereby leaving RAR in the nucleoplasm for transcriptional activation. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Mechanisms of transcriptional repression by EWS-FLl1 in Ewing Sarcoma

    International Nuclear Information System (INIS)

    Niedan, S.

    2012-01-01

    The EWS-FLI1 chimeric oncoprotein characterizing Ewing Sarcoma (ES) is a prototypic aberrant ETS transcription factor with activating and repressive gene regulatory functions. Mechanisms of transcriptional regulation, especially transcriptional repression by EWS-FLI1, are poorly understood. We report that EWS-FLI1 repressed promoters are enriched in forkhead box recognition motifs, and identify FOXO1 as a EWS-FLI1 suppressed master regulator responsible for a significant subset of EWS-FLI1 repressed genes. In addition to transcriptional FOXO1 regulation by direct promoter binding of EWS-FLI1, its subcellular localization and activity is regulated by CDK2 and AKT mediated phosphorylation downstream of EWS-FLI1. Functional restoration of nuclear FOXO1 expression in ES cells impaired proliferation and significantly reduced clonogenicity. Gene-expression profiling revealed a significant overlap between EWS-FLI1 repressed and FOXO1-activated genes. Treatment of ES cell lines with Methylseleninic acid (MSA) evoked reactivation of endogenous FOXO1 in the presence of EWS-FLI1 in a dose- and time-dependent manner and induced massive cell death which was found to be partially FOXO1-dependent. In an orthotopic xenograft mouse model, MSA increased FOXO1 expression in the tumor paralleled by a significant decrease in ES tumor growth. Together, these data suggest that a repressive sub-signature of EWS-FLI1 repressed genes precipitates suppression of FOXO1. FOXO1 re-activation by small molecules may therefore constitute a novel therapeutic strategy in the treatment of ES. (author) [de

  3. Natural memory beyond the storage model: Repression, trauma, and the construction of a personal past

    Directory of Open Access Journals (Sweden)

    Nikolai Axmacher

    2010-11-01

    Full Text Available Naturally occurring memory processes show features which are difficult to investigate by conventional cognitive neuroscience paradigms. Distortions of memory for problematic contents are described both by psychoanalysis (internal conflicts and research on post-traumatic stress disorder (external traumata. Typically, declarative memory for these contents is impaired – possibly due to repression in the case of internal conflicts or due to dissociation in the case of external traumata – but they continue to exert an unconscious pathological influence: neurotic symptoms or psychosomatic disorders after repression or flashbacks and intrusions in post-traumatic stress disorder after dissociation. Several experimental paradigms aim at investigating repression in healthy control subjects. We argue that these paradigms do not adequately operationalize the clinical process of repression, because they rely on an intentional inhibition of random stimuli (suppression. Furthermore, these paradigms ignore that memory distortions due to repression or dissociation are most accurately characterized by a lack of self-referential processing, resulting in an impaired integration of these contents into the self. This aspect of repression and dissociation cannot be captured by the concept of memory as a storage device which is usually employed in the cognitive neurosciences. It can only be assessed within the framework of a constructivist memory concept, according to which successful memory involves a reconstruction of experiences such that they fit into a representation of the self. We suggest several experimental paradigms that allow for the investigation of the neural correlates of repressed memories and trauma-induced memory distortions based on a constructivist memory concept.

  4. Social adjustment and repressive adaptive style in survivors of pediatric cancer.

    Science.gov (United States)

    Schulte, Fiona; Wurz, Amanda; Russell, K Brooke; Reynolds, Kathleen; Strother, Douglas; Dewey, Deborah

    2018-01-01

    The aim of the study was to explore the relationship between repressive adaptive style and self-reports of social adjustment in survivors of pediatric cancer compared to their siblings. We hypothesized that there would be a greater proportion of repressors among survivors of pediatric cancer compared to siblings, and that repressive adaptive style would be significantly associated with more positive self-reports of social adjustment. We utilized a cross-sectional approach. Seventy-seven families participated. Survivors of pediatric cancer (n = 77, 48% male; 8-18 years of age) and one sibling (n = 50, 48% male; 8-18 years of age) completed measures assessing repressive adaptive style and social adjustment. As well, one parent from each family completed a socio-demographic questionnaire. Questionnaire packages were mailed to eligible families who agreed to participate, and were mailed back to investigators in a pre-addressed, pre-stamped envelope. Chi-square analyses revealed there was no significant difference in the proportion of repressors among survivors and siblings. Social adjustment scores were subjected to a two (group: survivor, sibling) by two (repressor, nonrepressor) ANCOVA with gender and age as covariates. There was a significant main effect of repressive adaptive style (F = 5.69, p < .05, η 2 = 0.05) with a modest effect. Survivors and siblings with a repressive style reported significantly higher social adjustment scores (M = 106.91, SD = 11.69) compared to nonrepressors (M = 99.57, SD = 13.45). Repressive adaptive style explains some of the variance in survivors and siblings' self-reports of social adjustment. Future research should aim to better understand the role of the repressive adaptive style in survivors and siblings of children with cancer.

  5. Derangement of a factor upstream of RARalpha triggers the repression of a pleiotropic epigenetic network.

    Directory of Open Access Journals (Sweden)

    Francesca Corlazzoli

    Full Text Available Chromatin adapts and responds to extrinsic and intrinsic cues. We hypothesize that inheritable aberrant chromatin states in cancer and aging are caused by genetic/environmental factors. In previous studies we demonstrated that either genetic mutations, or loss, of retinoic acid receptor alpha (RARalpha, can impair the integration of the retinoic acid (RA signal at the chromatin of RA-responsive genes downstream of RARalpha, and can lead to aberrant repressive chromatin states marked by epigenetic modifications. In this study we tested whether the mere interference with the availability of RA signal at RARalpha, in cells with an otherwise functional RARalpha, can also induce epigenetic repression at RA-responsive genes downstream of RARalpha.To hamper the availability of RA at RARalpha in untransformed human mammary epithelial cells, we targeted the cellular RA-binding protein 2 (CRABP2, which transports RA from the cytoplasm onto the nuclear RARs. Stable ectopic expression of a CRABP2 mutant unable to enter the nucleus, as well as stable knock down of endogenous CRABP2, led to the coordinated transcriptional repression of a few RA-responsive genes downstream of RARalpha. The chromatin at these genes acquired an exacerbated repressed state, or state "of no return". This aberrant state is unresponsive to RA, and therefore differs from the physiologically repressed, yet "poised" state, which is responsive to RA. Consistent with development of homozygosis for epigenetically repressed loci, a significant proportion of cells with a defective CRABP2-mediated RA transport developed heritable phenotypes indicative of loss of function.Derangement/lack of a critical factor necessary for RARalpha function induces epigenetic repression of a RA-regulated gene network downstream of RARalpha, with major pleiotropic biological outcomes.

  6. An Alternative Transcript of the FOG-2 Gene Encodes a FOG-2 Isoform lacking the FOG Repression Motif

    OpenAIRE

    Dale, Rodney M.; Remo, Benjamin F.; Svensson, Eric C.

    2007-01-01

    The FOG family of transcriptional co-factors is composed of two members in mammals: FOG-1 and FOG-2. Both have been shown to bind to GATA factors and function as transcriptional co-repressors in specific cell and promoter contexts. We have previously defined a novel repression domain localized to the N-terminus of each FOG family member, the FOG Repression Motif, which is necessary for FOG-mediated transcriptional repression. In this report, we describe the identification and characterization...

  7. The Transcription Factor STAT6 Mediates Direct Repression of Inflammatory Enhancers and Limits Activation of Alternatively Polarized Macrophages

    OpenAIRE

    Czimmerer, Zsolt; Daniel, Bence; Horvath, Attila; Rückerl, Dominik; Nagy, Gergely; Kiss, Mate; Peloquin, Matthew; Budai, Marietta M.; Cuaranta-Monroy, Ixchelt; Simandi, Zoltan; Steiner, Laszlo; Nagy, Bela; Poliska, Szilard; Banko, Csaba; Bacso, Zsolt

    2018-01-01

    Summary The molecular basis of signal-dependent transcriptional activation has been extensively studied in macrophage polarization, but our understanding remains limited regarding the molecular determinants of repression. Here we show that IL-4-activated STAT6 transcription factor is required for the direct transcriptional repression of a large number of genes during in vitro and in vivo alternative macrophage polarization. Repression results in decreased lineage-determining transcription fac...

  8. Repression of meiotic genes by antisense transcription and by Fkh2 transcription factor in Schizosaccharomyces pombe.

    Science.gov (United States)

    Chen, Huei-Mei; Rosebrock, Adam P; Khan, Sohail R; Futcher, Bruce; Leatherwood, Janet K

    2012-01-01

    In S. pombe, about 5% of genes are meiosis-specific and accumulate little or no mRNA during vegetative growth. Here we use Affymetrix tiling arrays to characterize transcripts in vegetative and meiotic cells. In vegetative cells, many meiotic genes, especially those induced in mid-meiosis, have abundant antisense transcripts. Disruption of the antisense transcription of three of these mid-meiotic genes allowed vegetative sense transcription. These results suggest that antisense transcription represses sense transcription of meiotic genes in vegetative cells. Although the mechanism(s) of antisense mediated transcription repression need to be further explored, our data indicates that RNAi machinery is not required for repression. Previously, we and others used non-strand specific methods to study splicing regulation of meiotic genes and concluded that 28 mid-meiotic genes are spliced only in meiosis. We now demonstrate that the "unspliced" signal in vegetative cells comes from the antisense RNA, not from unspliced sense RNA, and we argue against the idea that splicing regulates these mid-meiotic genes. Most of these mid-meiotic genes are induced in mid-meiosis by the forkhead transcription factor Mei4. Interestingly, deletion of a different forkhead transcription factor, Fkh2, allows low levels of sense expression of some mid-meiotic genes in vegetative cells. We propose that vegetative expression of mid-meiotic genes is repressed at least two independent ways: antisense transcription and Fkh2 repression.

  9. The Efficiency of Repressive Anti-Corruption Measures in Conditions of High-Level Corruption

    Directory of Open Access Journals (Sweden)

    Abramov Fedir V.

    2017-12-01

    Full Text Available The article is aimed at determining the efficiency of repressive anti-corruption measures in conditions of high-level corruption. It is shown that the formal rules regulating the use of repressive methods of countering corruption are characterized by a significant level of the target inefficiency of formal rules. Resulting from ignorance as to the causes of both occurence and spread of corruption – the inefficiency of the current formal rules – repressive anti-corruption measures are fundamentally incapable of achieving a significant reduction in the level of corruptness. It has been proved that, in addition to significant target inefficiency, repressive anti-corruption methods can potentially lead to increased levels of corruption because of abusing by supervisory officials of their official duties and the spread of internal corruption within anti-corruption structures. The potential threats from the uncontrolled anti-corruption structures towards other controlling organizations were considered. It is shown that in conditions of high-level corruption repressive anti-corruption measures can lead to expansion of imitation of anti-corruption activity.

  10. Real-time PCR analysis of carbon catabolite repression of cellobiose gene transcription in Trametes versicolor

    Energy Technology Data Exchange (ETDEWEB)

    Stapleton, P. C.; O' Mahoney, J.; Dobson, A. D. W. [National University of Ireland, Microbiology Department, Cork (Ireland)

    2004-02-01

    Previous reports indicate that in white rot fungi such as Trametes versicolor, the production of cellobiose dehydrogenase (CDH), an extracellular haemo-flavo-enzyme, is subject to carbon catabolite repression by both glucose and maltose, and that the repression is mediated at the transcriptional level. This paper describes the results of an investigation of CDH gene transcription in cellulolytic cultures of T. versicolor, in the presence of other additional carbon sources such as glucose, arabinose, and xylose. Using real time polymerase chain reaction (RT-PCR) assay methods in the presence of these other additional carbon sources, the levels of repression observed are quantitatively determined in an effort to obtain more accurate measurements of carbon catabolite repression of CDH production in this ligninolytic fungus. Ninety-six hours after addition, results of the analysis showed reduction in CDH transcript levels of 19-fold for galactose, 92-fold for arabinose and 114-fold for xylose. The greatest repressive effect was exhibited by glucose. In this case the reduction in CDH transcript levels was 3400-fold. CDH plays an important role in lignin degradation, and there is also substantial interest in the biotechnological applications of CDH, most particularly in the pulp and paper industry. 24 refs., 4 figs.

  11. Repression of Meiotic Genes by Antisense Transcription and by Fkh2 Transcription Factor in Schizosaccharomyces pombe

    Science.gov (United States)

    Chen, Huei-Mei; Rosebrock, Adam P.; Khan, Sohail R.; Futcher, Bruce; Leatherwood, Janet K.

    2012-01-01

    In S. pombe, about 5% of genes are meiosis-specific and accumulate little or no mRNA during vegetative growth. Here we use Affymetrix tiling arrays to characterize transcripts in vegetative and meiotic cells. In vegetative cells, many meiotic genes, especially those induced in mid-meiosis, have abundant antisense transcripts. Disruption of the antisense transcription of three of these mid-meiotic genes allowed vegetative sense transcription. These results suggest that antisense transcription represses sense transcription of meiotic genes in vegetative cells. Although the mechanism(s) of antisense mediated transcription repression need to be further explored, our data indicates that RNAi machinery is not required for repression. Previously, we and others used non-strand specific methods to study splicing regulation of meiotic genes and concluded that 28 mid-meiotic genes are spliced only in meiosis. We now demonstrate that the “unspliced” signal in vegetative cells comes from the antisense RNA, not from unspliced sense RNA, and we argue against the idea that splicing regulates these mid-meiotic genes. Most of these mid-meiotic genes are induced in mid-meiosis by the forkhead transcription factor Mei4. Interestingly, deletion of a different forkhead transcription factor, Fkh2, allows low levels of sense expression of some mid-meiotic genes in vegetative cells. We propose that vegetative expression of mid-meiotic genes is repressed at least two independent ways: antisense transcription and Fkh2 repression. PMID:22238674

  12. Repression of meiotic genes by antisense transcription and by Fkh2 transcription factor in Schizosaccharomyces pombe.

    Directory of Open Access Journals (Sweden)

    Huei-Mei Chen

    Full Text Available In S. pombe, about 5% of genes are meiosis-specific and accumulate little or no mRNA during vegetative growth. Here we use Affymetrix tiling arrays to characterize transcripts in vegetative and meiotic cells. In vegetative cells, many meiotic genes, especially those induced in mid-meiosis, have abundant antisense transcripts. Disruption of the antisense transcription of three of these mid-meiotic genes allowed vegetative sense transcription. These results suggest that antisense transcription represses sense transcription of meiotic genes in vegetative cells. Although the mechanism(s of antisense mediated transcription repression need to be further explored, our data indicates that RNAi machinery is not required for repression. Previously, we and others used non-strand specific methods to study splicing regulation of meiotic genes and concluded that 28 mid-meiotic genes are spliced only in meiosis. We now demonstrate that the "unspliced" signal in vegetative cells comes from the antisense RNA, not from unspliced sense RNA, and we argue against the idea that splicing regulates these mid-meiotic genes. Most of these mid-meiotic genes are induced in mid-meiosis by the forkhead transcription factor Mei4. Interestingly, deletion of a different forkhead transcription factor, Fkh2, allows low levels of sense expression of some mid-meiotic genes in vegetative cells. We propose that vegetative expression of mid-meiotic genes is repressed at least two independent ways: antisense transcription and Fkh2 repression.

  13. Obacunone Represses Salmonella Pathogenicity Islands 1 and 2 in an envZ-Dependent Fashion

    Science.gov (United States)

    Vikram, Amit; Jayaprakasha, Guddadarangavvanahally K.; Jesudhasan, Palmy R.

    2012-01-01

    Obacunone belongs to a class of unique triterpenoids called limonoids, present in Citrus species. Previous studies from our laboratory suggested that obacunone possesses antivirulence activity and demonstrates inhibition of cell-cell signaling in Vibrio harveyi and Escherichia coli O157:H7. The present work sought to determine the effect of obacunone on the food-borne pathogen Salmonella enterica serovar Typhimurium LT2 by using a cDNA microarray. Transcriptomic studies indicated that obacunone represses Salmonella pathogenicity island 1 (SPI1), the maltose transporter, and the hydrogenase operon. Furthermore, phenotypic data for the Caco-2 infection assay and maltose utilization were in agreement with microarray data suggesting repression of SPI1 and maltose transport. Further studies demonstrated that repression of SPI1 was plausibly mediated through hilA. Additionally, obacunone seems to repress SPI2 under SPI2-inducing conditions as well as in Caco-2 infection models. Furthermore, obacunone seems to repress hilA in an EnvZ-dependent fashion. Altogether, the results of the study seems to suggest that obacunone exerts an antivirulence effect on S. Typhimurium and may serve as a lead compound for development of antivirulence strategies for S. Typhimurium. PMID:22843534

  14. Lactose-mediated carbon catabolite repression of putrescine production in dairy Lactococcus lactis is strain dependent.

    Science.gov (United States)

    del Rio, Beatriz; Ladero, Victor; Redruello, Begoña; Linares, Daniel M; Fernández, Maria; Martín, Maria Cruz; Alvarez, Miguel A

    2015-06-01

    Lactococcus lactis is the lactic acid bacterial (LAB) species most widely used as a primary starter in the dairy industry. However, several strains of L. lactis produce the biogenic amine putrescine via the agmatine deiminase (AGDI) pathway. We previously reported the putrescine biosynthesis pathway in L. lactis subsp. cremoris GE2-14 to be regulated by carbon catabolic repression (CCR) via glucose but not lactose (Linares et al., 2013). The present study shows that both these sugars repress putrescine biosynthesis in L. lactis subsp. lactis T3/33, a strain isolated from a Spanish artisanal cheese. Furthermore, we demonstrated that both glucose and lactose repressed the transcriptional activity of the aguBDAC catabolic genes of the AGDI route. Finally, a screening performed in putrescine-producing dairy L. lactis strains determined that putrescine biosynthesis was repressed by lactose in all the L. lactis subsp. lactis strains tested, but in only one L. lactis subsp. cremoris strain. Given the obvious importance of the lactose-repression in cheese putrescine accumulation, it is advisable to consider the diversity of L. lactis in this sense and characterize consequently the starter cultures to select the safest strains. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Glucocorticoid and cytokine crosstalk: Feedback, feedforward, and co-regulatory interactions determine repression or resistance.

    Science.gov (United States)

    Newton, Robert; Shah, Suharsh; Altonsy, Mohammed O; Gerber, Antony N

    2017-04-28

    Inflammatory signals induce feedback and feedforward systems that provide temporal control. Although glucocorticoids can repress inflammatory gene expression, glucocorticoid receptor recruitment increases expression of negative feedback and feedforward regulators, including the phosphatase, DUSP1, the ubiquitin-modifying enzyme, TNFAIP3, or the mRNA-destabilizing protein, ZFP36. Moreover, glucocorticoid receptor cooperativity with factors, including nuclear factor-κB (NF-κB), may enhance regulator expression to promote repression. Conversely, MAPKs, which are inhibited by glucocorticoids, provide feedforward control to limit expression of the transcription factor IRF1, and the chemokine, CXCL10. We propose that modulation of feedback and feedforward control can determine repression or resistance of inflammatory gene expression toglucocorticoid. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. Existential Choice as Repressed Theism: Jean-Paul Sartre and Giorgio Agamben in Conversation

    Directory of Open Access Journals (Sweden)

    Marcos Antonio Norris

    2018-04-01

    Full Text Available This article brings Sartre’s notion of existential authenticity, or sovereign decisionism, into conversation with the work of contemporary political theorist Giorgio Agamben, who argues that sovereign decisionism is the repressed theological foundation of authoritarian governments. As such, the article seeks to accomplish two goals. The first is to show that Sartre’s depiction of sovereign decisionism directly parallels how modern democratic governments conduct themselves during a state of emergency. The second is to show that Sartre’s notion of existential authenticity models, what Agamben calls, secularized theism. Through an ontotheological critique of Sartre’s professed atheism, the article concludes that an existential belief in sovereign decision represses, rather than profanes, the divine origins of authoritarian law. I frame the argument with a reading of Sartre’s 1943 play The Flies, which models the repressed theological underpinnings of Sartre’s theory.

  17. Dopamine signaling leads to loss of Polycomb repression and aberrant gene activation in experimental parkinsonism.

    Directory of Open Access Journals (Sweden)

    Erik Södersten

    2014-09-01

    Full Text Available Polycomb group (PcG proteins bind to and repress genes in embryonic stem cells through lineage commitment to the terminal differentiated state. PcG repressed genes are commonly characterized by the presence of the epigenetic histone mark H3K27me3, catalyzed by the Polycomb repressive complex 2. Here, we present in vivo evidence for a previously unrecognized plasticity of PcG-repressed genes in terminally differentiated brain neurons of parkisonian mice. We show that acute administration of the dopamine precursor, L-DOPA, induces a remarkable increase in H3K27me3S28 phosphorylation. The induction of the H3K27me3S28p histone mark specifically occurs in medium spiny neurons expressing dopamine D1 receptors and is dependent on Msk1 kinase activity and DARPP-32-mediated inhibition of protein phosphatase-1. Chromatin immunoprecipitation (ChIP experiments showed that increased H3K27me3S28p was accompanied by reduced PcG binding to regulatory regions of genes. An analysis of the genome wide distribution of L-DOPA-induced H3K27me3S28 phosphorylation by ChIP sequencing (ChIP-seq in combination with expression analysis by RNA-sequencing (RNA-seq showed that the induction of H3K27me3S28p correlated with increased expression of a subset of PcG repressed genes. We found that induction of H3K27me3S28p persisted during chronic L-DOPA administration to parkisonian mice and correlated with aberrant gene expression. We propose that dopaminergic transmission can activate PcG repressed genes in the adult brain and thereby contribute to long-term maladaptive responses including the motor complications, or dyskinesia, caused by prolonged administration of L-DOPA in Parkinson's disease.

  18. Clinical events in coronary patients who report low distress: adverse effect of repressive coping.

    Science.gov (United States)

    Denollet, Johan; Martens, Elisabeth J; Nyklícek, Ivan; Conraads, Viviane M; de Gelder, Beatrice

    2008-05-01

    Coronary artery disease (CAD) patients who report low distress are considered to be at low psychological risk for clinical events. However, patients with a repressive coping style may fail to detect and report signals of emotional distress. The authors hypothesized that repressive CAD patients are at risk for clinical events, despite low self-rated distress. This was a prospective 5- to 10-year follow-up study, with a mean follow-up of 6.6 years. At baseline, 731 CAD patients filled out Trait-Anxiety (distress), Marlowe-Crowne (defensiveness), and Type D scales; 159 patients were classified as "repressive," 360 as "nonrepressive," and 212 as "Type D." The primary endpoint was a composite of total mortality or myocardial infarction (MI); the secondary endpoint was cardiac mortality/MI. No patients were lost to follow-up; 91 patients had a clinical event (including 35 cardiac death and 32 MI). Repressive patients reported low levels of anxiety, anger and depression at baseline, but were at increased risk for death/MI (21/159 = 13%) compared with nonrepressive patients (22/360 = 6%), p = .009. Poor systolic function, poor exercise tolerance, 3-vessel disease, index MI and Type-D personality--but not depression, anxiety or anger--also independently predicted clinical events. After controlling for these variables, repressive patients still had a twofold increased risk of death/MI, OR = 2.17, 95% CI = 1.10-4.08, p = .025). These findings were replicated for cardiac mortality/MI. CAD patients who use a repressive coping style are at increased risk for clinical events, despite their claims of low emotional distress. This phenomenon may cause an underestimation of the effect of stress on the heart. (PsycINFO Database Record (c) 2008 APA, all rights reserved).

  19. Molecular mechanism underlying juvenile hormone-mediated repression of precocious larval-adult metamorphosis.

    Science.gov (United States)

    Kayukawa, Takumi; Jouraku, Akiya; Ito, Yuka; Shinoda, Tetsuro

    2017-01-31

    Juvenile hormone (JH) represses precocious metamorphosis of larval to pupal and adult transitions in holometabolous insects. The early JH-inducible gene Krüppel homolog 1 (Kr-h1) plays a key role in the repression of metamorphosis as a mediator of JH action. Previous studies demonstrated that Kr-h1 inhibits precocious larval-pupal transition in immature larva via direct transcriptional repression of the pupal specifier Broad-Complex (BR-C). JH was recently reported to repress the adult specifier gene Ecdysone-induced protein 93F (E93); however, its mechanism of action remains unclear. Here, we found that JH suppressed ecdysone-inducible E93 expression in the epidermis of the silkworm Bombyx mori and in a B. mori cell line. Reporter assays in the cell line revealed that the JH-dependent suppression was mediated by Kr-h1. Genome-wide ChIP-seq analysis identified a consensus Kr-h1 binding site (KBS, 14 bp) located in the E93 promoter region, and EMSA confirmed that Kr-h1 directly binds to the KBS. Moreover, we identified a C-terminal conserved domain in Kr-h1 essential for the transcriptional repression of E93 Based on these results, we propose a mechanism in which JH-inducible Kr-h1 directly binds to the KBS site upstream of the E93 locus to repress its transcription in a cell-autonomous manner, thereby preventing larva from bypassing the pupal stage and progressing to precocious adult development. These findings help to elucidate the molecular mechanisms regulating the metamorphic genetic network, including the functional significance of Kr-h1, BR-C, and E93 in holometabolous insect metamorphosis.

  20. Nicotinamide Promotes Adipogenesis in Umbilical Cord-Derived Mesenchymal Stem Cells and Is Associated with Neonatal Adiposity: The Healthy Start BabyBUMP Project.

    Directory of Open Access Journals (Sweden)

    Allison L B Shapiro

    Full Text Available The cellular mechanisms whereby excess maternal nutrition during pregnancy increases adiposity of the offspring are not well understood. However, nicotinamide (NAM, a fundamental micronutrient that is important in energy metabolism, has been shown to regulate adipogenesis through inhibition of SIRT1. Here we tested three novel hypotheses: 1 NAM increases the adipogenic response of human umbilical cord tissue-derived mesenchymal stem cells (MSCs through a SIRT1 and PPARγ pathway; 2 lipid potentiates the NAM-enhanced adipogenic response; and 3 the adipogenic response to NAM is associated with increased percent fat mass (%FM among neonates. MSCs were derived from the umbilical cord of 46 neonates born to non-obese mothers enrolled in the Healthy Start study. Neonatal %FM was measured using air displacement plethysmography (Pea Pod shortly after birth. Adipogenic differentiation was induced for 21 days in the 46 MSC sets under four conditions, +NAM (3mM/-lipid (200 μM oleate/palmitate mix, +NAM/+lipid, -NAM/+lipid, and vehicle-control (-NAM/-lipid. Cells incubated in the presence of NAM had significantly higher PPARγ protein (+24%, p <0.01, FABP4 protein (+57%, p <0.01, and intracellular lipid content (+51%, p <0.01. Lipid did not significantly increase either PPARγ protein (p = 0.98 or FABP4 protein content (p = 0.82. There was no evidence of an interaction between NAM and lipid on adipogenic response of PPARγ or FABP4 protein (p = 0.99 and p = 0.09. In a subset of 9 MSC, SIRT1 activity was measured in the +NAM/-lipid and vehicle control conditions. SIRT1 enzymatic activity was significantly lower (-70%, p <0.05 in the +NAM/-lipid condition than in vehicle-control. In a linear model with neonatal %FM as the outcome, the percent increase in PPARγ protein in the +NAM/-lipid condition compared to vehicle-control was a significant predictor (β = 0.04, 95% CI 0.01-0.06, p <0.001. These are the first data to support that chronic NAM exposure

  1. Regulation of the cellulolytic system in Trichoderma reesei by sophorose: induction of cellulase and repression of beta-glucosidase.

    OpenAIRE

    Sternberg, D; Mandels, G R

    1980-01-01

    Sophorose has two regulatory roles in the production of cellulase enzymes in Trichoderma reesei: beta-glucosidase repression and cellulase induction. Sophorose also is hydrolyzed by the mycelial-associated beta-glucosidase. Repression of beta-glucosidase reduces sophorose hydrolysis and thus may increase cellulase induction.

  2. Repression of both isoforms of disproportionating enzyme leads to higher malto-oligosaccharide content and reduced growth in potato

    DEFF Research Database (Denmark)

    Mogensen, Henrik Lütken; Lloyd, James Richard; Glaring, Mikkel A.

    2010-01-01

    Two glucanotransferases, disproportionating enzyme 1 (StDPE1) and disproportionating enzyme 2 (StDPE2), were repressed using RNA interference technology in potato, leading to plants repressed in either isoform individually, or both simultaneously. This is the first detailed report of their combin...

  3. Direct Repression of Evening Genes by CIRCADIAN CLOCK-ASSOCIATED1 in the Arabidopsis Circadian Clock.

    Science.gov (United States)

    Kamioka, Mari; Takao, Saori; Suzuki, Takamasa; Taki, Kyomi; Higashiyama, Tetsuya; Kinoshita, Toshinori; Nakamichi, Norihito

    2016-03-01

    The circadian clock is a biological timekeeping system that provides organisms with the ability to adapt to day-night cycles. Timing of the expression of four members of the Arabidopsis thaliana PSEUDO-RESPONSE REGULATOR(PRR) family is crucial for proper clock function, and transcriptional control of PRRs remains incompletely defined. Here, we demonstrate that direct regulation of PRR5 by CIRCADIAN CLOCK-ASSOCIATED1 (CCA1) determines the repression state of PRR5 in the morning. Chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) analyses indicated that CCA1 associates with three separate regions upstream of PRR5 CCA1 and its homolog LATE ELONGATED HYPOCOTYL (LHY) suppressed PRR5 promoter activity in a transient assay. The regions bound by CCA1 in the PRR5 promoter gave rhythmic patterns with troughs in the morning, when CCA1 and LHY are at high levels. Furthermore,ChIP-seq revealed that CCA1 associates with at least 449 loci with 863 adjacent genes. Importantly, this gene set contains genes that are repressed but upregulated incca1 lhy double mutants in the morning. This study shows that direct binding by CCA1 in the morning provides strong repression of PRR5, and repression by CCA1 also temporally regulates an evening-expressed gene set that includes PRR5. © 2016 American Society of Plant Biologists. All rights reserved.

  4. Glucose-mediated repression of autolysis and conidiogenesis in Emericella nidulans.

    Science.gov (United States)

    Emri, Tamás; Molnár, Zsolt; Veres, Tünde; Pusztahelyi, Tünde; Dudás, Gábor; Pócsi, István

    2006-10-01

    Glucose-mediated repression of autolysis and sporulation was studied in submerged Emericellanidulans (anam. Aspergillus nidulans) cultures. Null mutation of the creA gene, which encodes the major carbon catabolite repressor CreA in E. nidulans, resulted in a hyperautolytic phenotype characterized by increased extracellular hydrolase production and dry cell mass declination. Interestingly, glucose, as well as the glucose antimetabolite 2-deoxy-d-glucose, repressed autolysis and sporulation in both the control and the creA null mutant strains suggesting that these processes were also subjected to CreA-independent carbon regulation. For example, the glucose-mediated, but CreA-independent, repression of the sporulation transcription factor BrlA was likely to contribute to the negative regulation of conidiogenesis by glucose. Although CreA played a prominent role in the regulation of autolysis via the repression of genes encoding important autolytic hydrolases like ChiB chitinase and PrtA protease the age-related production of the chitinase activity was also negatively affected by the down-regulation of brlA expression. However, neither CreA-dependent nor CreA-independent elements of carbon regulation affected the initiation and regulation of cell death in E. nidulans under carbon starvation.

  5. I-mfa domain proteins specifically interact with HTLV-1 Tax and repress its transactivating functions

    Energy Technology Data Exchange (ETDEWEB)

    Kusano, Shuichi, E-mail: skusano@m2.kufm.kagoshima-u.ac.jp [Division of Persistent and Oncogenic Viruses, Center for Chronic Viral Diseases, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8544 (Japan); Yoshimitsu, Makoto; Hachiman, Miho [Division of Hematology and Immunology, Center for Chronic Viral Diseases, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8544 (Japan); Ikeda, Masanori [Division of Persistent and Oncogenic Viruses, Center for Chronic Viral Diseases, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8544 (Japan)

    2015-12-15

    The I-mfa domain proteins HIC (also known as MDFIC) and I-mfa (also known as MDFI) are candidate tumor suppressor genes that are involved in cellular and viral transcriptional regulation. Here, we show that HIC and I-mfa directly interact with human T-cell leukemia virus type-1 (HTLV-1) Tax protein in vitro. In addition, HIC and I-mfa repress Tax-dependent transactivation of an HTLV-1 long terminal repeat (LTR) reporter construct in COS-1, Jurkat and high-Tax-producing HTLV-1-infected T cells. HIC also interacts with Tax through its I-mfa domain in vivo and represses Tax-dependent transactivation of HTLV-1 LTR and NF-κB reporter constructs in an interaction-dependent manner. Furthermore, we show that HIC decreases the nuclear distribution and stimulates the proteasomal degradation of Tax. These data reveal that HIC specifically interacts with HTLV-1 Tax and negatively regulates Tax transactivational activity by altering its subcellular distribution and stability. - Highlights: • I-mfa domain proteins, HIC and I-mfa, specifically interact with HTLV-1 Tax. • HIC and I-mfa repress the Tax-dependent transactivation of HTLV-1 LTR. • HIC represses the Tax-dependent transactivation of NF-κΒ. • HIC decreases the nuclear distribution of Tax. • HIC stimulates the proteasomal degradation of Tax.

  6. "The Neurosis That Has Possessed Us": Political Repression in the Cold War Medical Profession.

    Science.gov (United States)

    Chowkwanyun, Merlin

    2018-04-27

    Political repression played a central role in shaping the political complexion of the American medical profession, the policies it advocated, and those allowed to function comfortably in it. Previous work on the impact of McCarthyism and medicine focuses heavily on the mid-century failure of national health insurance (NHI) and medical reform organizations that suffered from McCarthyist attacks. The focus is national and birds-eye but says less about the impact on day-to-day life of physicians caught in a McCarthyist web; and how exactly the machinery of political repression within the medical profession worked on the ground. This study shifts orientation by using the abrupt dismissal of three Los Angeles physicians from their jobs as a starting point for exploring these dynamics. I argue that the rise of the medical profession and the repressive state in the mid-century, frequently studied apart, worked hand-in-hand, with institutions from each playing symbiotic and mutually reinforcing roles. I also explore tactics of resistance - rhetorical and organizational - to medical repression by physicians who came under attack.

  7. Global transcriptional repression in C. elegans germline precursors by regulated sequestration of TFIID component TAF-4

    Science.gov (United States)

    Guven-Ozkan, Tugba; Nishi, Yuichi; Robertson, Scott M.; Lin, Rueyling

    2008-01-01

    In C. elegans, four asymmetric divisions, beginning with the zygote (P0), generate transcriptionally repressed germline blastomeres (P1–P4) and somatic sisters that become transcriptionally active. The protein PIE-1 represses transcription in the later germline blastomeres, but not in the earlier germline blastomeres P0 and P1. We show here that OMA-1 and OMA-2, previously shown to regulate oocyte maturation, repress transcription in P0 and P1 by binding to and sequestering in the cytoplasm TAF-4, a component critical for assembly of TFIID and the pol II preinitiation complex. OMA-1/2 binding to TAF-4 is developmentally regulated, requiring phosphorylation by the DYRK kinase MBK-2, which is activated at meiosis II following fertilization. OMA-1/2 are normally degraded after the first mitosis, but ectopic expression of wildtype OMA-1 is sufficient to repress transcription in both somatic and later germline blastomeres. We propose that phosphorylation by MBK-2 serves as a developmental switch, converting OMA-1/2 from oocyte to embryo regulators. PMID:18854162

  8. Global transcriptional repression in C. elegans germline precursors by regulated sequestration of TAF-4.

    Science.gov (United States)

    Guven-Ozkan, Tugba; Nishi, Yuichi; Robertson, Scott M; Lin, Rueyling

    2008-10-03

    In C. elegans, four asymmetric divisions, beginning with the zygote (P0), generate transcriptionally repressed germline blastomeres (P1-P4) and somatic sisters that become transcriptionally active. The protein PIE-1 represses transcription in the later germline blastomeres but not in the earlier germline blastomeres P0 and P1. We show here that OMA-1 and OMA-2, previously shown to regulate oocyte maturation, repress transcription in P0 and P1 by binding to and sequestering in the cytoplasm TAF-4, a component critical for assembly of TFIID and the pol II preinitiation complex. OMA-1/2 binding to TAF-4 is developmentally regulated, requiring phosphorylation by the DYRK kinase MBK-2, which is activated at meiosis II after fertilization. OMA-1/2 are normally degraded after the first mitosis, but ectopic expression of wild-type OMA-1 is sufficient to repress transcription in both somatic and later germline blastomeres. We propose that phosphorylation by MBK-2 serves as a developmental switch, converting OMA-1/2 from oocyte to embryo regulators.

  9. Financial Repression as a Policy Choice: The Case of Ukraine, 1992—2000

    Directory of Open Access Journals (Sweden)

    Robert S. Kravchuk

    2004-10-01

    Full Text Available By their nature, instruments of financial repression distort interest rates, foreign exchange rates, patterns of investment, and the economic incentives of both borrowers and lenders. In order to deal with the economic pathologies introduced by the government’s own credit and financial policies, governments inevitably find that they must intervene further, to ration credit and impose controls, generally on prices, wages, interest rates, foreign exchange rates and other transactions. Not only did Ukraine exhibit all of the symptoms of financial repression in the 1990s, but the basic policy instruments of financial repression also became too familiar in Ukraine. In fact, to one extent or another, in the 1990s Ukraine employed several of these measures (often in combination as means to suppress the effects of excessive amounts of state consumption, the resultant inflation, and its own credit policies. In the long run, economic growth will suffer, however, because repression reduces the capacity of the financial system to respond to the needs of firms and households in the real economy.

  10. SMRT repression of nuclear receptors controls the adipogenic set point and metabolic homeostasis

    NARCIS (Netherlands)

    Nofsinger, Russell R.; Li, Pingping; Hong, Suk-Hyun; Jonker, Johan W.; Barish, Grant D.; Ying, Hao; Cheng, Sheue-Yann; LeBlanc, Mathias; Xu, Wei; Pei, Liming; Kang, Yeon-Joo; Nelson, Michael; Downes, Michael; Yu, Ruth T.; Olefsky, Jerrold M.; Lee, Chih-Hao; Evans, Ronald M.

    2008-01-01

    The nuclear receptor corepressor, silencing mediator of retinoid and thyroid hormone receptors (SMRT), is recruited by a plethora of transcription factors to mediate lineage and signal-dependent transcriptional repression. We generated a knockin mutation in the receptor interaction domain (RID) of

  11. Engineering of carbon catabolite repression in recombinant xylose fermenting Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Roca, Christophe Francois Aime; Haack, Martin Brian; Olsson, Lisbeth

    2004-01-01

    analysed for changes in xylose consumption rate and ethanol production rate during anaerobic batch and chemostat cultivations on a mixture of 20 g l(-1) glucose and 50 g l(-1) xylose, and their characteristics were compared to the parental strain S. cerevisiae TMB3001 (XYL1, XYL2, XKS1). Improvement...... that xylose is a repressive sugar for S. cerevisiae....

  12. Examining the Influence of Trait Anxiety/Repression-Sensitization on Individuals' Reactions to Fear Appeals.

    Science.gov (United States)

    Witte, Kim; Morrison, Kelly

    2000-01-01

    Examines the impact of persuasive fear appeals promoting condom usage to prevent AIDS. Indicates that inherent level of anxiety influences how both the threat and the efficacy of recommended responses are perceived, but that trait anxiety/repression-sensitization has no influence on attitudes, intentions, behaviors, perceived manipulation, or…

  13. The transcription factor Slug represses E-cadherin expression and induces epithelial to mesenchymal transitions

    DEFF Research Database (Denmark)

    Bolós, Victoria; Peinado, Hector; Pérez-Moreno, Mirna A

    2003-01-01

    Transcriptional repression mechanisms have emerged as one of the crucial processes for the downregulation of E-cadherin expression during development and tumour progression. Recently, several E-cadherin transcriptional repressors have been characterized (Snail, E12/E47, ZEB-1 and SIP-1) and shown...

  14. Pluripotency factors and Polycomb Group proteins repress aryl hydrocarbon receptor expression in murine embryonic stem cells

    Directory of Open Access Journals (Sweden)

    Chia-I Ko

    2014-01-01

    Full Text Available The aryl hydrocarbon receptor (AHR is a transcription factor and environmental sensor that regulates expression of genes involved in drug-metabolism and cell cycle regulation. Chromatin immunoprecipitation analyses, Ahr ablation in mice and studies with orthologous genes in invertebrates suggest that AHR may also play a significant role in embryonic development. To address this hypothesis, we studied the regulation of Ahr expression in mouse embryonic stem cells and their differentiated progeny. In ES cells, interactions between OCT3/4, NANOG, SOX2 and Polycomb Group proteins at the Ahr promoter repress AHR expression, which can also be repressed by ectopic expression of reprogramming factors in hepatoma cells. In ES cells, unproductive RNA polymerase II binds at the Ahr transcription start site and drives the synthesis of short abortive transcripts. Activation of Ahr expression during differentiation follows from reversal of repressive marks in Ahr promoter chromatin, release of pluripotency factors and PcG proteins, binding of Sp factors, establishment of histone marks of open chromatin, and engagement of active RNAPII to drive full-length RNA transcript elongation. Our results suggest that reversible Ahr repression in ES cells holds the gene poised for expression and allows for a quick switch to activation during embryonic development.

  15. Repressive Adaptive Style and Self-Reported Psychological Functioning in Adolescent Cancer Survivors

    Science.gov (United States)

    Erickson, Sarah J.; Gerstle, Melissa; Montague, Erica Q.

    2008-01-01

    Low levels of posttraumatic stress disorder (PTSD), posttraumatic stress symptoms (PTSS), and psychosocial distress have been reported in pediatric cancer survivors. One explanation is the relatively high prevalence of the repressive adaptive style (low distress, high restraint) in this population. We investigated the relationship between this…

  16. I-mfa domain proteins specifically interact with HTLV-1 Tax and repress its transactivating functions

    International Nuclear Information System (INIS)

    Kusano, Shuichi; Yoshimitsu, Makoto; Hachiman, Miho; Ikeda, Masanori

    2015-01-01

    The I-mfa domain proteins HIC (also known as MDFIC) and I-mfa (also known as MDFI) are candidate tumor suppressor genes that are involved in cellular and viral transcriptional regulation. Here, we show that HIC and I-mfa directly interact with human T-cell leukemia virus type-1 (HTLV-1) Tax protein in vitro. In addition, HIC and I-mfa repress Tax-dependent transactivation of an HTLV-1 long terminal repeat (LTR) reporter construct in COS-1, Jurkat and high-Tax-producing HTLV-1-infected T cells. HIC also interacts with Tax through its I-mfa domain in vivo and represses Tax-dependent transactivation of HTLV-1 LTR and NF-κB reporter constructs in an interaction-dependent manner. Furthermore, we show that HIC decreases the nuclear distribution and stimulates the proteasomal degradation of Tax. These data reveal that HIC specifically interacts with HTLV-1 Tax and negatively regulates Tax transactivational activity by altering its subcellular distribution and stability. - Highlights: • I-mfa domain proteins, HIC and I-mfa, specifically interact with HTLV-1 Tax. • HIC and I-mfa repress the Tax-dependent transactivation of HTLV-1 LTR. • HIC represses the Tax-dependent transactivation of NF-κΒ. • HIC decreases the nuclear distribution of Tax. • HIC stimulates the proteasomal degradation of Tax.

  17. Trichostatin A enhances estrogen receptor-alpha repression in MCF-7 breast cancer cells under hypoxia

    International Nuclear Information System (INIS)

    Noh, Hyunggyun; Park, Joonwoo; Shim, Myeongguk; Lee, YoungJoo

    2016-01-01

    Estrogen receptor (ER) is a crucial determinant of resistance to endocrine therapy, which may change during the progression of breast cancer. We previously showed that hypoxia induces ESR1 gene repression and ERα protein degradation via proteasome-mediated pathway in breast cancer cells. HDAC plays important roles in the regulation of histone and non-histone protein post-translational modification. HDAC inhibitors can induce epigenetic changes and have therapeutic potential for targeting various cancers. Trichostatin A exerts potent antitumor activities against breast cancer cells in vitro and in vivo. In this report, we show that TSA augments ESR1 gene repression at the transcriptional level and downregulates ERα protein expression under hypoxic conditions through a proteasome-mediated pathway. TSA-induced estrogen response element-driven reporter activity in the absence of estrogen was synergistically enhanced under hypoxia; however, TSA inhibited cell proliferation under both normoxia and hypoxia. Our data show that the hypoxia-induced repression of ESR1 and degradation of ERα are enhanced by concomitant treatment with TSA. These findings expand our understanding of hormone responsiveness in the tumor microenvironment; however, additional in-depth studies are required to elucidate the detailed mechanisms of TSA-induced ERα regulation under hypoxia. - Highlights: • TSA augments ESR1 gene repression at the transcriptional level under hypoxia. • TSA downregulates ERα protein expression under hypoxia. • TSA-induced ERα regulation under hypoxia is essential for understanding the behavior and progression of breast cancer.

  18. Bullying the media : Cultural and climato-economic readings of press repression versus press freedom

    NARCIS (Netherlands)

    Van de Vliert, E.

    Journalists and media assistants in many places are murdered, imprisoned, censored, threatened, and similarly harrassed. Here I document that, and explain why, there are three climato-economic niches of press repression versus press freedom as part of broader syndromes of national culture. A

  19. The natural product peiminine represses colorectal carcinoma tumor growth by inducing autophagic cell death

    International Nuclear Information System (INIS)

    Lyu, Qing; Tou, Fangfang; Su, Hong; Wu, Xiaoyong; Chen, Xinyi; Zheng, Zhi

    2015-01-01

    Autophagy is evolutionarily conservative in eukaryotic cells that engulf cellular long-lived proteins and organelles, and it degrades the contents through fusion with lysosomes, via which the cell acquires recycled building blocks for the synthesis of new molecules. In this study, we revealed that peiminine induces cell death and enhances autophagic flux in colorectal carcinoma HCT-116 cells. We determined that peiminine enhances the autophagic flux by repressing the phosphorylation of mTOR through inhibiting upstream signals. Knocking down ATG5 greatly reduced the peiminine-induced cell death in wild-type HCT-116 cells, while treating Bax/Bak-deficient cells with peiminine resulted in significant cell death. In summary, our discoveries demonstrated that peiminine represses colorectal carcinoma cell proliferation and cell growth by inducing autophagic cell death. - Highlights: • Peiminine induces autophagy and upregulates autophagic flux. • Peiminine represses colorectal carcinoma tumor growth. • Peiminine induces autophagic cell death. • Peiminine represses mTOR phosphorylation by influencing PI3K/Akt and AMPK pathway

  20. The MSX1 homeoprotein recruits G9a methyltransferase to repressed target genes in myoblast cells.

    Directory of Open Access Journals (Sweden)

    Jingqiang Wang

    Full Text Available Although the significance of lysine modifications of core histones for regulating gene expression is widely appreciated, the mechanisms by which these modifications are incorporated at specific regulatory elements during cellular differentiation remains largely unknown. In our previous studies, we have shown that in developing myoblasts the Msx1 homeoprotein represses gene expression by influencing the modification status of chromatin at its target genes. We now show that genomic binding by Msx1 promotes enrichment of the H3K9me2 mark on repressed target genes via recruitment of G9a histone methyltransferase, the enzyme responsible for catalyzing this histone mark. Interaction of Msx1 with G9a is mediated via the homeodomain and is required for transcriptional repression and regulation of cellular differentiation, as well as enrichment of the H3K9me2 mark in proximity to Msx1 binding sites on repressed target genes in myoblast cells as well as the developing limb. We propose that regulation of chromatin status by Msx1 recruitment of G9a and other histone modifying enzymes to regulatory regions of target genes represents an important means of regulating the gene expression during development.

  1. The natural product peiminine represses colorectal carcinoma tumor growth by inducing autophagic cell death

    Energy Technology Data Exchange (ETDEWEB)

    Lyu, Qing [School of Life Sciences, Tsinghua University, Beijing, 100084 (China); Key Lab in Healthy Science and Technology, Division of Life Science, Graduate School at Shenzhen, Tsinghua University, Shenzhen, 518055 (China); Tou, Fangfang [Jiangxi Provincial Key Lab of Oncology Translation Medicine, Jiangxi Cancer Hospital, Nanchang, 330029 (China); Su, Hong; Wu, Xiaoyong [First Affiliated Hospital, Guiyang College of Traditional Chinese Medicine, Guiyang, 550002 (China); Chen, Xinyi [Department of Hematology and Oncology, Beijing University of Chinese Medicine, Beijing, 100029 (China); Zheng, Zhi, E-mail: zheng_sheva@hotmail.com [Jiangxi Provincial Key Lab of Oncology Translation Medicine, Jiangxi Cancer Hospital, Nanchang, 330029 (China)

    2015-06-19

    Autophagy is evolutionarily conservative in eukaryotic cells that engulf cellular long-lived proteins and organelles, and it degrades the contents through fusion with lysosomes, via which the cell acquires recycled building blocks for the synthesis of new molecules. In this study, we revealed that peiminine induces cell death and enhances autophagic flux in colorectal carcinoma HCT-116 cells. We determined that peiminine enhances the autophagic flux by repressing the phosphorylation of mTOR through inhibiting upstream signals. Knocking down ATG5 greatly reduced the peiminine-induced cell death in wild-type HCT-116 cells, while treating Bax/Bak-deficient cells with peiminine resulted in significant cell death. In summary, our discoveries demonstrated that peiminine represses colorectal carcinoma cell proliferation and cell growth by inducing autophagic cell death. - Highlights: • Peiminine induces autophagy and upregulates autophagic flux. • Peiminine represses colorectal carcinoma tumor growth. • Peiminine induces autophagic cell death. • Peiminine represses mTOR phosphorylation by influencing PI3K/Akt and AMPK pathway.

  2. Repression of RNA polymerase by the archaeo-viral regulator ORF145/RIP

    DEFF Research Database (Denmark)

    Sheppard, Carol; Blombach, Fabian; Belsom, Adam

    2016-01-01

    Little is known about how archaeal viruses perturb the transcription machinery of their hosts. Here we provide the first example of an archaeo-viral transcription factor that directly targets the host RNA polymerase (RNAP) and efficiently represses its activity. ORF145 from the temperate Acidianus...

  3. Trichostatin A enhances estrogen receptor-alpha repression in MCF-7 breast cancer cells under hypoxia

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Hyunggyun; Park, Joonwoo; Shim, Myeongguk; Lee, YoungJoo, E-mail: yjlee@sejong.ac.kr

    2016-02-12

    Estrogen receptor (ER) is a crucial determinant of resistance to endocrine therapy, which may change during the progression of breast cancer. We previously showed that hypoxia induces ESR1 gene repression and ERα protein degradation via proteasome-mediated pathway in breast cancer cells. HDAC plays important roles in the regulation of histone and non-histone protein post-translational modification. HDAC inhibitors can induce epigenetic changes and have therapeutic potential for targeting various cancers. Trichostatin A exerts potent antitumor activities against breast cancer cells in vitro and in vivo. In this report, we show that TSA augments ESR1 gene repression at the transcriptional level and downregulates ERα protein expression under hypoxic conditions through a proteasome-mediated pathway. TSA-induced estrogen response element-driven reporter activity in the absence of estrogen was synergistically enhanced under hypoxia; however, TSA inhibited cell proliferation under both normoxia and hypoxia. Our data show that the hypoxia-induced repression of ESR1 and degradation of ERα are enhanced by concomitant treatment with TSA. These findings expand our understanding of hormone responsiveness in the tumor microenvironment; however, additional in-depth studies are required to elucidate the detailed mechanisms of TSA-induced ERα regulation under hypoxia. - Highlights: • TSA augments ESR1 gene repression at the transcriptional level under hypoxia. • TSA downregulates ERα protein expression under hypoxia. • TSA-induced ERα regulation under hypoxia is essential for understanding the behavior and progression of breast cancer.

  4. Estradiol represses Insulin-like 3 expression and promoter activity in MA-10 Leydig cells

    International Nuclear Information System (INIS)

    Lague, Eric; Tremblay, Jacques J.

    2009-01-01

    There are increasing evidence in the literature reporting the detrimental effects of endocrine disruptors on the development and function of the male reproductive system. One example is cryptorchidism, or undescended testis, caused by exposure to excessive estrogens. Estrogens, acting through the estrogen receptor α (ERα), have been shown to repress expression of the gene encoding insulin-like 3 (INSL3), a small peptide produced by testicular Leydig cells that is essential for normal testis descent. The molecular mechanism of estrogen/ER action on Insl3 expression, however, remains poorly understood. Here we report estradiol (E 2 ) represses Insl3 mRNA levels in MA-10 cells, a Leydig cell line model. We also found that E 2 represses the activity of the human and mouse Insl3 promoter in these cells. The E 2 -responsive region of the human INSL3 promoter was located to the proximal INSL3 promoter. This region does not contain a consensus estrogen response element indicating an indirect mechanism of action. In agreement with this, we found that E 2 -responsiveness was lost when two previously characterized binding sites for the nuclear receptors NUR77 and SF1 were mutated. Finally we show that the E 2 repressive effect could be overcome by cotreatment with testosterone, a positive regulator of Insl3 transcription. Collectively our data provide important new insights into the molecular mechanism of estrogen action in Insl3 transcription in Leydig cells

  5. Catabolite repression and nitrogen control of allantoin-degrading enzymes in Pseudomonas aeruginosa

    NARCIS (Netherlands)

    Janssen, D.B.; Drift, C. van der

    1983-01-01

    The formation of the allantoin-degrading enzymes allantoinase, allantoicase and ureidoglycolase in Pseudomonas aeruginosa was found to be regulated by induction, catabolite repression and nitrogen control. Induction was observed when urate, allantoin or allantoate were included in the growth medium,

  6. Tenebrio molitor Larvae Inhibit Adipogenesis through AMPK and MAPKs Signaling in 3T3-L1 Adipocytes and Obesity in High-Fat Diet-Induced Obese Mice.

    Science.gov (United States)

    Seo, Minchul; Goo, Tae-Won; Chung, Mi Yeon; Baek, Minhee; Hwang, Jae-Sam; Kim, Mi-Ae; Yun, Eun-Young

    2017-02-28

    Despite the increasing interest in insect-based bioactive products, the biological activities of these products are rarely studied adequately. Larvae of Tenebrio molitor , the yellow mealworm, have been eaten as a traditional food and provide many health benefits. Therefore, we hypothesized that T. molitor larvae might influence adipogenesis and obesity-related disorders. In the present study, we investigated the anti-adipogenic and antiobesity effects of T. molitor larvae in vitro and in vivo. The lipid accumulation and triglyceride content in mature adipocytes was reduced significantly (up to 90%) upon exposure to an ethanol extract of T. molitor larvae, without a reduction in cell viability. Exposure also resulted in key adipogenic and lipogenic transcription factors. Additionally, in adipogenic differentiation medium the extract induced phosphorylation of adenosine monophosphate (AMP)-activated protein kinase and mitogen-activated protein kinases. Daily oral administration of T. molitor larvae powder to obese mice fed high-fat diet attenuated body weight gain. We also found that the powder efficiently reduced hepatic steatosis as well as aspartate and alanine transaminase enzyme levels in mice fed a high-fat diet. Our results suggest that T. molitor larvae extract has an antiobesity effect when administered as a food supplement and has potential as a therapeutic agent for obesity.

  7. Tenebrio molitor Larvae Inhibit Adipogenesis through AMPK and MAPKs Signaling in 3T3-L1 Adipocytes and Obesity in High-Fat Diet-Induced Obese Mice

    Directory of Open Access Journals (Sweden)

    Minchul Seo

    2017-02-01

    Full Text Available Despite the increasing interest in insect-based bioactive products, the biological activities of these products are rarely studied adequately. Larvae of Tenebrio molitor, the yellow mealworm, have been eaten as a traditional food and provide many health benefits. Therefore, we hypothesized that T. molitor larvae might influence adipogenesis and obesity-related disorders. In the present study, we investigated the anti-adipogenic and antiobesity effects of T. molitor larvae in vitro and in vivo. The lipid accumulation and triglyceride content in mature adipocytes was reduced significantly (up to 90% upon exposure to an ethanol extract of T. molitor larvae, without a reduction in cell viability. Exposure also resulted in key adipogenic and lipogenic transcription factors. Additionally, in adipogenic differentiation medium the extract induced phosphorylation of adenosine monophosphate (AMP-activated protein kinase and mitogen-activated protein kinases. Daily oral administration of T. molitor larvae powder to obese mice fed high-fat diet attenuated body weight gain. We also found that the powder efficiently reduced hepatic steatosis as well as aspartate and alanine transaminase enzyme levels in mice fed a high-fat diet. Our results suggest that T. molitor larvae extract has an antiobesity effect when administered as a food supplement and has potential as a therapeutic agent for obesity.

  8. Genome-wide analysis of gene expression during adipogenesis in human adipose-derived stromal cells reveals novel patterns of gene expression during adipocyte differentiation

    Directory of Open Access Journals (Sweden)

    Melvin Anyasi Ambele

    2016-05-01

    Full Text Available We have undertaken an in-depth transcriptome analysis of adipogenesis in human adipose-derived stromal cells (ASCs induced to differentiate into adipocytes in vitro. Gene expression was assessed on days 1, 7, 14 and 21 post-induction and genes differentially expressed numbered 128, 218, 253 and 240 respectively. Up-regulated genes were associated with blood vessel development, leukocyte migration, as well as tumor growth, invasion and metastasis. They also shared common pathways with certain obesity-related pathophysiological conditions. Down-regulated genes were enriched for immune response processes. KLF15, LMO3, FOXO1 and ZBTB16 transcription factors were up-regulated throughout the differentiation process. CEBPA, PPARG, ZNF117, MLXIPL, MMP3 and RORB were up-regulated only on days 14 and 21, which coincide with the maturation of adipocytes and could possibly serve as candidates for controlling fat accumulation and the size of mature adipocytes. In summary, we have identified genes that were up-regulated only on days 1 and 7 or days 14 and 21 that could serve as potential early and late-stage differentiation markers.

  9. 10-oxo-12(Z)-octadecenoic acid, a linoleic acid metabolite produced by gut lactic acid bacteria, potently activates PPARγ and stimulates adipogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Goto, Tsuyoshi, E-mail: tgoto@kais.kyoto-u.ac.jp [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011 (Japan); Research Unit for Physiological Chemistry, The Center for the Promotion of Interdisciplinary Education and Research, Kyoto University (Japan); Kim, Young-Il; Furuzono, Tomoya [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011 (Japan); Takahashi, Nobuyuki [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011 (Japan); Research Unit for Physiological Chemistry, The Center for the Promotion of Interdisciplinary Education and Research, Kyoto University (Japan); Yamakuni, Kanae; Yang, Ha-Eun; Li, Yongjia [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011 (Japan); Ohue, Ryuji [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011 (Japan); Research Unit for Physiological Chemistry, The Center for the Promotion of Interdisciplinary Education and Research, Kyoto University (Japan); Nomura, Wataru [Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji 611-0011 (Japan); Sugawara, Tatsuya [Laboratory of Marine Bioproducts Technology, Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502 (Japan); Yu, Rina [Department of Food Science and Nutrition, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Kitamura, Nahoko [Laboratory of Fermentation Physiology and Applied Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502 (Japan); and others

    2015-04-17

    Our previous study has shown that gut lactic acid bacteria generate various kinds of fatty acids from polyunsaturated fatty acids such as linoleic acid (LA). In this study, we investigated the effects of LA and LA-derived fatty acids on the activation of peroxisome proliferator-activated receptors (PPARs) which regulate whole-body energy metabolism. None of the fatty acids activated PPARδ, whereas almost all activated PPARα in luciferase assays. Two fatty acids potently activated PPARγ, a master regulator of adipocyte differentiation, with 10-oxo-12(Z)-octadecenoic acid (KetoA) having the most potency. In 3T3-L1 cells, KetoA induced adipocyte differentiation via the activation of PPARγ, and increased adiponectin production and insulin-stimulated glucose uptake. These findings suggest that fatty acids, including KetoA, generated in gut by lactic acid bacteria may be involved in the regulation of host energy metabolism. - Highlights: • Most LA-derived fatty acids from gut lactic acid bacteria potently activated PPARα. • Among tested fatty acids, KetoA and KetoC significantly activated PPARγ. • KetoA induced adipocyte differentiation via the activation of PPARγ. • KetoA enhanced adiponectin production and glucose uptake during adipogenesis.

  10. 10-oxo-12(Z)-octadecenoic acid, a linoleic acid metabolite produced by gut lactic acid bacteria, potently activates PPARγ and stimulates adipogenesis

    International Nuclear Information System (INIS)

    Goto, Tsuyoshi; Kim, Young-Il; Furuzono, Tomoya; Takahashi, Nobuyuki; Yamakuni, Kanae; Yang, Ha-Eun; Li, Yongjia; Ohue, Ryuji; Nomura, Wataru; Sugawara, Tatsuya; Yu, Rina; Kitamura, Nahoko

    2015-01-01

    Our previous study has shown that gut lactic acid bacteria generate various kinds of fatty acids from polyunsaturated fatty acids such as linoleic acid (LA). In this study, we investigated the effects of LA and LA-derived fatty acids on the activation of peroxisome proliferator-activated receptors (PPARs) which regulate whole-body energy metabolism. None of the fatty acids activated PPARδ, whereas almost all activated PPARα in luciferase assays. Two fatty acids potently activated PPARγ, a master regulator of adipocyte differentiation, with 10-oxo-12(Z)-octadecenoic acid (KetoA) having the most potency. In 3T3-L1 cells, KetoA induced adipocyte differentiation via the activation of PPARγ, and increased adiponectin production and insulin-stimulated glucose uptake. These findings suggest that fatty acids, including KetoA, generated in gut by lactic acid bacteria may be involved in the regulation of host energy metabolism. - Highlights: • Most LA-derived fatty acids from gut lactic acid bacteria potently activated PPARα. • Among tested fatty acids, KetoA and KetoC significantly activated PPARγ. • KetoA induced adipocyte differentiation via the activation of PPARγ. • KetoA enhanced adiponectin production and glucose uptake during adipogenesis

  11. Investigating Behavioral and Psychophysiological Reactions to Conflict-Related and Individualized Stimuli as Potential Correlates of Repression

    Directory of Open Access Journals (Sweden)

    Henrik Kessler

    2017-09-01

    Full Text Available Background: Repression is considered as a central defense mechanism in psychodynamic theory. It refers to the process by which “unbearable” mental contents (e.g., those related to internal conflicts are kept out of consciousness. The process of repression is probably closely related to concepts of emotion regulation derived from a different theoretical background. This relationship is particularly relevant because it relates repression to current research in the affective neurosciences as well as to experimental studies on emotion regulation. Due to its complex and highly individual nature, repression has been notoriously difficult to investigate. We investigated repression with an individualized experiment in healthy subjects in order to establish methods to study repression in clinical populations. To this end we operationalized repression using individualized experimental conditions, and then studied potential behavioral [memory and reaction time (RT] and psychophysiological correlates [skin conductance response (SCR].Method: Twenty-nine healthy female subjects were asked to freely associate to individualized cue sentences. Sentences were generated from individual psychodynamic interviews based on operationlized psychodynamic diagnosis (OPD, and were comprised of three different types: positive, negative non-conflictual, and negative conflict-related sentences. Subjects were asked to name the first three associations coming into their mind. Afterward, the remaining time was used for free association. SCR during each association trial and RT of the first given association were recorded. The memory for the first three associations was subsequently tested in an unexpected recall.Results: Associations to conflict-related cue sentences were associated with longer RTs and increased SCRs. Moreover, the unexpected recall task showed memory for these associations to be reduced.Conclusion: We interpret these findings as possible correlates of

  12. Investigating Behavioral and Psychophysiological Reactions to Conflict-Related and Individualized Stimuli as Potential Correlates of Repression.

    Science.gov (United States)

    Kessler, Henrik; Schmidt, Anna Christine; Hildenbrand, Oliver; Scharf, Daniela; Kehyayan, Aram; Axmacher, Nikolai

    2017-01-01

    Background: Repression is considered as a central defense mechanism in psychodynamic theory. It refers to the process by which "unbearable" mental contents (e.g., those related to internal conflicts) are kept out of consciousness. The process of repression is probably closely related to concepts of emotion regulation derived from a different theoretical background. This relationship is particularly relevant because it relates repression to current research in the affective neurosciences as well as to experimental studies on emotion regulation. Due to its complex and highly individual nature, repression has been notoriously difficult to investigate. We investigated repression with an individualized experiment in healthy subjects in order to establish methods to study repression in clinical populations. To this end we operationalized repression using individualized experimental conditions, and then studied potential behavioral [memory and reaction time (RT)] and psychophysiological correlates [skin conductance response (SCR)]. Method: Twenty-nine healthy female subjects were asked to freely associate to individualized cue sentences. Sentences were generated from individual psychodynamic interviews based on operationlized psychodynamic diagnosis (OPD), and were comprised of three different types: positive, negative non-conflictual, and negative conflict-related sentences. Subjects were asked to name the first three associations coming into their mind. Afterward, the remaining time was used for free association. SCR during each association trial and RT of the first given association were recorded. The memory for the first three associations was subsequently tested in an unexpected recall. Results: Associations to conflict-related cue sentences were associated with longer RTs and increased SCRs. Moreover, the unexpected recall task showed memory for these associations to be reduced. Conclusion: We interpret these findings as possible correlates of repression, in line

  13. Repression of violence at public meetings and sporting events within the European legal space

    Directory of Open Access Journals (Sweden)

    Božović Milenko

    2014-01-01

    Full Text Available Violence and unbecoming behaviour at sporting events stand for a most acute problem in numerous European countries. However, the method and modes of its' repression have been determined within the frames of each country, that is its' national legislation. Thus, a wide range of various regulations referring to the distinctions of this type of violence can be spotted in legislative of each European country. Nevertheless, along with the development and maturing of the idea of the necessity of implementation of both international and regional legal instruments, used for setting up national law of individual states, a number of European legal instruments have also come to life. It comes as no surprise, though, the growing need for more both general and separate legal instruments in the repression of violence and unbecoming behaviour at sporting events in the European legislative. Based on the analysis, it is possible to single out the ones to achieve the strongest effect to our national legislative. Consequently, the general frames of the repression of violence and unbecoming behaviour at sporting events are founded on European Convention on Human Rights and Fundamental Freedoms (1950, whereas the separated ones lie in the Convention of the European Council on the Repression of Violence and Unbecoming Behaviour at Sporting Events, especially the soccer games, with the Recommendation (1985. The subject of this paper is based on analysis of the legal frames established by the European legal instruments in the field of the repression of violence and unbecoming behaviour at sporting events. The methodological framework throughout the research considers the usage of various methods: historical, linguistic, sociological, logical, normative, analysis of content, etc.

  14. Targeted repression of AXIN2 and MYC gene expression using designer TALEs

    International Nuclear Information System (INIS)

    Rennoll, Sherri A.; Scott, Samantha A.; Yochum, Gregory S.

    2014-01-01

    Highlights: • We designed TALE–SID fusion proteins to target AXIN2 and MYC. • TALE–SIDs bound the chromosomal AXIN2 and MYC genes and repressed their expression. • TALE–SIDs repress β-catenin S45F -dependent AXIN2 and MYC transcription. - Abstract: Designer TALEs (dTALEs) are chimeric transcription factors that can be engineered to regulate gene expression in mammalian cells. Whether dTALEs can block gene transcription downstream of signal transduction cascades, however, has yet to be fully explored. Here we tested whether dTALEs can be used to target genes whose expression is controlled by Wnt/β-catenin signaling. TALE DNA binding domains were engineered to recognize sequences adjacent to Wnt responsive enhancer elements (WREs) that control expression of axis inhibition protein 2 (AXIN2) and c-MYC (MYC). These custom DNA binding domains were linked to the mSin3A interaction domain (SID) to generate TALE–SID chimeric repressors. The TALE–SIDs repressed luciferase reporter activity, bound their genomic target sites, and repressed AXIN2 and MYC expression in HEK293 cells. We generated a novel HEK293 cell line to determine whether the TALE–SIDs could function downstream of oncogenic Wnt/β-catenin signaling. Treating these cells with doxycycline and tamoxifen stimulates nuclear accumulation of a stabilized form of β-catenin found in a subset of colorectal cancers. The TALE–SIDs repressed AXIN2 and MYC expression in these cells, which suggests that dTALEs could offer an effective therapeutic strategy for the treatment of colorectal cancer

  15. Targeted repression of AXIN2 and MYC gene expression using designer TALEs

    Energy Technology Data Exchange (ETDEWEB)

    Rennoll, Sherri A.; Scott, Samantha A.; Yochum, Gregory S., E-mail: gsy3@psu.edu

    2014-04-18

    Highlights: • We designed TALE–SID fusion proteins to target AXIN2 and MYC. • TALE–SIDs bound the chromosomal AXIN2 and MYC genes and repressed their expression. • TALE–SIDs repress β-catenin{sup S45F}-dependent AXIN2 and MYC transcription. - Abstract: Designer TALEs (dTALEs) are chimeric transcription factors that can be engineered to regulate gene expression in mammalian cells. Whether dTALEs can block gene transcription downstream of signal transduction cascades, however, has yet to be fully explored. Here we tested whether dTALEs can be used to target genes whose expression is controlled by Wnt/β-catenin signaling. TALE DNA binding domains were engineered to recognize sequences adjacent to Wnt responsive enhancer elements (WREs) that control expression of axis inhibition protein 2 (AXIN2) and c-MYC (MYC). These custom DNA binding domains were linked to the mSin3A interaction domain (SID) to generate TALE–SID chimeric repressors. The TALE–SIDs repressed luciferase reporter activity, bound their genomic target sites, and repressed AXIN2 and MYC expression in HEK293 cells. We generated a novel HEK293 cell line to determine whether the TALE–SIDs could function downstream of oncogenic Wnt/β-catenin signaling. Treating these cells with doxycycline and tamoxifen stimulates nuclear accumulation of a stabilized form of β-catenin found in a subset of colorectal cancers. The TALE–SIDs repressed AXIN2 and MYC expression in these cells, which suggests that dTALEs could offer an effective therapeutic strategy for the treatment of colorectal cancer.

  16. Nitrogen Metabolite Repression of Metabolism and Virulence in the Human Fungal Pathogen Cryptococcus neoformans

    Science.gov (United States)

    Lee, I. Russel; Chow, Eve W. L.; Morrow, Carl A.; Djordjevic, Julianne T.; Fraser, James A.

    2011-01-01

    Proper regulation of metabolism is essential to maximizing fitness of organisms in their chosen environmental niche. Nitrogen metabolite repression is an example of a regulatory mechanism in fungi that enables preferential utilization of easily assimilated nitrogen sources, such as ammonium, to conserve resources. Here we provide genetic, transcriptional, and phenotypic evidence of nitrogen metabolite repression in the human pathogen Cryptococcus neoformans. In addition to loss of transcriptional activation of catabolic enzyme-encoding genes of the uric acid and proline assimilation pathways in the presence of ammonium, nitrogen metabolite repression also regulates the production of the virulence determinants capsule and melanin. Since GATA transcription factors are known to play a key role in nitrogen metabolite repression, bioinformatic analyses of the C. neoformans genome were undertaken and seven predicted GATA-type genes were identified. A screen of these deletion mutants revealed GAT1, encoding the only global transcription factor essential for utilization of a wide range of nitrogen sources, including uric acid, urea, and creatinine—three predominant nitrogen constituents found in the C. neoformans ecological niche. In addition to its evolutionarily conserved role in mediating nitrogen metabolite repression and controlling the expression of catabolic enzyme and permease-encoding genes, Gat1 also negatively regulates virulence traits, including infectious basidiospore production, melanin formation, and growth at high body temperature (39°–40°). Conversely, Gat1 positively regulates capsule production. A murine inhalation model of cryptococcosis revealed that the gat1Δ mutant is slightly more virulent than wild type, indicating that Gat1 plays a complex regulatory role during infection. PMID:21441208

  17. A central regulatory system largely controls transcriptional activation and repression responses to phosphate starvation in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Regla Bustos

    2010-09-01

    Full Text Available Plants respond to different stresses by inducing or repressing transcription of partially overlapping sets of genes. In Arabidopsis, the PHR1 transcription factor (TF has an important role in the control of phosphate (Pi starvation stress responses. Using transcriptomic analysis of Pi starvation in phr1, and phr1 phr1-like (phl1 mutants and in wild type plants, we show that PHR1 in conjunction with PHL1 controls most transcriptional activation and repression responses to phosphate starvation, regardless of the Pi starvation specificity of these responses. Induced genes are enriched in PHR1 binding sequences (P1BS in their promoters, whereas repressed genes do not show such enrichment, suggesting that PHR1(-like control of transcriptional repression responses is indirect. In agreement with this, transcriptomic analysis of a transgenic plant expressing PHR1 fused to the hormone ligand domain of the glucocorticoid receptor showed that PHR1 direct targets (i.e., displaying altered expression after GR:PHR1 activation by dexamethasone in the presence of cycloheximide corresponded largely to Pi starvation-induced genes that are highly enriched in P1BS. A minimal promoter containing a multimerised P1BS recapitulates Pi starvation-specific responsiveness. Likewise, mutation of P1BS in the promoter of two Pi starvation-responsive genes impaired their responsiveness to Pi starvation, but not to other stress types. Phylogenetic footprinting confirmed the importance of P1BS and PHR1 in Pi starvation responsiveness and indicated that P1BS acts in concert with other cis motifs. All together, our data show that PHR1 and PHL1 are partially redundant TF acting as central integrators of Pi starvation responses, both specific and generic. In addition, they indicate that transcriptional repression responses are an integral part of adaptive responses to stress.

  18. The transcription factor Mlc promotes Vibrio cholerae biofilm formation through repression of phosphotransferase system components.

    Science.gov (United States)

    Pickering, Bradley S; Lopilato, Jane E; Smith, Daniel R; Watnick, Paula I

    2014-07-01

    The phosphoenol phosphotransferase system (PTS) is a multicomponent signal transduction cascade that regulates diverse aspects of bacterial cellular physiology in response to the availability of high-energy sugars in the environment. Many PTS components are repressed at the transcriptional level when the substrates they transport are not available. In Escherichia coli, the transcription factor Mlc (for makes large colonies) represses transcription of the genes encoding enzyme I (EI), histidine protein (HPr), and the glucose-specific enzyme IIBC (EIIBC(Glc)) in defined media that lack PTS substrates. When glucose is present, the unphosphorylated form of EIIBC(Glc) sequesters Mlc to the cell membrane, preventing its interaction with DNA. Very little is known about Vibrio cholerae Mlc. We found that V. cholerae Mlc activates biofilm formation in LB broth but not in defined medium supplemented with either pyruvate or glucose. Therefore, we questioned whether V. cholerae Mlc functions differently than E. coli Mlc. Here we have shown that, like E. coli Mlc, V. cholerae Mlc represses transcription of PTS components in both defined medium and LB broth and that E. coli Mlc is able to rescue the biofilm defect of a V. cholerae Δmlc mutant. Furthermore, we provide evidence that Mlc indirectly activates transcription of the vps genes by repressing expression of EI. Because activation of the vps genes by Mlc occurs under only a subset of the conditions in which repression of PTS components is observed, we conclude that additional inputs present in LB broth are required for activation of vps gene transcription by Mlc. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  19. Drosophila Pumilio protein contains multiple autonomous repression domains that regulate mRNAs independently of Nanos and brain tumor.

    Science.gov (United States)

    Weidmann, Chase A; Goldstrohm, Aaron C

    2012-01-01

    Drosophila melanogaster Pumilio is an RNA-binding protein that potently represses specific mRNAs. In developing embryos, Pumilio regulates a key morphogen, Hunchback, in collaboration with the cofactor Nanos. To investigate repression by Pumilio and Nanos, we created cell-based assays and found that Pumilio inhibits translation and enhances mRNA decay independent of Nanos. Nanos robustly stimulates repression through interactions with the Pumilio RNA-binding domain. We programmed Pumilio to recognize a new binding site, which garners repression of new target mRNAs. We show that cofactors Brain Tumor and eIF4E Homologous Protein are not obligatory for Pumilio and Nanos activity. The conserved RNA-binding domain of Pumilio was thought to be sufficient for its function. Instead, we demonstrate that three unique domains in the N terminus of Pumilio possess the major repressive activity and can function autonomously. The N termini of insect and vertebrate Pumilio and Fem-3 binding factors (PUFs) are related, and we show that corresponding regions of human PUM1 and PUM2 have repressive activity. Other PUF proteins lack these repression domains. Our findings suggest that PUF proteins have evolved new regulatory functions through protein sequences appended to their conserved PUF repeat RNA-binding domains.

  20. Repression/depression of conjugative plasmids and their influence on the mutation-selection balance in static environments.

    Directory of Open Access Journals (Sweden)

    Yoav Atsmon-Raz

    Full Text Available We study the effect that conjugation-mediated Horizontal Gene Transfer (HGT has on the mutation-selection balance of a population in a static environment. We consider a model whereby a population of unicellular organisms, capable of conjugation, comes to mutation-selection balance in the presence of an antibiotic, which induces a first-order death rate constant [Formula: see text] for genomes that are not resistant. We explicitly take into consideration the repression/de-repression dynamics of the conjugative plasmid, and assume that a de-repressed plasmid remains temporarily de-repressed after copying itself into another cell. We assume that both repression and de-repression are characterized by first-order rate constants [Formula: see text]and [Formula: see text], respectively. We find that conjugation has a deleterious effect on the mean fitness of the population, suggesting that HGT does not provide a selective advantage in a static environment, but is rather only useful for adapting to new environments. This effect can be ameliorated by repression, suggesting that while HGT is not necessarily advantageous for a population in a static environment, its deleterious effect on the mean fitness can be negated via repression. Therefore, it is likely that HGT is much more advantageous in a dynamic landscape. Furthermore, in the limiting case of a vanishing spontaneous de-repression rate constant, we find that the fraction of conjugators in the population undergoes a phase transition as a function of population density. Below a critical population density, the fraction of conjugators is zero, while above this critical population density the fraction of conjugators rises continuously to one. Our model for conjugation-mediated HGT is related to models of infectious disease dynamics, where the conjugators play the role of the infected (I class, and the non-conjugators play the role of the susceptible (S class.

  1. Impact of embryo number and periconceptional undernutrition on factors regulating adipogenesis, lipogenesis, and metabolism in adipose tissue in the sheep fetus.

    Science.gov (United States)

    Lie, Shervi; Morrison, Janna L; Williams-Wyss, Olivia; Ozanne, Susan E; Zhang, Song; Walker, Simon K; Kleemann, David O; MacLaughlin, Severence M; Roberts, Claire T; McMillen, I Caroline

    2013-10-15

    Maternal undernutrition around the time of conception is associated with an increased risk of insulin resistance in adulthood. We hypothesized that maternal undernutrition during the periconceptional (PCUN: -60 to 7 days) and/or preimplantation (PIUN: 0-7 days) periods would result in a decrease in UCP1 expression and the abundance of insulin signaling molecules and an increase in the abundance of factors that regulate adipogenesis and lipogenesis in fetal perirenal adipose tissue (PAT) and that these effects would be different in singletons and twins. Maternal PCUN and PIUN resulted in a decrease in UCP1 expression in PAT, and PIUN resulted in higher circulating insulin concentrations, an increased abundance of pPKCζ and PDK4, and a decreased abundance of Akt1, phosphorylated mTOR, and PPARγ in PAT in singleton and twin fetuses. In singletons, there was also a decrease in the abundance of p110β in PAT in the PCUN and PIUN groups and an increase in total AMPKα in PAT in the PIUN group. In twins, however, there was an increase in the abundance of mTOR in the PCUN group and an increase in PDK2 and decrease in total AMPKα in the PIUN group. Thus exposure to periconceptional undernutrition programs changes in the thermogenic capacity and the insulin and fatty acid oxidation signaling pathway in visceral fat, and these effects are different in singletons and twins. These findings are important, as the thermogenic capacity of brown fat and the insulin sensitivity of visceral fat are important determinants of the risk of developing obesity and an insulin resistance phenotype in later life.

  2. MYC association with cancer risk and a new model of MYC-mediated repression.

    Science.gov (United States)

    Cole, Michael D

    2014-07-01

    MYC is one of the most frequently mutated and overexpressed genes in human cancer but the regulation of MYC expression and the ability of MYC protein to repress cellular genes (including itself) have remained mysterious. Recent genome-wide association studies show that many genetic polymorphisms associated with disease risk map to distal regulatory elements that regulate the MYC promoter through large chromatin loops. Cancer risk-associated single-nucleotide polymorphisms (SNPs) contain more potent enhancer activity, promoting higher MYC levels and a greater risk of disease. The MYC promoter is also subject to complex regulatory circuits and limits its own expression by a feedback loop. A model for MYC autoregulation is discussed which involves a signaling pathway between the PTEN (phosphatase and tensin homolog) tumor suppressor and repressive histone modifications laid down by the EZH2 methyltransferase. Copyright © 2014 Cold Spring Harbor Laboratory Press; all rights reserved.

  3. Repressing the Foreign Fighters Phenomenon in Western Europe: Towards an Effective Response Based on Human Rights

    Directory of Open Access Journals (Sweden)

    Christophe Paulussen

    2016-11-01

    Full Text Available This Research Paper explores how the foreign fighters phenomenon and terrorism more generally is repressed in Western Europe. It looks at a few specific repressive measures announced or adopted by France and the Netherlands, as well as criticism expressed against these proposals and measures. In addition to these two detailed analyses, references will also be made to other developments in Western Europe which appear to be indicative of a more general trend in which human rights increasingly seem to be put on the back seat when countering the phenomenon of foreign fighters and terrorism more generally. In the final section, a number of concluding thoughts and recommendations will be offered which explain why only a response based on human rights will be effective in countering this global problem in the long run.

  4. Targeted transcriptional repression using a chimeric TALE-SRDX repressor protein

    KAUST Repository

    Mahfouz, Magdy M.

    2011-12-14

    Transcriptional activator-like effectors (TALEs) are proteins secreted by Xanthomonas bacteria when they infect plants. TALEs contain a modular DNA binding domain that can be easily engineered to bind any sequence of interest, and have been used to provide user-selected DNA-binding modules to generate chimeric nucleases and transcriptional activators in mammalian cells and plants. Here we report the use of TALEs to generate chimeric sequence-specific transcriptional repressors. The dHax3 TALE was used as a scaffold to provide a DNA-binding module fused to the EAR-repression domain (SRDX) to generate a chimeric repressor that targets the RD29A promoter. The dHax3. SRDX protein efficiently repressed the transcription of the RD29A

  5. Revisiting progesterone receptor (PR) actions in breast cancer: Insights into PR repressive functions.

    Science.gov (United States)

    Proietti, Cecilia J; Cenciarini, Mauro E; Elizalde, Patricia V

    2018-05-01

    Progesterone receptor (PR) is a master regulator in female reproductive tissues that controls developmental processes and proliferation and differentiation during the reproductive cycle and pregnancy. PR also plays a role in progression of endocrine-dependent breast cancer. As a member of the nuclear receptor family of ligand-dependent transcription factors, the main action of PR is to regulate networks of target gene expression in response to binding its cognate steroid hormone, progesterone. Liganded-PR transcriptional activation has been thoroughly studied and associated mechanisms have been described while progesterone-mediated repression has remained less explored. The present work summarizes recent advances in the understanding of how PR-mediated repression is accomplished in breast cancer cells and highlights the significance of fully understanding the determinants of context-dependent PR action. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. Alleviation of glucose repression of maltose metabolism by MIG1 disruption in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Klein, Christopher; Olsson, Lisbeth; Rønnow, B.

    1996-01-01

    The MIG1 gene was disrupted in a haploid laboratory strain (B224) and in an industrial polyploid strain (DGI 342) of Saccharomyces cerevisiae. The alleviation of glucose repression of the expression of MAL genes and alleviation of glucose control of maltose metabolism were investigated in batch...... cultivations on glucose-maltose mixtures. In the MIG1-disrupted haploid strain, glucose repression was partly alleviated; i.e., maltose metabolism was initiated at higher glucose concentrations than in the corresponding wild-type strain. In contrast, the polyploid Delta mig1 strain exhibited an even more...... stringent glucose control of maltose metabolism than the corresponding wild-type strain, which could be explained by a more rigid catabolite inactivation of maltose permease, affecting the uptake of maltose. Growth on the glucose-sucrose mixture showed that the polyploid Delta mig1 strain was relieved...

  7. Cinema e contraluz: limiares da repressão na cultura midiática argentina

    Directory of Open Access Journals (Sweden)

    Márcio Serelle

    2014-12-01

    Full Text Available This paper examines the backlighting technique used in Argentine movies (mainly Valentín, Kamchatka, and The Secret in Their Eyes, seen as a kind of narrative composition in which events related to dictatorships and other forms of repression operate in the dark, but strongly affect the fate of the characters. Starting from a brief overview of the internationalization of the Argentine film industry, which, as early as the mid-1980s, had already articulated conventional dramatic structures and political denunciation, this study analyzes how part of the cinema of this century represents the violence of authoritarian states. Be it through imaginative investment, metalanguage, or allegory, these narratives renounce graphic images of the violence of repressive apparatuses and create dramaturgical compositions of highly effective communication. Thus, this work discusses the reflective capacity of these films as it pertains to the relationship between the fictional, mediatic and social contexts.

  8. EVEN-SKIPPED HOMEOBOX 1 controls human ES cell differentiation by directly repressing GOOSECOID expression

    DEFF Research Database (Denmark)

    Kalisz, Mark; Winzi, Maria Karin; Bisgaard, Hanne Cathrine

    2012-01-01

    (EVX1) and GOOSECOID (GSC) regulate cell fate decisions in streak-like progenitors derived from human ES cells exposed to BMP4 and/or activin. We found that EVX1 repressed GSC expression and promoted formation of posterior streak-like progeny in response to BMP4, and conversely that GSC repressed EVX1...... expression and was required for development of anterior streak-like progeny in response to activin. Chromatin immunoprecipitation assays showed that EVX1 bound to the GSC 5'-flanking region in BMP4 treated human ES cells, and band shift assays identified two EVX1 binding sites in the GSC 5'-region......TGFß signaling patterns the primitive streak, yet little is known about transcriptional effectors that mediate the cell fate choices during streak-like development in mammalian embryos and in embryonic stem (ES) cells. Here we demonstrate that cross-antagonistic actions of EVEN-SKIPPED HOMEOBOX 1...

  9. Targeted transcriptional repression using a chimeric TALE-SRDX repressor protein

    KAUST Repository

    Mahfouz, Magdy M.; Li, Lixin; Piatek, Marek J.; Fang, Xiaoyun; Mansour, Hicham; Bangarusamy, Dhinoth K.; Zhu, Jian-Kang

    2011-01-01

    Transcriptional activator-like effectors (TALEs) are proteins secreted by Xanthomonas bacteria when they infect plants. TALEs contain a modular DNA binding domain that can be easily engineered to bind any sequence of interest, and have been used to provide user-selected DNA-binding modules to generate chimeric nucleases and transcriptional activators in mammalian cells and plants. Here we report the use of TALEs to generate chimeric sequence-specific transcriptional repressors. The dHax3 TALE was used as a scaffold to provide a DNA-binding module fused to the EAR-repression domain (SRDX) to generate a chimeric repressor that targets the RD29A promoter. The dHax3. SRDX protein efficiently repressed the transcription of the RD29A

  10. The role of the concentration camps in the Nazi repression of prostitutes, 1933-9.

    Science.gov (United States)

    Harris, Victoria

    2010-01-01

    This article uses prostitutes as a case study in order to investigate the role of the early concentration camps as centres of detention for social deviants. In contrasting the intensification of repressive policies towards prostitutes against narratives which demonstrate the unexpectedly lax treatment of these women, it explores what the reasons behind these contradictions might have been, and what this demonstrates about the development of these institutions. It asks the following questions. How and why were prostitutes interned? Which bureaucrats were responsible for incarcerating these women and what did they view the role of the camp to be? Were such policies centrally directed or the product of local decision-making? Through asking these questions, the article explores to what extent these camps were unique as mechanisms for the repression and marginalization of prostitutes.

  11. Secularization versus religious revival in Eastern Europe: Church institutional resilience, state repression and divergent paths.

    Science.gov (United States)

    Northmore-Ball, Ksenia; Evans, Geoffrey

    2016-05-01

    Despite continuing for over two decades, the debate about the nature of the trends in religiosity in post-Communist Eastern Europe remains unresolved: some arguing that these countries are undergoing the same process of secularization as the West, while others insist that the entire region is experiencing a religious revival. Using national sample surveys from the early 1990s to 2007 to examine the change in demographic predictors of religiosity, we show that Catholic and Orthodox countries are experiencing different trends, the first group displaying evidence of secularization and the second of revival, and that these two different trends are likely to derive from the legacies of state repression and the differing abilities of the churches to resist such repression. We argue that the current literature has thus taken a mistakenly general approach, and that the post-Communist region consists of at least two distinct groups of societies with different trends in religiosity. Copyright © 2016. Published by Elsevier Inc.

  12. Malondialdehyde inhibits an AMPK-mediated nuclear translocation and repression activity of ALDH2 in transcription

    International Nuclear Information System (INIS)

    Choi, Ji-Woong; Kim, Jae-Hwan; Cho, Sung-Chun; Ha, Moon-Kyung; Song, Kye-Yong; Youn, Hong-Duk; Park, Sang Chul

    2011-01-01

    Research highlights: → ALDH2 is an MDA-modified protein in old rat kidney tissues. → AMPK associates with ALDH2 and triggers the nuclear localization of ALDH2. → ALDH2 serves as a general transcriptional repressor by associating with HDACs. → MDA inhibits the AMPK-mediated translocation of ALDH2 and its repression activity. -- Abstract: Aging process results from deleterious damages by reactive oxygen species, in particular, various metabolic aldehydes. Aldehyde dehydrogenase 2 (ALDH2) is one of metabolic enzymes detoxifying various aldehydes under oxidative conditions. AMP-activated protein kinase (AMPK) plays a key role in controlling metabolic process. However, little was known about the relationship of ALDH2 with AMPK under oxidative conditions. Here, we, by using MDA-specific monoclonal antibody, screened the tissues of young and old rats for MDA-modified proteins and identified an ALDH2 as a prominent MDA-modified protein band in the old rat kidney tissue. ALDH2 associates with AMPK and is phosphorylated by AMPK. In addition, AICAR, an activator of AMP-activated protein kinase, induces the nuclear translocation of ALDH2. ALDH2 in nucleus is involved in general transcription repression by association with histone deacetylases. Furthermore, MDA modification inhibited the translocation of ALDH2 and the association with AMPK, and ultimately led to de-repression of transcription in the reporter system analysis. In this study, we have demonstrated that ALDH2 acts as a transcriptional repressor in response to AMPK activation, and MDA modifies ALDH2 and inhibits repressive activity of ALDH2 in general transcription. We thus suggest that increasing amount of MDA during aging process may interrupt the nuclear function of ALDH2, modulated by AMPK.

  13. Malondialdehyde inhibits an AMPK-mediated nuclear translocation and repression activity of ALDH2 in transcription

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Ji-Woong [Department of Biomedical Sciences and Biochemistry and Molecular Biology, Seoul National University College of Medicine, 28 Yongon-dong, Chongro-gu, Seoul 110-799 (Korea, Republic of); Aging and Apoptosis Research Center (AARC), Seoul National University College of Medicine, 28 Yongon-dong, Chongro-gu, Seoul 110-799, (Korea, Republic of); Kim, Jae-Hwan [Department of Biomedical Sciences and Biochemistry and Molecular Biology, Seoul National University College of Medicine, 28 Yongon-dong, Chongro-gu, Seoul 110-799 (Korea, Republic of); Cho, Sung-Chun; Ha, Moon-Kyung [Department of Biomedical Sciences and Biochemistry and Molecular Biology, Seoul National University College of Medicine, 28 Yongon-dong, Chongro-gu, Seoul 110-799 (Korea, Republic of); Aging and Apoptosis Research Center (AARC), Seoul National University College of Medicine, 28 Yongon-dong, Chongro-gu, Seoul 110-799, (Korea, Republic of); Song, Kye-Yong [Department of Pathology, Chung-Ang University College of Medicine, Seoul 156-756 (Korea, Republic of); Youn, Hong-Duk, E-mail: hdyoun@snu.ac.kr [Department of Biomedical Sciences and Biochemistry and Molecular Biology, Seoul National University College of Medicine, 28 Yongon-dong, Chongro-gu, Seoul 110-799 (Korea, Republic of); Park, Sang Chul, E-mail: scpark@snu.ac.kr [Department of Biomedical Sciences and Biochemistry and Molecular Biology, Seoul National University College of Medicine, 28 Yongon-dong, Chongro-gu, Seoul 110-799 (Korea, Republic of); Aging and Apoptosis Research Center (AARC), Seoul National University College of Medicine, 28 Yongon-dong, Chongro-gu, Seoul 110-799, (Korea, Republic of)

    2011-01-07

    Research highlights: {yields} ALDH2 is an MDA-modified protein in old rat kidney tissues. {yields} AMPK associates with ALDH2 and triggers the nuclear localization of ALDH2. {yields} ALDH2 serves as a general transcriptional repressor by associating with HDACs. {yields} MDA inhibits the AMPK-mediated translocation of ALDH2 and its repression activity. -- Abstract: Aging process results from deleterious damages by reactive oxygen species, in particular, various metabolic aldehydes. Aldehyde dehydrogenase 2 (ALDH2) is one of metabolic enzymes detoxifying various aldehydes under oxidative conditions. AMP-activated protein kinase (AMPK) plays a key role in controlling metabolic process. However, little was known about the relationship of ALDH2 with AMPK under oxidative conditions. Here, we, by using MDA-specific monoclonal antibody, screened the tissues of young and old rats for MDA-modified proteins and identified an ALDH2 as a prominent MDA-modified protein band in the old rat kidney tissue. ALDH2 associates with AMPK and is phosphorylated by AMPK. In addition, AICAR, an activator of AMP-activated protein kinase, induces the nuclear translocation of ALDH2. ALDH2 in nucleus is involved in general transcription repression by association with histone deacetylases. Furthermore, MDA modification inhibited the translocation of ALDH2 and the association with AMPK, and ultimately led to de-repression of transcription in the reporter system analysis. In this study, we have demonstrated that ALDH2 acts as a transcriptional repressor in response to AMPK activation, and MDA modifies ALDH2 and inhibits repressive activity of ALDH2 in general transcription. We thus suggest that increasing amount of MDA during aging process may interrupt the nuclear function of ALDH2, modulated by AMPK.

  14. VDAC electronics: 4. Novel electrical mechanism and thermodynamic estimations of glucose repression of yeast respiration.

    Science.gov (United States)

    Lemeshko, Victor V

    2017-11-01

    Inhibition of cell respiration by high concentrations of glucose (glucose repression), known as "Crabtree effect", has been demonstrated for various cancerous strains, highly proliferating cells and yeast lines. Although significant progress in understanding metabolic events associated with the glucose repression of cell respiration has been achieved, it is not yet clear whether the Crabtree effect is the result of a limited activity of the respiratory chain, or of some glucose-mediated regulation of mitochondrial metabolic state. In this work we propose an electrical mechanism of glucose repression of the yeast S. cerevisiae, resulting from generation of the mitochondrial outer membrane potential (OMP) coupled to the direct oxidation of cytosolic NADH in mitochondria. This yeast-type mechanism of OMP generation is different from the earlier proposed VDAC-hexokinase-mediated voltage generation of cancer-type, associated with the mitochondrial outer membrane. The model was developed assuming that VDAC is more permeable to NADH than to NAD + . Thermodynamic estimations of OMP, generated as a result of NADH(2-)/NAD + (1-) turnover through the outer membrane, demonstrated that the values of calculated negative OMP match the known range of VDAC voltage sensitivity, thus suggesting a possibility of OMP-dependent VDAC-mediated regulation of cell energy metabolism. According to the proposed mechanism, we suggest that the yeast-type Crabtree effect is the result of a fast VDAC-mediated electrical repression of mitochondria due to a decrease in the outer membrane permeability to charged metabolites and owing their redistribution between the mitochondrial intermembrane space and the cytosol, both controlled by metabolically-derived OMP. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Fate of the H-NS-repressed bgl operon in evolution of Escherichia coli.

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    T Sabari Sankar

    2009-03-01

    Full Text Available In the enterobacterial species Escherichia coli and Salmonella enterica, expression of horizontally acquired genes with a higher than average AT content is repressed by the nucleoid-associated protein H-NS. A classical example of an H-NS-repressed locus is the bgl (aryl-beta,D-glucoside operon of E. coli. This locus is "cryptic," as no laboratory growth conditions are known to relieve repression of bgl by H-NS in E. coli K12. However, repression can be relieved by spontaneous mutations. Here, we investigated the phylogeny of the bgl operon. Typing of bgl in a representative collection of E. coli demonstrated that it evolved clonally and that it is present in strains of the phylogenetic groups A, B1, and B2, while it is presumably replaced by a cluster of ORFans in the phylogenetic group D. Interestingly, the bgl operon is mutated in 20% of the strains of phylogenetic groups A and B1, suggesting erosion of bgl in these groups. However, bgl is functional in almost all B2 isolates and, in approximately 50% of them, it is weakly expressed at laboratory growth conditions. Homologs of bgl genes exist in Klebsiella, Enterobacter, and Erwinia species and also in low GC-content Gram-positive bacteria, while absent in E. albertii and Salmonella sp. This suggests horizontal transfer of bgl genes to an ancestral Enterobacterium. Conservation and weak expression of bgl in isolates of phylogenetic group B2 may indicate a functional role of bgl in extraintestinal pathogenic E. coli.

  16. Red Light Represses the Photophysiology of the Scleractinian Coral Stylophora pistillata

    OpenAIRE

    Wijgerde, Tim; van Melis, Anne; Silva, Catarina I. F.; Leal, Miguel C.; Vogels, Luc; Mutter, Claudia; Osinga, Ronald

    2014-01-01

    Light spectrum plays a key role in the biology of symbiotic corals, with blue light resulting in higher coral growth, zooxanthellae density, chlorophyll a content and photosynthesis rates as compared to red light. However, it is still unclear whether these physiological processes are blue-enhanced or red-repressed. This study investigated the individual and combined effects of blue and red light on the health, zooxanthellae density, photophysiology and colouration of the scleractinian coral S...

  17. Orphan nuclear receptor TLX recruits histone deacetylases to repress transcription and regulate neural stem cell proliferation

    OpenAIRE

    Sun, GuoQiang; Yu, Ruth T.; Evans, Ronald M.; Shi, Yanhong

    2007-01-01

    TLX is a transcription factor that is essential for neural stem cell proliferation and self-renewal. However, the molecular mechanism of TLX-mediated neural stem cell proliferation and self-renewal is largely unknown. We show here that TLX recruits histone deacetylases (HDACs) to its downstream target genes to repress their transcription, which in turn regulates neural stem cell proliferation. TLX interacts with HDAC3 and HDAC5 in neural stem cells. The HDAC5-interaction domain was mapped to ...

  18. Telomeric trans-silencing: an epigenetic repression combining RNA silencing and heterochromatin formation.

    Directory of Open Access Journals (Sweden)

    Thibaut Josse

    2007-09-01

    Full Text Available The study of P-element repression in Drosophila melanogaster led to the discovery of the telomeric Trans-Silencing Effect (TSE, a repression mechanism by which a transposon or a transgene inserted in subtelomeric heterochromatin (Telomeric Associated Sequence or TAS has the capacity to repress in trans in the female germline, a homologous transposon, or transgene located in euchromatin. TSE shows variegation among egg chambers in ovaries when silencing is incomplete. Here, we report that TSE displays an epigenetic transmission through meiosis, which involves an extrachromosomal maternally transmitted factor. We show that this silencing is highly sensitive to mutations affecting both heterochromatin formation (Su(var205 encoding Heterochromatin Protein 1 and Su(var3-7 and the repeat-associated small interfering RNA (or rasiRNA silencing pathway (aubergine, homeless, armitage, and piwi. In contrast, TSE is not sensitive to mutations affecting r2d2, which is involved in the small interfering RNA (or siRNA silencing pathway, nor is it sensitive to a mutation in loquacious, which is involved in the micro RNA (or miRNA silencing pathway. These results, taken together with the recent discovery of TAS homologous small RNAs associated to PIWI proteins, support the proposition that TSE involves a repeat-associated small interfering RNA pathway linked to heterochromatin formation, which was co-opted by the P element to establish repression of its own transposition after its recent invasion of the D. melanogaster genome. Therefore, the study of TSE provides insight into the genetic properties of a germline-specific small RNA silencing pathway.

  19. Interferon-Stimulated Genes Are Transcriptionally Repressed by PR in Breast Cancer.

    Science.gov (United States)

    Walter, Katherine R; Goodman, Merit L; Singhal, Hari; Hall, Jade A; Li, Tianbao; Holloran, Sean M; Trinca, Gloria M; Gibson, Katelin A; Jin, Victor X; Greene, Geoffrey L; Hagan, Christy R

    2017-10-01

    The progesterone receptor (PR) regulates transcriptional programs that drive proliferation, survival, and stem cell phenotypes. Although the role of native progesterone in the development of breast cancer remains controversial, PR clearly alters the transcriptome in breast tumors. This study identifies a class of genes, Interferon (IFN)-stimulated genes (ISGs), potently downregulated by ligand-activated PR which have not been previously shown to be regulated by PR. Progestin-dependent transcriptional repression of ISGs was observed in breast cancer cell line models and human breast tumors. Ligand-independent regulation of ISGs was also observed, as basal transcript levels were markedly higher in cells with PR knockdown. PR repressed ISG transcription in response to IFN treatment, the canonical mechanism through which these genes are activated. Liganded PR is robustly recruited to enhancer regions of ISGs, and ISG transcriptional repression is dependent upon PR's ability to bind DNA. In response to PR activation, key regulatory transcription factors that are required for IFN-activated ISG transcription, STAT2 and IRF9, exhibit impaired recruitment to ISG promoter regions, correlating with PR/ligand-dependent ISG transcriptional repression. IFN activation is a critical early step in nascent tumor recognition and destruction through immunosurveillance. As the large majority of breast tumors are PR positive at the time of diagnosis, PR-dependent downregulation of IFN signaling may be a mechanism through which early PR-positive breast tumors evade the immune system and develop into clinically relevant tumors. Implications: This study highlights a novel transcriptional mechanism through which PR drives breast cancer development and potentially evades the immune system. Mol Cancer Res; 15(10); 1331-40. ©2017 AACR . ©2017 American Association for Cancer Research.

  20. From sensorimotor inhibition to Freudian repression: insights from psychosis applied to neurosis

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    Ariane eBazan

    2012-11-01

    Full Text Available First, three case studies are presented of psychotic patients having in common an inability to hold something down or out. In line with other theories on psychosis, we propose that a key change is at the efference copy system. Going back to Freud’s mental apparatus, we propose that the messages of discharge of the motor neurones, mobilised to direct perception, also called indications of reality, are equivalent to the modern efference copies. With this key, the reading of the cases is coherent with the psychodynamic understanding of psychosis, being a downplay of secondary processes, and consequently, a dominance of primary processes. Moreover, putting together the sensorimotor idea of a failure of efference copy-mediated inhibition with the psychoanalytic idea of a failing repression in psychosis, the hypothesis emerges that the attenuation enabled by the efference copy dynamics is, in some instances, the physiological instantiation of repression. Second, we applied this idea to the mental organisation in neurosis. Indeed, the efference copy-mediated attenuation is thought to be the mechanism through which sustained activation of an intention, without reaching it – i.e. inhibition of an action – gives rise to mental imagery. Therefore, as inhibition is needed for any targeted action or for normal language understanding, acting in the world or processing language structurally induces mental imagery, constituting a subjective unconscious mental reality. Repression is a special instance of inhibition for emotionally threatening stimuli. These stimuli require stronger inhibition, leaving (the attenuation of the motor intentions totally unanswered, in order to radically prevent execution which would lead to development of excess affect. This inhibition, then, yields a specific type of motor imagery, called phantoms, which induce mental preoccupation, as well as symptoms which, especially through their form, refer to the repressed motor

  1. Conscious Anxiety, Conscious Repression and Ego-strength as Related to Dream Recall, Content and Vividness

    OpenAIRE

    Newbold, David

    1980-01-01

    Subjects' reported dream recall frequency, dream content and vividness or recall were discussed and examined in relation to sex of the subject and MMPI Conscious Anxiety, Conscious Repression and Ego-strength scores. Fifty-three Utah State University students, who volunteered to participate in a study of dreaming behavior, were administered the MMPI and asked to complete a dream log diary. The dream log required a daily recording of total number of dreams recalled, the number of vividly an...

  2. Benzoate Catabolite Repression of the Phthalate Degradation Pathway in Rhodococcus sp. Strain DK17▿

    OpenAIRE

    Choi, Ki Young; Zylstra, Gerben J.; Kim, Eungbin

    2006-01-01

    Rhodococcus sp. strain DK17 exhibits a catabolite repression-like response when provided simultaneously with benzoate and phthalate as carbon and energy sources. Benzoate in the medium is depleted to detection limits before the utilization of phthalate begins. The transcription of the genes encoding benzoate and phthalate dioxygenase paralleled the substrate utilization profile. Two mutant strains with defective benzoate dioxygenases were unable to utilize phthalate in the presence of benzoat...

  3. Cyclin D1 represses p300 transactivation through a cyclin-dependent kinase-independent mechanism.

    Science.gov (United States)

    Fu, Maofu; Wang, Chenguang; Rao, Mahadev; Wu, Xiaofang; Bouras, Toula; Zhang, Xueping; Li, Zhiping; Jiao, Xuanmao; Yang, Jianguo; Li, Anping; Perkins, Neil D; Thimmapaya, Bayar; Kung, Andrew L; Munoz, Alberto; Giordano, Antonio; Lisanti, Michael P; Pestell, Richard G

    2005-08-19

    Cyclin D1 encodes a regulatory subunit, which with its cyclin-dependent kinase (Cdk)-binding partner forms a holoenzyme that phosphorylates and inactivates the retinoblastoma protein. In addition to its Cdk binding-dependent functions, cyclin D1 regulates cellular differentiation in part by modifying several transcription factors and nuclear receptors. The molecular mechanism through which cyclin D1 regulates the function of transcription factors involved in cellular differentiation remains to be clarified. The histone acetyltransferase protein p300 is a co-integrator required for regulation of multiple transcription factors. Here we show that cyclin D1 physically interacts with p300 and represses p300 transactivation. We demonstrated further that the interaction of the two proteins occurs at the peroxisome proliferator-activated receptor gamma-responsive element of the lipoprotein lipase promoter in the context of the local chromatin structure. We have mapped the domains in p300 and cyclin D1 involved in this interaction. The bromo domain and cysteine- and histidine-rich domains of p300 were required for repression by cyclin D1. Cyclin D1 repression of p300 was independent of the Cdk- and retinoblastoma protein-binding domains of cyclin D1. Cyclin D1 inhibits histone acetyltransferase activity of p300 in vitro. Microarray analysis identified a signature of genes repressed by cyclin D1 and induced by p300 that promotes cellular differentiation and induces cell cycle arrest. Together, our results suggest that cyclin D1 plays an important role in cellular proliferation and differentiation through regulation of p300.

  4. Imidacloprid Promotes High Fat Diet-Induced Adiposity in Female C57BL/6J Mice and Enhances Adipogenesis in 3T3-L1 Adipocytes via the AMPKα-Mediated Pathway.

    Science.gov (United States)

    Sun, Quancai; Qi, Weipeng; Xiao, Xiao; Yang, Szu-Hao; Kim, Daeyoung; Yoon, Kyong Sup; Clark, John M; Park, Yeonhwa

    2017-08-09

    Imidacloprid, a neonicotinoid insecticide, was previously reported to enhance adipogenesis and resulted in insulin resistance in cell culture models. It was also reported to promote high fat diet-induced obesity and insulin resistance in male C57BL/6J mice. Thus, the goal of the present study was to determine the effects of imidacloprid and dietary fat interaction on the development of adiposity and insulin resistance in female C57BL/6J mice. Mice were fed with a low (4% w/w) or high fat (20% w/w) diet containing imidacloprid (0.06, 0.6, or 6 mg/kg bw/day) for 12 weeks. Mice fed with imidacloprid (0.6 mg/kg bw/day) significantly enhanced high fat diet-induced weight gain and adiposity. Treatment with imidacloprid significantly increased serum insulin levels with high fat diet without effects on other markers of glucose homeostasis. AMPKα activation was significantly inhibited by 0.6 and 6 mg imidacloprid/kg bw/day in white adipose tissue. Moreover, AMPKα activation with 5-aminoimidazole-4-carboxamide ribonucleotide abolished the effects of imidacloprid (10 μM) on enhanced adipogenesis in 3T3-L1 adipocytes. N-Acetyl cysteine also partially reversed the effects of imidacloprid on reduced phosphorylation of protein kinase B (AKT) in C2C12 myotubes. These results indicate that imidacloprid may potentiate high fat diet-induced adiposity in female C57BL/6J mice and enhance adipogenesis in 3T3-L1 adipocytes via the AMPKα-mediated pathway. Imidacloprid might also influence glucose homeostasis partially by inducing cellular oxidative stress in C2C12 myotubes.

  5. Oncolytic adenovirus targeting cyclin E overexpression repressed tumor growth in syngeneic immunocompetent mice

    International Nuclear Information System (INIS)

    Cheng, Pei-Hsin; Rao, Xiao-Mei; Wechman, Stephen L.; Li, Xiao-Feng; McMasters, Kelly M.; Zhou, Heshan Sam

    2015-01-01

    Clinical trials have indicated that preclinical results obtained with human tumor xenografts in mouse models may overstate the potential of adenovirus (Ad)-mediated oncolytic therapies. We have previously demonstrated that the replication of human Ads depends on cyclin E dysregulation or overexpression in cancer cells. ED-1 cell derived from mouse lung adenocarcinomas triggered by transgenic overexpression of human cyclin E may be applied to investigate the antitumor efficacy of oncolytic Ads. Ad-cycE was used to target cyclin E overexpression in ED-1 cells and repress tumor growth in a syngeneic mouse model for investigation of oncolytic virotherapies. Murine ED-1 cells were permissive for human Ad replication and Ad-cycE repressed ED-1 tumor growth in immunocompetent FVB mice. ED-1 cells destroyed by oncolytic Ads in tumors were encircled in capsule-like structures, while cells outside the capsules were not infected and survived the treatment. Ad-cycE can target cyclin E overexpression in cancer cells and repress tumor growth in syngeneic mouse models. The capsule structures formed after Ad intratumoral injection may prevent viral particles from spreading to the entire tumor. The online version of this article (doi:10.1186/s12885-015-1731-x) contains supplementary material, which is available to authorized users

  6. Functional improvement of dystrophic muscle by repression of utrophin: let-7c interaction.

    Directory of Open Access Journals (Sweden)

    Manoj K Mishra

    Full Text Available Duchenne muscular dystrophy (DMD is a fatal genetic disease caused by an absence of the 427kD muscle-specific dystrophin isoform. Utrophin is the autosomal homolog of dystrophin and when overexpressed, can compensate for the absence of dystrophin and rescue the dystrophic phenotype of the mdx mouse model of DMD. Utrophin is subject to miRNA mediated repression by several miRNAs including let-7c. Inhibition of utrophin: let-7c interaction is predicted to 'repress the repression' and increase utrophin expression. We developed and tested the ability of an oligonucleotide, composed of 2'-O-methyl modified bases on a phosphorothioate backbone, to anneal to the utrophin 3'UTR and prevent let-7c miRNA binding, thereby upregulating utrophin expression and improving the dystrophic phenotype in vivo. Suppression of utrophin: let-7c interaction using bi-weekly intraperitoneal injections of let7 site blocking oligonucleotides (SBOs for 1 month in the mdx mouse model for DMD, led to increased utrophin expression along with improved muscle histology, decreased fibrosis and increased specific force. The functional improvement of dystrophic muscle achieved using let7-SBOs suggests a novel utrophin upregulation-based therapeutic strategy for DMD.

  7. Identification of phlebovirus and arenavirus RNA sequences that stall and repress the exoribonuclease XRN1.

    Science.gov (United States)

    Charley, Phillida A; Wilusz, Carol J; Wilusz, Jeffrey

    2018-01-05

    Regulated mRNA decay plays a vital role in determining both the level and quality of cellular gene expression. Viral RNAs must successfully evade this host RNA decay machinery to establish a productive infection. One way for RNA viruses to accomplish this is to target the cellular exoribonuclease XRN1, because this enzyme is accessible in the cytoplasm and plays a major role in mRNA decay. Members of the Flaviviridae use RNA structures in their 5'- or 3'-untranslated regions to stall and repress XRN1, effectively stabilizing viral RNAs while also causing significant dysregulation of host cell mRNA stability. Here, we use a series of biochemical assays to demonstrate that the 3'-terminal portion of the nucleocapsid (N) mRNA of Rift Valley fever virus, a phlebovirus of the Bunyaviridae family, also can effectively stall and repress XRN1. The region responsible for impeding XRN1 includes a G-rich portion that likely forms a G-quadruplex structure. The 3'-terminal portions of ambisense-derived transcripts of multiple arenaviruses also stalled XRN1. Therefore, we conclude that RNAs from two additional families of mammalian RNA viruses stall and repress XRN1. This observation. emphasizes the importance and commonality of this viral strategy to interfere with the 5'-to-3'-exoribonuclease component of the cytoplasmic RNA decay machinery. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. Reconstruction and logical modeling of glucose repression signaling pathways in Saccharomyces cerevisiae

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    Oliveira Ana

    2009-01-01

    Full Text Available Abstract Background In the yeast Saccharomyces cerevisiae, the presence of high levels of glucose leads to an array of down-regulatory effects known as glucose repression. This process is complex due to the presence of feedback loops and crosstalk between different pathways, complicating the use of intuitive approaches to analyze the system. Results We established a logical model of yeast glucose repression, formalized as a hypergraph. The model was constructed based on verified regulatory interactions and it includes 50 gene transcripts, 22 proteins, 5 metabolites and 118 hyperedges. We computed the logical steady states of all nodes in the network in order to simulate wildtype and deletion mutant responses to different sugar availabilities. Evaluation of the model predictive power was achieved by comparing changes in the logical state of gene nodes with transcriptome data. Overall, we observed 71% true predictions, and analyzed sources of errors and discrepancies for the remaining. Conclusion Though the binary nature of logical (Boolean models entails inherent limitations, our model constitutes a primary tool for storing regulatory knowledge, searching for incoherencies in hypotheses and evaluating the effect of deleting regulatory elements involved in glucose repression.

  9. Generation of a glucose de-repressed mutant of Trichoderma reesei using disparity mutagenesis.

    Science.gov (United States)

    Iwakuma, Hidekazu; Koyama, Yoshiyuki; Miyachi, Ayako; Nasukawa, Masashi; Matsumoto, Hitoshi; Yano, Shuntaro; Ogihara, Jun; Kasumi, Takafumi

    2016-01-01

    We obtained a novel glucose de-repressed mutant of Trichoderma reesei using disparity mutagenesis. A plasmid containing DNA polymerase δ lacking proofreading activity, and AMAI, an autonomously replicating sequence was introduced into T. reesei ATCC66589. The rate of mutation evaluated with 5-fluoroorotic acid resistance was approximately 30-fold higher than that obtained by UV irradiation. The transformants harboring incompetent DNA polymerase δ were then selected on 2-deoxyglucose agar plates with hygromycin B. The pNP-lactoside hydrolyzing activities of mutants were 2 to 5-fold higher than the parent in liquid medium containing glucose. Notably, the amino acid sequence of cre1, a key gene involved in glucose repression, was identical in the mutant and parent strains, and further, the cre1 expression levels was not abolished in the mutant. Taken together, these results demonstrate that the strains of T. reesei generated by disparity mutagenesis are glucose de-repressed variants that contain mutations in yet-unidentified factors other than cre1.

  10. Dissecting miRNA gene repression on single cell level with an advanced fluorescent reporter system

    Science.gov (United States)

    Lemus-Diaz, Nicolas; Böker, Kai O.; Rodriguez-Polo, Ignacio; Mitter, Michael; Preis, Jasmin; Arlt, Maximilian; Gruber, Jens

    2017-01-01

    Despite major advances on miRNA profiling and target predictions, functional readouts for endogenous miRNAs are limited and frequently lead to contradicting conclusions. Numerous approaches including functional high-throughput and miRISC complex evaluations suggest that the functional miRNAome differs from the predictions based on quantitative sRNA profiling. To resolve the apparent contradiction of expression versus function, we generated and applied a fluorescence reporter gene assay enabling single cell analysis. This approach integrates and adapts a mathematical model for miRNA-driven gene repression. This model predicts three distinct miRNA-groups with unique repression activities (low, mid and high) governed not just by expression levels but also by miRNA/target-binding capability. Here, we demonstrate the feasibility of the system by applying controlled concentrations of synthetic siRNAs and in parallel, altering target-binding capability on corresponding reporter-constructs. Furthermore, we compared miRNA-profiles with the modeled predictions of 29 individual candidates. We demonstrate that expression levels only partially reflect the miRNA function, fitting to the model-projected groups of different activities. Furthermore, we demonstrate that subcellular localization of miRNAs impacts functionality. Our results imply that miRNA profiling alone cannot define their repression activity. The gene regulatory function is a dynamic and complex process beyond a minimalistic conception of “highly expressed equals high repression”. PMID:28338079

  11. RNAi mediates post-transcriptional repression of gene expression in fission yeast Schizosaccharomyces pombe

    International Nuclear Information System (INIS)

    Smialowska, Agata; Djupedal, Ingela; Wang, Jingwen; Kylsten, Per; Swoboda, Peter; Ekwall, Karl

    2014-01-01

    Highlights: • Protein coding genes accumulate anti-sense sRNAs in fission yeast S. pombe. • RNAi represses protein-coding genes in S. pombe. • RNAi-mediated gene repression is post-transcriptional. - Abstract: RNA interference (RNAi) is a gene silencing mechanism conserved from fungi to mammals. Small interfering RNAs are products and mediators of the RNAi pathway and act as specificity factors in recruiting effector complexes. The Schizosaccharomyces pombe genome encodes one of each of the core RNAi proteins, Dicer, Argonaute and RNA-dependent RNA polymerase (dcr1, ago1, rdp1). Even though the function of RNAi in heterochromatin assembly in S. pombe is established, its role in controlling gene expression is elusive. Here, we report the identification of small RNAs mapped anti-sense to protein coding genes in fission yeast. We demonstrate that these genes are up-regulated at the protein level in RNAi mutants, while their mRNA levels are not significantly changed. We show that the repression by RNAi is not a result of heterochromatin formation. Thus, we conclude that RNAi is involved in post-transcriptional gene silencing in S. pombe

  12. Repression of calcitonin gene-related peptide expression in trigeminal neurons by a Theobroma cacao extract☆

    Science.gov (United States)

    Abbey, Marcie J.; Patil, Vinit V.; Vause, Carrie V.; Durham, Paul L.

    2008-01-01

    Ethnopharmacological relevance Cocoa bean preparations were first used by the ancient Maya and Aztec civilizations of South America to treat a variety of medical ailments involving the cardiovascular, gastrointestinal, and nervous systems. Diets rich in foods containing abundant polyphenols, as found in cocoa, underlie the protective effects reported in chronic inflammatory diseases. Release of calcitonin gene-related peptide (CGRP) from trigeminal nerves promotes inflammation in peripheral tissues and nociception. Aim of the study To determine whether a methanol extract of Theobroma cacao L. (Sterculiaceae) beans enriched for polyphenols could inhibit CGRP expression, both an in vitro and an in vivo approach was taken. Results Treatment of rat trigeminal ganglia cultures with depolarizing stimuli caused a significant increase in CGRP release that was repressed by pretreatment with Theobroma cacao extract. Pretreatment with Theobroma cacao was also shown to block the KCl- and capsaicin-stimulated increases in intracellular calcium. Next, the effects of Theobroma cacao on CGRP levels were determined using an in vivo model of temporomandibular joint (TMJ) inflammation. Capsaicin injection into the TMJ capsule caused an ipsilateral decrease in CGRP levels. Theobroma cacao extract injected into the TMJ capsule 24 h prior to capsaicin treatment repressed the stimulatory effects of capsaicin. Conclusions Our results demonstrate that Theobroma cacao extract can repress stimulated CGRP release by a mechanism that likely involves blockage of calcium channel activity. Furthermore, our findings suggest that the beneficial effects of diets rich in cocoa may include suppression of sensory trigeminal nerve activation. PMID:17997062

  13. Repression of calcitonin gene-related peptide expression in trigeminal neurons by a Theobroma cacao extract.

    Science.gov (United States)

    Abbey, Marcie J; Patil, Vinit V; Vause, Carrie V; Durham, Paul L

    2008-01-17

    Cocoa bean preparations were first used by the ancient Maya and Aztec civilizations of South America to treat a variety of medical ailments involving the cardiovascular, gastrointestinal, and nervous systems. Diets rich in foods containing abundant polyphenols, as found in cocoa, underlie the protective effects reported in chronic inflammatory diseases. Release of calcitonin gene-related peptide (CGRP) from trigeminal nerves promotes inflammation in peripheral tissues and nociception. To determine whether a methanol extract of Theobroma cacao L. (Sterculiaceae) beans enriched for polyphenols could inhibit CGRP expression, both an in vitro and an in vivo approach was taken. Treatment of rat trigeminal ganglia cultures with depolarizing stimuli caused a significant increase in CGRP release that was repressed by pretreatment with Theobroma cacao extract. Pretreatment with Theobroma cacao was also shown to block the KCl- and capsaicin-stimulated increases in intracellular calcium. Next, the effects of Theobroma cacao on CGRP levels were determined using an in vivo model of temporomandibular joint (TMJ) inflammation. Capsaicin injection into the TMJ capsule caused an ipsilateral decrease in CGRP levels. Theobroma cacao extract injected into the TMJ capsule 24h prior to capsaicin treatment repressed the stimulatory effects of capsaicin. Our results demonstrate that Theobroma cacao extract can repress stimulated CGRP release by a mechanism that likely involves blockage of calcium channel activity. Furthermore, our findings suggest that the beneficial effects of diets rich in cocoa may include suppression of sensory trigeminal nerve activation.

  14. Epigenetic regulation of puberty via Zinc finger protein-mediated transcriptional repression.

    Science.gov (United States)

    Lomniczi, Alejandro; Wright, Hollis; Castellano, Juan Manuel; Matagne, Valerie; Toro, Carlos A; Ramaswamy, Suresh; Plant, Tony M; Ojeda, Sergio R

    2015-12-16

    In primates, puberty is unleashed by increased GnRH release from the hypothalamus following an interval of juvenile quiescence. GWAS implicates Zinc finger (ZNF) genes in timing human puberty. Here we show that hypothalamic expression of several ZNFs decreased in agonadal male monkeys in association with the pubertal reactivation of gonadotropin secretion. Expression of two of these ZNFs, GATAD1 and ZNF573, also decreases in peripubertal female monkeys. However, only GATAD1 abundance increases when gonadotropin secretion is suppressed during late infancy. Targeted delivery of GATAD1 or ZNF573 to the rat hypothalamus delays puberty by impairing the transition of a transcriptional network from an immature repressive epigenetic configuration to one of activation. GATAD1 represses transcription of two key puberty-related genes, KISS1 and TAC3, directly, and reduces the activating histone mark H3K4me2 at each promoter via recruitment of histone demethylase KDM1A. We conclude that GATAD1 epitomizes a subset of ZNFs involved in epigenetic repression of primate puberty.

  15. Snail recruits Ring1B to mediate transcriptional repression and cell migration in pancreatic cancer cells.

    Science.gov (United States)

    Chen, Jiangzhi; Xu, Hong; Zou, Xiuqun; Wang, Jiamin; Zhu, Yi; Chen, Hao; Shen, Baiyong; Deng, Xiaxing; Zhou, Aiwu; Chin, Y Eugene; Rauscher, Frank J; Peng, Chenghong; Hou, Zhaoyuan

    2014-08-15

    Transcriptional repressor Snail is a master regulator of epithelial-mesenchymal transition (EMT), yet the epigenetic mechanism governing Snail to induce EMT is not well understood. Here, we report that in pancreatic ductal adenocarcinoma (PDAC), elevated levels of the ubiquitin E3 ligase Ring1B and Snail, along with elevated monoubiquitination of H2A at K119 (H2AK119Ub1), are highly correlated with poor survival. Mechanistic investigations identified Ring1B as a Snail-interacting protein and showed that the carboxyl zinc fingers of Snail recruit Ring1B and its paralog Ring1A to repress its target promoters. Simultaneous depletion of Ring1A and Ring1B in pancreatic cancer cells decreased Snail binding to the target chromatin, abolished H2AK119Ub1 modification, and thereby compromised Snail-mediated transcriptional repression and cell migration. We found that Ring1B and the SNAG-associated chromatin modifier EZH2 formed distinct protein complexes with Snail and that EZH2 was required for Snail-Ring1A/B recruitment to the target promoter. Collectively, our results unravel an epigenetic mechanism underlying transcriptional repression by Snail, suggest Ring1A/B as a candidate therapeutic target, and identify H2AK119Ub1 as a potential biomarker for PDAC diagnosis and prognosis. ©2014 American Association for Cancer Research.

  16. Inhibition of tumor cell growth by Sigma1 ligand mediated translational repression

    International Nuclear Information System (INIS)

    Kim, Felix J.; Schrock, Joel M.; Spino, Christina M.; Marino, Jacqueline C.; Pasternak, Gavril W.

    2012-01-01

    Highlights: ► Sigma1 ligand treatment mediates decrease in tumor cell mass. ► Identification of a Sigma1 ligand with reversible translational repressor actions. ► Demonstration of a role for Sigma1 in cellular protein synthesis. -- Abstract: Treatment with sigma1 receptor (Sigma1) ligands can inhibit cell proliferation in vitro and tumor growth in vivo. However, the cellular pathways engaged in response to Sigma1 ligand treatment that contribute to these outcomes remain largely undefined. Here, we show that treatment with putative antagonists of Sigma1 decreases cell mass. This effect corresponds with repressed cap-dependent translation initiation in multiple breast and prostate cancer cell lines. Sigma1 antagonist treatment suppresses phosphorylation of translational regulator proteins p70S6K, S6, and 4E-BP1. RNAi-mediated knockdown of Sigma1 also results in translational repression, consistent with the effects of antagonist treatment. Sigma1 antagonist mediated translational repression and decreased cell size are both reversible. Together, these data reveal a role for Sigma1 in tumor cell protein synthesis, and demonstrate that small molecule Sigma1 ligands can be used as modulators of protein translation.

  17. Light represses transcription of asparagine synthetase genes in photosynthetic and nonphotosynthetic organs of plants

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Fongying; Coruzzi, G. (Rockefeller Univ., New York, NY (United States))

    1991-10-01

    Asparagine synthetase (AS) mRNA in Pisum sativum accumulates preferentially in plants grown in the dark. Nuclear run-on experiments demonstrate that expression of both the AS1 and AS2 genes is negatively regulated by light at the level of transcription. A decrease in the transcriptional rate of the AS1 gene can be detected as early as 20 min after exposure to light. Time course experiments reveal that the levels of AS mRNA fluctuate dramatically during a normal light/dark cycle. This is due to a direct effect of light and not to changes associated with circadian rhythm. A novel finding is that the light-repressed expression of the AS1 gene is as dramatic nonphotosynthetic organs such as roots as it is in leaves. Experiments demonstrate that the small amount of light which passes through the soil is sufficient to repress AS1 expression in roots, indicating that light has a direct effect on AS1 gene expression in roots. The negative regulation of AS gene expression by light was shown to be a general phenomenon in plants which also occurs in nonlegumes such as Nicotiana plumbaginifolia and Nicotiana tabacum. Thus, the AS genes can serve as a model with which to dissect the molecular basis for light-regulated transcriptional repression in plants.

  18. Determinants of RNA binding and translational repression by the Bicaudal-C regulatory protein.

    Science.gov (United States)

    Zhang, Yan; Park, Sookhee; Blaser, Susanne; Sheets, Michael D

    2014-03-14

    Bicaudal-C (Bic-C) RNA binding proteins function as important translational repressors in multiple biological contexts within metazoans. However, their RNA binding sites are unknown. We recently demonstrated that Bic-C functions in spatially regulated translational repression of the xCR1 mRNA during Xenopus development. This repression contributes to normal development by confining the xCR1 protein, a regulator of key signaling pathways, to specific cells of the embryo. In this report, we combined biochemical approaches with in vivo mRNA reporter assays to define the minimal Bic-C target site within the xCR1 mRNA. This 32-nucleotide Bic-C target site is predicted to fold into a stem-loop secondary structure. Mutational analyses provided evidence that this stem-loop structure is important for Bic-C binding. The Bic-C target site was sufficient for Bic-C mediated repression in vivo. Thus, we describe the first RNA binding site for a Bic-C protein. This identification provides an important step toward understanding the mechanisms by which evolutionarily conserved Bic-C proteins control cellular function in metazoans.

  19. Hes1 Directly Controls Cell Proliferation through the Transcriptional Repression of p27Kip1

    Science.gov (United States)

    Murata, Kaoru; Hattori, Masakazu; Hirai, Norihito; Shinozuka, Yoriko; Hirata, Hiromi; Kageyama, Ryoichiro; Sakai, Toshiyuki; Minato, Nagahiro

    2005-01-01

    A transcriptional regulator, Hes1, plays crucial roles in the control of differentiation and proliferation of neuronal, endocrine, and T-lymphocyte progenitors during development. Mechanisms for the regulation of cell proliferation by Hes1, however, remain to be verified. In embryonic carcinoma cells, endogenous Hes1 expression was repressed by retinoic acid in concord with enhanced p27Kip1 expression and cell cycle arrest. Conversely, conditional expression of a moderate but not maximal level of Hes1 in HeLa cells by a tetracycline-inducible system resulted in reduced p27Kip1 expression, which was attributed to decreased basal transcript rather than enhanced proteasomal degradation, with concomitant increases in the growth rate and saturation density. Hes1 induction repressed the promoter activity of a 5′ flanking basal enhancer region of p27Kip1 gene in a manner dependent on Hes1 expression levels, and this was mediated by its binding to class C sites in the promoter region. Finally, hypoplastic fetal thymi, as well as livers and brains of Hes1-deficient mice, showed significantly increased p27Kip1 transcripts compared with those of control littermates. These results have suggested that Hes1 directly contributes to the promotion of progenitor cell proliferation through transcriptional repression of a cyclin-dependent kinase inhibitor, p27Kip1. PMID:15870295

  20. Interpreting suffering from illness: The role of culture and repressive suffering construal.

    Science.gov (United States)

    Yang, Qian; Liu, Shi; Sullivan, Daniel; Pan, Shengdong

    2016-07-01

    Mental and physical illnesses are among the most prominent forms of suffering. Cultural worldviews provide tools for making sense of and coping with suffering. In this research, we examine how culture influences both experts' and laypeople's interpretation of suffering from illness. We focus on one type of interpretation of suffering- repressive suffering construal-an interpretation that frames suffering both as the result of immorality on the part of the sufferer and as having the function of maintaining social order by curtailing deviance. We sought to test whether this type of suffering interpretation is more common in cultural ecologies (e.g., urban vs. rural; higher vs. lower status) traditionally associated with collectivist values. Study 1 used data from the General Social Survey to examine variation in suffering interpretation in a representative sample of the U.S. Study 2 examined variation in suffering interpretation with a survey completed by a subsample of Chinese health-care professionals. Study 1 found that U.S. citizens living in a rural environment are more likely to interpret illnesses as being the fault of the sufferer. Study 2 found that those from a lower-SES background are more likely to interpret illnesses in a repressive fashion. In these studies, family size mediates the effect of ecological conditions on RSC. Our research highlights how ecological variables associated with collectivism may bias both laypeople and professionals to interpret suffering from illness in a more repressive way. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Insomnia symptoms and repressive coping in a sample of older Black and White women

    Directory of Open Access Journals (Sweden)

    Pierre-Louis Jessy

    2007-01-01

    Full Text Available Abstract Background This study examined whether ethnic differences in insomnia symptoms are mediated by differences in repressive coping styles. Methods A total of 1274 women (average age = 59.36 ± 6.53 years participated in the study; 28% were White and 72% were Black. Older women in Brooklyn, NY were recruited using a stratified, cluster-sampling technique. Trained staff conducted face-to-face interviews lasting 1.5 hours acquiring sociodemographic data, health characteristics, and risk factors. A sleep questionnaire was administered and individual repressive coping styles were assessed. Fisher's exact test and Spearman and Pearson analyses were used to analyze the data. Results The rate of insomnia symptoms was greater among White women [74% vs. 46%; χ2 = 87.67, p 1,1272 = 304.75, p s = -0.43, p s = -0.18, p Conclusion Relationships between ethnicity and insomnia symptoms are jointly dependent on the degree of repressive coping, suggesting that Black women may be reporting fewer insomnia symptoms because of a greater ability to route negative emotions from consciousness. It may be that Blacks cope with sleep problems within a positive self-regulatory framework, which allows them to deal more effectively with sleep-interfering psychological processes to stressful life events and to curtail dysfunctional sleep-interpreting processes.

  2. Repressive coping among British college women: A potential protective factor against body image concerns, drive for thinness, and bulimia symptoms.

    Science.gov (United States)

    Mohiyeddini, Changiz

    2017-09-01

    Repressive coping, as a means of preserving a positive self-image, has been widely explored in the context of dealing with self-evaluative cues. The current study extends this research by exploring whether repressive coping is associated with lower levels of body image concerns, drive for thinness, bulimic symptoms, and higher positive rational acceptance. A sample of 229 female college students was recruited in South London. Repressive coping was measured via the interaction between trait anxiety and defensiveness. The results of moderated regression analysis with simple slope analysis show that compared to non-repressors, repressors reported lower levels of body image concerns, drive for thinness, and bulimic symptoms while exhibiting a higher use of positive rational acceptance. These findings, in line with previous evidence, suggest that repressive coping may be adaptive particularly in the context of body image. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Adipogenic Differentiation of Muscle Derived Cells is Repressed by Inhibition of GSK-3 Activity

    Directory of Open Access Journals (Sweden)

    Zoe Redshaw

    2018-06-01

    Full Text Available Intramuscular fat is important in large animal livestock species in regard to meat quality and in humans is of clinical significance in particular in relation to insulin resistance. The canonical Wnt signalling pathway has been implicated at a whole body level in regulating relative levels of adiposity versus lean body mass. Previously we have shown that pig muscle cells can undergo adipogenic differentiation to a degree that is dependent upon the specific muscle source. In this work we examine the role of the canonical Wnt pathway which acts through inactivation of glycogen synthase kinase-3 (GSK-3 in the regulation of adipogenic differentiation in muscle cells derived from the pig semimembranosus muscle.The application of lithium chloride to muscle derived cells significantly increased the phosphorylation of GSK-3β and thus inhibited its activity thus mimicking Wnt signaling. This was associated with a significant decrease in the expression of the adipogenic transcription factor PPARγ and an almost complete inhibition of adipogenesis in the cells. The data also suggest that GSK-3α plays, at most, a small role in this process.Studies in vivo have suggested that the Wnt pathway is a major regulator of whole body adiposity. In this study we have shown that the ability of cells derived from porcine skeletal muscle to differentiate along an adipogenic lineage, in vitro, is severely impaired by mimicking the action of this pathway. This was done by inactivation of GSK-3β by the use of Lithium Chloride.

  4. Stability of XIST repression in relation to genomic imprinting following global genome demethylation in a human cell line

    International Nuclear Information System (INIS)

    Araújo, E.S.S. de; Vasques, L.R.; Stabellini, R.; Krepischi, A.C.V.; Pereira, L.V.

    2014-01-01

    DNA methylation is essential in X chromosome inactivation and genomic imprinting, maintaining repression of XIST in the active X chromosome and monoallelic repression of imprinted genes. Disruption of the DNA methyltransferase genes DNMT1 and DNMT3B in the HCT116 cell line (DKO cells) leads to global DNA hypomethylation and biallelic expression of the imprinted gene IGF2 but does not lead to reactivation of XIST expression, suggesting that XIST repression is due to a more stable epigenetic mark than imprinting. To test this hypothesis, we induced acute hypomethylation in HCT116 cells by 5-aza-2′-deoxycytidine (5-aza-CdR) treatment (HCT116-5-aza-CdR) and compared that to DKO cells, evaluating DNA methylation by microarray and monitoring the expression of XIST and imprinted genes IGF2, H19, and PEG10. Whereas imprinted genes showed biallelic expression in HCT116-5-aza-CdR and DKO cells, the XIST locus was hypomethylated and weakly expressed only under acute hypomethylation conditions, indicating the importance of XIST repression in the active X to cell survival. Given that DNMT3A is the only active DNMT in DKO cells, it may be responsible for ensuring the repression of XIST in those cells. Taken together, our data suggest that XIST repression is more tightly controlled than genomic imprinting and, at least in part, is due to DNMT3A

  5. Gene Repression in Haloarchaea Using the CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)-Cas I-B System.

    Science.gov (United States)

    Stachler, Aris-Edda; Marchfelder, Anita

    2016-07-15

    The clustered regularly interspaced short palindromic repeats (CRISPR)-Cas system is used by bacteria and archaea to fend off foreign genetic elements. Since its discovery it has been developed into numerous applications like genome editing and regulation of transcription in eukaryotes and bacteria. For archaea currently no tools for transcriptional repression exist. Because molecular biology analyses in archaea become more and more widespread such a tool is vital for investigating the biological function of essential genes in archaea. Here we use the model archaeon Haloferax volcanii to demonstrate that its endogenous CRISPR-Cas system I-B can be harnessed to repress gene expression in archaea. Deletion of cas3 and cas6b genes results in efficient repression of transcription. crRNAs targeting the promoter region reduced transcript levels down to 8%. crRNAs targeting the reading frame have only slight impact on transcription. crRNAs that target the coding strand repress expression only down to 88%, whereas crRNAs targeting the template strand repress expression down to 8%. Repression of an essential gene results in reduction of transcription levels down to 22%. Targeting efficiencies can be enhanced by expressing a catalytically inactive Cas3 mutant. Genes can be targeted on plasmids or on the chromosome, they can be monocistronic or part of a polycistronic operon. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  6. Stability of XIST repression in relation to genomic imprinting following global genome demethylation in a human cell line

    Energy Technology Data Exchange (ETDEWEB)

    Araújo, E.S.S. de [Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP (Brazil); Centro Internacional de Pesquisa, A.C. Camargo Cancer Center, São Paulo, SP (Brazil); Vasques, L.R. [Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP (Brazil); Stabellini, R.; Krepischi, A.C.V. [Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP (Brazil); Centro Internacional de Pesquisa, A.C. Camargo Cancer Center, São Paulo, SP (Brazil); Pereira, L.V. [Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP (Brazil)

    2014-10-17

    DNA methylation is essential in X chromosome inactivation and genomic imprinting, maintaining repression of XIST in the active X chromosome and monoallelic repression of imprinted genes. Disruption of the DNA methyltransferase genes DNMT1 and DNMT3B in the HCT116 cell line (DKO cells) leads to global DNA hypomethylation and biallelic expression of the imprinted gene IGF2 but does not lead to reactivation of XIST expression, suggesting that XIST repression is due to a more stable epigenetic mark than imprinting. To test this hypothesis, we induced acute hypomethylation in HCT116 cells by 5-aza-2′-deoxycytidine (5-aza-CdR) treatment (HCT116-5-aza-CdR) and compared that to DKO cells, evaluating DNA methylation by microarray and monitoring the expression of XIST and imprinted genes IGF2, H19, and PEG10. Whereas imprinted genes showed biallelic expression in HCT116-5-aza-CdR and DKO cells, the XIST locus was hypomethylated and weakly expressed only under acute hypomethylation conditions, indicating the importance of XIST repression in the active X to cell survival. Given that DNMT3A is the only active DNMT in DKO cells, it may be responsible for ensuring the repression of XIST in those cells. Taken together, our data suggest that XIST repression is more tightly controlled than genomic imprinting and, at least in part, is due to DNMT3A.

  7. Gene Repression in Haloarchaea Using the CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)-Cas I-B System*

    Science.gov (United States)

    Stachler, Aris-Edda; Marchfelder, Anita

    2016-01-01

    The clustered regularly interspaced short palindromic repeats (CRISPR)-Cas system is used by bacteria and archaea to fend off foreign genetic elements. Since its discovery it has been developed into numerous applications like genome editing and regulation of transcription in eukaryotes and bacteria. For archaea currently no tools for transcriptional repression exist. Because molecular biology analyses in archaea become more and more widespread such a tool is vital for investigating the biological function of essential genes in archaea. Here we use the model archaeon Haloferax volcanii to demonstrate that its endogenous CRISPR-Cas system I-B can be harnessed to repress gene expression in archaea. Deletion of cas3 and cas6b genes results in efficient repression of transcription. crRNAs targeting the promoter region reduced transcript levels down to 8%. crRNAs targeting the reading frame have only slight impact on transcription. crRNAs that target the coding strand repress expression only down to 88%, whereas crRNAs targeting the template strand repress expression down to 8%. Repression of an essential gene results in reduction of transcription levels down to 22%. Targeting efficiencies can be enhanced by expressing a catalytically inactive Cas3 mutant. Genes can be targeted on plasmids or on the chromosome, they can be monocistronic or part of a polycistronic operon. PMID:27226589

  8. Timing is critical for effective glucocorticoid receptor mediated repression of the cAMP-induced CRH gene.

    Directory of Open Access Journals (Sweden)

    Siem van der Laan

    Full Text Available Glucocorticoid negative feedback of the hypothalamus-pituitary-adrenal axis is mediated in part by direct repression of gene transcription in glucocorticoid receptor (GR expressing cells. We have investigated the cross talk between the two main signaling pathways involved in activation and repression of corticotrophin releasing hormone (CRH mRNA expression: cyclic AMP (cAMP and GR. We report that in the At-T20 cell-line the glucocorticoid-mediated repression of the cAMP-induced human CRH proximal promoter activity depends on the relative timing of activation of both signaling pathways. Activation of the GR prior to or in conjunction with cAMP signaling results in an effective repression of the cAMP-induced transcription of the CRH gene. In contrast, activation of the GR 10 minutes after onset of cAMP treatment, results in a significant loss of GR-mediated repression. In addition, translocation of ligand-activated GR to the nucleus was found as early as 10 minutes after glucocorticoid treatment. Interestingly, while both signaling cascades counteract each other on the CRH proximal promoter, they synergize on a synthetic promoter containing 'positive' response elements. Since the order of activation of both signaling pathways may vary considerably in vivo, we conclude that a critical time-window exists for effective repression of the CRH gene by glucocorticoids.

  9. A Herbal Formula HT048, Citrus unshiu and Crataegus pinnatifida, Prevents Obesity by Inhibiting Adipogenesis and Lipogenesis in 3T3-L1 Preadipocytes and HFD-Induced Obese Rats

    Directory of Open Access Journals (Sweden)

    Yoon Hee Lee

    2015-05-01

    Full Text Available HT048 is a combination composed of Crataegus pinnatifida leaf and Citrus unshiu peel extracts. This study aimed to investigate potential anti-obesity effect of the combination. The 3T3-L1 adipocytes were treated with different doses of HT048 and triglyceride accumulation, glycerol release and adipogenesis-related genes were analyzed. For in vivo study, male Sprague Dawley rats were divided according to experimental diets: the chow diet group, the high-fat diet (HFD group, the HFD supplemented with orlistat group, the HFD supplemented with HT048 group (0.2% or 0.4% for 12 weeks. We measured the body weight, serum lipid levels and the expression of genes involved lipid metabolism. HT048 treatment dose-dependently suppressed adipocyte differentiation and stimulated glycerol release. The expressions of PPARγ and C/EBPα mRNA were decreased by HT048 treatment in adipocytes. HT048 supplementation significantly reduced the body and fat weights in vivo. Serum lipid levels were significantly lower in the HT048 supplemented groups than those of the HFD group. Expression of the hepatic lipogenesis-related genes were decreased and expression of the β-oxidation-related genes were increased in rats fed HT048 compared to that of animals fed HFD. These results suggest that HT048 has a potential benefit in preventing obesity through the inhibition of lipogenesis and adipogenesis.

  10. Novel pathway of adipogenesis through cross-talk between adipose tissue macrophages, adipose stem cells and adipocytes: evidence of cell plasticity.

    Directory of Open Access Journals (Sweden)

    Gregorio Chazenbalk

    proliferation of new preadipocytes. This phenomenon may reflect the in vivo plasticity of adipose tissue in which ATMs play an additional role during inflammation and other disease states. Understanding this novel pathway could influence adipogenesis, leading to new treatments for obesity, inflammation, and type 2 diabetes.

  11. Cucumis melo ssp. Agrestis var. Agrestis Ameliorates High Fat Diet Induced Dyslipidemia in Syrian Golden Hamsters and Inhibits Adipogenesis in 3T3-L1 Adipocytes.

    Science.gov (United States)

    Shankar, Kripa; Singh, Sumit K; Kumar, Durgesh; Varshney, Salil; Gupta, Abhishek; Rajan, Sujith; Srivastava, Ankita; Beg, Muheeb; Srivastava, Anurag Kumar; Kanojiya, Sanjeev; Mishra, Dipak K; Gaikwad, Anil N

    2015-10-01

    Cucumis melo ssp. agrestis var. agrestis (CMA) is a wild variety of C. melo. This study aimed to explore anti-dyslipidemic and anti-adipogenic potential of CMA. For initial anti-dyslipidemic and antihyperglycemic potential of CMA fruit extract (CMFE), male Syrian golden hamsters were fed a chow or high-fat diet with or without CMFE (100 mg/kg). Further, we did fractionation of this CMFE into two fractions namely; CMA water fraction (CMWF) and CMA hexane fraction (CMHF). Phytochemical screening was done with liquid chromatography-mass spectrometry LC- (MS)/MS and direct analysis in real time-MS to detect active compounds in the fractions. Further, high-fat diet fed dyslipidemic hamsters were treated with CMWF and CMHF at 50 mg/kg for 7 days. Oral administration of CMFE and both fractions (CMWF and CMHF) reduced the total cholesterol, triglycerides, low-density lipoprotein cholesterol, and very low-density lipoprotein-cholesterol levels in high fat diet-fed dyslipidemic hamsters. CMHF also modulated expression of genes involved in lipogenesis, lipid metabolism, and reverse cholesterol transport. Standard biochemical diagnostic tests suggested that neither of fractions causes any toxicity to hamster liver or kidneys. CMFE and CMHF also decreased oil-red-O accumulation in 3T3-L1 adipocytes. Based on these results, it is concluded that CMA possesses anti-dyslipidemic and anti-hyperglycemic activity along with the anti-adipogenic activity. The oral administration of Cucumis melo agrestis fruit extract (CMFE) and its fractions (CMWF and CMHF) improved serum lipid profile in HFD fed dyslipidemic hamsters.CMFE, CMWF and CMHF significantly attenuated body weight gain and eWAT hypertrophy.The CMHF decreased lipogenesis in both liver and adipose tissue.CMFE and CMHF also inhibited adipogenesis in 3T3-L1 adipocytes. Abbreviation used: CMA: Cucumis melo ssp. agrestis var. agrestis, CMFE: CMA fruit extract, CMWF: CMA water fraction, CMHF: CMA hexane fraction, FAS: Fatty acid

  12. Very low amounts of glucose cause repression of the stress-responsive gene HSP12 in Saccharomyces cerevisiae.

    Science.gov (United States)

    de Groot, E; Bebelman, J P; Mager, W H; Planta, R J

    2000-02-01

    Changing the growth mode of Saccharomyces cerevisiae by adding fermentable amounts of glucose to cells growing on a non-fermentable carbon source leads to rapid repression of general stress-responsive genes like HSP12. Remarkably, glucose repression of HSP12 appeared to occur even at very low glucose concentrations, down to 0.005%. Although these low levels of glucose do not induce fermentative growth, they do act as a growth signal, since upon addition of glucose to a concentration of 0.02%, growth rate increased and ribosomal protein gene transcription was up-regulated. In an attempt to elucidate how this type of glucose signalling may operate, several signalling mutants were examined. Consistent with the low amounts of glucose that elicit HSP12 repression, neither the main glucose-repression pathway nor cAMP-dependent activation of protein kinase A appeared to play a role in this regulation. Using mutants involved in glucose metabolism, evidence was obtained suggesting that glucose 6-phosphate serves as a signalling molecule. To identify the target for glucose repression on the promoter of the HSP12 gene, a promoter deletion series was used. The major transcription factors governing (stress-induced) transcriptional activation of HSP12 are Msn2p and Msn4p, binding to the general stress-responsive promoter elements (STREs). Surprisingly, glucose repression of HSP12 appeared to be independent of Msn2/4p: HSP12 transcription in glycerol-grown cells was unaffected in a deltamsn2deltamsn4 strain. Nevertheless, evidence was obtained that STRE-mediated transcription is the target of repression by low amounts of glucose. These data suggest that an as yet unidentified factor is involved in STRE-mediated transcriptional regulation of HSP12.

  13. Orphan nuclear receptor TLX recruits histone deacetylases to repress transcription and regulate neural stem cell proliferation.

    Science.gov (United States)

    Sun, Guoqiang; Yu, Ruth T; Evans, Ronald M; Shi, Yanhong

    2007-09-25

    TLX is a transcription factor that is essential for neural stem cell proliferation and self-renewal. However, the molecular mechanism of TLX-mediated neural stem cell proliferation and self-renewal is largely unknown. We show here that TLX recruits histone deacetylases (HDACs) to its downstream target genes to repress their transcription, which in turn regulates neural stem cell proliferation. TLX interacts with HDAC3 and HDAC5 in neural stem cells. The HDAC5-interaction domain was mapped to TLX residues 359-385, which contains a conserved nuclear receptor-coregulator interaction motif IXXLL. Both HDAC3 and HDAC5 have been shown to be recruited to the promoters of TLX target genes along with TLX in neural stem cells. Recruitment of HDACs led to transcriptional repression of TLX target genes, the cyclin-dependent kinase inhibitor, p21(CIP1/WAF1)(p21), and the tumor suppressor gene, pten. Either inhibition of HDAC activity or knockdown of HDAC expression led to marked induction of p21 and pten gene expression and dramatically reduced neural stem cell proliferation, suggesting that the TLX-interacting HDACs play an important role in neural stem cell proliferation. Moreover, expression of a TLX peptide containing the minimal HDAC5 interaction domain disrupted the TLX-HDAC5 interaction. Disruption of this interaction led to significant induction of p21 and pten gene expression and to dramatic inhibition of neural stem cell proliferation. Taken together, these findings demonstrate a mechanism for neural stem cell proliferation through transcriptional repression of p21 and pten gene expression by TLX-HDAC interactions.

  14. The Pseudomonas aeruginosa catabolite repression control protein Crc is devoid of RNA binding activity.

    Science.gov (United States)

    Milojevic, Tetyana; Grishkovskaya, Irina; Sonnleitner, Elisabeth; Djinovic-Carugo, Kristina; Bläsi, Udo

    2013-01-01

    The Crc protein has been shown to mediate catabolite repression control in Pseudomonas, leading to a preferential assimilation of carbon sources. It has been suggested that Crc acts as a translational repressor of mRNAs, encoding functions involved in uptake and breakdown of different carbon sources. Moreover, the regulatory RNA CrcZ, the level of which is increased in the presence of less preferred carbon sources, was suggested to bind to and sequester Crc, resulting in a relief of catabolite repression. Here, we determined the crystal structure of Pseudomonas aeruginosa Crc, a member of apurinic/apyrimidinic (AP) endonuclease family, at 1.8 Å. Although Crc displays high sequence similarity with its orthologs, there are amino acid alterations in the area corresponding to the active site in AP proteins. Unlike typical AP endonuclease family proteins, Crc has a reduced overall positive charge and the conserved positively charged amino-acid residues of the DNA-binding surface of AP proteins are partially substituted by negatively charged, polar and hydrophobic residues. Crc protein purified to homogeneity from P. aeruginosa did neither display DNase activity, nor did it bind to previously identified RNA substrates. Rather, the RNA chaperone Hfq was identified as a contaminant in His-tagged Crc preparations purified by one step Ni-affinity chromatography from Escherichia coli, and was shown to account for the RNA binding activity observed with the His-Crc preparations. Taken together, these data challenge a role of Crc as a direct translational repressor in carbon catabolite repression in P. aeruginosa.

  15. MicroRNA-22 promotes cell survival upon UV radiation by repressing PTEN

    International Nuclear Information System (INIS)

    Tan, Guangyun; Shi, Yuling; Wu, Zhao-Hui

    2012-01-01

    Highlights: ► miR-22 is induced in cells treated with UV radiation. ► ATM is required for miR-22 induction in response to UV. ► miR-22 targets 3′-UTR of PTEN to repress its expression in UV-treated cells. ► Upregulated miR-22 inhibits apoptosis in cells exposed to UV. -- Abstract: DNA damage response upon UV radiation involves a complex network of cellular events required for maintaining the homeostasis and restoring genomic stability of the cells. As a new class of players involved in DNA damage response, the regulation and function of microRNAs in response to UV remain poorly understood. Here we show that UV radiation induces a significant increase of miR-22 expression, which appears to be dependent on the activation of DNA damage responding kinase ATM (ataxia telangiectasia mutated). Increased miR-22 expression may result from enhanced miR-22 maturation in cells exposed to UV. We further found that tumor suppressor gene phosphatase and tensin homolog (PTEN) expression was inversely correlated with miR-22 induction and UV-induced PTEN repression was attenuated by overexpression of a miR-22 inhibitor. Moreover, increased miR-22 expression significantly inhibited the activation of caspase signaling cascade, leading to enhanced cell survival upon UV radiation. Collectively, these results indicate that miR-22 is an important player in the cellular stress response upon UV radiation, which may promote cell survival via the repression of PTEN expression.

  16. Dominant Repression by Arabidopsis Transcription Factor MYB44 Causes Oxidative Damage and Hypersensitivity to Abiotic Stress

    Directory of Open Access Journals (Sweden)

    Helene Persak

    2014-02-01

    Full Text Available In any living species, stress adaptation is closely linked with major changes of the gene expression profile. As a substrate protein of the rapidly stress-induced mitogen-activated protein kinase MPK3, Arabidopsis transcription factor MYB44 likely acts at the front line of stress-induced re-programming. We recently characterized MYB44 as phosphorylation-dependent positive regulator of salt stress signaling. Molecular events downstream of MYB44 are largely unknown. Although MYB44 binds to the MBSII element in vitro, it has no discernible effect on MBSII-driven reporter gene expression in plant co-transfection assays. This may suggest limited abundance of a synergistic co-regulator. MYB44 carries a putative transcriptional repression (Ethylene responsive element binding factor-associated Amphiphilic Repression, EAR motif. We employed a dominant repressor strategy to gain insights into MYB44-conferred stress resistance. Overexpression of a MYB44-REP fusion markedly compromised salt and drought stress tolerance—the opposite was seen in MYB44 overexpression lines. MYB44-mediated resistance likely results from induction of tolerance-enhancing, rather than from repression of tolerance-diminishing factors. Salt stress-induced accumulation of destructive reactive oxygen species is efficiently prevented in transgenic MYB44, but accelerated in MYB44-REP lines. Furthermore, heterologous overexpression of MYB44-REP caused tissue collapse in Nicotiana. A mechanistic model of MAPK-MYB-mediated enhancement in the antioxidative capacity and stress tolerance is proposed. Genetic engineering of MYB44 variants with higher trans-activating capacity may be a means to further raise stress resistance in crops.

  17. Endocytosis of a maltose permease is induced when amylolytic enzyme production is repressed in Aspergillus oryzae.

    Science.gov (United States)

    Hiramoto, Tetsuya; Tanaka, Mizuki; Ichikawa, Takanori; Matsuura, Yuka; Hasegawa-Shiro, Sachiko; Shintani, Takahiro; Gomi, Katsuya

    2015-09-01

    In the filamentous fungus Aspergillus oryzae, amylolytic enzyme production is induced by the presence of maltose. Previously, we identified a putative maltose permease (MalP) gene in the maltose-utilizing cluster of A. oryzae. malP disruption causes a significant decrease in α-amylase activity and maltose consumption, indicating that MalP is a maltose transporter required for amylolytic enzyme production in A. oryzae. Although the expression of amylase genes and malP is repressed by the presence of glucose, the effect of glucose on the abundance of functional MalP is unknown. In this study, we examined the effect of glucose and other carbon sources on the subcellular localization of green fluorescence protein (GFP)-tagged MalP. After glucose addition, GFP-MalP at the plasma membrane was internalized and delivered to the vacuole. This glucose-induced internalization of GFP-MalP was inhibited by treatment with latrunculin B, an inhibitor of actin polymerization. Furthermore, GFP-MalP internalization was inhibited by repressing the HECT ubiquitin ligase HulA (ortholog of yeast Rsp5). These results suggest that MalP is transported to the vacuole by endocytosis in the presence of glucose. Besides glucose, mannose and 2-deoxyglucose also induced the endocytosis of GFP-MalP and amylolytic enzyme production was inhibited by the addition of these sugars. However, neither the subcellular localization of GFP-MalP nor amylolytic enzyme production was influenced by the addition of xylose or 3-O-methylglucose. These results imply that MalP endocytosis is induced when amylolytic enzyme production is repressed. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. A feedback regulatory model for RifQ-mediated repression of rifamycin export in Amycolatopsis mediterranei.

    Science.gov (United States)

    Lei, Chao; Wang, Jingzhi; Liu, Yuanyuan; Liu, Xinqiang; Zhao, Guoping; Wang, Jin

    2018-01-29

    Due to the important role of rifamycin in curing tuberculosis infection, the study on rifamycin has never been stopped. Although RifZ, which locates within the rifamycin biosynthetic cluster, has recently been characterized as a pathway-specific regulator for rifamycin biosynthesis, little is known about the regulation of rifamycin export. In this work, we proved that the expression of the rifamycin efflux pump (RifP) was regulated by RifQ, a TetR-family transcriptional regulator. Deletion of rifQ had little impact on bacterial growth, but resulted in improved rifamycin production, which was consistent with the reverse transcription PCR results that RifQ negatively regulated rifP's transcription. With electrophoretic mobility shift assay and DNase I Footprinting assay, RifQ was found to directly bind to the promoter region of rifP, and a typical inverted repeat was identified within the RifQ-protected sequences. The transcription initiation site of rifP was further characterized and found to be upstream of the RifQ binding sites, well explaining the RifQ-mediated repression of rifP's transcription in vivo. Moreover, rifamycin B (the end product of rifamycin biosynthesis) remarkably decreased the DNA binding affinity of RifQ, which led to derepression of rifamycin export, reducing the intracellular concentration of rifamycin B as well as its toxicity against the host. Here, we proved that the export of rifamycin B was repressed by RifQ in Amycolatopsis mediterranei, and the RifQ-mediated repression could be specifically relieved by rifamycin B, the end product of rifamycin biosynthesis, based on which a feedback model was proposed for regulation of rifamycin export. With the findings here, one could improve the antibiotic yield by simply inactivating the negative regulator of the antibiotic transporter.

  19. Dictyostelium cells bind a secreted autocrine factor that represses cell proliferation

    OpenAIRE

    Choe, Jonathan M; Bakthavatsalam, Deenadayalan; Phillips, Jonathan E; Gomer, Richard H

    2009-01-01

    Abstract Background Dictyostelium cells secrete the proteins AprA and CfaD. Cells lacking either AprA or CfaD proliferate faster than wild type, while AprA or CfaD overexpressor cells proliferate slowly, indicating that AprA and CfaD are autocrine factors that repress proliferation. CfaD interacts with AprA and requires the presence of AprA to slow proliferation. To determine if CfaD is necessary for the ability of AprA to slow proliferation, whether AprA binds to cells, and if so whether the...

  20. Epigenetic repression of male gametophyte-specific genes in the Arabidopsis sporophyte

    DEFF Research Database (Denmark)

    Hoffmann, Robert D; Palmgren, Michael Broberg

    2013-01-01

    Tissue formation, the identity of cells, and the functions they fulfill, are results of gene regulation. The male gametophyte of plants, pollen, is outstanding in this respect as several hundred genes expressed in pollen are not expressed in the sporophyte. How pollen-specific genes are down......-regulated in the sporophyte has yet to be established. In this study, we have performed a bioinformatics analysis of publicly available genome-wide epigenetics data of several sporophytic tissues. By combining this analysis with DNase I footprinting data, we assessed means by which the repression of pollen-specific genes...

  1. Bureau-repression: Administrative Sanction and Social Control in Modern Spain

    Directory of Open Access Journals (Sweden)

    Pedro Oliver Olmo

    2015-12-01

    Full Text Available This paper explains the creation of an intelligible suggestion for better understanding the administrative sanction in many disciplines in social sciences: the bureau-repression. The coining of this concept is due especially to the repression to which social protestors and demonstrators have been subject since the birth of the 15-M movement in Spain. However, bureau-repression had already begun being exercised in the years following the Transition, and it has developed in parallel to the stage of Security State that characterizes the state system of social control. A detailed analysis of the administrative sanction is performed for many benefits which such sanction provides for those in power, who use it both to silence voices from the street and to dispose of elements which are harmful for the neoliberal system (disadvantaged groups or immigrants. In short, the reader will find the underlying political and repressive background which, at first glance, is usually a monetary fine, and will discover that there are ways to avoid this dense surveillance exercised over the governed people (bureau-resistance. Este artículo explica la creación de una sugerencia inteligible para una mejor comprensión de la sanción administrativa en muchas disciplinas de las ciencias sociales: la burorrepresión. Este término nació especialmente a raíz de la represión que han sufrido los manifestantes de las protestas sociales desde el nacimiento del movimiento 15-M en España. Sin embargo, la burorrepresión ya había comenzado a ejercerse en los años que siguieron a la Transición, y se ha desarrollado de forma paralela al estado de seguridad que caracteriza el sistema estatal de control social. Se realiza un análisis detallado de la sanción administrativa, desarrollada en beneficio de los que están en el poder, quienes la usan tanto para silenciar las voces de la calle como para deshacerse de elementos que sean perjudiciales para el sistema neoliberal

  2. Dopamine signaling leads to loss of Polycomb repression and aberrant gene activation in experimental parkinsonism

    DEFF Research Database (Denmark)

    Södersten, Erik; Feyder, Michael; Lerdrup, Mads

    2014-01-01

    . Here, we present in vivo evidence for a previously unrecognized plasticity of PcG-repressed genes in terminally differentiated brain neurons of parkisonian mice. We show that acute administration of the dopamine precursor, L-DOPA, induces a remarkable increase in H3K27me3S28 phosphorylation....... The induction of the H3K27me3S28p histone mark specifically occurs in medium spiny neurons expressing dopamine D1 receptors and is dependent on Msk1 kinase activity and DARPP-32-mediated inhibition of protein phosphatase-1. Chromatin immunoprecipitation (ChIP) experiments showed that increased H3K27me3S28p...

  3. The adverse effect on innovation, of state repression, and of groups with undesirable work ethics

    Directory of Open Access Journals (Sweden)

    William R. DiPietro

    2016-07-01

    Full Text Available Innovation is crucial for economic growth, development, and progress. Using cross country regression analysis, this paper tests for two hypothesis regarding the determinants of innovation. The first is that state repression has a negative effect on innovation. The second is that lifestyles that devalue work, such as those obtaining their incomes from criminal activity or through natural resource rents, are detrimental to innovation. The findings from the empirical work of the paper provide evidence that tends to uphold both of these hypothesizes

  4. Substrate uptake, phosphorus repression, and effect of seed culture on glycopeptide antibiotic production

    DEFF Research Database (Denmark)

    Maiti, Soumen K.; Singh, Kamaleshwar P.; Eliasson Lantz, Anna

    2010-01-01

    may experience catabolite repression by one or more of the substrates. Availability of reliable process models is a key bottleneck in optimization of such processes. Here we present a structured kinetic model to describe the growth, substrate uptake and product formation for the glycopeptide....... The model is also able to predict key phenomena such as simultaneous uptake of glucose and glycerol but with different specific uptake rates, and inhibition of glycopeptide production by high intracellular phosphate levels. The model is successfully applied to both production and seed medium with varying....... The model may have applications in optimizing seed transfer, medium composition, and feeding strategy for maximizing production....

  5. The base pairing RNA Spot 42 participates in a multi-output feedforward loop to help enact catabolite repression in Escherichia coli

    Science.gov (United States)

    Beisel, Chase L.; Storz, Gisela

    2011-01-01

    SUMMARY Bacteria selectively consume some carbon sources over others through a regulatory mechanism termed catabolite repression. Here, we show that the base pairing RNA Spot 42 plays a broad role in catabolite repression in Escherichia coli by directly repressing genes involved in central and secondary metabolism, redox balancing, and the consumption of diverse non-preferred carbon sources. Many of the genes repressed by Spot 42 are transcriptionally activated by the global regulator CRP. Since CRP represses Spot 42, these regulators participate in a specific regulatory circuit called a multi-output feedforward loop. We found that this loop can reduce leaky expression of target genes in the presence of glucose and can maintain repression of target genes under changing nutrient conditions. Our results suggest that base pairing RNAs in feedforward loops can help shape the steady-state levels and dynamics of gene expression. PMID:21292161

  6. The Transcriptional Repressive Activity of KRAB Zinc Finger Proteins Does Not Correlate with Their Ability to Recruit TRIM28.

    Directory of Open Access Journals (Sweden)

    Kristin E Murphy

    Full Text Available KRAB domain Zinc finger proteins are one of the most abundant families of transcriptional regulators in higher vertebrates. The prevailing view is that KRAB domain proteins function as potent transcriptional repressors by recruiting TRIM28 and promoting heterochromatin spreading. However, the extent to which all KRAB domain proteins are TRIM28-dependent transcriptional repressors is currently unclear. Our studies on mouse ZFP568 revealed that TRIM28 recruitment by KRAB domain proteins is not sufficient to warrant transcriptional repressive activity. By using luciferase reporter assays and yeast two-hybrid experiments, we tested the ability of ZFP568 and other mouse KRAB domain proteins to repress transcription and bind TRIM28. We found that some mouse KRAB domain proteins are poor transcriptional repressors despite their ability to recruit TRIM28, while others showed strong KRAB-dependent transcriptional repression, but no TRIM28 binding. Together, our results show that the transcriptional repressive activity of KRAB-ZNF proteins does not correlate with their ability to recruit TRIM28, and provide evidence that KRAB domains can regulate transcription in a TRIM28-independent fashion. Our findings challenge the current understanding of the molecular mechanisms used by KRAB domain proteins to control gene expression and highlight that a high percentage of KRAB domain proteins in the mouse genome differ from the consensus KRAB sequence at amino acid residues that are critical for TRIM28 binding and/or repressive activity.

  7. Polycomb repressive complex 2 regulates MiR-200b in retinal endothelial cells: potential relevance in diabetic retinopathy.

    Directory of Open Access Journals (Sweden)

    Michael Anthony Ruiz

    Full Text Available Glucose-induced augmented vascular endothelial growth factor (VEGF production is a key event in diabetic retinopathy. We have previously demonstrated that downregulation of miR-200b increases VEGF, mediating structural and functional changes in the retina in diabetes. However, mechanisms regulating miR-200b in diabetes are not known. Histone methyltransferase complex, Polycomb Repressive Complex 2 (PRC2, has been shown to repress miRNAs in neoplastic process. We hypothesized that, in diabetes, PRC2 represses miR-200b through its histone H3 lysine-27 trimethylation mark. We show that human retinal microvascular endothelial cells exposed to high levels of glucose regulate miR-200b repression through histone methylation and that inhibition of PRC2 increases miR-200b while reducing VEGF. Furthermore, retinal tissue from animal models of diabetes showed increased expression of major PRC2 components, demonstrating in vivo relevance. This research established a repressive relationship between PRC2 and miR-200b, providing evidence of a novel mechanism of miRNA regulation through histone methylation.

  8. Retinoids repress Ah receptor CYP1A1 induction pathway through the SMRT corepressor

    International Nuclear Information System (INIS)

    Fallone, Frederique; Villard, Pierre-Henri; Seree, Eric; Rimet, Odile; Nguyen, Quock Binh; Bourgarel-Rey, Veronique; Fouchier, Francis; Barra, Yves; Durand, Alain; Lacarelle, Bruno

    2004-01-01

    CYP1A1 isoform is mainly regulated by the transcription factor AhR and to a lesser extent by the nuclear receptor RAR. The effect of a coexposure with 3MC, a AhR ligand, and RA, a RAR ligand, which are, respectively, strong and weak CYP1A1 inducers, is poorly known. We showed in Caco-2 cells that addition of RA significantly decreased 3MC-induced CYP1A1 expression by -55% for mRNA level and -30% for promoter and enzymatic activities. We further showed that RA decreased AhR protein level. Moreover, a physical interaction between AhR and the RAR-corepressor SMRT has been described in vitro. Using the corepressor inhibitor TSA, transfected-cells with SMRT cDNA, and coimmunoprecipitation experiments, we demonstrated that RA addition repressed AhR function through a marked AhR/SMRT physical interaction. This interaction explains the decrease of 3MC-induced CYP1A1 expression. This new mechanism involving the repression of AhR-induced CYP1A1 expression by retinoids allows better knowledge of the CYP1A1 regulation

  9. Nitric oxide inhibits larval settlement in Amphibalanus amphitrite cyprids by repressing muscle locomotion and molting

    KAUST Repository

    Zhang, Gen; Wong, Yue-Him; Zhang, Yu; He, Li-sheng; Xu, Ying; Qian, Pei-Yuan

    2015-01-01

    Nitric oxide (NO) is a universal signaling molecule and plays a negative role in the metamorphosis of many biphasic organisms. Recently, the NO/NO (cyclic guanosine monophosphate) signaling pathway was reported to repress larval settlement in the barnacle Amphibalanus amphitrite. To understand the underlying molecular mechanism, we analyzed changes in the proteome of A. amphitrite cyprids in response to different concentrations of the NO donor sodium nitroprusside (SNP; 62.5, 250 and 1000 μM) using a label-free proteomics method. Compared with the control, the expression of 106 proteins differed in all three treatments. These differentially expressed proteins were assigned to 13 pathways based on KEGG pathway enrichment analysis. SNP treatment stimulated the expression of heat shock proteins and arginine kinase, which are functionally related to NO synthases, increased the expression levels of glutathione transferases for detoxification, and activated the iron-mediated fatty acid degradation pathway and the citrate cycle through ferritin. Moreover, NO repressed the level of myosins and cuticular proteins, which indicated that NO might inhibit larval settlement in A. amphitrite by modulating the process of muscle locomotion and molting.

  10. MicroRNA MiR-17 retards tissue growth and represses fibronectin expression.

    Science.gov (United States)

    Shan, Sze Wan; Lee, Daniel Y; Deng, Zhaoqun; Shatseva, Tatiana; Jeyapalan, Zina; Du, William W; Zhang, Yaou; Xuan, Jim W; Yee, Siu-Pok; Siragam, Vinayakumar; Yang, Burton B

    2009-08-01

    MicroRNAs (miRNAs) are single-stranded regulatory RNAs, frequently expressed as clusters. Previous studies have demonstrated that the six-miRNA cluster miR-17~92 has important roles in tissue development and cancers. However, the precise role of each miRNA in the cluster is unknown. Here we show that overexpression of miR-17 results in decreased cell adhesion, migration and proliferation. Transgenic mice overexpressing miR-17 showed overall growth retardation, smaller organs and greatly reduced haematopoietic cell lineages. We found that fibronectin and the fibronectin type-III domain containing 3A (FNDC3A) are two targets that have their expression repressed by miR-17, both in vitro and in transgenic mice. Several lines of evidence support the notion that miR-17 causes cellular defects through its repression of fibronectin expression. Our single miRNA expression assay may be evolved to allow the manipulation of individual miRNA functions in vitro and in vivo. We anticipate that this could serve as a model for studying gene regulation by miRNAs in the development of gene therapy.

  11. Repression of class I transcription by cadmium is mediated by the protein phosphatase 2A

    Science.gov (United States)

    Zhou, Lei; Le Roux, Gwenaëlle; Ducrot, Cécile; Chédin, Stéphane; Labarre, Jean; Riva, Michel; Carles, Christophe

    2013-01-01

    Toxic metals are part of our environment, and undue exposure to them leads to a variety of pathologies. In response, most organisms adapt their metabolism and have evolved systems to limit this toxicity and to acquire tolerance. Ribosome biosynthesis being central for protein synthesis, we analyzed in yeast the effects of a moderate concentration of cadmium (Cd2+) on Pol I transcription that represents >60% of the transcriptional activity of the cells. We show that Cd2+ rapidly and drastically shuts down the expression of the 35S rRNA. Repression does not result from a poisoning of any of the components of the class I transcriptional machinery by Cd2+, but rather involves a protein phosphatase 2A (PP2A)-dependent cellular signaling pathway that targets the formation/dissociation of the Pol I–Rrn3 complex. We also show that Pol I transcription is repressed by other toxic metals, such as Ag+ and Hg2+, which likewise perturb the Pol I–Rrn3 complex, but through PP2A-independent mechanisms. Taken together, our results point to a central role for the Pol I–Rrn3 complex as molecular switch for regulating Pol I transcription in response to toxic metals. PMID:23640330

  12. Authoritarianism, control and vigilance: Jacob Gorender on the aim of the repression (1940-1980

    Directory of Open Access Journals (Sweden)

    Lucileide Costa Cardoso

    2013-12-01

    Full Text Available The purpose of the article is to demonstrate through analysis of documents of repressive nature, the elements highlighted by the Military Justice to establish the trace of persecution of the intellectuals among other social sectors which dared to challenge the Dictatorship. The complete mapping, involving the combat strategies against the “communism”, including the knowledge of the political parties and their military staff, was accumulated by police and military sectors along the 20th century. We intended to follow, through these records, the political trajectory of the intellectual Jacob Gorender. As a journalist, he got involved in the discussion about the Brazilian participation in the World War II, joined the FEB in 1943. Before that, however, Gorender became a communist, recruited by Mario Alves in 1942. In the early 60’s, he acted as a militant and coordinator of PCB, when he decided to join PCBR, founded in 1968. The historian, in the beginning of the 1964 Strike, with his life already devastated by the Information and Security Community, experienced marginalization, imprisonment, torture and censorship of his writings among other abuses that also reached his closest friends, political companions and family members. The crossing of this amount of information with the memorial documents helps to understand the political repression tricks and the different Revolutionary projects in course.

  13. The Chistopol Prison as a Space of Political Repression (1978-1990

    Directory of Open Access Journals (Sweden)

    Elena A. Gerasimova

    2017-09-01

    Full Text Available The importance of the problem lies in the need for a deep, consistent and comprehensive study of the history of political repressions in the USSR as an integral part of the Soviet past. Although the history of political repression of the Stalinist period has been studied in-depth in Russian and foreign historiography, it does not cover the late Soviet period. The article discusses the history of the infamous "special" prison in Chistopol (Tatarstan, which functioned as a prison for political prisoners in 1978−1990. There has been performed the analysis of the prison’s social composition, detention regime, and daily practices of subsistence and survival. The basic approach to the problem was the method of complex analysis of different types of sources of official and personal origin and their comparative analysis. The results of the study include the characteristics of such an unexplored form of punishment of dissidents in the late Soviet Russia as imprisonment of "special purpose." It is proved that the regulatory "corrective" practices of the government and the actual practice of the prisoners’ everyday life were at times directly contrary to each other, which resulted not only in the lack of "re-education" of the "political" prisoners, but also in the growth of their number through joining of former criminal elements.

  14. Arctigenin represses TGF-β-induced epithelial mesenchymal transition in human lung cancer cells.

    Science.gov (United States)

    Xu, Yanrui; Lou, Zhiyuan; Lee, Seong-Ho

    2017-11-18

    Arctigenin (ARC) is a lignan that is abundant in Asteraceae plants, which show anti-inflammatory and anti-cancer activities. The current study investigated whether ARC affects cancer progression and metastasis, focusing on EMT using invasive human non-small cell lung cancer (NSCLC) cells. No toxicity was observed in the cells treated with different doses of ARC (12-100 μM). The treatment of ARC repressed TGF-β-stimulated changes of metastatic morphology and cell invasion and migration. ARC inhibited TGF-β-induced phosphorylation and transcriptional activity of smad2/3, and expression of snail. ARC also decreased expression of N-cadherin and increased expression of E-cadherin in dose-dependent and time-dependent manners. These changes were accompanied by decreased amount of phospho-smad2/3 in nucleus and nuclear translocation of smad2/3. Moreover, ARC repressed TGF-β-induced phosphorylation of ERK and transcriptional activity of β-catenin. Our data demonstrate anti-metastatic activity of ARC in lung cancer model. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Melanie Klein and Repression: an examination of some unpublished Notes of 1934.

    Science.gov (United States)

    Hinshelwood, R D

    2006-01-01

    Fifteen pages of unpublished Notes were found in the Melanie Klein Archives dating from early 1934, a crucial moment in Klein's development. She was at this time, 1934, moving away from child analysis, whilst also rethinking and revising her allegiance to Karl Abraham's theory of the phases of libidinal development. These Notes, entitled "Early Repression Mechanism," show Klein struggling to develop what became her characteristic theories of the depressive position and the paranoid-schizoid position. Although these Notes are precursors of the paper Klein gave later to the IPA Congress in 1934, they also show the origins of the emphasis she and her followers eventually gave to "splitting" rather than repression. The Notes give us an insight into the way that she worked clinically at the time. We see Klein's confidence develop as she diverged from the classical theories and technique. Her ideas were based on close attention to the detail of her clinical material, rather than attacking theoretical problems directly. The Notes show her method of struggling to her own conclusions, and they offer us a chance to grasp the roots of the subsequent controversy over Kleinian thought.

  16. Cell type-specific translational repression of Cyclin B during meiosis in males.

    Science.gov (United States)

    Baker, Catherine Craig; Gim, Byung Soo; Fuller, Margaret T

    2015-10-01

    The unique cell cycle dynamics of meiosis are controlled by layers of regulation imposed on core mitotic cell cycle machinery components by the program of germ cell development. Although the mechanisms that regulate Cdk1/Cyclin B activity in meiosis in oocytes have been well studied, little is known about the trans-acting factors responsible for developmental control of these factors in male gametogenesis. During meiotic prophase in Drosophila males, transcript for the core cell cycle protein Cyclin B1 (CycB) is expressed in spermatocytes, but the protein does not accumulate in spermatocytes until just before the meiotic divisions. Here, we show that two interacting proteins, Rbp4 and Fest, expressed at the onset of spermatocyte differentiation under control of the developmental program of male gametogenesis, function to direct cell type- and stage-specific repression of translation of the core G2/M cell cycle component cycB during the specialized cell cycle of male meiosis. Binding of Fest to Rbp4 requires a 31-amino acid region within Rbp4. Rbp4 and Fest are required for translational repression of cycB in immature spermatocytes, with Rbp4 binding sequences in a cell type-specific shortened form of the cycB 3' UTR. Finally, we show that Fest is required for proper execution of meiosis I. © 2015. Published by The Company of Biologists Ltd.

  17. Functional Analysis of the Nitrogen Metabolite Repression Regulator Gene nmrA in Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Xiaoyun Han

    2016-11-01

    Full Text Available In Aspergillus nidulans, the nitrogen metabolite repression regulator NmrA plays a major role in regulating the activity of the GATA transcription factor AreA during nitrogen metabolism. However, the function of nmrA in Aspergillus flavus has notbeen previously studied. Here, we report the identification and functional analysis of nmrA in A. flavus. Our work showed that the amino acid sequences of NmrA are highly conserved among Aspergillus species and that A. flavus NmrA protein contains a canonical Rossmann fold motif. Deletion of nmrA slowed the growth of A. flavus but significantly increased conidiation and sclerotia production. Moreover, seed infection experiments indicated that nmrA is required for the invasive virulence of A. flavus. In addition, the ΔnmrA mutant showed increased sensitivity to rapamycin and methyl methanesulfonate, suggesting that nmrA could be responsive to target of rapamycin signaling and DNA damage. Furthermore, quantitative real-time reverse transcription polymerase chain reaction analysis suggested that nmrA might interact with other nitrogen regulatory and catabolic genes. Our study provides a better understanding of nitrogen metabolite repression and the nitrogen metabolism network in fungi.

  18. Nitric oxide inhibits larval settlement in Amphibalanus amphitrite cyprids by repressing muscle locomotion and molting

    KAUST Repository

    Zhang, Gen

    2015-08-28

    Nitric oxide (NO) is a universal signaling molecule and plays a negative role in the metamorphosis of many biphasic organisms. Recently, the NO/NO (cyclic guanosine monophosphate) signaling pathway was reported to repress larval settlement in the barnacle Amphibalanus amphitrite. To understand the underlying molecular mechanism, we analyzed changes in the proteome of A. amphitrite cyprids in response to different concentrations of the NO donor sodium nitroprusside (SNP; 62.5, 250 and 1000 μM) using a label-free proteomics method. Compared with the control, the expression of 106 proteins differed in all three treatments. These differentially expressed proteins were assigned to 13 pathways based on KEGG pathway enrichment analysis. SNP treatment stimulated the expression of heat shock proteins and arginine kinase, which are functionally related to NO synthases, increased the expression levels of glutathione transferases for detoxification, and activated the iron-mediated fatty acid degradation pathway and the citrate cycle through ferritin. Moreover, NO repressed the level of myosins and cuticular proteins, which indicated that NO might inhibit larval settlement in A. amphitrite by modulating the process of muscle locomotion and molting.

  19. Intact implicit and reduced explicit memory for negative self-related information in repressive coping.

    Science.gov (United States)

    Fujiwara, Esther; Levine, Brian; Anderson, Adam K

    2008-09-01

    Voluntary emotional memory control has recently been shown to involve prefrontal down-regulation of medial temporal lobe activity during memory retrieval. However, little is known about instances of uninstructed, naturally occurring forgetting. In the present study, we examined whether memory suppression extends to involuntary, uninstructed down-regulation of memory in individuals thought to be experts in forgetting negative memories--those with a repressive coping style. We contrasted explicit and implicit memory for negative information in repressor and nonrepressor groups and examined whether self-relevance is a moderating variable. To delineate the specificity of repressors' selective memory reductions, we contrasted encoding and retrieval of emotional words as a function of self-reference, subjective self-relevance, and explicitness of the memory task in nonrepressors and repressors. Self-descriptiveness judgments, lexical decisions (implicit memory), and free recall (explicit memory) were investigated. Repressors had selectively lowered free recall only for negative, self-relevant information. Their implicit memory for the same information was unaffected. This pattern suggests that regulation of emotional memory in repressive individuals is a case of motivated forgetting, possibly sharing much of the neural underpinnings of voluntary memory suppression.

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

    Science.gov (United States)

    Perdomo, José; Jiang, Xing-Mai; Carter, Daniel R; Khachigian, Levon M; Chong, Beng H

    2012-01-01

    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.

  1. The Brakeless co-regulator can directly activate and repress transcription in early Drosophila embryos.

    Science.gov (United States)

    Crona, Filip; Holmqvist, Per-Henrik; Tang, Min; Singla, Bhumica; Vakifahmetoglu-Norberg, Helin; Fantur, Katrin; Mannervik, Mattias

    2015-11-01

    The Brakeless protein performs many important functions during Drosophila development, but how it controls gene expression is poorly understood. We previously showed that Brakeless can function as a transcriptional co-repressor. In this work, we perform transcriptional profiling of brakeless mutant embryos. Unexpectedly, the majority of affected genes are down-regulated in brakeless mutants. We demonstrate that genomic regions in close proximity to some of these genes are occupied by Brakeless, that over-expression of Brakeless causes a reciprocal effect on expression of these genes, and that Brakeless remains an activator of the genes upon fusion to an activation domain. Together, our results show that Brakeless can both repress and activate gene expression. A yeast two-hybrid screen identified the Mediator complex subunit Med19 as interacting with an evolutionarily conserved part of Brakeless. Both down- and up-regulated Brakeless target genes are also affected in Med19-depleted embryos, but only down-regulated targets are influenced in embryos depleted of both Brakeless and Med19. Our data provide support for a Brakeless activator function that regulates transcription by interacting with Med19. We conclude that the transcriptional co-regulator Brakeless can either activate or repress transcription depending on context. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Ascites promotes cell migration through the repression of miR-125b in ovarian cancer.

    Science.gov (United States)

    Yang, Lan; Zhang, Xiaoli; Ma, Yiming; Zhao, Xinhua; Li, Bin; Wang, Hongying

    2017-08-01

    Interactions between ovarian cancer cells and the surrounding tumor microenvironment are not well characterized. Here, we investigated the molecular mechanisms by which malignant ascites promote the metastasis of ovarian cancer. It was found that ovarian cancer ascites promoted ovarian cancer cell migration which was attenuated by either heat inactivation or antibody blockade of TGF-β. High level (at ng/ml level) of TGF-β was detected in the ascites. In addition, ascites repressed the expression of miRNA-125b in a TGF-β-dependent manner. Mimic of miR-125b blocked ascites-induced cell migration. Furthermore, Gab2 (a target gene of miR-125b) was elevated by ascites in a TGF-β-dependent manner. And forced expression of Gab2 reversed the inhibition of migration induced by miR-125b mimic. Most importantly, the expression of miR-125b and Gab2 mRNA was negatively correlated in ovarian cancer specimens. Taken together, our finding suggested that TGF-β in ascites promoted cancer cell migration through repression of miR-125b in ovarian cancer. This might provide a novel therapeutic target for ovarian cancer in the future.

  3. Targeting MUC1-C suppresses polycomb repressive complex 1 in multiple myeloma.

    Science.gov (United States)

    Tagde, Ashujit; Markert, Tahireh; Rajabi, Hasan; Hiraki, Masayuki; Alam, Maroof; Bouillez, Audrey; Avigan, David; Anderson, Kenneth; Kufe, Donald

    2017-09-19

    The polycomb repressive complex 1 (PRC1) includes the BMI1, RING1 and RING2 proteins. BMI1 is required for survival of multiple myeloma (MM) cells. The MUC1-C oncoprotein is aberrantly expressed by MM cells, activates MYC and is also necessary for MM cell survival. The present studies show that targeting MUC1-C with (i) stable and inducible silencing and CRISPR/Cas9 editing and (ii) the pharmacologic inhibitor GO-203, which blocks MUC1-C function, downregulates BMI1, RING1 and RING2 expression. The results demonstrate that MUC1-C drives BMI1 transcription by a MYC-dependent mechanism. MUC1-C thus promotes MYC occupancy on the BMI1 promoter and thereby activates BMI1 expression. We also show that the MUC1-C→MYC pathway induces RING2 expression. Moreover, in contrast to BMI1 and RING2, we found that MUC1-C drives RING1 by an NF-κB p65-dependent mechanism. Targeting MUC1-C and thereby the suppression of these key PRC1 proteins was associated with downregulation of the PRC1 E3 ligase activity as evidenced by decreases in ubiquitylation of histone H2A. Targeting MUC1-C also resulted in activation of the PRC1-repressed tumor suppressor genes, PTEN, CDNK2A and BIM . These findings identify a heretofore unrecognized role for MUC1-C in the epigenetic regulation of MM cells.

  4. Neural Progenitors Adopt Specific Identities by Directly Repressing All Alternative Progenitor Transcriptional Programs.

    Science.gov (United States)

    Kutejova, Eva; Sasai, Noriaki; Shah, Ankita; Gouti, Mina; Briscoe, James

    2016-03-21

    In the vertebrate neural tube, a morphogen-induced transcriptional network produces multiple molecularly distinct progenitor domains, each generating different neuronal subtypes. Using an in vitro differentiation system, we defined gene expression signatures of distinct progenitor populations and identified direct gene-regulatory inputs corresponding to locations of specific transcription factor binding. Combined with targeted perturbations of the network, this revealed a mechanism in which a progenitor identity is installed by active repression of the entire transcriptional programs of other neural progenitor fates. In the ventral neural tube, sonic hedgehog (Shh) signaling, together with broadly expressed transcriptional activators, concurrently activates the gene expression programs of several domains. The specific outcome is selected by repressive input provided by Shh-induced transcription factors that act as the key nodes in the network, enabling progenitors to adopt a single definitive identity from several initially permitted options. Together, the data suggest design principles relevant to many developing tissues. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  5. Low doses of Paclitaxel repress breast cancer invasion through DJ-1/KLF17 signalling pathway.

    Science.gov (United States)

    Ismail, Ismail Ahmed; El-Sokkary, Gamal H; Saber, Saber H

    2018-04-27

    Paclitaxel (taxol) is an important agent against many tumours, including breast cancer. Ample data documents that paclitaxel inhibits breast cancer metastasis while others prove that paclitaxel enhances breast cancer metastasis. The mechanisms by which paclitaxel exerts its action are not well established. This study focuses on the effect of paclitaxel, particularly the low doses on breast cancer metastasis and the mechanisms that regulate it. Current results show that, paclitaxel exerts significant cytotoxicity even at low doses in both MCF-7 and MDA-MB-231 cells. Interestingly, paclitaxel significantly inhibits cell invasion and migration, decreases Snail and increases E-cadherin mRNA expression levels at the indicated low doses. Furthermore, paclitaxel-inhibiting breast cancer metastasis is associated with down-regulation of DJ-1 and ID-1 mRNA expression level with a concurrent increase in KLF17 expression. Under the same experimental conditions, paclitaxel induces KLF17 and concurrently represses ID-1 protein levels. Our results show for the first time that paclitaxel inhibits breast cancer metastasis through regulating DJ-1/KLF17/ID-1 signalling pathway; repressed DJ-1 and ID-1 and enhanced KLF17 expression. © 2018 John Wiley & Sons Australia, Ltd.

  6. nilR is necessary for co-ordinate repression of Xenorhabdus nematophila mutualism genes.

    Science.gov (United States)

    Cowles, Charles E; Goodrich-Blair, Heidi

    2006-11-01

    The bacterial mutualist Xenorhabdus nematophila colonizes a specific region of its nematode host Steinernema carpocapsae. We previously reported the identification of a chromosomal locus encoding three X. nematophila genes of unknown function, nilA, B and C, that are each necessary for colonization. Subsequent work indicated the global regulator Lrp is a repressor of nilC: nilC transcription is elevated in an lrp mutant and Lrp interacts directly with the nilC promoter. In this manuscript, we report the identification of an additional gene, nilR, required for repression of nilC transcription. We show that nilR and lrp mutants also have elevated expression of nilA and nilB, demonstrating that nilA, B and C are co-ordinately regulated. nil gene expression is derepressed most strongly when both nilR and lrp are lacking, suggesting NilR and Lrp synergistically repress nil transcription. NilR contains a helix-turn-helix-type DNA binding domain and likely acts directly at promoters. A comparison of the wild type and nilR proteomes indicates that NilR, unlike Lrp, regulates a small number of genes. Finally, X. nematophila carrying an ectopic copy of nilR colonizes at approximately 60-fold lower levels than the control strain, suggesting that derepression of nil gene expression is necessary for nematode colonization.

  7. Military westernization and state repression in the post-Cold War era.

    Science.gov (United States)

    Swed, Ori; Weinreb, Alexander

    2015-09-01

    The waves of unrest that have shaken the Arab world since December 2010 have highlighted significant differences in the readiness of the military to intervene in political unrest by forcefully suppressing dissent. We suggest that in the post-Cold War period, this readiness is inversely associated with the level of military westernization, which is a product of the acquisition of arms from western countries. We identify two mechanisms linking the acquisition of arms from western countries to less repressive responses: dependence and conditionality; and a longer-term diffusion of ideologies regarding the proper form of civil-military relations. Empirical support for our hypothesis is found in an analysis of 2523 cases of government response to political unrest in 138 countries in the 1996-2005 period. We find that military westernization mitigates state repression in general, with more pronounced effects in the poorest countries. However, we also identify substantial differences between the pre- and post-9/11 periods. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Repression of protein translation and mTOR signaling by proteasome inhibitor in colon cancer cells

    International Nuclear Information System (INIS)

    Wu, William Ka Kei; Volta, Viviana; Cho, Chi Hin; Wu, Ya Chun; Li, Hai Tao; Yu, Le; Li, Zhi Jie; Sung, Joseph Jao Yiu

    2009-01-01

    Protein homeostasis relies on a balance between protein synthesis and protein degradation. The ubiquitin-proteasome system is a major catabolic pathway for protein degradation. In this respect, proteasome inhibition has been used therapeutically for the treatment of cancer. Whether inhibition of protein degradation by proteasome inhibitor can repress protein translation via a negative feedback mechanism, however, is unknown. In this study, proteasome inhibitor MG-132 lowered the proliferation of colon cancer cells HT-29 and SW1116. In this connection, MG-132 reduced the phosphorylation of mammalian target of rapamycin (mTOR) at Ser2448 and Ser2481 and the phosphorylation of its downstream targets 4E-BP1 and p70/p85 S6 kinases. Further analysis revealed that MG-132 inhibited protein translation as evidenced by the reductions of 35 S-methionine incorporation and polysomes/80S ratio. Knockdown of raptor, a structural component of mTOR complex 1, mimicked the anti-proliferative effect of MG-132. To conclude, we demonstrate that the inhibition of protein degradation by proteasome inhibitor represses mTOR signaling and protein translation in colon cancer cells.

  9. Investigation of repressive and enhancive effects of fruit extracts on the activity of glucose-6-phophatase.

    Science.gov (United States)

    Zahoor, Muhammad; Jan, Muhammad Rasul; Naz, Sumaira

    2016-11-01

    Glucose-6-phosphatase is a key enzyme of glucose metabolic pathways. Deficiency of this enzyme leads to glycogen storage disease. This enzyme also plays a negative role in diabetes mellitus disorder in which the catalytic activity of this enzyme increases. Thus there is need for activators to enhance the activity of glucose-6-phosphatase in glycogen storage disease of type 1b while in diabetes mellitus repressors are needed to reduce its activity. Crude extracts of apricot, fig, mulberry and apple fruits were investigated for their repressive/enhancive effects on glucose-6-phosphatase in vivo. Albino mice were used as experimental animal. All the selected extracts showed depressive effects on glucose-6-phosphatase, which shows that all these extracts can be used as antidiabetic supplement of food. The inhibitory pattern was competitive one, which was evident from the effect of increasing dose from 1g/Kg body weight to 3g/Kg body weight for all the selected fruit extracts. However fig and apple fruit extracts showed high repressive effects for high doses as compared to apricot and mulberry fruit extracts. None of these selected fruit extracts showed enhancive effect on glucose-6-phosphatase activity. All these fruits or their extracts can be used as antidiabetic dietary supplement for diabetes mellitus.

  10. Pax6 represses androgen receptor-mediated transactivation by inhibiting recruitment of the coactivator SPBP.

    Directory of Open Access Journals (Sweden)

    Julianne Elvenes

    Full Text Available The androgen receptor (AR has a central role in development and maintenance of the male reproductive system and in the etiology of prostate cancer. The transcription factor Pax6 has recently been reported to act as a repressor of AR and to be hypermethylated in prostate cancer cells. SPBP is a transcriptional regulator that previously has been shown to enhance the activity of Pax6. In this study we have identified SPBP to act as a transcriptional coactivator of AR. We also show that Pax6 inhibits SPBP-mediated enhancement of AR activity on the AR target gene probasin promoter, a repression that was partly reversed by increased expression of SPBP. Enhanced expression of Pax6 reduced the amount of SPBP associated with the probasin promoter when assayed by ChIP in HeLa cells. We mapped the interaction between both AR and SPBP, and AR and Pax6 to the DNA-binding domains of the involved proteins. Further binding studies revealed that Pax6 and SPBP compete for binding to AR. These results suggest that Pax6 represses AR activity by displacing and/or inhibiting recruitment of coactivators to AR target promoters. Understanding the mechanism for inhibition of AR coactivators can give rise to molecular targeted drugs for treatment of prostate cancer.

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

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    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.

  12. Mycobacterium leprae induces NF-κB-dependent transcription repression in human Schwann cells

    International Nuclear Information System (INIS)

    Pereira, Renata M.S.; Calegari-Silva, Teresa Cristina; Hernandez, Maristela O.; Saliba, Alessandra M.; Redner, Paulo; Pessolani, Maria Cristina V.; Sarno, Euzenir N.; Sampaio, Elizabeth P.; Lopes, Ulisses G.

    2005-01-01

    Mycobacterium leprae, the causative agent of leprosy, invades peripheral nerve Schwann cells, resulting in deformities associated with this disease. NF-κB is an important transcription factor involved in the regulation of host immune antimicrobial responses. We aimed in this work to investigate NF-κB signaling pathways in the human ST88-14 Schwannoma cell line infected with M. leprae. Gel shift and supershift assays indicate that two NF-κB dimers, p65/p50 and p50/p50, translocate to the nucleus in Schwann cells treated with lethally irradiated M. leprae. Consistent with p65/p50 and p50/p50 activation, we observed IκB-α degradation and reduction of p105 levels. The nuclear translocation of p50/p50 complex due to M. leprae treatment correlated with repression of NF-κB-driven transcription induced by TNF-α. Moreover, thalidomide inhibited p50 homodimer nuclear translocation induced by M. leprae and consequently rescues Schwann cells from NF-κB-dependent transcriptional repression. Here, we report for the first time that M. leprae induces NF-κB activation in Schwann cells and thalidomide is able to modulate this activation

  13. A Saccharomyces cerevisiae mitochondrial DNA fragment activates Reg1p-dependent glucose-repressible transcription in the nucleus.

    Science.gov (United States)

    Santangelo, G M; Tornow, J

    1997-12-01

    As part of an effort to identify random carbon-source-regulated promoters in the Saccharomyces cerevisiae genome, we discovered that a mitochondrial DNA fragment is capable of directing glucose-repressible expression of a reporter gene. This fragment (CR24) originated from the mitochondrial genome adjacent to a transcription initiation site. Mutational analyses identified a GC cluster within the fragment that is required for transcriptional induction. Repression of nuclear CR24-driven transcription required Reg1p, indicating that this mitochondrially derived promoter is a member of a large group of glucose-repressible nuclear promoters that are similarly regulated by Reg1p. In vivo and in vitro binding assays indicated the presence of factors, located within the nucleus and the mitochondria, that bind to the GC cluster. One or more of these factors may provide a regulatory link between the nucleus and mitochondria.

  14. Arabidopsis ETR1 and ERS1 Differentially Repress the Ethylene Response in Combination with Other Ethylene Receptor Genes1[W

    Science.gov (United States)

    Liu, Qian; Wen, Chi-Kuang

    2012-01-01

    The ethylene response is negatively regulated by a family of five ethylene receptor genes in Arabidopsis (Arabidopsis thaliana). The five members of the ethylene receptor family can physically interact and form complexes, which implies that cooperativity for signaling may exist among the receptors. The ethylene receptor gene mutations etr1-1(C65Y)(for ethylene response1-1), ers1-1(I62P) (for ethylene response sensor1-1), and ers1C65Y are dominant, and each confers ethylene insensitivity. In this study, the repression of the ethylene response by these dominant mutant receptor genes was examined in receptor-defective mutants to investigate the functional significance of receptor cooperativity in ethylene signaling. We showed that etr1-1(C65Y), but not ers1-1(I62P), substantially repressed various ethylene responses independent of other receptor genes. In contrast, wild-type receptor genes differentially supported the repression of ethylene responses by ers1-1(I62P); ETR1 and ETHYLENE INSENSITIVE4 (EIN4) supported ers1-1(I62P) functions to a greater extent than did ERS2, ETR2, and ERS1. The lack of both ETR1 and EIN4 almost abolished the repression of ethylene responses by ers1C65Y, which implied that ETR1 and EIN4 have synergistic effects on ers1C65Y functions. Our data indicated that a dominant ethylene-insensitive receptor differentially repressed ethylene responses when coupled with a wild-type ethylene receptor, which supported the hypothesis that the formation of a variety of receptor complexes may facilitate differential receptor signal output, by which ethylene responses can be repressed to different extents. We hypothesize that plants can respond to a broad ethylene concentration range and exhibit tissue-specific ethylene responsiveness with differential cooperation of the multiple ethylene receptors. PMID:22227969

  15. Regulating repression: roles for the sir4 N-terminus in linker DNA protection and stabilization of epigenetic states.

    Directory of Open Access Journals (Sweden)

    Stephanie Kueng

    Full Text Available Silent information regulator proteins Sir2, Sir3, and Sir4 form a heterotrimeric complex that represses transcription at subtelomeric regions and homothallic mating type (HM loci in budding yeast. We have performed a detailed biochemical and genetic analysis of the largest Sir protein, Sir4. The N-terminal half of Sir4 is dispensable for SIR-mediated repression of HM loci in vivo, except in strains that lack Yku70 or have weak silencer elements. For HM silencing in these cells, the C-terminal domain (Sir4C, residues 747-1,358 must be complemented with an N-terminal domain (Sir4N; residues 1-270, expressed either independently or as a fusion with Sir4C. Nonetheless, recombinant Sir4C can form a complex with Sir2 and Sir3 in vitro, is catalytically active, and has sedimentation properties similar to a full-length Sir4-containing SIR complex. Sir4C-containing SIR complexes bind nucleosomal arrays and protect linker DNA from nucleolytic digestion, but less effectively than wild-type SIR complexes. Consistently, full-length Sir4 is required for the complete repression of subtelomeric genes. Supporting the notion that the Sir4 N-terminus is a regulatory domain, we find it extensively phosphorylated on cyclin-dependent kinase consensus sites, some being hyperphosphorylated during mitosis. Mutation of two major phosphoacceptor sites (S63 and S84 derepresses natural subtelomeric genes when combined with a serendipitous mutation (P2A, which alone can enhance the stability of either the repressed or active state. The triple mutation confers resistance to rapamycin-induced stress and a loss of subtelomeric repression. We conclude that the Sir4 N-terminus plays two roles in SIR-mediated silencing: it contributes to epigenetic repression by stabilizing the SIR-mediated protection of linker DNA; and, as a target of phosphorylation, it can destabilize silencing in a regulated manner.

  16. SUN2 Modulates HIV-1 Infection and Latency through Association with Lamin A/C To Maintain the Repressive Chromatin.

    Science.gov (United States)

    Sun, Wei-Wei; Jiao, Shi; Sun, Li; Zhou, Zhaocai; Jin, Xia; Wang, Jian-Hua

    2018-05-01

    The postintegrational latency of HIV-1 is characterized by reversible silencing of long terminal repeat (LTR)-driven transcription of the HIV genome. It is known that the formation of repressive chromatin at the 5'-LTR of HIV-1 proviral DNA impedes viral transcription by blocking the recruitment of positive transcription factors. How the repressive chromatin is formed and modulated during HIV-1 infection remains elusive. Elucidation of which chromatin reassembly factor mediates the reorganization of chromatin is likely to facilitate the understanding of the host's modulation of HIV-1 transcription and latency. Here we revealed that "Sad1 and UNC84 domain containing 2" (SUN2), an inner nuclear membrane protein, maintained the repressive chromatin and inhibited HIV LTR-driven transcription of proviral DNA through an association with lamin A/C. Specifically, lamin A/C tethered SUN2 to the nucleosomes 1 and 2 of the HIV-1 5'-LTR to block the initiation and elongation of HIV-1 transcription. SUN2 knockdown converted chromatin to an active form and thus enhanced the phosphorylation of RNA polymerase II and its recruitment to the 5'-LTR HIV-1 proviral DNA, leading to reactivation of HIV-1 from latency. Conversely, the exogenous factors such as tumor necrosis factor alpha (TNF-α) induced reactivation, and the replication of HIV-1 led to the disassociation between SUN2 and lamin A/C, suggesting that disruption of the association between SUN2 and lamin A/C to convert the repressive chromatin to the active form might be a prerequisite for the initiation of HIV-1 transcription and replication. Together, our findings indicate that SUN2 is a novel chromatin reassembly factor that helps to maintain chromatin in a repressive state and consequently inhibits HIV-1 transcription. IMPORTANCE Despite the successful use of scores of antiretroviral drugs, HIV latency poses a major impediment to virus eradication. Elucidation of the mechanism of latency facilitates the discovery of new

  17. Wild type p53 transcriptionally represses the SALL2 transcription factor under genotoxic stress.

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    Carlos Farkas

    Full Text Available SALL2- a member of the Spalt gene family- is a poorly characterized transcription factor found deregulated in various cancers, which suggests it plays a role in the disease. We previously identified SALL2 as a novel interacting protein of neurotrophin receptors and showed that it plays a role in neuronal function, which does not necessarily explain why or how SALL2 is deregulated in cancer. Previous evidences indicate that SALL2 gene is regulated by the WT1 and AP4 transcription factors. Here, we identified SALL2 as a novel downstream target of the p53 tumor suppressor protein. Bioinformatic analysis of the SALL2 gene revealed several putative p53 half sites along the promoter region. Either overexpression of wild-type p53 or induction of the endogenous p53 by the genotoxic agent doxorubicin repressed SALL2 promoter activity in various cell lines. However R175H, R249S, and R248W p53 mutants, frequently found in the tumors of cancer patients, were unable to repress SALL2 promoter activity, suggesting that p53 specific binding to DNA is important for the regulation of SALL2. Electrophoretic mobility shift assay demonstrated binding of p53 to one of the identified p53 half sites in the Sall2 promoter, and chromatin immunoprecipitation analysis confirmed in vivo interaction of p53 with the promoter region of Sall2 containing this half site. Importantly, by using a p53ER (TAM knockin model expressing a variant of p53 that is completely dependent on 4-hydroxy-tamoxifen for its activity, we show that p53 activation diminished SALL2 RNA and protein levels during genotoxic cellular stress in primary mouse embryo fibroblasts (MEFs and radiosensitive tissues in vivo. Thus, our finding indicates that p53 represses SALL2 expression in a context-specific manner, adding knowledge to the understanding of SALL2 gene regulation, and to a potential mechanism for its deregulation in cancer.

  18. ZEB1 limits adenoviral infectability by transcriptionally repressing the Coxsackie virus and Adenovirus Receptor

    Directory of Open Access Journals (Sweden)

    Lacher Markus D

    2011-07-01

    Full Text Available Abstract Background We have previously reported that RAS-MEK (Cancer Res. 2003 May 1;63(9:2088-95 and TGF-β (Cancer Res. 2006 Feb 1;66(3:1648-57 signaling negatively regulate coxsackie virus and adenovirus receptor (CAR cell-surface expression and adenovirus uptake. In the case of TGF-β, down-regulation of CAR occurred in context of epithelial-to-mesenchymal transition (EMT, a process associated with transcriptional repression of E-cadherin by, for instance, the E2 box-binding factors Snail, Slug, SIP1 or ZEB1. While EMT is crucial in embryonic development, it has been proposed to contribute to the formation of invasive and metastatic carcinomas by reducing cell-cell contacts and increasing cell migration. Results Here, we show that ZEB1 represses CAR expression in both PANC-1 (pancreatic and MDA-MB-231 (breast human cancer cells. We demonstrate that ZEB1 physically associates with at least one of two closely spaced and conserved E2 boxes within the minimal CAR promoter here defined as genomic region -291 to -1 relative to the translational start ATG. In agreement with ZEB1's established role as a negative regulator of the epithelial phenotype, silencing its expression in MDA-MB-231 cells induced a partial Mesenchymal-to-Epithelial Transition (MET characterized by increased levels of E-cadherin and CAR, and decreased expression of fibronectin. Conversely, knockdown of ZEB1 in PANC-1 cells antagonized both the TGF-β-induced down-regulation of E-cadherin and CAR and the reduction of adenovirus uptake. Interestingly, even though ZEB1 clearly contributes to the TGF-β-induced mesenchymal phenotype of PANC-1 cells, TGF-β did not seem to affect ZEB1's protein levels or subcellular localization. These findings suggest that TGF-β may inhibit CAR expression by regulating factor(s that cooperate with ZEB1 to repress the CAR promoter, rather than by regulating ZEB1 expression levels. In addition to the negative E2 box-mediated regulation the minimal

  19. Resveratrol represses YKL-40 expression in human glioma U87 cells

    International Nuclear Information System (INIS)

    Zhang, Wei; Tamiya, Takashi; Murao, Koji; Zhang, Xiang; Matsumoto, Kensuke; Diah, Suwarni; Okada, Masaki; Miyake, Keisuke; Kawai, Nobuyuki; Fei, Zhou

    2010-01-01

    Glioblastoma multiforme (GBM) is the most malignant intracranial tumour that develops in both adults and children. Microarray gene analyses have confirmed that the human YKL-40 gene is one of the most over-expressed genes in these tumours but not in normal brain tissue. Clinical studies have shown that serum YKL-40 levels are positively correlated with tumour burden in addition to being an independent prognostic factor of a short relapse-free interval as well as short overall survival in patients with various cancers. Our previous study revealed that YKL-40 was closely correlated with the pathological grades of human primary astrocytomas and played a crucial role in glioma cell proliferation. Hence, YKL-40 could be an attractive target in the design of anti-cancer therapies. Cell viability and invasion assays were performed to detect the cell proliferation and invasive ability of U87 cells induced by resveratrol (3, 5, 4'-trihydroxystilbene; Res) or YKL-40 small-interfering RNAs (siRNAs). In addition, the luciferase assay, real-time RT-PCR, western blotting, and ELISA were used to measure YKL-40 promoter activity, mRNA, and protein expression, respectively. The expressions of phosphor-ERK1/2 and ERK1/2 were determined by western blotting. Res inhibited U87 cell proliferation and invasion in vitro and repressed YKL-40 in U87 cells by decreasing the activity of its promoter and reducing mRNA transcription and protein expression in vitro. YKL-40 siRNA treatment also impaired the invasiveness of U87 cells. When U87 cells were cultured with 20 μM PD98059 (an ERK1/2 inhibitor) alone, with 20 μM PD98059 and 100 μM Res, or with 100 μM Res alone for 48 h, YKL-40 protein expression decreased most significantly in the Res-treated group. PD98059 partially reversed the decrease of YKL-40 protein expression induced by Res. Furthermore, phosphor-ERK1/2 expression was reduced by Res treatment in a time-dependent manner. We demonstrated for the first time that Res

  20. Microarray analysis of early adipogenesis in C3H10T1/2 cells: Cooperative inhibitory effects of growth factors and 2,3,7,8-tetrachlorodibenzo-p-dioxin

    International Nuclear Information System (INIS)

    Hanlon, Paul R.; Cimafranca, Melissa A.; Liu Xueqing; Cho, Young C.; Jefcoate, Colin R.

    2005-01-01

    C3H10T1/2 mouse embryo fibroblasts differentiate into adipocytes when stimulated by a standard hormonal mixture (IDMB). 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), via the aryl hydrocarbon receptor (AhR), inhibits induction of the key adipogenic gene peroxisome proliferator-activated receptor γ (PPARγ) and subsequent adipogenesis. This TCDD-mediated inhibition requires activation of the extracellular signal-regulated kinase (ERK) pathway, which can be accomplished by serum, epidermal growth factor (EGF), or fibroblast growth factor (FGF). In the absence of serum or growth factors, IDMB induced adipogenesis without mitosis. Microarray analysis identified 200 genes that exhibited expression changes of at least twofold after 24 h of IDMB treatment. This time precedes most PPARγ stimulation but follows the period of TCDD/ERK cooperation and periods of increased cell contraction and DNA synthesis. Functionally related gene clusters include genes associated with cell structure, triglyceride and cholesterol metabolism, oxidative regulation, and secreted proteins. In the absence of growth factors TCDD inhibited 30% of these IDMB responses without inhibiting the process of differentiation. A combination of EGF and TCDD that blocks differentiation cooperatively blocked a further 44 IDMB-responsive genes, most of which have functional links to differentiation, including PPARγ. Cell cycle regulators that are stimulated by EGF were substantially inhibited by IDMB but these responses were unaffected by TCDD. By contrast, TCDD and EGF cooperatively reversed IDMB-induced changes in cell adhesion complexes immediately prior to increases in PPARγ1 expression. Changes in adhesion-linked signaling may play a key role in TCDD affects on differentiation

  1. Inhibition of Irvingia gabonensis seed extract (OB131 on adipogenesis as mediated via down regulation of the PPARgamma and Leptin genes and up-regulation of the adiponectin gene

    Directory of Open Access Journals (Sweden)

    Blum Kenneth

    2008-11-01

    Full Text Available Abstract Background Endeavors to manage obesity have been heavily reliant on controlling energy intake and expenditure equilibrium, but have failed to curtail the overweight and obesity epidemic. This dynamic equilibrium is more complex than originally postulated and is influenced by lifestyle, calorie and nutrient intake, reward cravings and satiation, energy metabolism, stress response capabilities, immune metabolism and genetics. Fat metabolism is an important indicator of how efficiently and to what extent these factors are competently integrating. We investigated whether an Irvingia gabonensis seed extract (IGOB131 would provide a more beneficial comprehensive approach influencing multiple mechanisms and specifically PPAR gamma, leptin and adiponectin gene expressions, important in anti-obesity strategies. Methods Using murine 3T3-L1 adipocytes as a model for adipose cell biology research, the effects of IGOB131 were investigated on PPAR gamma, adiponectin, and leptin. These adipocytes were harvested 8 days after the initiation of differentiation and treated with 0 to 250 microM of IGOB131 for 12 and 24 h at 37 degree C in a humidified 5 percent CO2 incubator. The relative expression of PPAR gamma, adiponectin, and leptin in 3T3-L1 adipocytes was quantified densitometrically using the software LabWorks 4.5, and calculated according to the reference bands of beta-actin. Results The IGOB131 significantly inhibited adipogenesis in adipocytes. The effect appears to be mediated through the down-regulated expression of adipogenic transcription factors (PPAR gamma [P less than 0.05] and adipocyte-specific proteins (leptin [P less than 0.05], and by up-regulated expression of adiponectin [P less than 0.05]. Conclusion IGOB131 may play an important multifaceted role in the control of adipogenesis and have further implications in in-vivo anti obesity effects by targeting the PPAR gamma gene, a known contributory factor to obesity in humans.

  2. A systems biology approach to study glucose repression in the yeast Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Westergaard, Steen Lund; Soberano de Oliveira, Ana Paula; Bro, Christoffer

    2007-01-01

    in repression of a wide range of genes involved to utilization of alternative carbon sources. In this work, we applied a systems biology approach to study the interaction between these two pathways. Through genome-wide transcription analysis of strains with disruption of HXK2, GRR1, MIG1, the combination of MIG......1 and MIG2, and the parentel strain, we identified 393 genes to have significantly changed expression levels. To identify co-regulation patterns in the different strains we applied principal component analysis. Disruption of either GRR1 or HXK2 were both found to have profound effects...... reporter metabolites, and found that there is a high degree of consistency between the identified reporter metabolites and the physiological effects observed in the different mutants . Our systems biology approach points to close interaction between the two pathways, and our metabolism driven analysis...

  3. Teaching microbial physiology using glucose repression phenomenon in baker's yeast as an examplele

    DEFF Research Database (Denmark)

    Vijayendran, Raghavendran; Nielsen, Jens; Olsson, Lisbeth

    2005-01-01

    The yeast Saccharomyces cerevisiae has been used by human beings since ancient times for its ability to convert sugar to alcohol. Continual exposure to glucose in the natural environment for innumerable generations has probably enabled S. cerevisiae to grow in fermentative mode on sugars by switc......The yeast Saccharomyces cerevisiae has been used by human beings since ancient times for its ability to convert sugar to alcohol. Continual exposure to glucose in the natural environment for innumerable generations has probably enabled S. cerevisiae to grow in fermentative mode on sugars...... by switching off the genes responsible for respiration even under aerobic conditions. This phenomenon is referred to as the Crabtree effect. The present review focuses on glucose repression in S. cerevisiae from a physiological perspective. Physiological studies presented involve batch and chemostat...

  4. An X11alpha/FSBP complex represses transcription of the GSK3beta gene promoter.

    LENUS (Irish Health Repository)

    Lau, Kwok-Fai

    2010-08-04

    X11alpha is a neuronal adaptor protein that interacts with the amyloid precursor protein (APP) through a centrally located phosphotyrosine binding domain to inhibit the production of Abeta peptide that is deposited in Alzheimer\\'s disease brains. X11alpha also contains two C-terminal postsynaptic density-95, large discs, zona occludens 1 (PDZ) domains, and we show here that through its PDZ domains, X11alpha interacts with a novel transcription factor, fibrinogen silencer binding protein. Moreover, we show that an X11alpha\\/fibrinogen silencer binding protein complex signals to the nucleus to repress glycogen synthase kinase-3beta promoter activity. Glycogen synthase kinase-3beta is a favoured candidate kinase for phosphorylating tau in Alzheimer\\'s disease. Our findings show a new function for X11alpha that may impact on Alzheimer\\'s disease pathogenesis.

  5. La repression sexuelle: Un moteur du progres occidental, de 1500 a nos jours?

    Directory of Open Access Journals (Sweden)

    Robert Muchembled

    2017-08-01

    Full Text Available In this study the author examines the development and the impact of the strong sexual repression which settled in the heart of the Western Civilization around the middle of the XVI century and which really loosened only starting from the 1960’s. Within the founding tension between the libido of the person and the collective ideals, this process constantly developed during this long period, creating a strong effort of sublimation, under the different successive cultural expressions in relation to the religion, Enlightenment, medicine of the XIX century and the capitalist market. From 1960 to our days, a new approach to the Western sexuality has been developed, testifying about the profound cultural and societal movements.

  6. REST mediates androgen receptor actions on gene repression and predicts early recurrence of prostate cancer

    DEFF Research Database (Denmark)

    Svensson, Charlotte; Ceder, Jens; Iglesias Gato, Diego

    2014-01-01

    The androgen receptor (AR) is a key regulator of prostate tumorgenesis through actions that are not fully understood. We identified the repressor element (RE)-1 silencing transcription factor (REST) as a mediator of AR actions on gene repression. Chromatin immunoprecipitation showed that AR binds...... in cell cycle progression, including Aurora Kinase A, that has previously been implicated in the growth of NE-like castration-resistant tumors. The analysis of prostate cancer tissue microarrays revealed that tumors with reduced expression of REST have higher probability of early recurrence, independently...... of their Gleason score. The demonstration that REST modulates AR actions in prostate epithelia and that REST expression is negatively correlated with disease recurrence after prostatectomy, invite a deeper characterization of its role in prostate carcinogenesis....

  7. Viral MicroRNAs Repress the Cholesterol Pathway, and 25-Hydroxycholesterol Inhibits Infection.

    Science.gov (United States)

    Serquiña, Anna K P; Kambach, Diane M; Sarker, Ontara; Ziegelbauer, Joseph M

    2017-07-11

    From various screens, we found that Kaposi's sarcoma-associated herpesvirus (KSHV) viral microRNAs (miRNAs) target several enzymes in the mevalonate/cholesterol pathway. 3-Hydroxy-3-methylglutaryl-coenzyme A (CoA) synthase 1 (HMGCS1), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR [a rate-limiting step in the mevalonate pathway]), and farnesyl-diphosphate farnesyltransferase 1 (FDFT1 [a committed step in the cholesterol branch]) are repressed by multiple KSHV miRNAs. Transfection of viral miRNA mimics in primary endothelial cells (human umbilical vein endothelial cells [HUVECs]) is sufficient to reduce intracellular cholesterol levels; however, small interfering RNAs (siRNAs) targeting only HMGCS1 did not reduce cholesterol levels. This suggests that multiple targets are needed to perturb this tightly regulated pathway. We also report here that cholesterol levels were decreased in de novo -infected HUVECs after 7 days. This reduction is at least partially due to viral miRNAs, since the mutant form of KSHV lacking 10 of the 12 miRNA genes had increased cholesterol compared to wild-type infections. We hypothesized that KSHV is downregulating cholesterol to suppress the antiviral response by a modified form of cholesterol, 25-hydroxycholesterol (25HC). We found that the cholesterol 25-hydroxylase (CH25H) gene, which is responsible for generating 25HC, had increased expression in de novo -infected HUVECs but was strongly suppressed in long-term latently infected cell lines. We found that 25HC inhibits KSHV infection when added exogenously prior to de novo infection. In conclusion, we found that multiple KSHV viral miRNAs target enzymes in the mevalonate pathway to modulate cholesterol in infected cells during latency. This repression of cholesterol levels could potentially be beneficial to viral infection by decreasing the levels of 25HC. IMPORTANCE A subset of viruses express unique microRNAs (miRNAs), which act like cellular miRNAs to generally repress host gene

  8. High-power CO laser with RF discharge for isotope separation employing condensation repression

    Science.gov (United States)

    Baranov, I. Ya.; Koptev, A. V.

    2008-10-01

    High-power CO laser can be the effective tool in such applications as isotope separation using the free-jet CRISLA method. The way of transfer from CO small-scale experimental installation to industrial high-power CO lasers is proposed through the use of a low-current radio-frequency (RF) electric discharge in a supersonic stream without an electron gun. The calculation model of scaling CO laser with RF discharge in supersonic stream was developed. The developed model allows to calculate parameters of laser installation and optimize them with the purpose of reception of high efficiency and low cost of installation as a whole. The technical decision of industrial CO laser for isotope separation employing condensation repression is considered. The estimated cost of laser is some hundred thousand dollars USA and small sizes of laser head give possibility to install it in any place.

  9. Effect of amino acids on the repression of alkaline protease synthesis in haloalkaliphilic Nocardiopsis dassonvillei

    Directory of Open Access Journals (Sweden)

    Amit K. Sharma

    2016-12-01

    Full Text Available A newly isolated salt-tolerant alkaliphilic actinomycete, Nocardiopsis dassonvillei strain OK-18 grows on mineral salts medium with glucose as carbon source. It also grows and produces protease with amino acids as sole carbon source. The synthesis of extracellular alkaline protease parallel to growth was repressible by substrate concentrations. The absolute production of the protease was delinked with growth under nutritional stress, as protease production was high, despite poor growth. When amino acids served as the sole source of carbon and nitrogen, the enzyme production was significantly controlled by the number of amino acids. Maximal protease production was achieved with proline, asparagine, tyrosine, alanine, methionine and valine as sole source of carbon and nitrogen in minimal medium. With the increasing number of different amino acids in the presence and absence of glucose, the protease production was synergistically lower as compared to complex medium.

  10. Churchill regulates cell movement and mesoderm specification by repressing Nodal signaling

    Directory of Open Access Journals (Sweden)

    Mentzer Laura

    2007-11-01

    Full Text Available Abstract Background Cell movements are essential to the determination of cell fates during development. The zinc-finger transcription factor, Churchill (ChCh has been proposed to regulate cell fate by regulating cell movements during gastrulation in the chick. However, the mechanism of action of ChCh is not understood. Results We demonstrate that ChCh acts to repress the response to Nodal-related signals in zebrafish. When ChCh function is abrogated the expression of mesodermal markers is enhanced while ectodermal markers are expressed at decreased levels. In cell transplant assays, we observed that ChCh-deficient cells are more motile than wild-type cells. When placed in wild-type hosts, ChCh-deficient cells often leave the epiblast, migrate to the germ ring and are later found in mesodermal structures. We demonstrate that both movement of ChCh-compromised cells to the germ ring and acquisition of mesodermal character depend on the ability of the donor cells to respond to Nodal signals. Blocking Nodal signaling in the donor cells at the levels of Oep, Alk receptors or Fast1 inhibited migration to the germ ring and mesodermal fate change in the donor cells. We also detect additional unusual movements of transplanted ChCh-deficient cells which suggests that movement and acquisition of mesodermal character can be uncoupled. Finally, we demonstrate that ChCh is required to limit the transcriptional response to Nodal. Conclusion These data establish a broad role for ChCh in regulating both cell movement and Nodal signaling during early zebrafish development. We show that chch is required to limit mesodermal gene expression, inhibit Nodal-dependant movement of presumptive ectodermal cells and repress the transcriptional response to Nodal signaling. These findings reveal a dynamic role for chch in regulating cell movement and fate during early development.

  11. Evidence against translational repression by the carboxyltransferase component of Escherichia coli acetyl coenzyme A carboxylase.

    Science.gov (United States)

    Smith, Alexander C; Cronan, John E

    2014-11-01

    In Escherichia coli, synthesis of the malonyl coenzyme A (malonyl-CoA) required for membrane lipid synthesis is catalyzed by acetyl-CoA carboxylase, a large complex composed of four subunits. The subunit proteins are needed in a defined stoichiometry, and it remains unclear how such production is achieved since the proteins are encoded at three different loci. Meades and coworkers (G. Meades, Jr., B. K. Benson, A. Grove, and G. L. Waldrop, Nucleic Acids Res. 38:1217-1227, 2010, doi:http://dx.doi.org/10.1093/nar/gkp1079) reported that coordinated production of the AccA and AccD subunits is due to a translational repression mechanism exerted by the proteins themselves. The AccA and AccD subunits form the carboxyltransferase (CT) heterotetramer that catalyzes the second partial reaction of acetyl-CoA carboxylase. Meades et al. reported that CT tetramers bind the central portions of the accA and accD mRNAs and block their translation in vitro. However, long mRNA molecules (500 to 600 bases) were required for CT binding, but such long mRNA molecules devoid of ribosomes seemed unlikely to exist in vivo. This, plus problematical aspects of the data reported by Meades and coworkers, led us to perform in vivo experiments to test CT tetramer-mediated translational repression of the accA and accD mRNAs. We report that increased levels of CT tetramer have no detectable effect on translation of the CT subunit mRNAs. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  12. MicroRNA-193b represses cell proliferation and regulates cyclin D1 in melanoma.

    Science.gov (United States)

    Chen, Jiamin; Feilotter, Harriet E; Paré, Geneviève C; Zhang, Xiao; Pemberton, Joshua G W; Garady, Cherif; Lai, Dulcie; Yang, Xiaolong; Tron, Victor A

    2010-05-01

    Cutaneous melanoma is an aggressive form of human skin cancer characterized by high metastatic potential and poor prognosis. To better understand the role of microRNAs (miRNAs) in melanoma, the expression of 470 miRNAs was profiled in tissue samples from benign nevi and metastatic melanomas. We identified 31 miRNAs that were differentially expressed (13 up-regulated and 18 down-regulated) in metastatic melanomas relative to benign nevi. Notably, miR-193b was significantly down-regulated in the melanoma tissues examined. To understand the role of miR-193b in melanoma, functional studies were undertaken. Overexpression of miR-193b in melanoma cell lines repressed cell proliferation. Gene expression profiling identified 314 genes down-regulated by overexpression of miR-193b in Malme-3M cells. Eighteen of these down-regulated genes, including cyclin D1 (CCND1), were also identified as putative miR-193b targets by TargetScan. Overexpression of miR-193b in Malme-3M cells down-regulated CCND1 mRNA and protein by > or = 50%. A luciferase reporter assay confirmed that miR-193b directly regulates CCND1 by binding to the 3'untranslated region of CCND1 mRNA. These studies indicate that miR-193b represses cell proliferation and regulates CCND1 expression and suggest that dysregulation of miR-193b may play an important role in melanoma development.

  13. Sox2 Is an Androgen Receptor-Repressed Gene That Promotes Castration-Resistant Prostate Cancer

    Science.gov (United States)

    Kregel, Steven; Kiriluk, Kyle J.; Rosen, Alex M.; Cai, Yi; Reyes, Edwin E.; Otto, Kristen B.; Tom, Westin; Paner, Gladell P.; Szmulewitz, Russell Z.; Vander Griend, Donald J.

    2013-01-01

    Despite advances in detection and therapy, castration-resistant prostate cancer continues to be a major clinical problem. The aberrant activity of stem cell pathways, and their regulation by the Androgen Receptor (AR), has the potential to provide insight into novel mechanisms and pathways to prevent and treat advanced, castrate-resistant prostate cancers. To this end, we investigated the role of the embryonic stem cell regulator Sox2 [SRY (sex determining region Y)-box 2] in normal and malignant prostate epithelial cells. In the normal prostate, Sox2 is expressed in a portion of basal epithelial cells. Prostate tumors were either Sox2-positive or Sox2-negative, with the percentage of Sox2-positive tumors increasing with Gleason Score and metastases. In the castration-resistant prostate cancer cell line CWR-R1, endogenous expression of Sox2 was repressed by AR signaling, and AR chromatin-IP shows that AR binds the enhancer element within the Sox2 promoter. Likewise, in normal prostate epithelial cells and human embryonic stem cells, increased AR signaling also decreases Sox2 expression. Resistance to the anti-androgen MDV3100 results in a marked increase in Sox2 expression within three prostate cancer cell lines, and in the castration-sensitive LAPC-4 prostate cancer cell line ectopic expression of Sox2 was sufficient to promote castration-resistant tumor formation. Loss of Sox2 expression in the castration-resistant CWR-R1 prostate cancer cell line inhibited cell growth. Up-regulation of Sox2 was not associated with increased CD133 expression but was associated with increased FGF5 (Fibroblast Growth Factor 5) expression. These data propose a model of elevated Sox2 expression due to loss of AR-mediated repression during castration, and consequent castration-resistance via mechanisms not involving induction of canonical embryonic stem cell pathways. PMID:23326489

  14. Lysogeny with Shiga Toxin 2-Encoding Bacteriophages Represses Type III Secretion in Enterohemorrhagic Escherichia coli

    Science.gov (United States)

    Xu, Xuefang; McAteer, Sean P.; Tree, Jai J.; Shaw, Darren J.; Wolfson, Eliza B. K.; Beatson, Scott A.; Roe, Andrew J.; Allison, Lesley J.; Chase-Topping, Margo E.; Mahajan, Arvind; Tozzoli, Rosangela; Woolhouse, Mark E. J.; Morabito, Stefano; Gally, David L.

    2012-01-01

    Lytic or lysogenic infections by bacteriophages drive the evolution of enteric bacteria. Enterohemorrhagic Escherichia coli (EHEC) have recently emerged as a significant zoonotic infection of humans with the main serotypes carried by ruminants. Typical EHEC strains are defined by the expression of a type III secretion (T3S) system, the production of Shiga toxins (Stx) and association with specific clinical symptoms. The genes for Stx are present on lambdoid bacteriophages integrated into the E. coli genome. Phage type (PT) 21/28 is the most prevalent strain type linked with human EHEC infections in the United Kingdom and is more likely to be associated with cattle shedding high levels of the organism than PT32 strains. In this study we have demonstrated that the majority (90%) of PT 21/28 strains contain both Stx2 and Stx2c phages, irrespective of source. This is in contrast to PT 32 strains for which only a minority of strains contain both Stx2 and 2c phages (28%). PT21/28 strains had a lower median level of T3S compared to PT32 strains and so the relationship between Stx phage lysogeny and T3S was investigated. Deletion of Stx2 phages from EHEC strains increased the level of T3S whereas lysogeny decreased T3S. This regulation was confirmed in an E. coli K12 background transduced with a marked Stx2 phage followed by measurement of a T3S reporter controlled by induced levels of the LEE-encoded regulator (Ler). The presence of an integrated Stx2 phage was shown to repress Ler induction of LEE1 and this regulation involved the CII phage regulator. This repression could be relieved by ectopic expression of a cognate CI regulator. A model is proposed in which Stx2-encoding bacteriophages regulate T3S to co-ordinate epithelial cell colonisation that is promoted by Stx and secreted effector proteins. PMID:22615557

  15. Melatonin inhibits proliferation and invasion via repression of miRNA-155 in glioma cells.

    Science.gov (United States)

    Gu, Junyi; Lu, Zhongsheng; Ji, Chenghong; Chen, Yuchao; Liu, Yuzhao; Lei, Zhe; Wang, Longqiang; Zhang, Hong-Tao; Li, Xiangdong

    2017-09-01

    Melatonin, an indolamine mostly synthesized in the pineal gland, exerts the anti-cancer effect by various mechanisms in glioma cells. Our previous study showed that miR-155 promoted glioma cell proliferation and invasion. However, the question of whether melatonin may inhibit glioma by regulating miRNAs has not yet been addressed. In this study, we found that melatonin (100μM, 1μM and 1nM) significantly inhibited the expression of miR-155 in human glioma cell lines U87, U373 and U251. Especially, the lowest expression of miR-155 was detected in 1μM melatonin-treated glioma cells. Melatonin (1μM) inhibits cell proliferation of U87 by promoting cell apoptosis. Nevertheless, melatonin had no effect on cell cycle distribution of U87 cells. Moreover, U87 cells treated with 1μM melatonin presented significantly lower migration and invasion ability when compared with control cells. Importantly, melatonin inhibited c-MYB expression, and c-MYB knockdown reduced miR-155 expression and migration and invasion in U87 cells. Taken together, for the first time, our findings show that melatonin inhibits miR-155 expression and thereby represses glioma cell proliferation, migration and invasion, and suggest that melatonin may downregulate the expression of miR-155 via repression of c-MYB. This will provide a theoretical basis for revealing the anti-glioma mechanisms of melatonin. Copyright © 2017. Published by Elsevier Masson SAS.

  16. Sphingosine 1-phosphate induces neutrophil chemoattractant IL-8: repression by steroids.

    Directory of Open Access Journals (Sweden)

    Md Mostafizur Rahman

    Full Text Available The bioactive sphingolipid sphingosine 1-phosphate (S1P is found in increased amounts in the airways of asthmatics. S1P can regulate airway smooth muscle functions associated with asthmatic inflammation and remodeling, including cytokine secretion. To date however, whether S1P induces secretion of an important chemokine responsible for neutrophilia in airway inflammation--IL-8--was unexplored. The aim of this study was to investigate whether S1P induces IL-8 gene expression and secretion to enhance neutrophil chemotaxis in vitro, as well as examine the molecular mechanisms responsible for repression by the corticosteroid dexamethasone. We show that S1P upregulates IL-8 secretion from ASM cells and enhance neutrophil chemotaxis in vitro. The corticosteroid dexamethasone significantly represses IL-8 mRNA expression and protein secretion in a concentration- and time-dependent manner. Additionally, we reveal that S1P-induced IL-8 secretion is p38 MAPK and ERK-dependent and that these key phosphoproteins act on the downstream effector mitogen- and stress-activated kinase 1 (MSK1 to control secretion of the neutrophil chemoattractant cytokine IL-8. The functional relevance of this in vitro data was demonstrated by neutrophil chemotaxis assays where S1P-induced effects can be significantly attenuated by pretreatment with dexamethasone, pharmacological inhibition of p38 MAPK- or ERK-mediated pathways, or by knocking down MSK-1 with siRNA. Taken together, our study reveals the molecular pathways responsible for IL-8 secretion from ASM cells in response to S1P and indicates ways in which the impact on IL-8-driven neutrophilia may be lessened.

  17. Repression of Salmonella enterica phoP Expression by Small Molecules from Physiological Bile

    Science.gov (United States)

    Antunes, L. Caetano M.; Wang, Melody; Andersen, Sarah K.; Ferreira, Rosana B. R.; Kappelhoff, Reinhild; Han, Jun; Borchers, Christoph H.

    2012-01-01

    Infection with Salmonella enterica serovar Typhi in humans causes the life-threatening disease typhoid fever. In the laboratory, typhoid fever can be modeled through the inoculation of susceptible mice with Salmonella enterica serovar Typhimurium. Using this murine model, we previously characterized the interactions between Salmonella Typhimurium and host cells in the gallbladder and showed that this pathogen can successfully invade gallbladder epithelial cells and proliferate. Additionally, we showed that Salmonella Typhimurium can use bile phospholipids to grow at high rates. These abilities are likely important for quick colonization of the gallbladder during typhoid fever and further pathogen dissemination through fecal shedding. To further characterize the interactions between Salmonella and the gallbladder environment, we compared the transcriptomes of Salmonella cultures grown in LB broth or physiological murine bile. Our data showed that many genes involved in bacterial central metabolism are affected by bile, with the citric acid cycle being repressed and alternative respiratory systems being activated. Additionally, our study revealed a new aspect of Salmonella interactions with bile through the identification of the global regulator phoP as a bile-responsive gene. Repression of phoP expression could also be achieved using physiological, but not commercial, bovine bile. The biological activity does not involve PhoPQ sensing of a bile component and is not caused by bile acids, the most abundant organic components of bile. Bioactivity-guided purification allowed the identification of a subset of small molecules from bile that can elicit full activity; however, a single compound with phoP inhibitory activity could not be isolated, suggesting that multiple molecules may act in synergy to achieve this effect. Due to the critical role of phoP in Salmonella virulence, further studies in this area will likely reveal aspects of the interaction between Salmonella

  18. Host and bacterial proteins that repress recruitment of LC3 to Shigella early during infection.

    Directory of Open Access Journals (Sweden)

    Leigh A Baxt

    Full Text Available Shigella spp. are intracytosolic gram-negative pathogens that cause disease by invasion and spread through the colonic mucosa, utilizing host cytoskeletal components to form propulsive actin tails. We have previously identified the host factor Toca-1 as being recruited to intracellular S. flexneri and being required for efficient bacterial actin tail formation. We show that at early times during infection (40 min., the type three-secreted effector protein IcsB recruits Toca-1 to intracellular bacteria and that recruitment of Toca-1 is associated with repression of recruitment of LC3, as well as with repression of recruitment of the autophagy marker NDP52, around these intracellular bacteria. LC3 is best characterized as a marker of autophagosomes, but also marks phagosomal membranes in the process LC3-associated phagocytosis. IcsB has previously been demonstrated to be required for S. flexneri evasion of autophagy at late times during infection (4-6 hr by inhibiting binding of the autophagy protein Atg5 to the Shigella surface protein IcsA (VirG. Our results suggest that IcsB and Toca-1 modulation of LC3 recruitment restricts LC3-associated phagocytosis and/or LC3 recruitment to vacuolar membrane remnants. Together with published results, our findings suggest that IcsB inhibits innate immune responses in two distinct ways, first, by inhibiting LC3-associated phagocytosis and/or LC3 recruitment to vacuolar membrane remnants early during infection, and second, by inhibiting autophagy late during infection.

  19. Political repression, civil society and the politics of responding to AIDS in the BRICS nations.

    Science.gov (United States)

    Gómez, Eduardo J; Harris, Joseph

    2016-02-01

    The policy responses to human immunodeficiency virus/acquired immune deficiency syndrome (AIDS) in the Brazil, Russia, India, China and South Africa (BRICS) nations have played out amid radically different political environments that have shaped state-civil society relations in critical ways. In contrasting these different environments, this article offers the first comparison of the policy response to AIDS in the BRICS nations and seeks to understand the way in which political context matters for conditioning the response to a major epidemic. Using a comparative historical approach, we find that while collaborative state-civil society relations have produced an aggressive response and successful outcomes in Brazil, democratic openness and state-civil society engagement has not necessarily correlated with an aggressive response or better outcomes in the other cases. Response to the epidemic has been worst by far in democratic South Africa, followed by Russia, where in the former, denialism and antagonistic state-civil society relations fuelled a delayed response and proved extremely costly in terms of human lives. In Russia, a lack of civil societal opportunity for mobilization and non-governmental organization (NGO) growth, political centralization and the state's unwillingness to work with NGOs led to an ineffective government response. Top-down bureaucratic rule and a reluctance to fully engage civil society in democratic India substantially delayed the state's efforts to engage in a successful partnership with NGOs. Nevertheless, China has done surprisingly well, in spite of its repressive approach and narrow engagement with civil society. And in all cases, we find the relationship between state and civil society to be evolving over time in important ways. These findings suggest the need for more research on the links between democratic openness, political repression and policy responses to epidemics. © The Author 2015. Published by Oxford University Press in

  20. Discrimination of Korean ginseng (Panax ginseng Meyer cultivar Chunpoong and American ginseng (Panax quinquefolius using the auxin repressed protein gene

    Directory of Open Access Journals (Sweden)

    Jong-Hak Kim

    2016-10-01

    Conclusion: These results suggest that great impact to prevent authentication of precise Chunpoong and other cultivars using the auxin repressed protein gene. We therefore present an effective method for the authentication of the Chunpoong cultivar of P. ginseng and P. quinquefolius.

  1. SUMO modification of Stra13 is required for repression of cyclin D1 expression and cellular growth arrest.

    Directory of Open Access Journals (Sweden)

    Yaju Wang

    Full Text Available Stra13, a basic helix-loop-helix (bHLH transcription factor is involved in myriad biological functions including cellular growth arrest, differentiation and senescence. However, the mechanisms by which its transcriptional activity and function are regulated remain unclear. In this study, we provide evidence that post-translational modification of Stra13 by Small Ubiquitin-like Modifier (SUMO dramatically potentiates its ability to transcriptionally repress cyclin D1 and mediate G(1 cell cycle arrest in fibroblast cells. Mutation of SUMO acceptor lysines 159 and 279 located in the C-terminal repression domain has no impact on nuclear localization; however, it abrogates association with the co-repressor histone deacetylase 1 (HDAC1, attenuates repression of cyclin D1, and prevents Stra13-mediated growth suppression. HDAC1, which promotes cellular proliferation and cell cycle progression, antagonizes Stra13 sumoylation-dependent growth arrest. Our results uncover an unidentified regulatory axis between Stra13 and HDAC1 in progression through the G(1/S phase of the cell cycle, and provide new mechanistic insights into regulation of Stra13-mediated transcriptional repression by sumoylation.

  2. Interplay between the catabolite repression control protein Crc, Hfq and RNA in Hfq-dependent translational regulation in Pseudomonas aeruginosa.

    Science.gov (United States)

    Sonnleitner, Elisabeth; Wulf, Alexander; Campagne, Sébastien; Pei, Xue-Yuan; Wolfinger, Michael T; Forlani, Giada; Prindl, Konstantin; Abdou, Laetitia; Resch, Armin; Allain, Frederic H-T; Luisi, Ben F; Urlaub, Henning; Bläsi, Udo

    2018-02-16

    In Pseudomonas aeruginosa the RNA chaperone Hfq and the catabolite repression control protein (Crc) act as post-transcriptional regulators during carbon catabolite repression (CCR). In this regard Crc is required for full-fledged Hfq-mediated translational repression of catabolic genes. RNAseq based transcriptome analyses revealed a significant overlap between the Crc and Hfq regulons, which in conjunction with genetic data supported a concerted action of both proteins. Biochemical and biophysical approaches further suggest that Crc and Hfq form an assembly in the presence of RNAs containing A-rich motifs, and that Crc interacts with both, Hfq and RNA. Through these interactions, Crc enhances the stability of Hfq/Crc/RNA complexes, which can explain its facilitating role in Hfq-mediated translational repression. Hence, these studies revealed for the first time insights into how an interacting protein can modulate Hfq function. Moreover, Crc is shown to interfere with binding of a regulatory RNA to Hfq, which bears implications for riboregulation. These results are discussed in terms of a working model, wherein Crc prioritizes the function of Hfq toward utilization of favored carbon sources.

  3. Optimizing sgRNA position markedly improves the efficiency of CRISPR/dCas9-mediated transcriptional repression

    DEFF Research Database (Denmark)

    Radzisheuskaya, Aliaksandra; Shlyueva, Daria; Müller, Iris

    2016-01-01

    CRISPR interference (CRISPRi) represents a newly developed tool for targeted gene repression. It has great application potential for studying gene function and mapping gene regulatory elements. However, the optimal parameters for efficient single guide RNA (sgRNA) design for CRISPRi are not fully...

  4. The prohibitin-repressive interaction with E2F1 is rapidly inhibited by androgen signalling in prostate cancer cells

    NARCIS (Netherlands)

    Koushyar, S.; Economides, G.; Zaat, S.; Jiang, W.; Bevan, C. L.; Dart, D. A.

    2017-01-01

    Prohibitin (PHB) is a tumour suppressor molecule with pleiotropic activities across several cellular compartments including mitochondria, cell membrane and the nucleus. PHB and the steroid-activated androgen receptor (AR) have an interplay where AR downregulates PHB, and PHB represses AR.

  5. Genomic Analysis Reveals Contrasting PIFq Contribution to Diurnal Rhythmic Gene Expression in PIF-Induced and -Repressed Genes.

    Science.gov (United States)

    Martin, Guiomar; Soy, Judit; Monte, Elena

    2016-01-01

    Members of the PIF quartet (PIFq; PIF1, PIF3, PIF4, and PIF5) collectively contribute to induce growth in Arabidopsis seedlings under short day (SD) conditions, specifically promoting elongation at dawn. Their action involves the direct regulation of growth-related and hormone-associated genes. However, a comprehensive definition of the PIFq-regulated transcriptome under SD is still lacking. We have recently shown that SD and free-running (LL) conditions correspond to "growth" and "no growth" conditions, respectively, correlating with greater abundance of PIF protein in SD. Here, we present a genomic analysis whereby we first define SD-regulated genes at dawn compared to LL in the wild type, followed by identification of those SD-regulated genes whose expression depends on the presence of PIFq. By using this sequential strategy, we have identified 349 PIF/SD-regulated genes, approximately 55% induced and 42% repressed by both SD and PIFq. Comparison with available databases indicates that PIF/SD-induced and PIF/SD-repressed sets are differently phased at dawn and mid-morning, respectively. In addition, we found that whereas rhythmicity of the PIF/SD-induced gene set is lost in LL, most PIF/SD-repressed genes keep their rhythmicity in LL, suggesting differential regulation of both gene sets by the circadian clock. Moreover, we also uncovered distinct overrepresented functions in the induced and repressed gene sets, in accord with previous studies in other examined PIF-regulated processes. Interestingly, promoter analyses showed that, whereas PIF/SD-induced genes are enriched in direct PIF targets, PIF/SD-repressed genes are mostly indirectly regulated by the PIFs and might be more enriched in ABA-regulated genes.

  6. PPARγ partial agonist GQ-16 strongly represses a subset of genes in 3T3-L1 adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Milton, Flora Aparecida [Faculdade de Ciências da Saúde, Laboratório de Farmacologia Molecular, Universidade de Brasília (Brazil); Genomic Medicine, Houston Methodist Research Institute, Houston, TX (United States); Cvoro, Aleksandra [Genomic Medicine, Houston Methodist Research Institute, Houston, TX (United States); Amato, Angelica A. [Faculdade de Ciências da Saúde, Laboratório de Farmacologia Molecular, Universidade de Brasília (Brazil); Sieglaff, Douglas H.; Filgueira, Carly S.; Arumanayagam, Anithachristy Sigamani [Genomic Medicine, Houston Methodist Research Institute, Houston, TX (United States); Caro Alves de Lima, Maria do; Rocha Pitta, Ivan [Laboratório de Planejamento e Síntese de Fármacos – LPSF, Universidade Federal de Pernambuco (Brazil); Assis Rocha Neves, Francisco de [Faculdade de Ciências da Saúde, Laboratório de Farmacologia Molecular, Universidade de Brasília (Brazil); Webb, Paul, E-mail: pwebb@HoustonMethodist.org [Genomic Medicine, Houston Methodist Research Institute, Houston, TX (United States)

    2015-08-28

    Thiazolidinediones (TZDs) are peroxisome proliferator-activated receptor gamma (PPARγ) agonists that improve insulin resistance but trigger side effects such as weight gain, edema, congestive heart failure and bone loss. GQ-16 is a PPARγ partial agonist that improves glucose tolerance and insulin sensitivity in mouse models of obesity and diabetes without inducing weight gain or edema. It is not clear whether GQ-16 acts as a partial agonist at all PPARγ target genes, or whether it displays gene-selective actions. To determine how GQ-16 influences PPARγ activity on a gene by gene basis, we compared effects of rosiglitazone (Rosi) and GQ-16 in mature 3T3-L1 adipocytes using microarray and qRT-PCR. Rosi changed expression of 1156 genes in 3T3-L1, but GQ-16 only changed 89 genes. GQ-16 generally showed weak effects upon Rosi induced genes, consistent with partial agonist actions, but a subset of modestly Rosi induced and strongly repressed genes displayed disproportionately strong GQ-16 responses. PPARγ partial agonists MLR24 and SR1664 also exhibit disproportionately strong effects on transcriptional repression. We conclude that GQ-16 displays a continuum of weak partial agonist effects but efficiently represses some negatively regulated PPARγ responsive genes. Strong repressive effects could contribute to physiologic actions of GQ-16. - Highlights: • GQ-16 is an insulin sensitizing PPARγ ligand with reduced harmful side effects. • GQ-16 displays a continuum of weak partial agonist activities at PPARγ-induced genes. • GQ-16 exerts strong repressive effects at a subset of genes. • These inhibitor actions should be evaluated in models of adipose tissue inflammation.

  7. PPARγ partial agonist GQ-16 strongly represses a subset of genes in 3T3-L1 adipocytes

    International Nuclear Information System (INIS)

    Milton, Flora Aparecida; Cvoro, Aleksandra; Amato, Angelica A.; Sieglaff, Douglas H.; Filgueira, Carly S.; Arumanayagam, Anithachristy Sigamani; Caro Alves de Lima, Maria do; Rocha Pitta, Ivan; Assis Rocha Neves, Francisco de; Webb, Paul

    2015-01-01

    Thiazolidinediones (TZDs) are peroxisome proliferator-activated receptor gamma (PPARγ) agonists that improve insulin resistance but trigger side effects such as weight gain, edema, congestive heart failure and bone loss. GQ-16 is a PPARγ partial agonist that improves glucose tolerance and insulin sensitivity in mouse models of obesity and diabetes without inducing weight gain or edema. It is not clear whether GQ-16 acts as a partial agonist at all PPARγ target genes, or whether it displays gene-selective actions. To determine how GQ-16 influences PPARγ activity on a gene by gene basis, we compared effects of rosiglitazone (Rosi) and GQ-16 in mature 3T3-L1 adipocytes using microarray and qRT-PCR. Rosi changed expression of 1156 genes in 3T3-L1, but GQ-16 only changed 89 genes. GQ-16 generally showed weak effects upon Rosi induced genes, consistent with partial agonist actions, but a subset of modestly Rosi induced and strongly repressed genes displayed disproportionately strong GQ-16 responses. PPARγ partial agonists MLR24 and SR1664 also exhibit disproportionately strong effects on transcriptional repression. We conclude that GQ-16 displays a continuum of weak partial agonist effects but efficiently represses some negatively regulated PPARγ responsive genes. Strong repressive effects could contribute to physiologic actions of GQ-16. - Highlights: • GQ-16 is an insulin sensitizing PPARγ ligand with reduced harmful side effects. • GQ-16 displays a continuum of weak partial agonist activities at PPARγ-induced genes. • GQ-16 exerts strong repressive effects at a subset of genes. • These inhibitor actions should be evaluated in models of adipose tissue inflammation

  8. Genetic interactions of MAF1 identify a role for Med20 in transcriptional repression of ribosomal protein genes.

    Directory of Open Access Journals (Sweden)

    Ian M Willis

    2008-07-01

    Full Text Available Transcriptional repression of ribosomal components and tRNAs is coordinately regulated in response to a wide variety of environmental stresses. Part of this response involves the convergence of different nutritional and stress signaling pathways on Maf1, a protein that is essential for repressing transcription by RNA polymerase (pol III in Saccharomyces cerevisiae. Here we identify the functions buffering yeast cells that are unable to down-regulate transcription by RNA pol III. MAF1 genetic interactions identified in screens of non-essential gene-deletions and conditionally expressed essential genes reveal a highly interconnected network of 64 genes involved in ribosome biogenesis, RNA pol II transcription, tRNA modification, ubiquitin-dependent proteolysis and other processes. A survey of non-essential MAF1 synthetic sick/lethal (SSL genes identified six gene-deletions that are defective in transcriptional repression of ribosomal protein (RP genes following rapamycin treatment. This subset of MAF1 SSL genes included MED20 which encodes a head module subunit of the RNA pol II Mediator complex. Genetic interactions between MAF1 and subunits in each structural module of Mediator were investigated to examine the functional relationship between these transcriptional regulators. Gene expression profiling identified a prominent and highly selective role for Med20 in the repression of RP gene transcription under multiple conditions. In addition, attenuated repression of RP genes by rapamycin was observed in a strain deleted for the Mediator tail module subunit Med16. The data suggest that Mediator and Maf1 function in parallel pathways to negatively regulate RP mRNA and tRNA synthesis.

  9. EWS/FLI mediates transcriptional repression via NKX2.2 during oncogenic transformation in Ewing's sarcoma.

    Directory of Open Access Journals (Sweden)

    Leah A Owen

    2008-04-01

    Full Text Available EWS/FLI is a master regulator of Ewing's sarcoma formation. Gene expression studies in A673 Ewing's sarcoma cells have demonstrated that EWS/FLI downregulates more genes than it upregulates, suggesting that EWS/FLI, and/or its targets, function as transcriptional repressors. One critical EWS/FLI target, NKX2.2, is a transcription factor that contains both transcriptional activation and transcriptional repression domains, raising the possibility that it mediates portions of the EWS/FLI transcriptional signature. We now report that microarray analysis demonstrated that the transcriptional profile of NKX2.2 consists solely of downregulated genes, and overlaps with the EWS/FLI downregulated signature, suggesting that NKX2.2 mediates oncogenic transformation via transcriptional repression. Structure-function analysis revealed that the DNA binding and repressor domains in NKX2.2 are required for oncogenesis in Ewing's sarcoma cells, while the transcriptional activation domain is completely dispensable. Furthermore, blockade of TLE or HDAC function, two protein families thought to mediate the repressive function of NKX2.2, inhibited the transformed phenotype and reversed the NKX2.2 transcriptional profile in Ewing's sarcoma cells. Whole genome localization studies (ChIP-chip revealed that a significant portion of the NKX2.2-repressed gene expression signature was directly mediated by NKX2.2 binding. These data demonstrate that the transcriptional repressive function of NKX2.2 is necessary, and sufficient, for the oncogenic phenotype of Ewing's sarcoma, and suggest a therapeutic approach to this disease.

  10. Circuitry Linking the Catabolite Repression and Csr Global Regulatory Systems of Escherichia coli.

    Science.gov (United States)

    Pannuri, Archana; Vakulskas, Christopher A; Zere, Tesfalem; McGibbon, Louise C; Edwards, Adrianne N; Georgellis, Dimitris; Babitzke, Paul; Romeo, Tony

    2016-11-01

    Cyclic AMP (cAMP) and the cAMP receptor protein (cAMP-CRP) and CsrA are the principal regulators of the catabolite repression and carbon storage global regulatory systems, respectively. cAMP-CRP controls the transcription of genes for carbohydrate metabolism and other processes in response to carbon nutritional status, while CsrA binds to diverse mRNAs and regulates translation, RNA stability, and/or transcription elongation. CsrA also binds to the regulatory small RNAs (sRNAs) CsrB and CsrC, which antagonize its activity. The BarA-UvrY two-component signal transduction system (TCS) directly activates csrB and csrC (csrB/C) transcription, while CsrA does so indirectly. We show that cAMP-CRP inhibits csrB/C transcription without negatively regulating phosphorylated UvrY (P-UvrY) or CsrA levels. A crp deletion caused an elevation in CsrB/C levels in the stationary phase of growth and increased the expression of csrB-lacZ and csrC-lacZ transcriptional fusions, although modest stimulation of CsrB/C turnover by the crp deletion partially masked the former effects. DNase I footprinting and other studies demonstrated that cAMP-CRP bound specifically to three sites located upstream from the csrC promoter, two of which overlapped the P-UvrY binding site. These two proteins competed for binding at the overlapping sites. In vitro transcription-translation experiments confirmed direct repression of csrC-lacZ expression by cAMP-CRP. In contrast, cAMP-CRP effects on csrB transcription may be mediated indirectly, as it bound nonspecifically to csrB DNA. In the reciprocal direction, CsrA bound to crp mRNA with high affinity and specificity and yet exhibited only modest, conditional effects on expression. Our findings are incorporated into an emerging model for the response of Csr circuitry to carbon nutritional status. Csr (Rsm) noncoding small RNAs (sRNAs) CsrB and CsrC of Escherichia coli use molecular mimicry to sequester the RNA binding protein CsrA (RsmA) away from lower

  11. Gypsophila bermejoi G. López: A possible case of speciation repressed by bioclimatic factors.

    Science.gov (United States)

    de Luis, Miguel; Bartolomé, Carmen; García Cardo, Óscar; Álvarez-Jiménez, Julio

    2018-01-01

    Gypsophila bermejoi G. López is an allopolyploid species derived from the parental G. struthium L. subsp. struthium and G. tomentosa L. All these plants are gypsophytes endemic to the Iberian Peninsula of particular ecological, evolutionary and biochemical interest. In this study, we present evidence of a possible repression on the process of G. bermejoi speciation by climatic factors. We modelled the ecological niches of the three taxa considered here using a maximum entropy approach and employing a series of bioclimatic variables. Subsequently, we projected these models onto the geographical space of the Iberian Peninsula in the present age and at two past ages: the Last Glacial Maximum and the mid-Holocene period. Furthermore, we compared these niches using the statistical method devised by Warren to calculate their degree of overlap. We also evaluated the evolution of the bioclimatic habitat suitability at those sites were the soil favors the growth of these species. Both the maximum entropy model and the degree of overlap indicated that the ecological behavior of the hybrid differs notably from that of the parental species. During the Last Glacial Maximum, the two parental species appear to take refuge in the western coastal strip of the Peninsula, a region in which there are virtually no sites where G. bermejoi could potentially be found. However, in the mid-Holocene period the suitability of G. bermejoi to sites with favorable soils shifts from almost null to a strong adaptation, a clear change in this tendency. These results suggest that the ecological niches of hybrid allopolyploids can be considerably different to those of their parental species, which may have evolutionary and ecologically relevant consequences. The data obtained indicate that certain bioclimatic variables may possibly repress the processes by which new species are formed. The difference in the ecological niche of G. bermejoi with respect to its parental species prevented it from

  12. Inorganic arsenic represses interleukin-17A expression in human activated Th17 lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Morzadec, Claudie; Macoch, Mélinda; Robineau, Marc; Sparfel, Lydie [UMR INSERM U1085, Institut de Recherche sur la Santé, l' Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France); Fardel, Olivier [UMR INSERM U1085, Institut de Recherche sur la Santé, l' Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France); Pôle Biologie, Centre Hospitalier Universitaire (CHU) Rennes, 2 rue Henri Le Guilloux, 35033 Rennes (France); Vernhet, Laurent, E-mail: laurent.vernhet@univ-rennes1.fr [UMR INSERM U1085, Institut de Recherche sur la Santé, l' Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France)

    2012-08-01

    Trivalent inorganic arsenic [As(III)] is an efficient anticancer agent used to treat patients suffering from acute promyelocytic leukemia. Recently, experimental studies have clearly demonstrated that this metalloid can also cure lymphoproliferative and/or pro-inflammatory syndromes in different murine models of chronic immune-mediated diseases. T helper (Th) 1 and Th17 lymphocytes play a central role in development of these diseases, in mice and humans, especially by secreting the potent pro-inflammatory cytokine interferon-γ and IL-17A, respectively. As(III) impairs basic functions of human T cells but its ability to modulate secretion of pro-inflammatory cytokines by differentiated Th lymphocytes is unknown. In the present study, we demonstrate that As(III), used at concentrations clinically achievable in plasma of patients, has no effect on the secretion of interferon-γ from Th1 cells but almost totally blocks the expression and the release of IL-17A from human Th17 lymphocytes co-stimulated for five days with anti-CD3 and anti-CD28 antibodies, in the presence of differentiating cytokines. In addition, As(III) specifically reduces mRNA levels of the retinoic-related orphan receptor (ROR)C gene which encodes RORγt, a key transcription factor controlling optimal IL-17 expression in fully differentiated Th17 cells. The metalloid also blocks initial expression of IL-17 gene induced by the co-stimulation, probably in part by impairing activation of the JNK/c-Jun pathway. In conclusion, our results demonstrate that As(III) represses expression of the major pro-inflammatory cytokine IL-17A produced by human Th17 lymphocytes, thus strengthening the idea that As(III) may be useful to treat inflammatory immune-mediated diseases in humans. -- Highlights: ► Arsenic inhibits secretion of IL-17A from human naïve and memory Th17 lymphocytes. ► Arsenic represses early expression of IL-17A gene in human activated T lymphocytes. ► Arsenic interferes with activation of

  13. NiO nanoparticles induce apoptosis through repressing SIRT1 in human bronchial epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Wei-Xia; He, Min-Di; Mao, Lin [Department of Occupational Health, Third Military Medical University, Chongqing 400038 (China); Qian, Feng-Hua [Department of Hematology, Southwest Hospital, Third Military Medical University, Chongqing 400038 (China); Li, Yu-Ming [Institute of Hepatobiliary Surgery, XinQiao Hospital, Third Military Medical University, Chongqing 400038 (China); Pi, Hui-Feng; Liu, Chuan; Chen, Chun-Hai; Lu, Yong-Hui; Cao, Zheng-Wang; Zhang, Lei; Yu, Zheng-Ping [Department of Occupational Health, Third Military Medical University, Chongqing 400038 (China); Zhou, Zhou, E-mail: lunazhou00@163.com [Department of Occupational Health, Third Military Medical University, Chongqing 400038 (China)

    2015-07-15

    With application of nano-sized nickel-containing particles (Nano-Ni) expanding, the health concerns about their adverse effects on the pulmonary system are increasing. However, the mechanisms for the pulmonary toxicity of these materials remain unclear. In the present study, we focused on the impacts of NiO nanoparticles (NiONPs) on sirtuin1 (SIRT1), a NAD-dependent deacetylase, and investigated whether SIRT1 was involved in NiONPs-induced apoptosis. Although the NiONPs tended to agglomerate in fluid medium, they still entered into the human bronchial epithelial cells (BEAS-2B) and released Ni{sup 2+} inside the cells. NiONPs at doses of 5, 10, and 20 μg/cm{sup 2} inhibited the cell viability. NiONPs' produced cytotoxicity was demonstrated through an apoptotic process, indicated by increased numbers of Annexin V positive cells and caspase-3 activation. The expression of SIRT1 was markedly down-regulated by the NiONPs, accompanied by the hyperacetylation of p53 (tumor protein 53) and overexpression of Bax (Bcl-2-associated X protein). However, overexpression of SIRT1 through resveratrol treatment or transfection clearly attenuated the NiONPs-induced apoptosis and activation of p53 and Bax. Our results suggest that the repression of SIRT1 may underlie the NiONPs-induced apoptosis via p53 hyperacetylation and subsequent Bax activation. Because SIRT1 participates in multiple biologic processes by deacetylation of dozens of substrates, this knowledge of the impact of NiONPs on SIRT1 may lead to an improved understanding of the toxic mechanisms of Nano-Ni and provide a molecular target to antagonize Nano-Ni toxicity. - Highlights: • NiONPs were taken up by BEAS-2B cells and released Ni{sup 2+}. • NiONPs produced cytotoxicity was demonstrated through an apoptotic process. • NiONPs repressed SIRT1 expression and activated p53 and Bax. • Overexpression of SIRT1 attenuated NiONPs-induced apoptosis via deacetylation p53.

  14. Sulforaphane causes epigenetic repression of hTERT expression in human breast cancer cell lines.

    Directory of Open Access Journals (Sweden)

    Syed M Meeran

    Full Text Available BACKGROUND: Sulforaphane (SFN, an isothiocyanate found in cruciferous vegetables, is a common dietary component that has histone deacetylase inhibition activity and exciting potential in cancer prevention. The mechanisms by which SFN imparts its chemopreventive properties are of considerable interest and little is known of its preventive potential for breast cancer. PRINCIPAL FINDINGS: We found that SFN significantly inhibits the viability and proliferation of breast cancer cells in vitro while it has negligible effects on normal breast cells. Inhibition of telomerase has received considerable attention because of its high expression in cancer cells and extremely low level of expression in normal cells. SFN treatment dose- and time-dependently inhibited human telomerase reverse transcriptase (hTERT, the catalytic regulatory subunit of telomerase, in both MCF-7 and MDA-MB-231 human breast cancer cells. DNA methyltransferases (DNMTs, especially DNMT1 and DNMT3a, were also decreased in SFN-treated breast cancer cells suggesting that SFN may repress hTERT by impacting epigenetic pathways. Down-regulation of DNMTs in response to SFN induced site-specific CpG demethylation occurring primarily in the first exon of the hTERT gene thereby facilitating CTCF binding associated with hTERT repression. Chromatin immunoprecipitation (ChIP analysis of the hTERT promoter revealed that SFN increased the level of active chromatin markers acetyl-H3, acetyl-H3K9 and acetyl-H4, whereas the trimethyl-H3K9 and trimethyl-H3K27 inactive chromatin markers were decreased in a dose-dependent manner. SFN-induced hyperacetylation facilitated the binding of many hTERT repressor proteins such as MAD1 and CTCF to the hTERT regulatory region. Depletion of CTCF using siRNA reduced the SFN-induced down-regulation of hTERT mRNA transcription in these breast cancer cells. In addition, down-regulation of hTERT expression facilitated the induction of cellular apoptosis in human breast

  15. The politics of drug control in Nigeria: Exclusion, repression and obstacles to policy change.

    Science.gov (United States)

    Klantschnig, Gernot

    2016-04-01

    International agencies have viewed West Africa as a major player in the global trade in cocaine and heroin and in efforts to control that trade, as there have been reports of escalating arrests of drug smugglers, large-scale drug seizures and 'narco-states' in the subregion. It is claimed that a substantial share of the drugs available in Western markets transit through West Africa today and are increasingly used there as well. Notwithstanding this growing alarm, there is little serious scholarship addressing the issue of drugs and drug policy in West Africa. The article assesses and challenges some of the existing depictions of drugs and drug policy in West Africa through an empirical case study of drug control in Nigeria - one of West Africa's most notorious 'drug hubs' and recently hailed as a policy model by international experts. Based on previously inaccessible government documents, interviews with key officials in Nigeria, as well as ethnographic work at Nigeria's key drug agency, the article provides a unique insight into the politics of drug policy-making and implementation in West Africa. After describing the dominant official narratives of Nigeria's drug control, the article shows how the key political dynamics underlying drug policy remain obscured by these narratives. Nigerian drug policy has been characterised by a highly exclusive policy-making process, repression as the sole means of implementation and a strong bond with international drug agencies. This policy emerged in the 1980s and 1990s and has remained the unchallenged norm until today. The political processes underlying Nigerian drug policy also explain why policy reform has been and will be difficult to accomplish. These domestic political processes have largely been ignored in the existing depictions of drugs in West Africa, as they have mainly focused on externally driven drug threats and foreign policy responses. Most importantly, they have ignored the role played by the state. Rather

  16. A noncanonical Flt3ITD/NF-κB signaling pathway represses DAPK1 in acute myeloid leukemia.

    Science.gov (United States)

    Shanmugam, Rajasubramaniam; Gade, Padmaja; Wilson-Weekes, Annique; Sayar, Hamid; Suvannasankha, Attaya; Goswami, Chirayu; Li, Lang; Gupta, Sushil; Cardoso, Angelo A; Baghdadi, Tareq Al; Sargent, Katie J; Cripe, Larry D; Kalvakolanu, Dhananjaya V; Boswell, H Scott

    2012-01-15

    Death-associated protein kinase 1 (DAPK1), a tumor suppressor, is a rate-limiting effector in an endoplasmic reticulum (ER) stress-dependent apoptotic pathway. Its expression is epigenetically suppressed in several tumors. A mechanistic basis for epigenetic/transcriptional repression of DAPK1 was investigated in certain forms of acute myeloid leukemia (AML) with poor prognosis, which lacked ER stress-induced apoptosis. Heterogeneous primary AMLs were screened to identify a subgroup with Flt3ITD in which repression of DAPK1, among NF-κB-and c-Jun-responsive genes, was studied. RNA interference knockdown studies were carried out in an Flt3ITD(+) cell line, MV-4-11, to establish genetic epistasis in the pathway Flt3ITD-TAK1-DAPK1 repression, and chromatin immunoprecipitations were carried out to identify proximate effector proteins, including TAK1-activated p52NF-κB, at the DAPK1 locus. AMLs characterized by normal karyotype with Flt3ITD were found to have 10- to 100-fold lower DAPK1 transcripts normalized to the expression of c-Jun, a transcriptional activator of DAPK1, as compared with a heterogeneous cytogenetic category. In addition, Meis1, a c-Jun-responsive adverse AML prognostic gene signature was measured as control. These Flt3ITD(+) AMLs overexpress relB, a transcriptional repressor, which forms active heterodimers with p52NF-κB. Chromatin immunoprecipitation assays identified p52NF-κB binding to the DAPK1 promoter together with histone deacetylase 2 (HDAC2) and HDAC6 in the Flt3ITD(+) human AML cell line MV-4-11. Knockdown of p52NF-κB or its upstream regulator, NF-κB-inducing kinase (NIK), de-repressed DAPK1. DAPK1-repressed primary Flt3ITD(+) AMLs had selective nuclear activation of p52NF-κB. Flt3ITD promotes a noncanonical pathway via TAK1 and p52NF-κB to suppress DAPK1 in association with HDACs, which explains DAPK1 repression in Flt3ITD(+) AML. ©2011 AACR.

  17. Msx1 Homeodomain Protein Represses the αGSU and GnRH Receptor Genes During Gonadotrope Development

    Science.gov (United States)

    Xie, Huimin; Cherrington, Brian D.; Meadows, Jason D.; Witham, Emily A.

    2013-01-01

    Multiple homeodomain transcription factors are crucial for pituitary organogenesis and cellular differentiation. A homeodomain repressor, Msx1, is expressed from the ventral aspect of the developing anterior pituitary and implicated in gonadotrope differentiation. Here, we find that Msx1 represses transcription of lineage-specific pituitary genes such as the common α-glycoprotein subunit (αGSU) and GnRH receptor (GnRHR) promoters in the mouse gonadotrope-derived cell lines, αT3-1 and LβT2. Repression of the mouse GnRHR promoter by Msx1 is mediated through a consensus-binding motif in the downstream activin regulatory element (DARE). Truncation and mutation analyses of the human αGSU promoter map Msx1 repression to a site at −114, located at the junctional regulatory element (JRE). Dlx activators are closely related to the Msx repressors, acting through the same elements, and Dlx3 and Dlx2 act as transcriptional activators for GnRHR and αGSU, respectively. Small interfering RNA knockdown of Msx1 in αT3-1 cells increases endogenous αGSU and GnRHR mRNA expression. Msx1 gene expression reaches its maximal expression at the rostral edge at e13.5. The subsequent decline in Msx1 expression specifically coincides with the onset of expression of both αGSU and GnRHR. The expression levels of both αGSU and GnRHR in Msx1-null mice at e18.5 are higher compared with wild type, further confirming a role for Msx1 in the repression of αGSU and GnRHR. In summary, Msx1 functions as a negative regulator early in pituitary development by repressing the gonadotrope-specific αGSU and GnRHR genes, but a temporal decline in Msx1 expression alleviates this repression allowing induction of GnRHR and αGSU, thus serving to time the onset of gonadotrope-specific gene program. PMID:23371388

  18. Msx1 homeodomain protein represses the αGSU and GnRH receptor genes during gonadotrope development.

    Science.gov (United States)

    Xie, Huimin; Cherrington, Brian D; Meadows, Jason D; Witham, Emily A; Mellon, Pamela L

    2013-03-01

    Multiple homeodomain transcription factors are crucial for pituitary organogenesis and cellular differentiation. A homeodomain repressor, Msx1, is expressed from the ventral aspect of the developing anterior pituitary and implicated in gonadotrope differentiation. Here, we find that Msx1 represses transcription of lineage-specific pituitary genes such as the common α-glycoprotein subunit (αGSU) and GnRH receptor (GnRHR) promoters in the mouse gonadotrope-derived cell lines, αT3-1 and LβT2. Repression of the mouse GnRHR promoter by Msx1 is mediated through a consensus-binding motif in the downstream activin regulatory element (DARE). Truncation and mutation analyses of the human αGSU promoter map Msx1 repression to a site at -114, located at the junctional regulatory element (JRE). Dlx activators are closely related to the Msx repressors, acting through the same elements, and Dlx3 and Dlx2 act as transcriptional activators for GnRHR and αGSU, respectively. Small interfering RNA knockdown of Msx1 in αT3-1 cells increases endogenous αGSU and GnRHR mRNA expression. Msx1 gene expression reaches its maximal expression at the rostral edge at e13.5. The subsequent decline in Msx1 expression specifically coincides with the onset of expression of both αGSU and GnRHR. The expression levels of both αGSU and GnRHR in Msx1-null mice at e18.5 are higher compared with wild type, further confirming a role for Msx1 in the repression of αGSU and GnRHR. In summary, Msx1 functions as a negative regulator early in pituitary development by repressing the gonadotrope-specific αGSU and GnRHR genes, but a temporal decline in Msx1 expression alleviates this repression allowing induction of GnRHR and αGSU, thus serving to time the onset of gonadotrope-specific gene program.

  19. Using synthetic bacterial enhancers to reveal a looping-based mechanism for quenching-like repression

    Science.gov (United States)

    Brunwasser-Meirom, Michal; Pollak, Yaroslav; Goldberg, Sarah; Levy, Lior; Atar, Orna; Amit, Roee

    2016-01-01

    We explore a model for ‘quenching-like' repression by studying synthetic bacterial enhancers, each characterized by a different binding site architecture. To do so, we take a three-pronged approach: first, we compute the probability that a protein-bound dsDNA molecule will loop. Second, we use hundreds of synthetic enhancers to test the model's predictions in bacteria. Finally, we verify the mechanism bioinformatically in native genomes. Here we show that excluded volume effects generated by DNA-bound proteins can generate substantial quenching. Moreover, the type and extent of the regulatory effect depend strongly on the relative arrangement of the binding sites. The implications of these results are that enhancers should be insensitive to 10–11 bp insertions or deletions (INDELs) and sensitive to 5–6 bp INDELs. We test this prediction on 61 σ54-regulated qrr genes from the Vibrio genus and confirm the tolerance of these enhancers' sequences to the DNA's helical repeat. PMID:26832446

  20. Acid phosphatase turnover during repressed and derepressed cultivation of Aspergillus niger

    International Nuclear Information System (INIS)

    Komano, Teruya

    1975-01-01

    Enhancement of the activity of acid phosphatase (EC 3.1.3.2) by phosphate starvation in growing Aspergillus niger mycelia was prevented by cycloheximide. This indicates that the enhancement was due to de novo protein synthesis caused by derepression. Radioactive acid phosphatase extracted from mycelia labeled with 14 C-amino acid was separated into at least four fractions. Experiments on pulse labeling and the chasing of the four acid phosphatases revealed the synthesis and degradation of each fraction occurred at different rates; showing a different rate of turnover of the enzyme molecules. The results of similar experiments performed during culture in the presence of phosphate (partially repressed condition) suggested that the marked change in the activity ratios of the four acid phosphatases during cultivation was the result of the active turnover of enzyme molecules. In contrast, the slight changes in the ratios observed during derepressed cultivation seemed to be the result of similar of synthesis and degradation of each phosphatase fraction. (auth.)

  1. Inhibition of p53 acetylation by INHAT subunit SET/TAF-Iβ represses p53 activity.

    Science.gov (United States)

    Kim, Ji-Young; Lee, Kyu-Sun; Seol, Jin-Ee; Yu, Kweon; Chakravarti, Debabrata; Seo, Sang-Beom

    2012-01-01

    The tumor suppressor p53 responds to a wide variety of cellular stress signals. Among potential regulatory pathways, post-translational modifications such as acetylation by CBP/p300 and PCAF have been suggested for modulation of p53 activity. However, exactly how p53 acetylation is modulated remains poorly understood. Here, we found that SET/TAF-Iβ inhibited p300- and PCAF-mediated p53 acetylation in an INHAT (inhibitor of histone acetyltransferase) domain-dependent manner. SET/TAF-Iβ interacted with p53 and repressed transcription of p53 target genes. Consequently, SET/TAF-Iβ blocked both p53-mediated cell cycle arrest and apoptosis in response to cellular stress. Using different apoptosis analyses, including FACS, TUNEL and BrdU incorporation assays, we also found that SET/TAF-Iβ induced cellular proliferation via inhibition of p53 acetylation. Furthermore, we observed that apoptotic Drosophila eye phenotype induced by either dp53 overexpression or UV irradiation was rescued by expression of dSet. Inhibition of dp53 acetylation by dSet was observed in both cases. Our findings provide new insights into the regulation of stress-induced p53 activation by HAT-inhibiting histone chaperone SET/TAF-Iβ.

  2. Hemolytic anemia repressed hepcidin level without hepatocyte iron overload: lesson from Günther disease model.

    Science.gov (United States)

    Millot, Sarah; Delaby, Constance; Moulouel, Boualem; Lefebvre, Thibaud; Pilard, Nathalie; Ducrot, Nicolas; Ged, Cécile; Lettéron, Philippe; de Franceschi, Lucia; Deybach, Jean Charles; Beaumont, Carole; Gouya, Laurent; De Verneuil, Hubert; Lyoumi, Saïd; Puy, Hervé; Karim, Zoubida

    2017-02-01

    Hemolysis occurring in hematologic diseases is often associated with an iron loading anemia. This iron overload is the result of a massive outflow of hemoglobin into the bloodstream, but the mechanism of hemoglobin handling has not been fully elucidated. Here, in a congenital erythropoietic porphyria mouse model, we evaluate the impact of hemolysis and regenerative anemia on hepcidin synthesis and iron metabolism. Hemolysis was confirmed by a complete drop in haptoglobin, hemopexin and increased plasma lactate dehydrogenase, an increased red blood cell distribution width and osmotic fragility, a reduced half-life of red blood cells, and increased expression of heme oxygenase 1. The erythropoiesis-induced Fam132b was increased, hepcidin mRNA repressed, and transepithelial iron transport in isolated duodenal loops increased. Iron was mostly accumulated in liver and spleen macrophages but transferrin saturation remained within the normal range. The expression levels of hemoglobin-haptoglobin receptor CD163 and hemopexin receptor CD91 were drastically reduced in both liver and spleen, resulting in heme- and hemoglobin-derived iron elimination in urine. In the kidney, the megalin/cubilin endocytic complex, heme oxygenase 1 and the iron exporter ferroportin were induced, which is reminiscent of significant renal handling of hemoglobin-derived iron. Our results highlight ironbound hemoglobin urinary clearance mechanism and strongly suggest that, in addition to the sequestration of iron in macrophages, kidney may play a major role in protecting hepatocytes from iron overload in chronic hemolysis. Copyright© Ferrata Storti Foundation.

  3. Kctd10 regulates heart morphogenesis by repressing the transcriptional activity of Tbx5a in zebrafish

    Science.gov (United States)

    Tong, Xiangjun; Zu, Yao; Li, Zengpeng; Li, Wenyuan; Ying, Lingxiao; Yang, Jing; Wang, Xin; He, Shuonan; Liu, Da; Zhu, Zuoyan; Chen, Jianming; Lin, Shuo; Zhang, Bo

    2014-01-01

    The T-box transcription factor Tbx5 (Tbx5a in zebrafish) plays a crucial role in the formation of cardiac chambers in a dose-dependent manner. Its deregulation leads to congenital heart disease. However, little is known regarding its regulation. Here we isolate a zebrafish mutant with heart malformations, called 34c. The affected gene is identified as kctd10, a member of the potassium channel tetramerization domain (KCTD)-containing family. In the mutant, the expressions of the atrioventricular canal marker genes, such as tbx2b, hyaluronan synthase 2 (has2), notch1b and bmp4, are changed. The knockdown of tbx5 rescues the ectopic expression of has2, and knockdown of either tbx5a or has2 alleviates the heart defects. We show that Kctd10 directly binds to Tbx5 to repress its transcriptional activity. Our results reveal a new essential factor for cardiac development and suggest that KCTD10 could be considered as a new causative gene of congenital heart disease.

  4. miR-186 inhibits cell proliferation in multiple myeloma by repressing Jagged1

    International Nuclear Information System (INIS)

    Liu, Zengyan; Zhang, Guoqiang; Yu, Wenzheng; Gao, Na; Peng, Jun

    2016-01-01

    MicroRNAs (miRNAs) are small, noncoding ribonucleic acids that regulate gene expression by targeting mRNAs for translational repression and degradation. Accumulating experimental evidence supports a causal role of miRNAs in hematology tumorigenesis. However, the specific functions of miRNAs in the pathogenesis of multiple myeloma (MM) remain to be established. In this study, we demonstrated that miR-186 is commonly downregulated in MM cell lines and patient MM cells. Ectopic expression of miR-186 significantly inhibited cell growth, both in vitro and in vivo, and induced cell cycle G_0/G_1 arrest. Furthermore, miR-186 induced downregulation of Jagged1 protein expression by directly targeting its 3′-untranslated region (3′-UTR). Conversely, overexpression of Jagged1 rescued cells from miR-186-induced growth inhibition. Our collective results clearly indicate that miR-186 functions as a tumor suppressor in MM, supporting its potential as a therapeutic target for the disease. - Highlights: • miR-186 expression is decreased in MM. • miR-186 inhibits MM cell proliferation in vitro and in vivo. • Jagged1 is regulated by miR-186. • Overexpression of Jagged1 reverses the effects of miR-186.

  5. Three WRKY transcription factors additively repress abscisic acid and gibberellin signaling in aleurone cells.

    Science.gov (United States)

    Zhang, Liyuan; Gu, Lingkun; Ringler, Patricia; Smith, Stanley; Rushton, Paul J; Shen, Qingxi J

    2015-07-01

    Members of the WRKY transcription factor superfamily are essential for the regulation of many plant pathways. Functional redundancy due to duplications of WRKY transcription factors, however, complicates genetic analysis by allowing single-mutant plants to maintain wild-type phenotypes. Our analyses indicate that three group I WRKY genes, OsWRKY24, -53, and -70, act in a partially redundant manner. All three showed characteristics of typical WRKY transcription factors: each localized to nuclei and yeast one-hybrid assays indicated that they all bind to W-boxes, including those present in their own promoters. Quantitative real time-PCR (qRT-PCR) analyses indicated that the expression levels of the three WRKY genes varied in the different tissues tested. Particle bombardment-mediated transient expression analyses indicated that all three genes repress the GA and ABA signaling in a dosage-dependent manner. Combination of all three WRKY genes showed additive antagonism of ABA and GA signaling. These results suggest that these WRKY proteins function as negative transcriptional regulators of GA and ABA signaling. However, different combinations of these WRKY genes can lead to varied strengths in suppression of their targets. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  6. Sirt1 regulates insulin secretion by repressing UCP2 in pancreatic beta cells.

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    Laura Bordone

    2006-02-01

    Full Text Available Sir2 and insulin/IGF-1 are the major pathways that impinge upon aging in lower organisms. In Caenorhabditis elegans a possible genetic link between Sir2 and the insulin/IGF-1 pathway has been reported. Here we investigate such a link in mammals. We show that Sirt1 positively regulates insulin secretion in pancreatic beta cells. Sirt1 represses the uncoupling protein (UCP gene UCP2 by binding directly to the UCP2 promoter. In beta cell lines in which Sirt1 is reduced by SiRNA, UCP2 levels are elevated and insulin secretion is blunted. The up-regulation of UCP2 is associated with a failure of cells to increase ATP levels after glucose stimulation. Knockdown of UCP2 restores the ability to secrete insulin in cells with reduced Sirt1, showing that UCP2 causes the defect in glucose-stimulated insulin secretion. Food deprivation induces UCP2 in mouse pancreas, which may occur via a reduction in NAD (a derivative of niacin levels in the pancreas and down-regulation of Sirt1. Sirt1 knockout mice display constitutively high UCP2 expression. Our findings show that Sirt1 regulates UCP2 in beta cells to affect insulin secretion.

  7. Polycomb repressive complex 2 (PRC2 restricts hematopoietic stem cell activity.

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    Ian J Majewski

    2008-04-01

    Full Text Available Polycomb group proteins are transcriptional repressors that play a central role in the establishment and maintenance of gene expression patterns during development. Using mice with an N-ethyl-N-nitrosourea (ENU-induced mutation in Suppressor of Zeste 12 (Suz12, a core component of Polycomb Repressive Complex 2 (PRC2, we show here that loss of Suz12 function enhances hematopoietic stem cell (HSC activity. In addition to these effects on a wild-type genetic background, mutations in Suz12 are sufficient to ameliorate the stem cell defect and thrombocytopenia present in mice that lack the thrombopoietin receptor (c-Mpl. To investigate the molecular targets of the PRC2 complex in the HSC compartment, we examined changes in global patterns of gene expression in cells deficient in Suz12. We identified a distinct set of genes that are regulated by Suz12 in hematopoietic cells, including eight genes that appear to be highly responsive to PRC2 function within this compartment. These data suggest that PRC2 is required to maintain a specific gene expression pattern in hematopoiesis that is indispensable to normal stem cell function.

  8. Repression of HNF1α-mediated transcription by amino-terminal enhancer of split (AES)

    Energy Technology Data Exchange (ETDEWEB)

    Han, Eun Hee [Section of Structural Biology, Hormel Institute, University of Minnesota, Austin, MN 55912 (United States); Gorman, Amanda A. [Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536 (United States); Singh, Puja [Section of Structural Biology, Hormel Institute, University of Minnesota, Austin, MN 55912 (United States); Chi, Young-In, E-mail: ychi@hi.umn.edu [Section of Structural Biology, Hormel Institute, University of Minnesota, Austin, MN 55912 (United States)

    2015-12-04

    HNF1α (Hepatocyte Nuclear Factor 1α) is one of the master regulators in pancreatic beta-cell development and function, and the mutations in Hnf1α are the most common monogenic causes of diabetes mellitus. As a member of the POU transcription factor family, HNF1α exerts its gene regulatory function through various molecular interactions; however, there is a paucity of knowledge in their functional complex formation. In this study, we identified the Groucho protein AES (Amino-terminal Enhancer of Split) as a HNF1α-specific physical binding partner and functional repressor of HNF1α-mediated transcription, which has a direct link to glucose-stimulated insulin secretion in beta-cells that is impaired in the HNF1α mutation-driven diabetes. - Highlights: • We identified AES as a transcriptional repressor for HNF1α in pancreatic beta-cell. • AES's repressive activity was HNF1α-specific and was not observed with HNF1β. • AES interacts with the transactivation domain of HNF1α. • Small molecules can be designed or discovered to disrupt this interaction and improve insulin secretion and glucose homeostasis.

  9. Repression of HNF1α-mediated transcription by amino-terminal enhancer of split (AES)

    International Nuclear Information System (INIS)

    Han, Eun Hee; Gorman, Amanda A.; Singh, Puja; Chi, Young-In

    2015-01-01

    HNF1α (Hepatocyte Nuclear Factor 1α) is one of the master regulators in pancreatic beta-cell development and function, and the mutations in Hnf1α are the most common monogenic causes of diabetes mellitus. As a member of the POU transcription factor family, HNF1α exerts its gene regulatory function through various molecular interactions; however, there is a paucity of knowledge in their functional complex formation. In this study, we identified the Groucho protein AES (Amino-terminal Enhancer of Split) as a HNF1α-specific physical binding partner and functional repressor of HNF1α-mediated transcription, which has a direct link to glucose-stimulated insulin secretion in beta-cells that is impaired in the HNF1α mutation-driven diabetes. - Highlights: • We identified AES as a transcriptional repressor for HNF1α in pancreatic beta-cell. • AES's repressive activity was HNF1α-specific and was not observed with HNF1β. • AES interacts with the transactivation domain of HNF1α. • Small molecules can be designed or discovered to disrupt this interaction and improve insulin secretion and glucose homeostasis.

  10. PTP1B triggers integrin-mediated repression of myosin activity and modulates cell contractility

    Directory of Open Access Journals (Sweden)

    Ana E. González Wusener

    2016-01-01

    Full Text Available Cell contractility and migration by integrins depends on precise regulation of protein tyrosine kinase and Rho-family GTPase activities in specific spatiotemporal patterns. Here we show that protein tyrosine phosphatase PTP1B cooperates with β3 integrin to activate the Src/FAK signalling pathway which represses RhoA-myosin-dependent contractility. Using PTP1B null (KO cells and PTP1B reconstituted (WT cells, we determined that some early steps following cell adhesion to fibronectin and vitronectin occurred robustly in WT cells, including aggregation of β3 integrins and adaptor proteins, and activation of Src/FAK-dependent signalling at small puncta in a lamellipodium. However, these events were significantly impaired in KO cells. We established that cytoskeletal strain and cell contractility was highly enhanced at the periphery of KO cells compared to WT cells. Inhibition of the Src/FAK signalling pathway or expression of constitutive active RhoA in WT cells induced a KO cell phenotype. Conversely, expression of constitutive active Src or myosin inhibition in KO cells restored the WT phenotype. We propose that this novel function of PTP1B stimulates permissive conditions for adhesion and lamellipodium assembly at the protruding edge during cell spreading and migration.

  11. PTP1B triggers integrin-mediated repression of myosin activity and modulates cell contractility

    Science.gov (United States)

    González Wusener, Ana E.; González, Ángela; Nakamura, Fumihiko; Arregui, Carlos O.

    2016-01-01

    ABSTRACT Cell contractility and migration by integrins depends on precise regulation of protein tyrosine kinase and Rho-family GTPase activities in specific spatiotemporal patterns. Here we show that protein tyrosine phosphatase PTP1B cooperates with β3 integrin to activate the Src/FAK signalling pathway which represses RhoA-myosin-dependent contractility. Using PTP1B null (KO) cells and PTP1B reconstituted (WT) cells, we determined that some early steps following cell adhesion to fibronectin and vitronectin occurred robustly in WT cells, including aggregation of β3 integrins and adaptor proteins, and activation of Src/FAK-dependent signalling at small puncta in a lamellipodium. However, these events were significantly impaired in KO cells. We established that cytoskeletal strain and cell contractility was highly enhanced at the periphery of KO cells compared to WT cells. Inhibition of the Src/FAK signalling pathway or expression of constitutive active RhoA in WT cells induced a KO cell phenotype. Conversely, expression of constitutive active Src or myosin inhibition in KO cells restored the WT phenotype. We propose that this novel function of PTP1B stimulates permissive conditions for adhesion and lamellipodium assembly at the protruding edge during cell spreading and migration. PMID:26700725

  12. Murine craniofacial development requires Hdac3-mediated repression of Msx gene expression.

    Science.gov (United States)

    Singh, Nikhil; Gupta, Mudit; Trivedi, Chinmay M; Singh, Manvendra K; Li, Li; Epstein, Jonathan A

    2013-05-15

    Craniofacial development is characterized by reciprocal interactions between neural crest cells and neighboring cell populations of ectodermal, endodermal and mesodermal origin. Various genetic pathways play critical roles in coordinating the development of cranial structures by modulating the growth, survival and differentiation of neural crest cells. However, the regulation of these pathways, particularly at the epigenomic level, remains poorly understood. Using murine genetics, we show that neural crest cells exhibit a requirement for the class I histone deacetylase Hdac3 during craniofacial development. Mice in which Hdac3 has been conditionally deleted in neural crest demonstrate fully penetrant craniofacial abnormalities, including microcephaly, cleft secondary palate and dental hypoplasia. Consistent with these abnormalities, we observe dysregulation of cell cycle genes and increased apoptosis in neural crest structures in mutant embryos. Known regulators of cell cycle progression and apoptosis in neural crest, including Msx1, Msx2 and Bmp4, are upregulated in Hdac3-deficient cranial mesenchyme. These results suggest that Hdac3 serves as a critical regulator of craniofacial morphogenesis, in part by repressing core apoptotic pathways in cranial neural crest cells. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Red light represses the photophysiology of the scleractinian coral Stylophora pistillata.

    Science.gov (United States)

    Wijgerde, Tim; van Melis, Anne; Silva, Catarina I F; Leal, Miguel C; Vogels, Luc; Mutter, Claudia; Osinga, Ronald

    2014-01-01

    Light spectrum plays a key role in the biology of symbiotic corals, with blue light resulting in higher coral growth, zooxanthellae density, chlorophyll a content and photosynthesis rates as compared to red light. However, it is still unclear whether these physiological processes are blue-enhanced or red-repressed. This study investigated the individual and combined effects of blue and red light on the health, zooxanthellae density, photophysiology and colouration of the scleractinian coral Stylophora pistillata over 6 weeks. Coral fragments were exposed to blue, red, and combined 50/50% blue red light, at two irradiance levels (128 and 256 μmol m(-2) s(-1)). Light spectrum affected the health/survival, zooxanthellae density, and NDVI (a proxy for chlorophyll a content) of S. pistillata. Blue light resulted in highest survival rates, whereas red light resulted in low survival at 256 μmol m(-2) s(-1). Blue light also resulted in higher zooxanthellae densities compared to red light at 256 μmol m(-2) s(-1), and a higher NDVI compared to red and combined blue red light. Overall, our results suggest that red light negatively affects the health, survival, symbiont density and NDVI of S. pistillata, with a dominance of red over blue light for NDVI.

  14. Red light represses the photophysiology of the scleractinian coral Stylophora pistillata.

    Directory of Open Access Journals (Sweden)

    Tim Wijgerde

    Full Text Available Light spectrum plays a key role in the biology of symbiotic corals, with blue light resulting in higher coral growth, zooxanthellae density, chlorophyll a content and photosynthesis rates as compared to red light. However, it is still unclear whether these physiological processes are blue-enhanced or red-repressed. This study investigated the individual and combined effects of blue and red light on the health, zooxanthellae density, photophysiology and colouration of the scleractinian coral Stylophora pistillata over 6 weeks. Coral fragments were exposed to blue, red, and combined 50/50% blue red light, at two irradiance levels (128 and 256 μmol m(-2 s(-1. Light spectrum affected the health/survival, zooxanthellae density, and NDVI (a proxy for chlorophyll a content of S. pistillata. Blue light resulted in highest survival rates, whereas red light resulted in low survival at 256 μmol m(-2 s(-1. Blue light also resulted in higher zooxanthellae densities compared to red light at 256 μmol m(-2 s(-1, and a higher NDVI compared to red and combined blue red light. Overall, our results suggest that red light negatively affects the health, survival, symbiont density and NDVI of S. pistillata, with a dominance of red over blue light for NDVI.

  15. Insulators target active genes to transcription factories and polycomb-repressed genes to polycomb bodies.

    Directory of Open Access Journals (Sweden)

    Hua-Bing Li

    2013-04-01

    Full Text Available Polycomb bodies are foci of Polycomb proteins in which different Polycomb target genes are thought to co-localize in the nucleus, looping out from their chromosomal context. We have shown previously that insulators, not Polycomb response elements (PREs, mediate associations among Polycomb Group (PcG targets to form Polycomb bodies. Here we use live imaging and 3C interactions to show that transgenes containing PREs and endogenous PcG-regulated genes are targeted by insulator proteins to different nuclear structures depending on their state of activity. When two genes are repressed, they co-localize in Polycomb bodies. When both are active, they are targeted to transcription factories in a fashion dependent on Trithorax and enhancer specificity as well as the insulator protein CTCF. In the absence of CTCF, assembly of Polycomb bodies is essentially reduced to those representing genomic clusters of Polycomb target genes. The critical role of Trithorax suggests that stable association with a specialized transcription factory underlies the cellular memory of the active state.

  16. BMP7 and SHH regulate Pax2 in mouse retinal astrocytes by relieving TLX repression.

    Science.gov (United States)

    Sehgal, Rachna; Sheibani, Nader; Rhodes, Simon J; Belecky Adams, Teri L

    2009-08-15

    Pax2 is essential for development of the neural tube, urogenital system, optic vesicle, optic cup and optic tract. In the eye, Pax2 deficiency is associated with coloboma, a loss of astrocytes in the optic nerve and retina, and abnormal axonal pathfinding of the ganglion cell axons at the optic chiasm. Thus, appropriate expression of Pax2 is essential for astrocyte determination and differentiation. Although BMP7 and SHH have been shown to regulate Pax2 expression, the molecular mechanism by which this regulation occurs is not well understood. In this study, we determined that BMP7 and SHH activate Pax2 expression in mouse retinal astrocyte precursors in vitro. SHH appeared to play a dual role in Pax2 regulation; 1) SHH may regulate BMP7 expression, and 2) the SHH pathway cooperates with the BMP pathway to regulate Pax2 expression. BMP and SHH pathway members can interact separately or together with TLX, a repressor protein in the tailless transcription factor family. Here we show that the interaction of both pathways with TLX relieves the repression of Pax2 expression in mouse retinal astrocytes. Together these data reveal a new mechanism for the cooperative actions of signaling pathways in astrocyte determination and differentiation and suggest interactions of regulatory pathways that are applicable to other developmental programs.

  17. Red Light Represses the Photophysiology of the Scleractinian Coral Stylophora pistillata

    Science.gov (United States)

    Wijgerde, Tim; van Melis, Anne; Silva, Catarina I. F.; Leal, Miguel C.; Vogels, Luc; Mutter, Claudia; Osinga, Ronald

    2014-01-01

    Light spectrum plays a key role in the biology of symbiotic corals, with blue light resulting in higher coral growth, zooxanthellae density, chlorophyll a content and photosynthesis rates as compared to red light. However, it is still unclear whether these physiological processes are blue-enhanced or red-repressed. This study investigated the individual and combined effects of blue and red light on the health, zooxanthellae density, photophysiology and colouration of the scleractinian coral Stylophora pistillata over 6 weeks. Coral fragments were exposed to blue, red, and combined 50/50% blue red light, at two irradiance levels (128 and 256 μmol m−2 s−1). Light spectrum affected the health/survival, zooxanthellae density, and NDVI (a proxy for chlorophyll a content) of S. pistillata. Blue light resulted in highest survival rates, whereas red light resulted in low survival at 256 μmol m−2 s−1. Blue light also resulted in higher zooxanthellae densities compared to red light at 256 μmol m−2 s−1, and a higher NDVI compared to red and combined blue red light. Overall, our results suggest that red light negatively affects the health, survival, symbiont density and NDVI of S. pistillata, with a dominance of red over blue light for NDVI. PMID:24658108

  18. Trp53 activity is repressed in radio-adapted cultured murine limb bud cells

    International Nuclear Information System (INIS)

    Vares, Guillaume; Wang, Bing; Tanaka, Kaoru; Shang, Yi; Fujita, Kazuko; Hayata, Isamu; Nenoi, Mitsuru

    2011-01-01

    Understanding the effects of ionizing radiation (IR) at low dose in fetal models is of great importance, because the fetus is considered to be at the most radiosensitive stage of the development and prenatal radiation might influence subsequent development. We previously demonstrated the existence of an adaptive response (AR) in murine fetuses after pre-exposure to low doses of X-rays. Trp53-dependent apoptosis was suggested to be responsible for the teratogenic effects of IR; decreased apoptosis was observed in adapted animals. In this study, in order to investigate the role of Trp53 in AR, we developed a new model of irradiated micromass culture of fetal limb bud cells, which replicated proliferation, differentiation and response to IR in murine embryos. Murine fetuses were exposed to whole-body priming irradiation of 0.3 Gy or 0.5 Gy at embryonic day 11 (E11). Limb bud cells (collected from digital ray areas exhibiting radiation-induced apoptosis) were cultured and exposed to a challenging dose of 4 Gy at E12 equivalent. The levels of Trp53 protein and its phosphorylated form at Ser18 were investigated. Our results suggested that the induction of AR in mouse embryos was correlated with a repression of Trp53 activity. (author)

  19. Repression and black holes in Laurent Mauvignier novel about Algerian War

    Directory of Open Access Journals (Sweden)

    Giacomo Raccis

    2015-12-01

    Full Text Available XXth century history obliged narrators to clash with events that was literally inexpressible, measuring the potential and the lack of literary means. Laurent Mauvignier made this confrontarion the centre of his poetics: from minimal, private tragedies to great, historical dramas, passing through the media mystification of absurd fait divers, his novels face the Evil problem and its representation in words. With Des hommes (2009, Mauvignier addresses his question to one of the most problematic repression object in historical French memory: Algerian War. Building a polyphonic novel, he deals with an event deeply characterized by silence (the veteran silence studied by Benjamin Stora and Andrea Brazzoduro and that has been manipulated by the institutional and mediatic vulgata. Infact, the narration shows how the amnesty of collective faults is based on the "order to say nothing" (overturning Foucault, first of all caused by the social load of an history that nobody wants. This paper aims at showing how Mauvignier's work, inspired by modernist novel and "nouveau roman" (Duras, Simon, resorts to literary experimentalism to "défamiliariser" this historical event using the tools of a fiction claiming the value of a "secondary experience" to redeem a piece of history refused by the public discourse.

  20. Histone H3 Serine 28 Is Essential for Efficient Polycomb-Mediated Gene Repression in Drosophila

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    Philip Yuk Kwong Yung

    2015-06-01

    Full Text Available Trimethylation at histone H3K27 is central to the polycomb repression system. Juxtaposed to H3K27 is a widely conserved phosphorylatable serine residue (H3S28 whose function is unclear. To assess the importance of H3S28, we generated a Drosophila H3 histone mutant with a serine-to-alanine mutation at position 28. H3S28A mutant cells lack H3S28ph on mitotic chromosomes but support normal mitosis. Strikingly, all methylation states of H3K27 drop in H3S28A cells, leading to Hox gene derepression and to homeotic transformations in adult tissues. These defects are not caused by active H3K27 demethylation nor by the loss of H3S28ph. Biochemical assays show that H3S28A nucleosomes are a suboptimal substrate for PRC2, suggesting that the unphosphorylated state of serine 28 is important for assisting in the function of polycomb complexes. Collectively, our data indicate that the conserved H3S28 residue in metazoans has a role in supporting PRC2 catalysis.

  1. SIRT7 Represses Myc Activity to Suppress ER Stress and Prevent Fatty Liver Disease

    Directory of Open Access Journals (Sweden)

    Jiyung Shin

    2013-11-01

    Full Text Available Nonalcoholic fatty liver disease is the most common chronic liver disorder in developed countries. Its pathogenesis is poorly understood, and therapeutic options are limited. Here, we show that SIRT7, an NAD+-dependent H3K18Ac deacetylase, functions at chromatin to suppress ER stress and prevent the development of fatty liver disease. SIRT7 is induced upon ER stress and is stabilized at the promoters of ribosomal proteins through its interaction with the transcription factor Myc to silence gene expression and to relieve ER stress. SIRT7-deficient mice develop chronic hepatosteatosis resembling human fatty liver disease. Myc inactivation or pharmacological suppression of ER stress alleviates fatty liver caused by SIRT7 deficiency. Importantly, SIRT7 suppresses ER stress and reverts the fatty liver disease in diet-induced obese mice. Our study identifies SIRT7 as a cofactor of Myc for transcriptional repression and delineates a druggable regulatory branch of the ER stress response that prevents and reverts fatty liver disease.

  2. miR-186 inhibits cell proliferation in multiple myeloma by repressing Jagged1

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zengyan [Department of Hematology, Qilu Hospital, Shandong University, 107 Wenhuaxi Road, Jinan, Shandong 250012 (China); Department of Hematology, Hospital Affiliated to Binzhou Medical University, 661 Second Huanghe Street, Binzhou 256603 (China); Zhang, Guoqiang [Department of Thyroid and Breast Surgery, Hospital Affiliated to Binzhou Medical University, 661 Second Huanghe Street, Binzhou 256603 (China); Yu, Wenzheng; Gao, Na [Department of Hematology, Hospital Affiliated to Binzhou Medical University, 661 Second Huanghe Street, Binzhou 256603 (China); Peng, Jun, E-mail: junpeng885@sina.com [Department of Hematology, Qilu Hospital, Shandong University, 107 Wenhuaxi Road, Jinan, Shandong 250012 (China)

    2016-01-15

    MicroRNAs (miRNAs) are small, noncoding ribonucleic acids that regulate gene expression by targeting mRNAs for translational repression and degradation. Accumulating experimental evidence supports a causal role of miRNAs in hematology tumorigenesis. However, the specific functions of miRNAs in the pathogenesis of multiple myeloma (MM) remain to be established. In this study, we demonstrated that miR-186 is commonly downregulated in MM cell lines and patient MM cells. Ectopic expression of miR-186 significantly inhibited cell growth, both in vitro and in vivo, and induced cell cycle G{sub 0}/G{sub 1} arrest. Furthermore, miR-186 induced downregulation of Jagged1 protein expression by directly targeting its 3′-untranslated region (3′-UTR). Conversely, overexpression of Jagged1 rescued cells from miR-186-induced growth inhibition. Our collective results clearly indicate that miR-186 functions as a tumor suppressor in MM, supporting its potential as a therapeutic target for the disease. - Highlights: • miR-186 expression is decreased in MM. • miR-186 inhibits MM cell proliferation in vitro and in vivo. • Jagged1 is regulated by miR-186. • Overexpression of Jagged1 reverses the effects of miR-186.

  3. Selective translational repression of truncated proteins from frameshift mutation-derived mRNAs in tumors.

    Directory of Open Access Journals (Sweden)

    Kwon Tae You

    2007-05-01

    Full Text Available Frameshift and nonsense mutations are common in tumors with microsatellite instability, and mRNAs from these mutated genes have premature termination codons (PTCs. Abnormal mRNAs containing PTCs are normally degraded by the nonsense-mediated mRNA decay (NMD system. However, PTCs located within 50-55 nucleotides of the last exon-exon junction are not recognized by NMD (NMD-irrelevant, and some PTC-containing mRNAs can escape from the NMD system (NMD-escape. We investigated protein expression from NMD-irrelevant and NMD-escape PTC-containing mRNAs by Western blotting and transfection assays. We demonstrated that transfection of NMD-irrelevant PTC-containing genomic DNA of MARCKS generates truncated protein. In contrast, NMD-escape PTC-containing versions of hMSH3 and TGFBR2 generate normal levels of mRNA, but do not generate detectable levels of protein. Transfection of NMD-escape mutant TGFBR2 genomic DNA failed to generate expression of truncated proteins, whereas transfection of wild-type TGFBR2 genomic DNA or mutant PTC-containing TGFBR2 cDNA generated expression of wild-type protein and truncated protein, respectively. Our findings suggest a novel mechanism of gene expression regulation for PTC-containing mRNAs in which the deleterious transcripts are regulated either by NMD or translational repression.

  4. Sizzled controls dorso-ventral polarity by repressing cleavage of the Chordin protein.

    Science.gov (United States)

    Muraoka, Osamu; Shimizu, Takashi; Yabe, Taijiro; Nojima, Hideaki; Bae, Young-Ki; Hashimoto, Hisashi; Hibi, Masahiko

    2006-04-01

    The Bone morphogenetic protein (Bmp) signalling gradient has a major function in the formation of the dorso-ventral axis. The zebrafish ventralized mutant, ogon, encodes Secreted Frizzled (Sizzled). sizzled is ventrally expressed in a Bmp-dependent manner and is required for the suppression of Bmp signalling on the ventral side of zebrafish embryos. However, it remains unclear how Sizzled inhibits Bmp signalling and controls ventro-lateral cell fate. We found that Sizzled stabilizes Chordin, a Bmp antagonist, by binding and inhibiting the Tolloid-family metalloproteinase, Bmp1a, which cleaves and inactivates Chordin. The cysteine-rich domain of Sizzled is required for inhibition of Bmp1a activity. Loss of both Bmp1a and Tolloid-like1 (Tll1; another Tolloid-family metalloproteinase) function leads to a complete suppression and reversal of the ogon mutant phenotype. These results indicate that Sizzled represses the activities of Tolloid-family proteins, thereby creating the Chordin-Bmp activity gradient along the dorso-ventral axis. Here, we describe a previously unrecognized role for a secreted Frizzled-related protein.

  5. βig-h3 Represses T-Cell Activation in Type 1 Diabetes.

    Science.gov (United States)

    Patry, Maeva; Teinturier, Romain; Goehrig, Delphine; Zetu, Cornelia; Ripoche, Doriane; Kim, In-San; Bertolino, Philippe; Hennino, Ana

    2015-12-01

    βig-h3/TGF-βi is a secreted protein capable of binding to both extracellular matrix and cells. Human genetic studies recently revealed that in the tgfbi gene encoding for βig-h3, three single nucleotide polymorphisms were significantly associated with type 1 diabetes (T1D) risk. Pancreatic islets express βig-h3 in physiological conditions, but this expression is reduced in β-cell insult in T1D. Since the integrity of islets is destroyed by autoimmune T lymphocytes, we thought to investigate the impact of βig-h3 on T-cell activation. We show here that βig-h3 inhibits T-cell activation markers as well as cytotoxic molecule production as granzyme B and IFN-γ. Furthermore, βig-h3 inhibits early T-cell receptor signaling by repressing the activation of the early kinase protein Lck. Moreover, βig-h3-treated T cells are unable to induce T1D upon transfer in Rag2 knockout mice. Our study demonstrates for the first time that T-cell activation is modulated by βig-h3, an islet extracellular protein, in order to efficiently avoid autoimmune response. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  6. MUC1-C activates polycomb repressive complexes and downregulates tumor suppressor genes in human cancer cells.

    Science.gov (United States)

    Rajabi, Hasan; Hiraki, Masayuki; Kufe, Donald

    2018-04-01

    The PRC2 and PRC1 complexes are aberrantly expressed in human cancers and have been linked to decreases in patient survival. MUC1-C is an oncoprotein that is also overexpressed in diverse human cancers and is associated with a poor prognosis. Recent studies have supported a previously unreported function for MUC1-C in activating PRC2 and PRC1 in cancer cells. In the regulation of PRC2, MUC1-C (i) drives transcription of the EZH2 gene, (ii) binds directly to EZH2, and (iii) enhances occupancy of EZH2 on target gene promoters with an increase in H3K27 trimethylation. Regarding PRC1, which is recruited to PRC2 sites in the hierarchical model, MUC1-C induces BMI1 transcription, forms a complex with BMI1, and promotes H2A ubiquitylation. MUC1-C thereby contributes to the integration of PRC2 and PRC1-mediated repression of tumor suppressor genes, such as CDH1, CDKN2A, PTEN and BRCA1. Like PRC2 and PRC1, MUC1-C is associated with the epithelial-mesenchymal transition (EMT) program, cancer stem cell (CSC) state, and acquisition of anticancer drug resistance. In concert with these observations, targeting MUC1-C downregulates EZH2 and BMI1, inhibits EMT and the CSC state, and reverses drug resistance. These findings emphasize the significance of MUC1-C as a therapeutic target for inhibiting aberrant PRC function and reprogramming the epigenome in human cancers.

  7. p53 Represses the Oncogenic Sno-MiR-28 Derived from a SnoRNA.

    Directory of Open Access Journals (Sweden)

    Feng Yu

    Full Text Available p53 is a master tumour repressor that participates in vast regulatory networks, including feedback loops involving microRNAs (miRNAs that regulate p53 and that themselves are direct p53 transcriptional targets. We show here that a group of polycistronic miRNA-like non-coding RNAs derived from small nucleolar RNAs (sno-miRNAs are transcriptionally repressed by p53 through their host gene, SNHG1. The most abundant of these, sno-miR-28, directly targets the p53-stabilizing gene, TAF9B. Collectively, p53, SNHG1, sno-miR-28 and TAF9B form a regulatory loop which affects p53 stability and downstream p53-regulated pathways. In addition, SNHG1, SNORD28 and sno-miR-28 are all significantly upregulated in breast tumours and the overexpression of sno-miR-28 promotes breast epithelial cell proliferation. This research has broadened our knowledge of the crosstalk between small non-coding RNA pathways and roles of sno-miRNAs in p53 regulation.

  8. Gene repressive mechanisms in the mouse brain involved in memory formation.

    Science.gov (United States)

    Yu, Nam-Kyung; Kaang, Bong-Kiun

    2016-04-01

    Gene regulation in the brain is essential for long-term plasticity and memory formation. Despite this established notion, the quantitative translational map in the brain during memory formation has not been reported. To systematically probe the changes in protein synthesis during memory formation, our recent study exploited ribosome profiling using the mouse hippocampal tissues at multiple time points after a learning event. Analysis of the resulting database revealed novel types of gene regulation after learning. First, the translation of a group of genes was rapidly suppressed without change in mRNA levels. At later time points, the expression of another group of genes was downregulated through reduction in mRNA levels. This reduction was predicted to be downstream of inhibition of ESR1 (Estrogen Receptor 1) signaling. Overexpressing Nrsn1, one of the genes whose translation was suppressed, or activating ESR1 by injecting an agonist interfered with memory formation, suggesting the functional importance of these findings. Moreover, the translation of genes encoding the translational machineries was found to be suppressed, among other genes in the mouse hippocampus. Together, this unbiased approach has revealed previously unidentified characteristics of gene regulation in the brain and highlighted the importance of repressive controls. [BMB Reports 2016; 49(4): 199-200].

  9. DGCR8 Promotes Neural Progenitor Expansion and Represses Neurogenesis in the Mouse Embryonic Neocortex

    Directory of Open Access Journals (Sweden)

    Nadin Hoffmann

    2018-04-01

    Full Text Available DGCR8 and DROSHA are the minimal functional core of the Microprocessor complex essential for biogenesis of canonical microRNAs and for the processing of other RNAs. Conditional deletion of Dgcr8 and Drosha in the murine telencephalon indicated that these proteins exert crucial functions in corticogenesis. The identification of mechanisms of DGCR8- or DROSHA-dependent regulation of gene expression in conditional knockout mice are often complicated by massive apoptosis. Here, to investigate DGCR8 functions on amplification/differentiation of neural progenitors cells (NPCs in corticogenesis, we overexpress Dgcr8 in the mouse telencephalon, by in utero electroporation (IUEp. We find that DGCR8 promotes the expansion of NPC pools and represses neurogenesis, in absence of apoptosis, thus overcoming the usual limitations of Dgcr8 knockout-based approach. Interestingly, DGCR8 selectively promotes basal progenitor amplification at later developmental stages, entailing intriguing implications for neocortical expansion in evolution. Finally, despite a 3- to 5-fold increase of DGCR8 level in the mouse telencephalon, the composition, target preference and function of the DROSHA-dependent Microprocessor complex remain unaltered. Thus, we propose that DGCR8-dependent modulation of gene expression in corticogenesis is more complex than previously known, and possibly DROSHA-independent.

  10. Ezh2 represses the basal cell lineage during lung endoderm development.

    Science.gov (United States)

    Snitow, Melinda E; Li, Shanru; Morley, Michael P; Rathi, Komal; Lu, Min Min; Kadzik, Rachel S; Stewart, Kathleen M; Morrisey, Edward E

    2015-01-01

    The development of the lung epithelium is regulated in a stepwise fashion to generate numerous differentiated and stem cell lineages in the adult lung. How these different lineages are generated in a spatially and temporally restricted fashion remains poorly understood, although epigenetic regulation probably plays an important role. We show that the Polycomb repressive complex 2 component Ezh2 is highly expressed in early lung development but is gradually downregulated by late gestation. Deletion of Ezh2 in early lung endoderm progenitors leads to the ectopic and premature appearance of Trp63+ basal cells that extend the entire length of the airway. Loss of Ezh2 also leads to reduced secretory cell differentiation. In their place, morphologically similar cells develop that express a subset of basal cell genes, including keratin 5, but no longer express high levels of either Trp63 or of standard secretory cell markers. This suggests that Ezh2 regulates the phenotypic switch between basal cells and secretory cells. Together, these findings show that Ezh2 restricts the basal cell lineage during normal lung endoderm development to allow the proper patterning of epithelial lineages during lung formation. © 2015. Published by The Company of Biologists Ltd.

  11. Id1 represses osteoclast-dependent transcription and affects bone formation and hematopoiesis.

    Directory of Open Access Journals (Sweden)

    April S Chan

    2009-11-01

    Full Text Available The bone-bone marrow interface is an area of the bone marrow microenvironment in which both bone remodeling cells, osteoblasts and osteoclasts, and hematopoietic cells are anatomically juxtaposed. The close proximity of these cells naturally suggests that they interact with one another, but these interactions are just beginning to be characterized.An Id1(-/- mouse model was used to assess the role of Id1 in the bone marrow microenvironment. Micro-computed tomography and fracture tests showed that Id1(-/- mice have reduced bone mass and increased bone fragility, consistent with an osteoporotic phenotype. Osteoclastogenesis and pit formation assays revealed that loss of Id1 increased osteoclast differentiation and resorption activity, both in vivo and in vitro, suggesting a cell autonomous role for Id1 as a negative regulator of osteoclast differentiation. Examination by flow cytometry of the hematopoietic compartment of Id1(-/- mice showed an increase in myeloid differentiation. Additionally, we found increased expression of osteoclast genes, TRAP, Oscar, and CTSK in the Id1(-/- bone marrow microenvironment. Lastly, transplantation of wild-type bone marrow into Id1(-/- mice repressed TRAP, Oscar, and CTSK expression and activity and rescued the hematopoietic and bone phenotype in these mice.In conclusion, we demonstrate an osteoporotic phenotype in Id1(-/- mice and a mechanism for Id1 transcriptional control of osteoclast-associated genes. Our results identify Id1 as a principal player responsible for the dynamic cross-talk between bone and bone marrow hematopoietic cells.

  12. Autophagy induction under carbon starvation conditions is negatively regulated by carbon catabolite repression.

    Science.gov (United States)

    Adachi, Atsuhiro; Koizumi, Michiko; Ohsumi, Yoshinori

    2017-12-01

    Autophagy is a conserved process in which cytoplasmic components are sequestered for degradation in the vacuole/lysosomes in eukaryotic cells. Autophagy is induced under a variety of starvation conditions, such as the depletion of nitrogen, carbon, phosphorus, zinc, and others. However, apart from nitrogen starvation, it remains unclear how these stimuli induce autophagy. In yeast, for example, it remains contentious whether autophagy is induced under carbon starvation conditions, with reports variously suggesting both induction and lack of induction upon depletion of carbon. We therefore undertook an analysis to account for these inconsistencies, concluding that autophagy is induced in response to abrupt carbon starvation when cells are grown with glycerol but not glucose as the carbon source. We found that autophagy under these conditions is mediated by nonselective degradation that is highly dependent on the autophagosome-associated scaffold proteins Atg11 and Atg17. We also found that the extent of carbon starvation-induced autophagy is positively correlated with cells' oxygen consumption rate, drawing a link between autophagy induction and respiratory metabolism. Further biochemical analyses indicated that maintenance of intracellular ATP levels is also required for carbon starvation-induced autophagy and that autophagy plays an important role in cell viability during prolonged carbon starvation. Our findings suggest that carbon starvation-induced autophagy is negatively regulated by carbon catabolite repression. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. From Overcoming the fear to Protest, to using Fear as a repressive strategy towards the 15M movement

    Directory of Open Access Journals (Sweden)

    Clara Camps Calvet

    2015-12-01

    Full Text Available In this article we analyse the police repression strategies that were developed around the emergence of the 15M movement in Barcelona, which was an important turning point for protest and repression. Through press reviews, discussion groups and interviews we empirically contribute to previous theoretical studies that deal with strategies for policing protests. We recognize that "strategic incapacitation" is a new style of policing protests that has taken hold in the last decade. However, we reflect on the importance of understanding this new strategy, within an increasingly more punitive state under transformation, that creates enemies to erode the rights of most the population. In the case of the protests, this also seeks to create fear and consequently tries to dismantle and wear down current and potential participants of social movements.

  14. Members of the LBD Family of Transcription Factors Repress Anthocyanin Synthesis and Affect Additional Nitrogen Responses in Arabidopsis

    OpenAIRE

    Rubin, G.; Tohge, T.; Matsuda, F.; Saito, K.; Scheible, W.

    2009-01-01

    Nitrogen (N) and nitrate (NO3-) per se regulate many aspects of plant metabolism, growth, and development. N/NO3- also suppresses parts of secondary metabolism, including anthocyanin synthesis. Molecular components for this repression are unknown. We report that three N/NO3--induced members of the LATERAL ORGAN BOUNDARY DOMAIN (LBD) gene family of transcription factors (LBD37, LBD38, and LBD39) act as negative regulators of anthocyanin biosynthesis in Arabidopsis thaliana. Overexpression of e...

  15. A study of the evolution of human microRNAs by their apparent repression effectiveness on target genes.

    Directory of Open Access Journals (Sweden)

    Yong Huang

    Full Text Available BACKGROUND: Even though the genomes of many model species have already been sequenced, our knowledge of gene regulation in evolution is still very limited. One big obstacle is that it is hard to predict the target genes of transcriptional factors accurately from sequences. In this respect, microRNAs (miRNAs are different from transcriptional factors, as target genes of miRNAs can be readily predicted from sequences. This feature of miRNAs offers an unprecedented vantage point for evolutionary analysis of gene regulation. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we analyzed a particular aspect of miRNA evolution, the differences in the "apparent repression effectiveness (ARE" between human miRNAs of different conservational levels. ARE is a measure we designed to evaluate the repression effect of miRNAs on target genes based on publicly available gene expression data in normal tissues and miRNA targeting and expression data. We found that ARE values of more conserved miRNAs are significantly higher than those of less conserved miRNAs in general. We also found the gain in expression abundance and broadness of miRNAs in evolution contributed to the gain in ARE. CONCLUSIONS/SIGNIFICANCE: The ARE measure quantifies the repressive effects of miRNAs and enables us to study the influences of many factors on miRNA-mediated repression, such as conservational levels and expression levels of miRNAs. The gain in ARE can be explained by the existence of a trend of miRNAs in evolution to effectively control more target genes, which is beneficial to the miRNAs but not necessarily to the organism at all times. Our results from miRNAs gave us an insight of the complex interplay between regulators and target genes in evolution.

  16. Exogenous auxin represses soybean seed germination through decreasing the gibberellin/abscisic acid (GA/ABA) ratio

    OpenAIRE

    Shuai, Haiwei; Meng, Yongjie; Luo, Xiaofeng; Chen, Feng; Zhou, Wenguan; Dai, Yujia; Qi, Ying; Du, Junbo; Yang, Feng; Liu, Jiang; Yang, Wenyu; Shu, Kai

    2017-01-01

    Auxin is an important phytohormone which mediates diverse development processes in plants. Published research has demonstrated that auxin induces seed dormancy. However, the precise mechanisms underlying the effect of auxin on seed germination need further investigation, especially the relationship between auxins and both abscisic acid (ABA) and gibberellins (GAs), the latter two phytohormones being the key regulators of seed germination. Here we report that exogenous auxin treatment represse...

  17. CTCF and CohesinSA-1 Mark Active Promoters and Boundaries of Repressive Chromatin Domains in Primary Human Erythroid Cells.

    Directory of Open Access Journals (Sweden)

    Laurie A Steiner

    Full Text Available CTCF and cohesinSA-1 are regulatory proteins involved in a number of critical cellular processes including transcription, maintenance of chromatin domain architecture, and insulator function. To assess changes in the CTCF and cohesinSA-1 interactomes during erythropoiesis, chromatin immunoprecipitation coupled with high throughput sequencing and mRNA transcriptome analyses via RNA-seq were performed in primary human hematopoietic stem and progenitor cells (HSPC and primary human erythroid cells from single donors.Sites of CTCF and cohesinSA-1 co-occupancy were enriched in gene promoters in HSPC and erythroid cells compared to single CTCF or cohesin sites. Cell type-specific CTCF sites in erythroid cells were linked to highly expressed genes, with the opposite pattern observed in HSPCs. Chromatin domains were identified by ChIP-seq with antibodies against trimethylated lysine 27 histone H3, a modification associated with repressive chromatin. Repressive chromatin domains increased in both number and size during hematopoiesis, with many more repressive domains in erythroid cells than HSPCs. CTCF and cohesinSA-1 marked the boundaries of these repressive chromatin domains in a cell-type specific manner.These genome wide data, changes in sites of protein occupancy, chromatin architecture, and related gene expression, support the hypothesis that CTCF and cohesinSA-1 have multiple roles in the regulation of gene expression during erythropoiesis including transcriptional regulation at gene promoters and maintenance of chromatin architecture. These data from primary human erythroid cells provide a resource for studies of normal and perturbed erythropoiesis.

  18. pH-Dependent DNA Distortion and Repression of Gene Expression by Pectobacterium atrosepticum PecS.

    Science.gov (United States)

    Deochand, Dinesh K; Meariman, Jacob K; Grove, Anne

    2016-07-15

    Transcriptional activity is exquisitely sensitive to changes in promoter DNA topology. Transcription factors may therefore control gene activity by modulating the relative positioning of -10 and -35 promoter elements. The plant pathogen Pectobacterium atrosepticum, which causes soft rot in potatoes, must alter gene expression patterns to ensure growth in planta. In the related soft-rot enterobacterium Dickeya dadantii, PecS functions as a master regulator of virulence gene expression. Here, we report that P. atrosepticum PecS controls gene activity by altering promoter DNA topology in response to pH. While PecS binds the pecS promoter with high affinity regardless of pH, it induces significant DNA distortion only at neutral pH, the pH at which the pecS promoter is repressed in vivo. At pH ∼8, DNA distortions are attenuated, and PecS no longer represses the pecS promoter. A specific histidine (H142) located in a crevice between the dimerization- and DNA-binding regions is required for pH-dependent changes in DNA distortion and repression of gene activity, and mutation of this histidine renders the mutant protein incapable of repressing the pecS promoter. We propose that protonated PecS induces a DNA conformation at neutral pH in which -10 and -35 promoter elements are suboptimally positioned for RNA polymerase binding; on deprotonation of PecS, binding is no longer associated with significant changes in DNA conformation, allowing gene expression. We suggest that this mode of gene regulation leads to differential expression of the PecS regulon in response to alkalinization of the plant apoplast.

  19. Vertebrate-like CRYPTOCHROME 2 from monarch regulates circadian transcription via independent repression of CLOCK and BMAL1 activity.

    Science.gov (United States)

    Zhang, Ying; Markert, Matthew J; Groves, Shayna C; Hardin, Paul E; Merlin, Christine

    2017-09-05

    Circadian repression of CLOCK-BMAL1 by PERIOD and CRYPTOCHROME (CRY) in mammals lies at the core of the circadian timekeeping mechanism. CRY repression of CLOCK-BMAL1 and regulation of circadian period are proposed to rely primarily on competition for binding with coactivators on an α-helix located within the transactivation domain (TAD) of the BMAL1 C terminus. This model has, however, not been tested in vivo. Here, we applied CRISPR/Cas9-mediated mutagenesis in the monarch butterfly ( Danaus plexippus ), which possesses a vertebrate-like CRY (dpCRY2) and an ortholog of BMAL1, to show that insect CRY2 regulates circadian repression through TAD α-helix-dependent and -independent mechanisms. Monarch mutants lacking the BMAL1 C terminus including the TAD exhibited arrhythmic eclosion behavior. In contrast, mutants lacking the TAD α-helix but retaining the most distal C-terminal residues exhibited robust rhythms during the first day of constant darkness (DD1), albeit with a delayed peak of eclosion. Phase delay in this mutant on DD1 was exacerbated in the presence of a single functional allele of dpCry2 , and rhythmicity was abolished in the absence of dpCRY2. Reporter assays in Drosophila S2 cells further revealed that dpCRY2 represses through two distinct mechanisms: a TAD-dependent mechanism that involves the dpBMAL1 TAD α-helix and dpCLK W328 and a TAD-independent mechanism involving dpCLK E333. Together, our results provide evidence for independent mechanisms of vertebrate-like CRY circadian regulation on the BMAL1 C terminus and the CLK PAS-B domain and demonstrate the importance of a BMAL1 TAD-independent mechanism for generating circadian rhythms in vivo.

  20. Repression of multiple CYP2D genes in mouse primary hepatocytes with a single siRNA construct.

    Science.gov (United States)

    Elraghy, Omaima; Baldwin, William S

    2015-01-01

    The Cyp2d subfamily is the second most abun-dant subfamily of hepatic drug-metabolizing CYPs. In mice, there are nine Cyp2d members that are believed to have redundant catalytic activity. We are testing and optimizing the ability of one short interfering RNA (siRNA) construct to knockdown the expression of multiple mouse Cyp2ds in primary hepatocytes. Expression of Cyp2d10, Cyp2d11, Cyp2d22, and Cyp2d26 was observed in the primary male mouse hepatocytes. Cyp2d9, which is male-specific and growth hormone-dependent, was not expressed in male primary hepatocytes, potentially because of its dependence on pulsatile growth hormone release from the anterior pituitary. Several different siRNAs at different concentrations and with different reagents were used to knockdown Cyp2d expression. siRNA constructs designed to repress only one construct often mildly repressed several Cyp2d isoforms. A construct designed to knockdown every Cyp2d isoform provided the best results, especially when incubated with transfection reagents designed specifically for primary cell culture. Interestingly, a construct designed to knockdown all Cyp2d isoforms, except Cyp2d10, caused a 2.5× increase in Cyp2d10 expression, presumably because of a compensatory response. However, while RNA expression is repressed 24 h after siRNA treatment, associated changes in Cyp2d-mediated metabolism are tenuous. Overall, this study provides data on the expression of murine Cyp2ds in primary cell lines, valuable information on designing siRNAs for silencing multiple murine CYPs, and potential pros and cons of using siRNA as a tool for repressing Cyp2d and estimating Cyp2d's role in murine xenobiotic metabolism.

  1. A arqueologia da repressão no contexto das ditaduras militares da Argentina, Uruguai e Brasil

    Directory of Open Access Journals (Sweden)

    Giullia Caldas dos Anjos

    2015-06-01

    Full Text Available Este artigo propõe-se a analisar a chamada “arqueologia da repressão” no Uruguai, na Argentina e no Brasil, a partir de obra de alguns autores que elegeram esse tema enquanto objeto de estudo, como, por exemplo, a de Pedro Paulo Abreu Funari, Andrés Zarankin e José Alberioni dos Reis, “Arqueologia da repressão e da resistência: América Latina na era das ditaduras (décadas de 1960-1980”. Este artigo estrutura-se em quatro partes, abrangendo delimitação conceitual; breve histórico a respeito do período ditatorial nos três países tratados; como é trabalhada a arqueologia da repressão nos países em questão; e, por fim traçarei um paralelo entre a forma pela qual é visto este tipo de arqueologia em cada país, de que forma o seu estudo afeta as sociedades e qual é a importância que assumem tais evidências para estes países, que só muito recentemente, retomaram o estado de direito.

  2. Toward the Question of the Victims' Number of Political Repressions for Orthodox Belief in Russia in ХХ century

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    Somin Nikolai

    2015-06-01

    Full Text Available Toward the Question of the Victims’ Number of Political Repressions for Orthodox Belief in Russia in ХХ century Somin Nikolay Vladimirovich The author off ers the technique of the approximate estimate of the general number of orthodox believers suffering for the Christ during XX century in Russia. The technique is based on the process’s analysis of the data input of new persons to the Database of New Russian martyrs and Confessors which has been developed in PSTGU. The feature of it is the number of «twins» in the Database, i.e. persons who already are in the Base. It assists making the conclusion concerning the general number of victims. For experiments the author used the incoming stream received from Base of the subjected to repression persons, developed by the Society the Memorial. The author brings results of calculations and necessary historical inquiries. As a result he makes the conclusion, that the general number of the Victims of Political Repression for Orthodox Belief in Russia during XX c. was about 100 thousand persons (with a margin error in 40 %.

  3. SRSF3 represses the expression of PDCD4 protein by coordinated regulation of alternative splicing, export and translation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seung Kuk; Jeong, Sunjoo, E-mail: sjsj@dankook.ac.kr

    2016-02-05

    Gene expression is regulated at multiple steps, such as transcription, splicing, export, degradation and translation. Considering diverse roles of SR proteins, we determined whether the tumor-related splicing factor SRSF3 regulates the expression of the tumor-suppressor protein, PDCD4, at multiple steps. As we have reported previously, knockdown of SRSF3 increased the PDCD4 protein level in SW480 colon cancer cells. More interestingly, here we showed that the alternative splicing and the nuclear export of minor isoforms of pdcd4 mRNA were repressed by SRSF3, but the translation step was unaffected. In contrast, only the translation step of the major isoform of pdcd4 mRNA was repressed by SRSF3. Therefore, overexpression of SRSF3 might be relevant to the repression of all isoforms of PDCD4 protein levels in most types of cancer cell. We propose that SRSF3 could act as a coordinator of the expression of PDCD4 protein via two mechanisms on two alternatively spliced mRNA isoforms.

  4. Scaffold protein enigma homolog 1 overcomes the repression of myogenesis activation by inhibitor of DNA binding 2

    Energy Technology Data Exchange (ETDEWEB)

    Nakatani, Miyuki [Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Nagoya, 464-8106 (Japan); Ito, Jumpei [Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Nagoya, 464-8106 (Japan); Japan Society for the Promotion of Science, Tokyo, 102-0083 (Japan); Koyama, Riko [Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Nagoya, 464-8106 (Japan); Iijima, Masumi; Yoshimoto, Nobuo [The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047 (Japan); Niimi, Tomoaki [Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Nagoya, 464-8106 (Japan); Kuroda, Shun' ichi [Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Nagoya, 464-8106 (Japan); The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047 (Japan); Maturana, Andrés D., E-mail: maturana@agr.nagoya-u.ac.jp [Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Nagoya, 464-8106 (Japan)

    2016-05-27

    Enigma Homolog 1 (ENH1) is a scaffold protein for signaling proteins and transcription factors. Previously, we reported that ENH1 overexpression promotes the differentiation of C2C12 myoblasts. However, the molecular mechanism underlying the role of ENH1 in the C2C12 cells differentiation remains elusive. ENH1 was shown to inhibit the proliferation of neuroblastoma cells by sequestering Inhibitor of DNA binding protein 2 (Id2) in the cytosol. Id2 is a repressor of basic Helix-Loop-Helix transcription factors activity and prevents myogenesis. Here, we found that ENH1 overcome the Id2 repression of C2C12 cells myogenic differentiation and that ENH1 overexpression promotes mice satellite cells activation, the first step toward myogenic differentiation. In addition, we show that ENH1 interacted with Id2 in C2C12 cells and mice satellite cells. Collectively, our results suggest that ENH1 plays an important role in the activation of myogenesis through the repression of Id2 activity. -- Highlights: •Enigma Homolog 1 (ENH1) is a scaffold protein. •ENH1 binds to inhibitor of DNA binding 2 (Id2) in myoblasts. •ENH1 overexpression overcomes the Id2's repression of myogenesis. •The Id2-ENH1 complex play an important role in the activation of myogenesis.

  5. A WUSCHEL-Independent Stem Cell Specification Pathway Is Repressed by PHB, PHV and CNA in Arabidopsis

    Science.gov (United States)

    Lee, Chunghee; Clark, Steven E.

    2015-01-01

    The homeostatic maintenance of stem cells that carry out continuous organogenesis at the shoot meristem is crucial for plant development. Key known factors act to signal between the stem cells and an underlying group of cells thought to act as the stem cell niche. In Arabidopsis thaliana the homeodomain transcription factor WUSCHEL (WUS) is essential for stem cell initiation and maintenance at shoot and flower meristems. Recent data suggest that the WUS protein may move from the niche cells directly into the stem cells to maintain stem cell identity. Here we provide evidence for a second, previously unknown, pathway for stem cell specification at shoot and flower meristems that bypasses the requirement for WUS. We demonstrate that this novel stem cell specification pathway is normally repressed by the activity of the HD-zip III transcription factors PHABULOSA (PHB), PHAVOLUTA (PHV) and CORONA (CNA). When de-repressed, this second stem cell pathway leads to an accumulation of stem cells and an enlargement of the stem cell niche. When de-repressed in a wus mutant background, this second stem cell pathway leads to functional meristems with largely normal cell layering and meristem morphology, activation of WUS cis regulatory elements, and extensive, but not indeterminate, organogenesis. Thus, WUS is largely dispensable for stem cell specification and meristem function, suggesting a set of key stem cell specification factors, competitively regulated by WUS and PHB/PHV/CNA, remain unidentified. PMID:26011610

  6. Acute TNF-induced repression of cell identity genes is mediated by NFκB-directed redistribution of cofactors from super-enhancers

    DEFF Research Database (Denmark)

    Schmidt, Søren Fisker; Larsen, Bjørk Ditlev; Loft, Anne

    2015-01-01

    The proinflammatory cytokine tumor necrosis factor (TNF) plays a central role in low-grade adipose tissue inflammation and development of insulin resistance during obesity. In this context, nuclear factor κ-light-chain-enhancer of activated B cells (NFκB) is directly involved and required for the...... specifically repressing super-enhancer-associated cell identity genes....... binding to the associated enhancers but rather loss of cofactors and enhancer RNA (eRNA) selectively from high-occupancy sites within super-enhancers. Based on these data, we have developed models that, with high accuracy, predict which enhancers and genes are repressed by TNF in adipocytes. We show...... that these models are applicable to other cell types where TNF represses genes associated with super-enhancers in a highly cell-type-specific manner. Our results propose a novel paradigm for NFκB-mediated repression, whereby NFκB selectively redistributes cofactors from high-occupancy enhancers, thereby...

  7. EBNA3C Directs Recruitment of RBPJ (CBF1) to Chromatin during the Process of Gene Repression in EBV Infected B Cells.

    Science.gov (United States)

    Kalchschmidt, Jens S; Gillman, Adam C T; Paschos, Kostas; Bazot, Quentin; Kempkes, Bettina; Allday, Martin J

    2016-01-01

    It is well established that Epstein-Barr virus nuclear antigen 3C (EBNA3C) can act as a potent repressor of gene expression, but little is known about the sequence of events occurring during the repression process. To explore further the role of EBNA3C in gene repression-particularly in relation to histone modifications and cell factors involved-the three host genes previously reported as most robustly repressed by EBNA3C were investigated. COBLL1, a gene of unknown function, is regulated by EBNA3C alone and the two co-regulated disintegrin/metalloproteases, ADAM28 and ADAMDEC1 have been described previously as targets of both EBNA3A and EBNA3C. For the first time, EBNA3C was here shown to be the main regulator of all three genes early after infection of primary B cells. Using various EBV-recombinants, repression over orders of magnitude was seen only when EBNA3C was expressed. Unexpectedly, full repression was not achieved until 30 days after infection. This was accurately reproduced in established LCLs carrying EBV-recombinants conditional for EBNA3C function, demonstrating the utility of the conditional system to replicate events early after infection. Using this system, detailed chromatin immunoprecipitation analysis revealed that the initial repression was associated with loss of activation-associated histone modifications (H3K9ac, H3K27ac and H3K4me3) and was independent of recruitment of polycomb proteins and deposition of the repressive H3K27me3 modification, which were only observed later in repression. Most remarkable, and in contrast to current models of RBPJ in repression, was the observation that this DNA-binding factor accumulated at the EBNA3C-binding sites only when EBNA3C was functional. Transient reporter assays indicated that repression of these genes was dependent on the interaction between EBNA3C and RBPJ. This was confirmed with a novel EBV-recombinant encoding a mutant of EBNA3C unable to bind RBPJ, by showing this virus was incapable of

  8. The Reg1-interacting proteins, Bmh1, Bmh2, Ssb1, and Ssb2, have roles in maintaining glucose repression in Saccharomyces cerevisiae.

    Science.gov (United States)

    Dombek, Kenneth M; Kacherovsky, Nataly; Young, Elton T

    2004-09-10

    In Saccharomyces cerevisiae, a type 1 protein phosphatase complex composed of the Glc7 catalytic subunit and the Reg1 regulatory subunit represses expression of many glucose-regulated genes. Here we show that the Reg1-interacting proteins Bmh1, Bmh2, Ssb1, and Ssb2 have roles in glucose repression. Deleting both BMH genes causes partially constitutive ADH2 expression without significantly increasing the level of Adr1 protein, the major activator of ADH2 expression. Adr1 and Bcy1, the regulatory subunit of cAMP-dependent protein kinase, are both required for this effect indicating that constitutive expression in Deltabmh1Deltabmh2 cells uses the same activation pathway that operates in Deltareg1 cells. Deletion of both BMH genes and REG1 causes a synergistic relief from repression, suggesting that Bmh proteins also act independently of Reg1 during glucose repression. A two-hybrid interaction with the Bmh proteins was mapped to amino acids 187-232, a region of Reg1 that is conserved in different classes of fungi. Deleting this region partially releases SUC2 from glucose repression. This indicates a role for the Reg1-Bmh interaction in glucose repression and also suggests a broad role for Bmh proteins in this process. An in vivo Reg1-Bmh interaction was confirmed by copurification of Bmh proteins with HA(3)-TAP-tagged Reg1. The nonconventional heat shock proteins Ssb1 and Ssb2 are also copurified with HA(3)-TAP-tagged Reg1. Deletion of both SSB genes modestly decreases repression of ADH2 expression in the presence of glucose, suggesting that Ssb proteins, perhaps through their interaction with Reg1, play a minor role in glucose repression.

  9. Interplay between EZH2 and G9a Regulates CXCL10 Gene Repression in Idiopathic Pulmonary Fibrosis.

    Science.gov (United States)

    Coward, William R; Brand, Oliver J; Pasini, Alice; Jenkins, Gisli; Knox, Alan J; Pang, Linhua

    2018-04-01

    Selective repression of the antifibrotic gene CXCL10 contributes to tissue remodeling in idiopathic pulmonary fibrosis (IPF). We have previously reported that histone deacetylation and histone H3 lysine 9 (H3K9) methylation are involved in CXCL10 repression. In this study, we explored the role of H3K27 methylation and the interplay between the two histone lysine methyltransferases enhancer of zest homolog 2 (EZH2) and G9a in CXCL10 repression in IPF. By applying chromatin immunoprecipitation, Re-ChIP, and proximity ligation assays, we demonstrated that, like G9a-mediated H3K9 methylation, EZH2-mediated histone H3 lysine 27 trimethylation (H3K27me3) was significantly enriched at the CXCL10 promoter in fibroblasts from IPF lungs (F-IPF) compared with fibroblasts from nonfibrotic lungs, and we also found that EZH2 and G9a physically interacted with each other. EZH2 knockdown reduced not only EZH2 and H3K27me3 but also G9a and H3K9me3, and G9a knockdown reduced not only G9 and H3K9me3 but also EZH2 and H3K27me3. Depletion and inhibition of EZH2 and G9a also reversed histone deacetylation and restored CXCL10 expression in F-IPF. Furthermore, treatment of fibroblasts from nonfibrotic lungs with the profibrotic cytokine transforming growth factor-β1 increased EZH2, G9a, H3K27me3, H3K9me3, and histone deacetylation at the CXCL10 promoter, similar to that observed in F-IPF, which was correlated with CXCL10 repression and was prevented by EZH2 and G9a knockdown. These findings suggest that a novel and functionally interdependent interplay between EZH2 and G9a regulates histone methylation-mediated epigenetic repression of the antifibrotic CXCL10 gene in IPF. This interdependent interplay may prove to be a target for epigenetic intervention to restore the expression of CXCL10 and other antifibrotic genes in IPF.

  10. Distinct Residues Contribute to Motility Repression and Autoregulation in the Proteus mirabilis Fimbria-Associated Transcriptional Regulator AtfJ.

    Science.gov (United States)

    Bode, Nadine J; Chan, Kun-Wei; Kong, Xiang-Peng; Pearson, Melanie M

    2016-08-01

    Proteus mirabilis contributes to a significant number of catheter-associated urinary tract infections, where coordinated regulation of adherence and motility is critical for ascending disease progression. Previously, the mannose-resistant Proteus-like (MR/P) fimbria-associated transcriptional regulator MrpJ has been shown to both repress motility and directly induce the transcription of its own operon; in addition, it affects the expression of a wide range of cellular processes. Interestingly, 14 additional mrpJ paralogs are included in the P. mirabilis genome. Looking at a selection of MrpJ paralogs, we discovered that these proteins, which consistently repress motility, also have nonidentical functions that include cross-regulation of fimbrial operons. A subset of paralogs, including AtfJ (encoded by the ambient temperature fimbrial operon), Fim8J, and MrpJ, are capable of autoinduction. We identified an element of the atf promoter extending from 487 to 655 nucleotides upstream of the transcriptional start site that is responsive to AtfJ, and we found that AtfJ directly binds this fragment. Mutational analysis of AtfJ revealed that its two identified functions, autoregulation and motility repression, are not invariably linked. Residues within the DNA-binding helix-turn-helix domain are required for motility repression but not necessarily autoregulation. Likewise, the C-terminal domain is dispensable for motility repression but is essential for autoregulation. Supported by a three-dimensional (3D) structural model, we hypothesize that the C-terminal domain confers unique regulatory capacities on the AtfJ family of regulators. Balancing adherence with motility is essential for uropathogens to successfully establish a foothold in their host. Proteus mirabilis uses a fimbria-associated transcriptional regulator to switch between these antagonistic processes by increasing fimbrial adherence while simultaneously downregulating flagella. The discovery of multiple

  11. Induction of epithelial to mesenchymal transition (EMT) and inhibition on adipogenesis: Two different sides of the same coin? Feasible roles and mechanisms of transforming growth factor β1 (TGF-β1) in age-related thymic involution.

    Science.gov (United States)

    Tan, Jianxin; Wang, Yajun; Zhang, Nannan; Zhu, Xike

    2016-08-01

    Age-related thymic involution is characterized by a loss of thymic epithelial cells (TECs) and a concomitant increase in adipocytes, but the mechanisms involved in thymic adipogenesis are still not clear. Transforming growth factor β1 (TGF-β1) is a pleiotropic cytokine that has been reported to be up-regulated with age in thymic stromal cells in both human and mouse. However, the exact role of TGF-β1 in age-related thymic involution remains to be further elucidated. On the basis of previous findings, we propose a novel hypothesis that TGF-β1 functions a dual role in age-related thymic involution. On one hand, up-regulation of TGF-β1 promotes epithelial to mesenchymal transition (EMT) process in TECs via activating forkhead box protein C2 (FoxC2). On the other hand, TGF-β1 inhibits the transdifferentiation of EMT-derived mesenchymal cells to adipocytes in the thymus. If confirmed, our hypothesis will not only provide further evidence supporting that the transdifferentiation of TECs into pre-adipocytes represents a source of thymic adiposity during age-related thymic involution, but also uncover a unique role of TGF-β1 in the transdifferentiation of TECs into pre-adipocytes. Collectively, the inhibition of TGF-β1 may serve as a strategy to hinder age-related thymic involution or even to restore thymic function in the elderly. © 2016 International Federation for Cell Biology.

  12. Diabetes alters activation and repression of pro- and anti- inflammatory signalling pathways in the vasculature

    Directory of Open Access Journals (Sweden)

    Elyse eDi Marco

    2013-06-01

    Full Text Available A central mechanism driving vascular disease in diabetes is immune cell-mediated inflammation. In diabetes, enhanced oxidation and glycation of macromolecules, such as lipoproteins, insults the endothelium and activates both innate and adaptive arms of the immune system by generating new antigens for presentation to adaptive immune cells. Chronic inflammation of the endothelium in diabetes leads to continuous infiltration and accumulation of leukocytes at sites of endothelial cell injury. We will describe the central role of the macrophage as a source of signalling molecules and damaging by-products which activate infiltrating lymphocytes in the tissue and contribute to the pro-oxidant and pro-inflammatory micro-environment. An important aspect to be considered is the diabetes- associated defects in the immune system, such as fewer or dysfunctional athero-protective leukocyte subsets in the diabetic lesion compared to non-diabetic lesions. This review will discuss the key pro-inflammatory signalling pathways responsible for leukocyte recruitment and activation in the injured vessel, with particular focus on pro- and anti-inflammatory pathways aberrantly activated or repressed in diabetes. We aim to describe the interaction between advanced glycation end products (AGEs and their principle receptor RAGE, Angiotensin II (Ang II and the Ang II type 1 receptor (AT1R, in addition to reactive oxygen species (ROS production by NADPH oxidase (Nox enzymes that are relevant to vascular and immune cell function in the context of diabetic vasculopathy. Furthermore, we will touch on recent advances in epigenetic medicine that have revealed high glucose-mediated changes in the transcription of genes with known pro-inflammatory downstream targets. Finally, novel anti-atherosclerosis strategies that target the vascular immune interface will be explored; such as vaccination against modified LDL and pharmacological inhibition of ROS producing enzymes.

  13. Salt Stress Represses Soybean Seed Germination by Negatively Regulating GA Biosynthesis While Positively Mediating ABA Biosynthesis

    Directory of Open Access Journals (Sweden)

    Kai Shu

    2017-08-01

    Full Text Available Soybean is an important and staple oilseed crop worldwide. Salinity stress has adverse effects on soybean development periods, especially on seed germination and post-germinative growth. Improving seed germination and emergence will have positive effects under salt stress conditions on agricultural production. Here we report that NaCl delays soybean seed germination by negatively regulating gibberellin (GA while positively mediating abscisic acid (ABA biogenesis, which leads to a decrease in the GA/ABA ratio. This study suggests that fluridone (FLUN, an ABA biogenesis inhibitor, might be a potential plant growth regulator that can promote soybean seed germination under saline stress. Different soybean cultivars, which possessed distinct genetic backgrounds, showed a similar repressed phenotype during seed germination under exogenous NaCl application. Biochemical analysis revealed that NaCl treatment led to high MDA (malondialdehyde level during germination and the post-germinative growth stages. Furthermore, catalase, superoxide dismutase, and peroxidase activities also changed after NaCl treatment. Subsequent quantitative Real-Time Polymerase Chain Reaction analysis showed that the transcription levels of ABA and GA biogenesis and signaling genes were altered after NaCl treatment. In line with this, phytohormone measurement also revealed that NaCl considerably down-regulated active GA1, GA3, and GA4 levels, whereas the ABA content was up-regulated; and therefore ratios, such as GA1/ABA, GA3/ABA, and GA4/ABA, are decreased. Consistent with the hormonal quantification, FLUN partially rescued the delayed-germination phenotype caused by NaCl-treatment. Altogether, these results demonstrate that NaCl stress inhibits soybean seed germination by decreasing the GA/ABA ratio, and that FLUN might be a potential plant growth regulator that could promote soybean seed germination under salinity stress.

  14. Salt Stress Represses Soybean Seed Germination by Negatively Regulating GA Biosynthesis While Positively Mediating ABA Biosynthesis.

    Science.gov (United States)

    Shu, Kai; Qi, Ying; Chen, Feng; Meng, Yongjie; Luo, Xiaofeng; Shuai, Haiwei; Zhou, Wenguan; Ding, Jun; Du, Junbo; Liu, Jiang; Yang, Feng; Wang, Qiang; Liu, Weiguo; Yong, Taiwen; Wang, Xiaochun; Feng, Yuqi; Yang, Wenyu

    2017-01-01

    Soybean is an important and staple oilseed crop worldwide. Salinity stress has adverse effects on soybean development periods, especially on seed germination and post-germinative growth. Improving seed germination and emergence will have positive effects under salt stress conditions on agricultural production. Here we report that NaCl delays soybean seed germination by negatively regulating gibberellin (GA) while positively mediating abscisic acid (ABA) biogenesis, which leads to a decrease in the GA/ABA ratio. This study suggests that fluridone (FLUN), an ABA biogenesis inhibitor, might be a potential plant growth regulator that can promote soybean seed germination under saline stress. Different soybean cultivars, which possessed distinct genetic backgrounds, showed a similar repressed phenotype during seed germination under exogenous NaCl application. Biochemical analysis revealed that NaCl treatment led to high MDA (malondialdehyde) level during germination and the post-germinative growth stages. Furthermore, catalase, superoxide dismutase, and peroxidase activities also changed after NaCl treatment. Subsequent quantitative Real-Time Polymerase Chain Reaction analysis showed that the transcription levels of ABA and GA biogenesis and signaling ge