Introduction of a leucine half-zipper engenders multiple high-quality crystals of a recalcitrant tRNA synthetase

International Nuclear Information System (INIS)

Guo, Min; Shapiro, Ryan; Schimmel, Paul; Yang, Xiang-Lei

2010-01-01

E. coli alanyl-tRNA synthetase is recalcitrant to crystallization. A group of leucine substitutions has transformed the protein. Although Escherichia coli alanyl-tRNA synthetase was among the first tRNA synthetases to be sequenced and extensively studied by functional analysis, it has proved to be recalcitrant to crystallization. This challenge remained even for crystallization of the catalytic fragment. By mutationally introducing three stacked leucines onto the solvent-exposed side of an α-helix, an engineered catalytic fragment of the synthetase was obtained that yielded multiple high-quality crystals and cocrystals with different ligands. The engineered α-helix did not form a leucine zipper that interlocked with the same α-helix from another molecule. Instead, using the created hydrophobic spine, it interacted with other surfaces of the protein as a leucine half-zipper (LHZ) to enhance the crystal lattice interactions. The LHZ made crystal lattice contacts in all crystals of different space groups. These results illustrate the power of introducing an LHZ into helices to facilitate crystallization. The authors propose that the method can be unified with surface-entropy reduction and can be broadly used for protein-surface optimization in crystallization

Small leucine zipper protein functions as a negative regulator of estrogen receptor α in breast cancer.

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Juyeon Jeong

Full Text Available The nuclear transcription factor estrogen receptor α (ERα plays a critical role in breast cancer progression. ERα acts as an important growth stimulatory protein in breast cancer and the expression level of ERα is tightly related to the prognosis and treatment of patients. Small leucine zipper protein (sLZIP functions as a transcriptional cofactor by binding to various nuclear receptors, including glucocorticoid receptor, androgen receptor, and peroxisome proliferator-activated receptor γ. However, the role of sLZIP in the regulation of ERα and its involvement in breast cancer progression is unknown. We found that sLZIP binds to ERα and represses the transcriptional activity of ERα in ERα-positive breast cancer cells. sLZIP also suppressed the expression of ERα target genes. sLZIP disrupted the binding of ERα to the estrogen response element of the target gene promoter, resulting in suppression of cell proliferation. sLZIP is a novel co-repressor of ERα, and plays a negative role in ERα-mediated cell proliferation in breast cancer.

Leucine zipper, down regulated in cancer-1 gene expression in prostate cancer

OpenAIRE

Salemi, Michele; Barone, Nunziata; La Vignera, Sandro; Condorelli, Rosita A.; Recupero, Domenico; Galia, Antonio; Fraggetta, Filippo; Aiello, Anna Maria; Pepe, Pietro; Castiglione, Roberto; Vicari, Enzo; Calogero, Aldo E.

2016-01-01

Numerous genetic alterations have been implicated in the development of prostate cancer (PCa). DNA and protein microarrays have enabled the identification of genes associated with apoptosis, which is important in PCa development. Despite the molecular mechanisms are not entirely understood, inhibition of apoptosis is a critical pathophysiological factor that contributes to the onset and progression of PCa. Leucine zipper, down-regulated in cancer 1 (LDOC-1) is a known regulator of the nuclear...

Reduced expression of glucocorticoid-inducible genes GILZ and SGK-1: high IL-6 levels are associated with reduced hippocampal volumes in major depressive disorder.

LENUS (Irish Health Repository)

Frodl, T

2012-01-01

Neuroplasticity may have a core role in the pathophysiology of major depressive disorder (MDD), a concept supported by experimental studies that found that excessive cortisol secretion and\\/or excessive production of inflammatory cytokines impairs neuronal plasticity and neurogenesis in the hippocampus. The objective of this study was to examine how changes in the glucocorticoid and inflammatory systems may affect hippocampal volumes in MDD. A multimodal approach with structural neuroimaging of hippocampus and amygdala, measurement of peripheral inflammatory proteins interleukin (IL)-6 and C-reactive protein (CRP), glucocorticoid receptor (GR) mRNA expression, and expression of glucocorticoid-inducible genes (glucocorticoid-inducible genes Leucin Zipper (GILZ) and glucocorticoid-inducible kinase-1 (SGK-1)) was used in 40 patients with MDD and 43 healthy controls (HC). Patients with MDD showed smaller hippocampal volumes and increased inflammatory proteins IL-6 and CRP compared with HC. Childhood maltreatment was associated with increased CRP. Patients with MDD, who had less expression of the glucocorticoid-inducible genes GILZ or SGK-1 had smaller hippocampal volumes. Regression analysis showed a strong positive effect of GILZ and SGK-1 mRNA expression, and further inverse effects of IL-6 concentration, on hippocampal volumes. These findings suggest that childhood maltreatment, peripheral inflammatory and glucocorticoid markers and hippocampal volume are interrelated factors in the pathophysiology of MDD. Glucocorticoid-inducible genes GILZ and SGK-1 might be promising candidate markers for hippocampal volume changes relevant for diseases like MDD. Further studies need to explore the possible clinical usefulness of such a blood biomarker, for example, for diagnosis or prediction of therapy response.

Preliminary structural studies on the leucine-zipper homology region of the human protein Bap31

International Nuclear Information System (INIS)

Mukasa, Takashi; Santelli, Eugenio; Reed, John C.; Pascual, Jaime

2007-01-01

A leucine-zipper with properties as apoptotic regulator in the ER has been crystallized. X-ray data to 2.5 Å resolution were collected, molecular replacement solutions were identified and refinement has been started. B-cell receptor-associated protein 31 (Bap31) is an integral membrane protein located in the endoplasmic reticulum (ER) that participates in the transport and quality control of membrane proteins and plays a role in determining cell sensitivity to ER stress and apoptosis. Its cytoplasmic region contains two target sites for caspase cleavage in certain apoptotic pathways. Here, the subcloning, expression, purification and crystallization of the Homo sapiens Bap31 leucine-zipper C-terminal fragment, which spans residues Gly160–Glu246, are reported. An N-terminally His-tagged protein was overexpressed in Escherichia coli and purified by chromatographic methods. X-ray diffraction data were collected in-house to 2.5 Å resolution. Crystals belong to space group P6 1 22/P6 5 22, with unit-cell parameters a = b = 70.7, c = 80.6 Å. Data analysis indicates the presence of one molecule per asymmetric unit

Preliminary structural studies on the leucine-zipper homology region of the human protein Bap31

Energy Technology Data Exchange (ETDEWEB)

Mukasa, Takashi; Santelli, Eugenio [Program on Infectious Diseases, Center for Inflammation and Infectious Diseases, The Burnham Institute for Medical Research, 10901 North Torrey Pines Road, La Jolla, CA 92037 (United States); Reed, John C. [Program on Apoptosis, Cancer Center, The Burnham Institute for Medical Research, 10901 North Torrey Pines Road, La Jolla, CA 92037 (United States); Pascual, Jaime, E-mail: pascual@burnham.org [Program on Infectious Diseases, Center for Inflammation and Infectious Diseases, The Burnham Institute for Medical Research, 10901 North Torrey Pines Road, La Jolla, CA 92037 (United States)

2007-04-01

A leucine-zipper with properties as apoptotic regulator in the ER has been crystallized. X-ray data to 2.5 Å resolution were collected, molecular replacement solutions were identified and refinement has been started. B-cell receptor-associated protein 31 (Bap31) is an integral membrane protein located in the endoplasmic reticulum (ER) that participates in the transport and quality control of membrane proteins and plays a role in determining cell sensitivity to ER stress and apoptosis. Its cytoplasmic region contains two target sites for caspase cleavage in certain apoptotic pathways. Here, the subcloning, expression, purification and crystallization of the Homo sapiens Bap31 leucine-zipper C-terminal fragment, which spans residues Gly160–Glu246, are reported. An N-terminally His-tagged protein was overexpressed in Escherichia coli and purified by chromatographic methods. X-ray diffraction data were collected in-house to 2.5 Å resolution. Crystals belong to space group P6{sub 1}22/P6{sub 5}22, with unit-cell parameters a = b = 70.7, c = 80.6 Å. Data analysis indicates the presence of one molecule per asymmetric unit.

Thermodynamic analysis of cavity creating mutations in an engineered leucine zipper and energetics of glycerol-induced coiled coil stabilization.

Science.gov (United States)

Dürr, E; Jelesarov, I

2000-04-18

Protein stability in vitro can be influenced either by introduction of mutations or by changes in the chemical composition of the solvent. Recently, we have characterized the thermodynamic stability and the rate of folding of the engineered dimeric leucine zipper A(2), which has a strengthened hydrophobic core [Dürr, E., Jelesarov, I., and Bosshard, H. R. (1999) Biochemistry 38, 870-880]. Here we report on the energetic consequences of a cavity introduced by Leu/Ala substitution at the tightly packed dimeric interface and how addition of 30% glycerol affects the folding thermodynamics of A(2) and the cavity mutants. Folding could be described by a two-state transition from two unfolded monomers to a coiled coil dimer. Removal of six methylene groups by Leu/Ala substitutions destabilized the dimeric coiled coil by 25 kJ mol(-1) at pH 3.5 and 25 degrees C in aqueous buffer. Destabilization was purely entropic at around room temperature and became increasingly enthalpic at elevated temperatures. Mutations were accompanied by a decrease of the unfolding heat capacity by 0.5 kJ K(-1) mol(-1). Addition of 30% glycerol increased the free energy of folding of A(2) and the cavity mutants by 5-10 kJ mol(-1) and lowered the unfolding heat capacity by 25% for A(2) and by 50% for the Leu/Ala mutants. The origin of the stabilizing effect of glycerol varied with temperature. Stabilization of the parent leucine zipper A(2) was enthalpic with an unfavorable entropic component between 0 and 100 degrees C. In the case of cavity mutants, glycerol induced enthalpic stabilization below 50 degrees C and entropic stabilization above 50 degrees C. The effect of glycerol could not be accounted for solely by the enthalpy and entropy of transfer or protein surface from water to glycerol/water mixture. We propose that in the presence of glycerol the folded coiled coil dimer is better packed and displays less intramolecular fluctuations, leading to enhanced enthalpic interactions and to an

A Petunia Homeodomain-Leucine Zipper Protein, PhHD-Zip, Plays an Important Role in Flower Senescence

Science.gov (United States)

Chang, Xiaoxiao; Donnelly, Linda; Sun, Daoyang; Rao, Jingping; Reid, Michael S.; Jiang, Cai-Zhong

2014-01-01

Flower senescence is initiated by developmental and environmental signals, and regulated by gene transcription. A homeodomain-leucine zipper transcription factor, PhHD-Zip, is up-regulated during petunia flower senescence. Virus-induced gene silencing of PhHD-Zip extended flower life by 20% both in unpollinated and pollinated flowers. Silencing PhHD-Zip also dramatically reduced ethylene production and the abundance of transcripts of genes involved in ethylene (ACS, ACO), and ABA (NCED) biosynthesis. Abundance of transcripts of senescence-related genes (SAG12, SAG29) was also dramatically reduced in the silenced flowers. Over-expression of PhHD-Zip accelerated petunia flower senescence. Furthermore, PhHD-Zip transcript abundance in petunia flowers was increased by application of hormones (ethylene, ABA) and abiotic stresses (dehydration, NaCl and cold). Our results suggest that PhHD-Zip plays an important role in regulating petunia flower senescence. PMID:24551088

A Petunia homeodomain-leucine zipper protein, PhHD-Zip, plays an important role in flower senescence.

Science.gov (United States)

Chang, Xiaoxiao; Donnelly, Linda; Sun, Daoyang; Rao, Jingping; Reid, Michael S; Jiang, Cai-Zhong

2014-01-01

Flower senescence is initiated by developmental and environmental signals, and regulated by gene transcription. A homeodomain-leucine zipper transcription factor, PhHD-Zip, is up-regulated during petunia flower senescence. Virus-induced gene silencing of PhHD-Zip extended flower life by 20% both in unpollinated and pollinated flowers. Silencing PhHD-Zip also dramatically reduced ethylene production and the abundance of transcripts of genes involved in ethylene (ACS, ACO), and ABA (NCED) biosynthesis. Abundance of transcripts of senescence-related genes (SAG12, SAG29) was also dramatically reduced in the silenced flowers. Over-expression of PhHD-Zip accelerated petunia flower senescence. Furthermore, PhHD-Zip transcript abundance in petunia flowers was increased by application of hormones (ethylene, ABA) and abiotic stresses (dehydration, NaCl and cold). Our results suggest that PhHD-Zip plays an important role in regulating petunia flower senescence.

A Petunia homeodomain-leucine zipper protein, PhHD-Zip, plays an important role in flower senescence.

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Xiaoxiao Chang

Full Text Available Flower senescence is initiated by developmental and environmental signals, and regulated by gene transcription. A homeodomain-leucine zipper transcription factor, PhHD-Zip, is up-regulated during petunia flower senescence. Virus-induced gene silencing of PhHD-Zip extended flower life by 20% both in unpollinated and pollinated flowers. Silencing PhHD-Zip also dramatically reduced ethylene production and the abundance of transcripts of genes involved in ethylene (ACS, ACO, and ABA (NCED biosynthesis. Abundance of transcripts of senescence-related genes (SAG12, SAG29 was also dramatically reduced in the silenced flowers. Over-expression of PhHD-Zip accelerated petunia flower senescence. Furthermore, PhHD-Zip transcript abundance in petunia flowers was increased by application of hormones (ethylene, ABA and abiotic stresses (dehydration, NaCl and cold. Our results suggest that PhHD-Zip plays an important role in regulating petunia flower senescence.

GMP production and characterization of leucine zipper-tagged tumor necrosis factor-related apoptosis-inducing ligand (LZ-TRAIL) for phase I clinical trial.

Science.gov (United States)

Jiang, Jing; Liu, Xiaobin; Deng, Leixiu; Zhang, Peipei; Wang, Guangjun; Wang, Shifu; Liu, Honghao; Su, Yunpeng

2014-10-05

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) exhibits potent antitumor activity in a wide range of cancers without deleterious side effects on normal tissues. Several TRAIL derivatives have been developed to improve its pharmacokinetics and therapeutic effects through strategies such as adding a leucine zipper to increase the circulation half-life. To obtain clinical grade LZ-TRAIL for phase I clinical trial, a single batch of 30 L bioreactor culture was performed using the Escherichia coli BL21 (DE3) strain expressing the recombinant LZ-TRAIL. A robust LZ-TRAIL production fermentation process was developed, which could be scaled up from 5L to 50 L, and had a titer of approximately 1.4 g/l. A four-step purification strategy was carried out to obtain a final product with over 95% purity and 45% yield. The final material was filter sterilized, aseptically vialed, and stored at 4°C, and comprehensively characterized using multiple assays (vialed product was sterile, purity was 95%, aggregates were production of phase I clinical trial material. These preclinical investigations warrant further clinical development of this product for cancer therapy. Copyright © 2014. Published by Elsevier B.V.

Evolutionary and Expression Analyses of the Apple Basic Leucine Zipper Transcription Factor Family

Science.gov (United States)

Zhao, Jiao; Guo, Rongrong; Guo, Chunlei; Hou, Hongmin; Wang, Xiping; Gao, Hua

2016-01-01

Transcription factors (TFs) play essential roles in the regulatory networks controlling many developmental processes in plants. Members of the basic leucine (Leu) zipper (bZIP) TF family, which is unique to eukaryotes, are involved in regulating diverse processes, including flower and vascular development, seed maturation, stress signaling, and defense responses to pathogens. The bZIP proteins have a characteristic bZIP domain composed of a DNA-binding basic region and a Leu zipper dimerization region. In this study, we identified 112 apple (Malus domestica Borkh) bZIP TF-encoding genes, termed MdbZIP genes. Synteny analysis indicated that segmental and tandem duplication events, as well as whole genome duplication, have contributed to the expansion of the apple bZIP family. The family could be divided into 11 groups based on structural features of the encoded proteins, as well as on the phylogenetic relationship of the apple bZIP proteins to those of the model plant Arabidopsis thaliana (AtbZIP genes). Synteny analysis revealed that several paired MdbZIP genes and AtbZIP gene homologs were located in syntenic genomic regions. Furthermore, expression analyses of group A MdbZIP genes showed distinct expression levels in 10 different organs. Moreover, changes in these expression profiles in response to abiotic stress conditions and various hormone treatments identified MdbZIP genes that were responsive to high salinity and drought, as well as to different phytohormones. PMID:27066030

Evolutionary and Expression Analyses of the Apple Basic Leucine Zipper Transcription Factor Family

Directory of Open Access Journals (Sweden)

Jiao eZhao

2016-03-01

Full Text Available Transcription factors (TFs play essential roles in the regulatory networks controlling many developmental processes in plants. Members of the basic leucine (Leu zipper (bZIP TF family, which is unique to eukaryotes, are involved in regulating diverse processes, including flower and vascular development, seed maturation, stress signaling and defense responses to pathogens. The bZIP proteins have a characteristic bZIP domain composed of a DNA-binding basic region and a Leu zipper dimerization region. In this study, we identified 112 apple (Malus domestica Borkh bZIP TF-encoding genes, termed MdbZIP genes. Synteny analysis indicated that segmental and tandem duplication events, as well as whole genome duplication, have contributed to the expansion of the apple bZIP family. The family could be divided into 11 groups based on structural features of the encoded proteins, as well as on the phylogenetic relationship of the apple bZIP proteins to those of the model plant Arabidopsis thaliana (AtbZIP genes. Synteny analysis revealed that several paired MdbZIP genes and AtbZIP gene homologs were located in syntenic genomic regions. Furthermore, expression analyses of group A MdbZIP genes showed distinct expression levels in ten different organs. Moreover, changes in these expression profiles in response to abiotic stress conditions and various hormone treatments identified MdbZIP genes that were responsive to high salinity and drought, as well as to different phytohormones.

Arabidopsis basic leucine zipper transcription factors involved in an abscisic acid-dependent signal transduction pathway under drought and high-salinity conditions

OpenAIRE

Uno, Yuichi; Furihata, Takashi; Abe, Hiroshi; Yoshida, Riichiro; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

2000-01-01

The induction of the dehydration-responsive Arabidopsis gene, rd29B, is mediated mainly by abscisic acid (ABA). Promoter analysis of rd29B indicated that two ABA-responsive elements (ABREs) are required for the dehydration-responsive expression of rd29B as cis-acting elements. Three cDNAs encoding basic leucine zipper (bZIP)-type ABRE-binding proteins were isolated by using the yeast one-hybrid system and were designated AREB1, AREB2, and AREB3 (ABA-responsive ...

Maternal Embryonic Leucine Zipper Kinase (MELK: A Novel Regulator in Cell Cycle Control, Embryonic Development, and Cancer

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Pengfei Jiang

2013-10-01

Full Text Available Maternal embryonic leucine zipper kinase (MELK functions as a modulator of intracellular signaling and affects various cellular and biological processes, including cell cycle, cell proliferation, apoptosis, spliceosome assembly, gene expression, embryonic development, hematopoiesis, and oncogenesis. In these cellular processes, MELK functions by binding to numerous proteins. In general, the effects of multiple protein interactions with MELK are oncogenic in nature, and the overexpression of MELK in kinds of cancer provides some evidence that it may be involved in tumorigenic process. In this review, our current knowledge of MELK function and recent discoveries in MELK signaling pathway were discussed. The regulation of MELK in cancers and its potential as a therapeutic target were also described.

Regulation of MIR165/166 by class II and class III homeodomain leucine zipper proteins establishes leaf polarity

DEFF Research Database (Denmark)

Merelo, Paz; Ram, Hathi; Caggiano, Monica Pia

2016-01-01

A defining feature of plant leaves is their flattened shape. This shape depends on an antagonism between the genes that specify adaxial (top) and abaxial (bottom) tissue identity; however, the molecular nature of this antagonism remains poorly understood. Class III homeodomain leucine zipper (HD-...... show that class III and class II HD-ZIP proteins act together to repress MIR165/166 via a conserved cis-element in their promoters. Organ morphology and tissue patterning in plants, therefore, depend on a bidirectional repressive circuit involving a set of miRNAs and its targets....

Silencing of the glucocorticoid-induced leucine zipper improves the immunogenicity of clinical-grade dendritic cells

DEFF Research Database (Denmark)

Cathelin, Dominique; Met, Özcan; Svane, Inge Marie

2013-01-01

The maturation cocktail composed of interleukin (IL)-6, IL-1β, tumor necrosis factor-α and prostaglandin E2 is considered the "gold standard" for inducing the maturation of dendritic cells (DCs) for use in cancer immunotherapy. Nevertheless, although this maturation cocktail induces increased...

Glucocorticoid-induced hyperglycaemia

NARCIS (Netherlands)

Gerards, M.C.

2018-01-01

This thesis contains studies on current practice, clinical implications and treatment of excess glucocorticoid receptor (GCR) stimulation, with a focus on glucocorticoid-induced hyperglycaemia (GCIH). Chapter 1 is a general introduction to the glucocorticoid hormone. In chapter 2 , we have

Genome-wide analysis of the homeodomain-leucine zipper (HD-ZIP) gene family in peach (Prunus persica).

Science.gov (United States)

Zhang, C H; Ma, R J; Shen, Z J; Sun, X; Korir, N K; Yu, M L

2014-04-08

In this study, 33 homeodomain-leucine zipper (HD-ZIP) genes were identified in peach using the HD-ZIP amino acid sequences of Arabidopsis thaliana as a probe. Based on the phylogenetic analysis and the individual gene or protein characteristics, the HD-ZIP gene family in peach can be classified into 4 subfamilies, HD-ZIP I, II, III, and IV, containing 14, 7, 4, and 8 members, respectively. The most closely related peach HD-ZIP members within the same subfamilies shared very similar gene structure in terms of either intron/exon numbers or lengths. Almost all members of the same subfamily shared common motif compositions, thereby implying that the HD-ZIP proteins within the same subfamily may have functional similarity. The 33 peach HD-ZIP genes were distributed across scaffolds 1 to 7. Although the primary structure varied among HD-ZIP family proteins, their tertiary structures were similar. The results from this study will be useful in selecting candidate genes from specific subfamilies for functional analysis.

Leucine zipper, down regulated in cancer-1 gene expression in prostate cancer

Science.gov (United States)

Salemi, Michele; Barone, Nunziata; La Vignera, Sandro; Condorelli, Rosita A.; Recupero, Domenico; Galia, Antonio; Fraggetta, Filippo; Aiello, Anna Maria; Pepe, Pietro; Castiglione, Roberto; Vicari, Enzo; Calogero, Aldo E.

2016-01-01

Numerous genetic alterations have been implicated in the development of prostate cancer (PCa). DNA and protein microarrays have enabled the identification of genes associated with apoptosis, which is important in PCa development. Despite the molecular mechanisms are not entirely understood, inhibition of apoptosis is a critical pathophysiological factor that contributes to the onset and progression of PCa. Leucine zipper, down-regulated in cancer 1 (LDOC-1) is a known regulator of the nuclear factor (NF)-mediated pathway of apoptosis through the inhibition of NF-κB. The present study investigated the expression of the LDOC-1 gene in LNCaP, PC-3, PNT1A and PNT2 prostate cell lines by reverse transcription-quantitative polymerase chain reaction. In addition LDOC-1 protein expression in normal prostate tissues and PCa was studied by immunohistochemistry. LDOC-1 messenger RNA resulted overexpressed in LNCaP and PC-3 PCa cell lines compared with the two normal prostate cell lines PNT1A and PNT2. The results of immunohistochemistry demonstrated a positive cytoplasmic LDOC-1 staining in all PCa and normal prostate samples, whereas no nuclear staining was observed in any sample. Furthermore, a more intense signal was evidenced in PCa samples. LDOC-1 gene overexpression in PCa suggests an activity of LDOC-1 in PCa cell lines. PMID:27698860

[Glucocorticoid induced osteoporosis].

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Anić, Branimir; Mayer, Miroslav

2014-01-01

Secondary osteoporosis most often develops due to glucocorticoid therapy. Glucocorticoids affect all stages of the bone remodeling cycle, its formation and resorption. Osteoblasts are primarily affected, decreasing their activity and enhancing apoptosis. Patients treated with glucocorticoids have lower bone mineral density and increased fracture risk. Glucocorticoid-induced osteoporosis can be prevented by administering the minimal effective dose of glucocorticoids, calcium and vitamin D supplementation or, if possible, by hormone replace- ment therapy. Moreover, appropriate physical activity should be encouraged. Patients who are at higher risk for low-energy fractures (for example post-menopausal women) have to be actively treated, usually with antiresorptive drugs among which bisphosphonates are currently the first line therapy.

Glucocorticoid resistance in two key models of acute lymphoblastic leukemia occurs at the level of the glucocorticoid receptor.

Science.gov (United States)

Schmidt, Stefan; Irving, Julie A E; Minto, Lynne; Matheson, Elizabeth; Nicholson, Lindsay; Ploner, Andreas; Parson, Walther; Kofler, Anita; Amort, Melanie; Erdel, Martin; Hall, Andy; Kofler, Reinhard

2006-12-01

Glucocorticoids (GCs) specifically induce apoptosis in malignant lymphoblasts and are thus pivotal in the treatment of acute lymphoblastic leukemia (ALL). However, GC-resistance is a therapeutic problem with an unclear molecular mechanism. We generated approximately 70 GC-resistant sublines from a GC-sensitive B- and a T-ALL cell line and investigated their mechanisms of resistance. In response to GCs, all GC-resistant subclones analyzed by real-time polymerase chain reaction (PCR) showed a deficient up-regulation of the GC-receptor (GR) and its downstream target, GC-induced leucine zipper. This deficiency in GR up-regulation was confirmed by Western blotting and on retroviral overexpression of GR in resistant subclones GC-sensitivity was restored. All GC-resistant subclones were screened for GR mutations using denaturing high-pressure liquid chromatography (DHPLC), DNA-fingerprinting, and fluorescence in situ hybridization (FISH). Among the identified mutations were some previously not associated with GC resistance: A484D, P515H, L756N, Y663H, L680P, and R714W. This approach revealed three genotypes, complete loss of functional GR in the mismatch repair deficient T-ALL model, apparently normal GR genes in B-ALLs, and heterozygosity in both. In the first genotype, deficiency in GR up-regulation was fully explained by mutational events, in the second by a putative regulatory defect, and in the third by a combination thereof. In all instances, GC-resistance occurred at the level of the GR in both models.

Abscisic-acid-dependent basic leucine zipper (bZIP) transcription factors in plant abiotic stress.

Science.gov (United States)

Banerjee, Aditya; Roychoudhury, Aryadeep

2017-01-01

One of the major causes of significant crop loss throughout the world is the myriad of environmental stresses including drought, salinity, cold, heavy metal toxicity, and ultraviolet-B (UV-B) rays. Plants as sessile organisms have evolved various effective mechanism which enable them to withstand this plethora of stresses. Most of such regulatory mechanisms usually follow the abscisic-acid (ABA)-dependent pathway. In this review, we have primarily focussed on the basic leucine zipper (bZIP) transcription factors (TFs) activated by the ABA-mediated signalosome. Upon perception of ABA by specialized receptors, the signal is transduced via various groups of Ser/Thr kinases, which phosphorylate the bZIP TFs. Following such post-translational modification of TFs, they are activated so that they bind to specific cis-acting sequences called abscisic-acid-responsive elements (ABREs) or GC-rich coupling elements (CE), thereby influencing the expression of their target downstream genes. Several in silico techniques have been adopted so far to predict the structural features, recognize the regulatory modification sites, undergo phylogenetic analyses, and facilitate genome-wide survey of TF under multiple stresses. Current investigations on the epigenetic regulation that controls greater accessibility of the inducible regions of DNA of the target gene to the bZIP TFs exclusively under stress situations, along with the evolved stress memory responses via genomic imprinting mechanism, have been highlighted. The potentiality of overexpression of bZIP TFs, either in a homologous or in a heterologous background, in generating transgenic plants tolerant to various abiotic stressors have also been addressed by various groups. The present review will provide a coherent documentation on the functional characterization and regulation of bZIP TFs under multiple environmental stresses, with the major goal of generating multiple-stress-tolerant plant cultivars in near future.

MicroRNA-27a Is Induced by Leucine and Contributes to Leucine-Induced Proliferation Promotion in C2C12 Cells

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Guangmang Liu

2013-07-01

Full Text Available Leucine, a branched chain amino acid, is well known to stimulate protein synthesis in skeletal muscle. However, the role of leucine in myoblast proliferation remains unclear. In this study, we found that leucine could promote proliferation of C2C12 cells. Moreover, expressions of miR-27a and myostatin (a bona fide target of miR-27a were upregulated and downregulated, respectively, following leucine treatment. We also found that miR-27a loss-of-function by transfection of a miR-27a inhibitor suppressed the promotion of myoblast proliferation caused by leucine. Our results suggest that miR-27a is induced by leucine and contributes to leucine-induced proliferation promotion of myoblast.

Islet-cell dysfunction induced by glucocorticoid treatment

DEFF Research Database (Denmark)

van Raalte, Daniël H; Kwa, Kelly A A; van Genugten, Renate E

2013-01-01

Glucocorticoids impair glucose tolerance by inducing insulin resistance. We investigated the dose-dependent effects of glucocorticoid treatment on islet-cell function in healthy males and studied the role of the autonomic nervous system.......Glucocorticoids impair glucose tolerance by inducing insulin resistance. We investigated the dose-dependent effects of glucocorticoid treatment on islet-cell function in healthy males and studied the role of the autonomic nervous system....

The role of basic leucine zipper transcription factor E4BP4 in the immune system and immune-mediated diseases.

Science.gov (United States)

Yin, Jinghua; Zhang, Jian; Lu, Qianjin

2017-07-01

Basic leucine zipper transcription factor E4BP4 (also known as NFIL3) has been implicated in the molecular and cellular mechanisms of functions and activities in mammals. The interactions between E4BP4 and major regulators of cellular processes have triggered significant interest in the roles of E4BP4 in the pathogenesis of certain chronic diseases. Indeed, novel discoveries have been emerging to illustrate the involvement of E4BP4 in multiple disorders. It is recognized that E4BP4 is extensively involved in some immune-mediated diseases, but the mechanisms of E4BP4 involvement in these complex diseases remain poorly defined. Here we review the regulatory mechanisms of E4BP4 engaging in not only the biological function but also the development of immune-mediated diseases, paving the way for future therapies. Copyright © 2017. Published by Elsevier Inc.

Functional characterization of a competitive peptide antagonist of p65 in human macrophage-like cells suggests therapeutic potential for chronic inflammation

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Srinivasan M

2014-12-01

Full Text Available Mythily Srinivasan,1 Corinne Blackburn,1 Debomoy K Lahiri2,3 1Department of Oral Pathology, Medicine and Radiology, Indiana University School of Dentistry, 2Institute of Psychiatry Research, Department of Psychiatry, 3Department of Medical and Molecular Genetics, School of Medicine, Indiana University-Purdue University, Indianapolis, IN, USA Abstract: Glucocorticoid-induced leucine zipper (GILZ is a glucocorticoid responsive protein that links the nuclear factor-kappa B (NFκB and the glucocorticoid signaling pathways. Functional and binding studies suggest that the proline-rich region at the carboxy terminus of GILZ binds the p65 subunit of NFκB and suppresses the immunoinflammatory response. A widely-used strategy in the discovery of peptide drugs involves exploitation of the complementary surfaces of naturally occurring binding partners. Previously, we observed that a synthetic peptide (GILZ-P derived from the proline-rich region of GILZ bound activated p65 and ameliorated experimental encephalomyelitis. Here we characterize the secondary structure of GILZ-P by circular dichroic analysis. GILZ-P adopts an extended polyproline type II helical conformation consistent with the structural conformation commonly observed in interfaces of transient intermolecular interactions. To determine the potential application of GILZ-P in humans, we evaluated the toxicity and efficacy of the peptide drug in mature human macrophage-like THP-1 cells. Treatment with GILZ-P at a wide range of concentrations commonly used for peptide drugs was nontoxic as determined by cell viability and apoptosis assays. Functionally, GILZ-P suppressed proliferation and glutamate secretion by activated macrophages by inhibiting nuclear translocation of p65. Collectively, our data suggest that the GILZ-P has therapeutic potential in chronic CNS diseases where persistent inflammation leads to neurodegeneration such as multiple sclerosis and Alzheimer’s disease. Keywords

Arabidopsis basic leucine zipper transcription factors involved in an abscisic acid-dependent signal transduction pathway under drought and high-salinity conditions.

Science.gov (United States)

Uno, Y; Furihata, T; Abe, H; Yoshida, R; Shinozaki, K; Yamaguchi-Shinozaki, K

2000-10-10

The induction of the dehydration-responsive Arabidopsis gene, rd29B, is mediated mainly by abscisic acid (ABA). Promoter analysis of rd29B indicated that two ABA-responsive elements (ABREs) are required for the dehydration-responsive expression of rd29B as cis-acting elements. Three cDNAs encoding basic leucine zipper (bZIP)-type ABRE-binding proteins were isolated by using the yeast one-hybrid system and were designated AREB1, AREB2, and AREB3 (ABA-responsive element binding protein). Transcription of the AREB1 and AREB2 genes is up-regulated by drought, NaCl, and ABA treatment in vegetative tissues. In a transient transactivation experiment using Arabidopsis leaf protoplasts, both the AREB1 and AREB2 proteins activated transcription of a reporter gene driven by ABRE. AREB1 and AREB2 required ABA for their activation, because their transactivation activities were repressed in aba2 and abi1 mutants and enhanced in an era1 mutant. Activation of AREBs by ABA was suppressed by protein kinase inhibitors. These results suggest that both AREB1 and AREB2 function as transcriptional activators in the ABA-inducible expression of rd29B, and further that ABA-dependent posttranscriptional activation of AREB1 and AREB2, probably by phosphorylation, is necessary for their maximum activation by ABA. Using cultured Arabidopsis cells, we demonstrated that a specific ABA-activated protein kinase of 42-kDa phosphorylated conserved N-terminal regions in the AREB proteins.

A genome-wide survey of homeodomain-leucine zipper genes and analysis of cold-responsive HD-Zip I members' expression in tomato.

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Zhang, Zhenzhu; Chen, Xiuling; Guan, Xin; Liu, Yang; Chen, Hongyu; Wang, Tingting; Mouekouba, Liana Dalcantara Ongouya; Li, Jingfu; Wang, Aoxue

2014-01-01

Homeodomain-leucine zipper (HD-Zip) proteins are a kind of transcriptional factors that play a vital role in plant growth and development. However, no detailed information of HD-Zip family in tomato has been reported till now. In this study, 51 HD-Zip genes (SlHZ01-51) in this family were identified and categorized into 4 classes by exon-intron and protein structure in tomato (Solanum lycopersicum) genome. The synthetical phylogenetic tree of tomato, Arabidopsis and rice HD-Zip genes were established for an insight into their evolutionary relationships and putative functions. The results showed that the contribution of segmental duplication was larger than that of tandem duplication for expansion and evolution of genes in this family of tomato. The expression profile results under abiotic stress suggested that all SlHZ I genes were responsive to cold stress. This study will provide a clue for the further investigation of functional identification and the role of tomato HD-Zip I subfamily in plant cold stress responses and developmental events.

Glucocorticoid actions on L6 muscle cells in culture

International Nuclear Information System (INIS)

Max, S.R.; Konagaya, M.; Konagaya, Y.

1986-01-01

Glucocorticoids exert striking catabolic effects on skeletal muscle. The mechanism of these effects remains poorly understood. They employed L6 muscle cells in culture to ascertain whether intracellular glucocorticoid receptors are involved. Studies in vitro permit exploration of glucocorticoid effects in the absence of other hormonal influences. L6 myoblasts were induced to form differentiated myotubes by growth in 1% serum. L6 myotubes were found to possess a high-affinity, limited capacity intracellular glucocorticoid receptor (apparent K/sub D/ = 5 x 10 -10 M; B/sub max/ = 711 pmols/g protein) with ligand specificity similar to that of glucocorticoid receptors from classical glucocorticoid target tissues. Further, [ 3 H] triamcinolone acetonide specific binding to L6 cell homogenates was blocked by a glucocorticoid antagonist, RU38486 (11β-(4-dimethyl-aminophenyl)-17β-hydroxy-17α-(prop-l-ynyl)-estra-4,9-dien-3-one). Dexamethasone (10 -5 M) caused a 10-fold increase in the activity of gluatmine synthetase in L6 myotubes; this increase was prevented by RU38486. Similarly, dexamethasone (10 -5 M) caused a 20% decrease in [ 12 C] leucine incorporation into protein. This effect also was blocked by RU38486. Thus, induction of glutamine synthetase and diminution of protein synthesis by dexamethasone require intracellular glucocorticoid receptors. L6 cells should prove particularly valuable for further studies of glucocorticoid actions on skeletal muscle

Quantitative tissue-specific dynamics of in vivo GILZ mRNA expression and regulation by endogenous and exogenous glucocorticoids.

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Ayyar, Vivaswath S; Almon, Richard R; Jusko, William J; DuBois, Debra C

2015-06-01

Glucocorticoids (GC) are steroid hormones, which regulate metabolism and immune function. Synthetic GCs, or corticosteroids (CS), have appreciable clinical utility via their ability to suppress inflammation in immune-mediated diseases like asthma and rheumatoid arthritis. Recent work has provided insight to novel GC-induced genes that mediate their anti-inflammatory effects, including glucocorticoid-induced leucine zipper (GILZ). Since GILZ comprises an important part of GC action, its regulation by both drug and hormone will influence CS therapy. In addition, GILZ expression is often employed as a biomarker of GC action, which requires judicious selection of sampling time. Understanding the in vivo regulation of GILZ mRNA expression over time will provide insight into both the physiological regulation of GILZ by endogenous GC and the dynamics of its enhancement by CS. A highly quantitative qRT-PCR assay was developed for measuring GILZ mRNA expression in tissues obtained from normal and CS-treated rats. This assay was applied to measure GILZ mRNA expression in eight tissues; to determine its endogenous regulation over time; and to characterize its dynamics in adipose tissue, muscle, and liver following treatment with CS. We demonstrate that GILZ mRNA is expressed in several tissues. GILZ mRNA expression in adipose tissue displayed a robust circadian rhythm that was entrained with the circadian oscillation of endogenous corticosterone; and is strongly enhanced by acute and chronic dosing. Single dosing also enhanced GILZ mRNA in muscle and liver, but the dynamics varied. In conclusion, GILZ is widely expressed in the rat and highly regulated by endogenous and exogenous GCs. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Engineering of a novel zipFv using leucine zipper motif against rabies virus glycoprotein G with improved protection potency in vivo.

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Xi, Hualong; Zhang, Kaixin; Yin, Yanchun; Gu, Tiejun; Sun, Qing; Li, Zhuang; Cheng, Yue; Jiang, Chunlai; Kong, Wei; Wu, Yongge

2017-06-01

Rabies is an acute zoonotic infectious disease with a high fatality rate but is preventable with vaccination and rabies immunoglobulin (RIG). The single-chain Fv fragment (scFv), a small engineered antigen-binding protein derived from antibody variable heavy (V H ) and light (V L ) chains connected by a peptide linker, can potentially be used to replace RIG. Here, we produced two peptides V H -JUN-HIS and V L -FOS-HA separately in Escherichia coli and assembled them to form zipFv successfully in vitro. The new zipFv utilizes FOS and JUN leucine zippers to form an antibody structure similar to the IgG counterpart with two free N-terminal ends of V H and V L . The zipFv protein showed notable improvement in binding ability and affinity over its corresponding scFv. The zipFv also demonstrated greater stability in serum and the same protective rate as RIG against challenge with a standard rabies virus (CVS-24) in mice. Our results indicated zipFv as a novel and efficient antibody form with enhanced neutralizing potency. Copyright © 2017. Published by Elsevier B.V.

Dibutyltin disrupts glucocorticoid receptor function and impairs glucocorticoid-induced suppression of cytokine production.

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Christel Gumy

Full Text Available BACKGROUND: Organotins are highly toxic and widely distributed environmental chemicals. Dibutyltin (DBT is used as stabilizer in the production of polyvinyl chloride plastics, and it is also the major metabolite formed from tributyltin (TBT in vivo. DBT is immunotoxic, however, the responsible targets remain to be defined. Due to the importance of glucocorticoids in immune-modulation, we investigated whether DBT could interfere with glucocorticoid receptor (GR function. METHODOLOGY: We used HEK-293 cells transiently transfected with human GR as well as rat H4IIE hepatoma cells and native human macrophages and human THP-1 macrophages expressing endogenous receptor to study organotin effects on GR function. Docking of organotins was used to investigate the binding mechanism. PRINCIPAL FINDINGS: We found that nanomolar concentrations of DBT, but not other organotins tested, inhibit ligand binding to GR and its transcriptional activity. Docking analysis indicated that DBT inhibits GR activation allosterically by inserting into a site close to the steroid-binding pocket, which disrupts a key interaction between the A-ring of the glucocorticoid and the GR. DBT inhibited glucocorticoid-induced expression of phosphoenolpyruvate carboxykinase (PEPCK and tyrosine-aminotransferase (TAT and abolished the glucocorticoid-mediated transrepression of TNF-alpha-induced NF-kappaB activity. Moreover, DBT abrogated the glucocorticoid-mediated suppression of interleukin-6 (IL-6 and TNF-alpha production in lipopolysaccharide (LPS-stimulated native human macrophages and human THP-1 macrophages. CONCLUSIONS: DBT inhibits ligand binding to GR and subsequent activation of the receptor. By blocking GR activation, DBT may disturb metabolic functions and modulation of the immune system, providing an explanation for some of the toxic effects of this organotin.

A designated centre for people with disabilities operated by Acquired Brain Injury Ireland, Cork

LENUS (Irish Health Repository)

Frodl, T

2012-01-01

Neuroplasticity may have a core role in the pathophysiology of major depressive disorder (MDD), a concept supported by experimental studies that found that excessive cortisol secretion and\\/or excessive production of inflammatory cytokines impairs neuronal plasticity and neurogenesis in the hippocampus. The objective of this study was to examine how changes in the glucocorticoid and inflammatory systems may affect hippocampal volumes in MDD. A multimodal approach with structural neuroimaging of hippocampus and amygdala, measurement of peripheral inflammatory proteins interleukin (IL)-6 and C-reactive protein (CRP), glucocorticoid receptor (GR) mRNA expression, and expression of glucocorticoid-inducible genes (glucocorticoid-inducible genes Leucin Zipper (GILZ) and glucocorticoid-inducible kinase-1 (SGK-1)) was used in 40 patients with MDD and 43 healthy controls (HC). Patients with MDD showed smaller hippocampal volumes and increased inflammatory proteins IL-6 and CRP compared with HC. Childhood maltreatment was associated with increased CRP. Patients with MDD, who had less expression of the glucocorticoid-inducible genes GILZ or SGK-1 had smaller hippocampal volumes. Regression analysis showed a strong positive effect of GILZ and SGK-1 mRNA expression, and further inverse effects of IL-6 concentration, on hippocampal volumes. These findings suggest that childhood maltreatment, peripheral inflammatory and glucocorticoid markers and hippocampal volume are interrelated factors in the pathophysiology of MDD. Glucocorticoid-inducible genes GILZ and SGK-1 might be promising candidate markers for hippocampal volume changes relevant for diseases like MDD. Further studies need to explore the possible clinical usefulness of such a blood biomarker, for example, for diagnosis or prediction of therapy response.

Cytokine-induced loss of glucocorticoid function: effect of kinase inhibitors, long-acting β(2-adrenoceptor [corrected] agonist and glucocorticoid receptor ligands.

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Christopher F Rider

Full Text Available Acting on the glucocorticoid receptor (NR3C1, glucocorticoids are widely used to treat inflammatory diseases. However, glucocorticoid resistance often leads to suboptimal asthma control. Since glucocorticoid-induced gene expression contributes to glucocorticoid activity, the aim of this study was to use a 2 × glucocorticoid response element (GRE reporter and glucocorticoid-induced gene expression to investigate approaches to combat cytokine-induced glucocorticoid resistance. Pre-treatment with tumor necrosis factor-α (TNF or interleukin-1β inhibited dexamethasone-induced mRNA expression of the putative anti-inflammatory genes RGS2 and TSC22D3, or just TSC22D3, in primary human airway epithelial and smooth muscle cells, respectively. Dexamethasone-induced DUSP1 mRNA was unaffected. In human bronchial epithelial BEAS-2B cells, dexamethasone-induced TSC22D3 and CDKN1C expression (at 6 h was reduced by TNF pre-treatment, whereas DUSP1 and RGS2 mRNAs were unaffected. TNF pre-treatment also reduced dexamethasone-dependent 2×GRE reporter activation. This was partially reversed by PS-1145 and c-jun N-terminal kinase (JNK inhibitor VIII, inhibitors of IKK2 and JNK, respectively. However, neither inhibitor affected TNF-dependent loss of dexamethasone-induced CDKN1C or TSC22D3 mRNA. Similarly, inhibitors of the extracellular signal-regulated kinase, p38, phosphoinositide 3-kinase or protein kinase C pathways failed to attenuate TNF-dependent repression of the 2×GRE reporter. Fluticasone furoate, fluticasone propionate and budesonide were full agonists relative to dexamethasone, while GSK9027, RU24858, des-ciclesonide and GW870086X were partial agonists on the 2×GRE reporter. TNF reduced reporter activity in proportion with agonist efficacy. Full and partial agonists showed various degrees of agonism on RGS2 and TSC22D3 expression, but were equally effective at inducing CDKN1C and DUSP1, and did not affect the repression of CDKN1C or TSC22D3

Salt effects on hydrophobic interaction and charge screening in the folding of a negatively charged peptide to a coiled coil (leucine zipper).

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Jelesarov, I; Dürr, E; Thomas, R M; Bosshard, H R

1998-05-19

The stability of a coiled coil or leucine zipper is controlled by hydrophobic interactions and electrostatic forces between the constituent helices. We have designed a 30-residue peptide with the repeating seven-residue pattern of a coiled coil, (abcdefg)n, and with Glu in positions e and g of each heptad. The glutamate side chains prevented folding at pH values above 6 because of electrostatic repulsion across the helix dimer interface as well as within the individual helices. Protonation of the carboxylates changed the conformation from a random coil monomer to a coiled coil dimer. Folding at alkaline pH where the peptide had a net charge of -7e was promoted by the addition of salts. The nature of the charge screening cation was less important than that of the anion. The high salt concentrations (>1 M) necessary to induce folding indicated that the salt-induced folding resulted from alterations in the protein-water interaction. Folding was promoted by the kosmotropic anions sulfate and fluoride and to a lesser extent by the weak kosmotrope formate, whereas chloride and the strong chaotrope perchlorate were ineffective. Kosmotropes are excluded from the protein surface, which is preferentially hydrated, and this promotes folding by strengthening hydrophobic interactions at the coiled coil interface. Although charge neutralization also contributed to folding, it was effective only when the screening cation was partnered by a good kosmotropic anion. Folding conformed to a two-state transition from random coil monomer to coiled coil dimer and was enthalpy driven and characterized by a change in the heat capacity of unfolding of 3.9 +/- 1.2 kJ mol-1 K-1. The rate of folding was analyzed by fluorescence stopped-flow measurements. Folding occurred in a biphasic reaction in which the rapid formation of an initial dimer (kf = 2 x 10(7) M-1 s-1) was followed by an equally rapid concentration-independent rearrangement to the folded dimer (k > 100 s-1).

Application of HB17, an Arabidopsis class II homeodomain-leucine zipper transcription factor, to regulate chloroplast number and photosynthetic capacity.

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Hymus, Graham J; Cai, Suqin; Kohl, Elizabeth A; Holtan, Hans E; Marion, Colleen M; Tiwari, Shiv; Maszle, Don R; Lundgren, Marjorie R; Hong, Melissa C; Channa, Namitha; Loida, Paul; Thompson, Rebecca; Taylor, J Philip; Rice, Elena; Repetti, Peter P; Ratcliffe, Oliver J; Reuber, T Lynne; Creelman, Robert A

2013-11-01

Transcription factors are proposed as suitable targets for the control of traits such as yield or food quality in plants. This study reports the results of a functional genomics research effort that identified ATHB17, a transcription factor from the homeodomain-leucine zipper class II family, as a novel target for the enhancement of photosynthetic capacity. It was shown that ATHB17 is expressed natively in the root quiescent centre (QC) from Arabidopsis embryos and seedlings. Analysis of the functional composition of genes differentially expressed in the QC from a knockout mutant (athb17-1) compared with its wild-type sibling revealed the over-representation of genes involved in auxin stimulus, embryo development, axis polarity specification, and plastid-related processes. While no other phenotypes were observed in athb17-1 plants, overexpression of ATHB17 produced a number of phenotypes in Arabidopsis including enhanced chlorophyll content. Image analysis of isolated mesophyll cells of 35S::ATHB17 lines revealed an increase in the number of chloroplasts per unit cell size, which is probably due to an increase in the number of proplastids per meristematic cell. Leaf physiological measurements provided evidence of improved photosynthetic capacity in 35S::ATHB17 lines on a per unit leaf area basis. Estimates of the capacity for ribulose-1,5-bisphosphate-saturated and -limited photosynthesis were significantly higher in 35S::ATHB17 lines.

Basic leucine zipper protein Cnc-C is a substrate and transcriptional regulator of the Drosophila 26S proteasome.

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Grimberg, Kristian Björk; Beskow, Anne; Lundin, Daniel; Davis, Monica M; Young, Patrick

2011-02-01

While the 26S proteasome is a key proteolytic complex, little is known about how proteasome levels are maintained in higher eukaryotic cells. Here we describe an RNA interference (RNAi) screen of Drosophila melanogaster that was used to identify transcription factors that may play a role in maintaining levels of the 26S proteasome. We used an RNAi library against 993 Drosophila transcription factor genes to identify genes whose suppression in Schneider 2 cells stabilized a ubiquitin-green fluorescent protein reporter protein. This screen identified Cnc (cap 'n' collar [CNC]; basic region leucine zipper) as a candidate transcriptional regulator of proteasome component expression. In fact, 20S proteasome activity was reduced in cells depleted of cnc. Immunoblot assays against proteasome components revealed a general decline in both 19S regulatory complex and 20S proteasome subunits after RNAi depletion of this transcription factor. Transcript-specific silencing revealed that the longest of the seven transcripts for the cnc gene, cnc-C, was needed for proteasome and p97 ATPase production. Quantitative reverse transcription-PCR confirmed the role of Cnc-C in activation of transcription of genes encoding proteasome components. Expression of a V5-His-tagged form of Cnc-C revealed that the transcription factor is itself a proteasome substrate that is stabilized when the proteasome is inhibited. We propose that this single cnc gene in Drosophila resembles the ancestral gene family of mammalian nuclear factor erythroid-derived 2-related transcription factors, which are essential in regulating oxidative stress and proteolysis.

Unigenic Evolution: A Novel Genetic Method Localizes a Putative Leucine Zipper That Mediates Dimerization of the Saccharomyces Cerevisiae Regulator Gcr1p

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Deminoff, S. J.; Tornow, J.; Santangelo, G. M.

1995-01-01

The GCR1 gene of Saccharomyces cerevisiae encodes a transcriptional activator that complexes with Rap1p and, through UAS(RPG) elements (Rap1p DNA binding sites), stimulates efficient expression of glycolytic and translational component genes. To map the functionally important domains in Gcr1p, we combined multiple rounds of random mutagenesis in vitro with in vivo selection of functional genes to locate conserved, or hypomutable, regions. We name this method unigenic evolution, a statistical analysis of mutations in evolutionary variants of a single gene in an otherwise isogenic background. Examination of the distribution of 315 mutations in 24 variant alleles allowed the localization of four hypomutable regions in GCR1 (A, B, C, and D). Dispensable N-terminal (intronic) and C-terminal portions of the evolved region of GCR1 were included in the analysis as controls and were, as expected, not hypomutable. The analysis of several insertion, deletion, and point mutations, combined with a comparison of the hypomutability and hydrophobicity plots of Gcr1p, suggested that some of the hypomutable regions may individually or in combination correspond to functionally important surface domains. In particular, we determined that region D contains a putative leucine zipper and is necessary and sufficient for Gcr1p homodimerization. PMID:8601472

Gastroprotective role of glucocorticoids during NSAID-induced gastropathy.

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Filaretova, Ludmila

2013-01-01

Nonsteroidal anti-inflammatory drugs (NSAIDs) make significant contributions to gastric ulcer disease which remains widespread. Although several factors have been postulated as pathogenic elements of the gastric injury induced by NSAIDs, it is, however believed that prostaglandin deficiency plays a critical role in the pathogenesis of this injury. During prostaglandin deficiency, other defensive mechanisms might operate to attenuate NSAID-induced gastropathy. According to our results, NSAIDs, similar to stress, induce an increase in glucocorticoid production that in turn helps the gastric mucosa to resist the harmful actions of these drugs. In this article, we review our experimental data suggesting that glucocorticoids may play a role as natural defensive factors in maintaining the integrity of the gastric mucosa during NSAID therapy and might operate to attenuate NSAID-induced gastropathy.

Glucocorticoid-related bone changes from endogenous or exogenous glucocorticoids.

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Warriner, Amy H; Saag, Kenneth G

2013-12-01

Glucocorticoids have a negative impact on bone through direct effects on bone cells and indirect effects on calcium absorption. Here, recent findings regarding glucocorticoid-induced osteoporosis, bone changes in patients with endogenous glucocorticoid derangements, and treatment of steroid-induced bone disease are reviewed. Although the majority of our understanding arises from the outcomes of patients treated with exogenous steroids, endogenous overproduction appears to be similarly destructive to bone, but these effects are reversible with cure of the underlying disease process. Additionally, there are bone changes that occur in diseases that interrupt adrenal glucocorticoid production, both in response to our inability to perfectly match glucocorticoid replacement and also related to the underlying disease process. More investigation is required to understand which patients with endogenous overproduction or underproduction of glucocorticoid would benefit from osteoporosis treatment. Better understood is the benefit that can be achieved with currently approved treatments for glucocorticoid-induced osteoporosis from exogenous steroids. With growing concern of long-term use of bisphosphonates, however, further investigation into the duration of use and use in certain populations, such as children and premenopausal women, is essential. Glucocorticoid-induced osteoporosis is a complex disease that is becoming better understood through advances in the study of exogenous and endogenous glucocorticoid exposure. Further advancement of proper treatment and prevention is on the horizon.

Metabolic Mechanism for l-Leucine-Induced Metabolome To Eliminate Streptococcus iniae.

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Du, Chao-Chao; Yang, Man-Jun; Li, Min-Yi; Yang, Jun; Peng, Bo; Li, Hui; Peng, Xuan-Xian

2017-05-05

Crucial metabolites that modulate hosts' metabolome to eliminate bacterial pathogens have been documented, but the metabolic mechanisms are largely unknown. The present study explores the metabolic mechanism for l-leucine-induced metabolome to eliminate Streptococcus iniae in tilapia. GC-MS-based metabolomics was used to investigate the tilapia liver metabolic profile in the presence of exogenous l-leucine. Thirty-seven metabolites of differential abundance were determined, and 11 metabolic pathways were enriched. Pattern recognition analysis identified serine and proline as crucial metabolites, which are the two metabolites identified in survived tilapias during S. iniae infection, suggesting that the two metabolites play crucial roles in l-leucine-induced elimination of the pathogen by the host. Exogenous l-serine reduces the mortality of tilapias infected by S. iniae, providing a robust proof supporting the conclusion. Furthermore, exogenous l-serine elevates expression of genes IL-1β and IL-8 in tilapia spleen, but not TNFα, CXCR4 and Mx, suggesting that the metabolite promotes a phagocytosis role of macrophages, which is consistent with the finding that l-leucine promotes macrophages to kill both Gram-positive and Gram-negative bacterial pathogens. Therefore, the ability of phagocytosis enhanced by exogenous l-leucine is partly attributed to elevation of l-serine. These results demonstrate a metabolic mechanism by which exogenous l-leucine modulates tilapias' metabolome to enhance innate immunity and eliminate pathogens.

Elevated Hypothalamic Glucocorticoid Levels Are Associated With Obesity and Hyperphagia in Male Mice.

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Sefton, Charlotte; Harno, Erika; Davies, Alison; Small, Helen; Allen, Tiffany-Jayne; Wray, Jonathan R; Lawrence, Catherine B; Coll, Anthony P; White, Anne

2016-11-01

Glucocorticoid (Gc) excess, from endogenous overproduction in disorders of the hypothalamic-pituitary-adrenal axis or exogenous medical therapy, is recognized to cause adverse metabolic side effects. The Gc receptor (GR) is widely expressed throughout the body, including brain regions such as the hypothalamus. However, the extent to which chronic Gcs affect Gc concentrations in the hypothalamus and impact on GR and target genes is unknown. To investigate this, we used a murine model of corticosterone (Cort)-induced obesity and analyzed Cort levels in the hypothalamus and expression of genes relevant to Gc action. Mice were administered Cort (75 μg/mL) or ethanol (1%, vehicle) in drinking water for 4 weeks. Cort-treated mice had increased body weight, food intake, and adiposity. As expected, Cort increased plasma Cort levels at both zeitgeber time 1 and zeitgeber time 13, ablating the diurnal rhythm. Liquid chromatography dual tandem mass spectrometry revealed a 4-fold increase in hypothalamic Cort, which correlated with circulating levels and concentrations of Cort in other brain regions. This occurred despite decreased 11β-hydroxysteroid dehydrogenase (Hsd11b1) expression, the gene encoding the enzyme that regenerates active Gcs, whereas efflux transporter Abcb1 mRNA was unaltered. In addition, although Cort decreased hypothalamic GR (Nr3c1) expression 2-fold, the Gc-induced leucine zipper (Tsc22d3) mRNA increased, which indicated elevated GR activation. In keeping with the development of hyperphagia and obesity, Cort increased Agrp, but there were no changes in Pomc, Npy, or Cart mRNA in the hypothalamus. In summary, chronic Cort treatment causes chronic increases in hypothalamic Cort levels and a persistent elevation in Agrp, a mediator in the development of metabolic disturbances.

Instructions for producing a mouse model of glucocorticoid-induced osteoporosis

DEFF Research Database (Denmark)

Thiele, S.; Baschant, U.; Rauch, A.

2014-01-01

Glucocorticoids are effective drugs used for the treatment of inflammatory diseases such as rheumatoid arthritis or asthma. Furthermore, they regulate various physiological processes, including bone remodeling. However, long-term high- and even low-dose glucocorticoid use is associated...... with a compromised bone quality and an increased fracture risk. At the cellular level, glucocorticoids suppress bone formation and stimulate bone resorption, which leads to loss of bone mass. To investigate the underlying mechanisms and new therapeutic strategies, the in vivo model for glucocorticoid-induced bone...... loss is widely used. This protocol outlines the common procedure that is currently used for the induction of bone loss in mice using glucocorticoids. It further provides useful hints and highlights possible pitfalls to take into account before starting an experiment....

The homeodomain-leucine zipper (HD-Zip) class I transcription factors ATHB7 and ATHB12 modulate abscisic acid signalling by regulating protein phosphatase 2C and abscisic acid receptor gene activities.

Science.gov (United States)

Valdés, Ana Elisa; Overnäs, Elin; Johansson, Henrik; Rada-Iglesias, Alvaro; Engström, Peter

2012-11-01

Plants perceiving drought activate multiple responses to improve survival, including large-scale alterations in gene expression. This article reports on the roles in the drought response of two Arabidopsis thaliana homeodomain-leucine zipper class I genes; ATHB7 and ATHB12, both strongly induced by water-deficit and abscisic acid (ABA). ABA-mediated transcriptional regulation of both genes is shown to depend on the activity of protein phosphatases type 2C (PP2C). ATHB7 and ATHB12 are, thus, targets of the ABA signalling mechanism defined by the PP2Cs and the PYR/PYL family of ABA receptors, with which the PP2C proteins interact. Our results from chromatin immunoprecipitation and gene expression analyses demonstrate that ATHB7 and ATHB12 act as positive transcriptional regulators of PP2C genes, and thereby as negative regulators of abscisic acid signalling. In support of this notion, our results also show that ATHB7 and ATHB12 act to repress the transcription of genes encoding the ABA receptors PYL5 and PYL8 in response to an ABA stimulus. In summary, we demonstrate that ATHB7 and ATHB12 have essential functions in the primary response to drought, as mediators of a negative feedback effect on ABA signalling in the plant response to water deficit.

Seizures induced by carbachol, morphine, and leucine-enkephalin: a comparison.

Science.gov (United States)

Snead, O C

1983-04-01

The electrical, behavioral, and pharmacological properties of seizures induced by morphine, leucine-enkephalin, and the muscarinic cholinergic agonist carbachol were examined and compared. Low-dose carbachol given intracerebroventricularly (ICV) produced seizures similar electrically to those produced by ICV morphine and leucine-enkephalin, although there was some difference in site of subcortical origin of onset. Carbachol and morphine were similar in that they had the same anticonvulsant profile, produced similar behavioral changes, caused generalized absence seizures in low doses and generalized convulsive seizures in high doses, and were capable of chemical kindling. However, opiate-induced seizures were not overcome by cholinergic antagonists, nor were carbachol seizures blocked by opiate antagonists. These data suggest that there may be a common noncholinergic, nonopiatergic system involved in mediating carbachol- and morphine-induced seizures but not enkephalin seizures.

Glucocorticoid-induced myopathy in the intensive care unit

DEFF Research Database (Denmark)

Eddelien, Heidi Shil; Hoffmeyer, Henrik Westy; Lund, Eva Charlotte Løbner

2015-01-01

Glucocorticoids (GC) are used for intensive care unit (ICU) patients on several indications. We present a patient who was admitted to the ICU due to severe respiratory failure caused by bronchospasm requiring mechanical ventilation and treated with methylprednisolone 240 mg/day in addition...... to antibiotics and bronchiolytics. When the sedation was lifted on day 10, the patient was awake but quadriplegic. Blood samples revealed elevated muscle enzymes, electromyography showed myopathy, and a muscle biopsy was performed. Glucocorticoid-induced myopathy was suspected, GC treatment was tapered...

Glucocorticoid-Induced Avascular Bone Necrosis: Diagnosis and Management

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Chan, KL; Mok, CC

2012-01-01

Glucocorticoid use is one of the most important causes of avascular bone necrosis (AVN). The pathogenesis of glucocorticoid-induced AVN is not fully understood but postulated mechanisms include fat hypertrophy, fat emboli and intravascular coagulation that cause impedance of blood supply to the bones. Data regarding the relationship between AVN and dosage, route of administration and treatment duration of glucocorticoids are conflicting, with some studies demonstrating the cumulative dose of glucocorticoid being the most important determining factor. Early recognition of this complication is essential as the prognosis is affected by the stage of the disease. Currently, there is no consensus on whether universal screening of asymptomatic AVN should be performed for long-term glucocorticoid users. A high index of suspicion should be exhibited for bone and joint pain at typical sites. Magnetic resonance imaging (MRI) or bone scintigraphy is more sensitive than plain radiograph for diagnosing early-stage AVN. Conservative management of AVN includes rest and reduction of weight bearing. Minimization of glucocorticoid dose or a complete withdrawal of the drug should be considered if the underlying conditions allow. The efficacy of bisphosphonates in reducing the rate of collapse of femoral head in AVN is controversial. Surgical therapy of AVN includes core decompression, osteotomy, bone grafting and joint replacement. Recent advances in the treatment of AVN include the use of tantalum rod and the development of more wear resistant bearing surface in hip arthroplasty. PMID:23115605

Glucocorticoid-induced avascular bone necrosis: diagnosis and management.

Science.gov (United States)

Chan, K L; Mok, C C

2012-01-01

Glucocorticoid use is one of the most important causes of avascular bone necrosis (AVN). The pathogenesis of glucocorticoid-induced AVN is not fully understood but postulated mechanisms include fat hypertrophy, fat emboli and intravascular coagulation that cause impedance of blood supply to the bones. Data regarding the relationship between AVN and dosage, route of administration and treatment duration of glucocorticoids are conflicting, with some studies demonstrating the cumulative dose of glucocorticoid being the most important determining factor. Early recognition of this complication is essential as the prognosis is affected by the stage of the disease. Currently, there is no consensus on whether universal screening of asymptomatic AVN should be performed for long-term glucocorticoid users. A high index of suspicion should be exhibited for bone and joint pain at typical sites. Magnetic resonance imaging (MRI) or bone scintigraphy is more sensitive than plain radiograph for diagnosing early-stage AVN. Conservative management of AVN includes rest and reduction of weight bearing. Minimization of glucocorticoid dose or a complete withdrawal of the drug should be considered if the underlying conditions allow. The efficacy of bisphosphonates in reducing the rate of collapse of femoral head in AVN is controversial. Surgical therapy of AVN includes core decompression, osteotomy, bone grafting and joint replacement. Recent advances in the treatment of AVN include the use of tantalum rod and the development of more wear resistant bearing surface in hip arthroplasty.

The different roles of glucocorticoids in the hippocampus and hypothalamus in chronic stress-induced HPA axis hyperactivity.

Directory of Open Access Journals (Sweden)

Li-Juan Zhu

Full Text Available Hypothalamus-pituitary-adrenal (HPA hyperactivity is observed in many patients suffering from depression and the mechanism underling the dysfunction of HPA axis is not well understood. Chronic stress has a causal relationship with the hyperactivity of HPA axis. Stress induces the over-synthesis of glucocorticoids, which will arrive at all the body containing the brain. It is still complicated whether glucocorticoids account for chronic stress-induced HPA axis hyperactivity and in which part of the brain the glucocorticoids account for chronic stress-induced HPA axis hyperactivity. Here, we demonstrated that glucocorticoids were indispensable and sufficient for chronic stress-induced hyperactivity of HPA axis. Although acute glucocorticoids elevation in the hippocampus and hypothalamus exerted a negative regulation of HPA axis, we found that chronic glucocorticoids elevation in the hippocampus but not in the hypothalamus accounted for chronic stress-induced hyperactivity of HPA axis. Chronic glucocorticoids exposure in the hypothalamus still exerted a negative regulation of HPA axis activity. More importantly, we found mineralocorticoid receptor (MR - neuronal nitric oxide synthesis enzyme (nNOS - nitric oxide (NO pathway mediated the different roles of glucocorticoids in the hippocampus and hypothalamus in regulating HPA axis activity. This study suggests that the glucocorticoids in the hippocampus play an important role in the development of HPA axis hyperactivity and the glucocorticoids in the hypothalamus can't induce hyperactivity of HPA axis, revealing new insights into understanding the mechanism of depression.

Leucine and its transporter provide protection against cigarette smoke-induced cell death: A potential therapy for emphysema

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Bannhi Das

2014-01-01

Full Text Available Cigarette smoke (CS is a major risk factor for emphysematous changes in the lungs and the underlying mechanism involves CS-induced cell death. In the present study we investigated the ability of nutrients to rescue CS-induced cell death. We observed that pre-treatment with excess leucine can partially rescue CS extract-induced cell death in Saccharomyces cerevisiae and alveolar epithelial A549 cells. Excess dietary leucine was also effective in alleviating effects of CS in guinea pig lungs. Further investigation to understand the underlying mechanism showed that CS exposure causes downregulation of leucine transporter that results in inactivation of mTOR, which is a positive regulator of protein synthesis and cell proliferation. Notably, leucine supplemented diet ameliorated even existing CS-induced emphysematous changes in guinea pig lung, a condition hitherto thought to be irreversible. Thus the current study documents a new mechanism by which CS affects cellular physiology wherein leucine transporter is a key target.

Adaptor protein containing PH domain, PTB domain and leucine zipper (APPL1) regulates the protein level of EGFR by modulating its trafficking

International Nuclear Information System (INIS)

Lee, Jae-Rin; Hahn, Hwa-Sun; Kim, Young-Hoon; Nguyen, Hong-Hoa; Yang, Jun-Mo; Kang, Jong-Sun; Hahn, Myong-Joon

2011-01-01

Highlights: ► APPL1 regulates the protein level of EGFR in response to EGF stimulation. ► Depletion of APPL1 accelerates the movement of EGF/EGFR from the cell surface to the perinuclear region in response to EGF. ► Knockdown of APPL1 enhances the activity of Rab5. -- Abstract: The EGFR-mediated signaling pathway regulates multiple biological processes such as cell proliferation, survival and differentiation. Previously APPL1 (adaptor protein containing PH domain, PTB domain and leucine zipper 1) has been reported to function as a downstream effector of EGF-initiated signaling. Here we demonstrate that APPL1 regulates EGFR protein levels in response to EGF stimulation. Overexpression of APPL1 enhances EGFR stabilization while APPL1 depletion by siRNA reduces EGFR protein levels. APPL1 depletion accelerates EGFR internalization and movement of EGF/EGFR from cell surface to the perinuclear region in response to EGF treatment. Conversely, overexpression of APPL1 decelerates EGFR internalization and translocation of EGF/EGFR to the perinuclear region. Furthermore, APPL1 depletion enhances the activity of Rab5 which is involved in internalization and trafficking of EGFR and inhibition of Rab5 in APPL1-depleted cells restored EGFR levels. Consistently, APPL1 depletion reduced activation of Akt, the downstream signaling effector of EGFR and this is restored by inhibition of Rab5. These findings suggest that APPL1 is required for EGFR signaling by regulation of EGFR stabilities through inhibition of Rab5.

Long-term safety, efficacy, and patient acceptability of teriparatide in the management of glucocorticoid-induced osteoporosis

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Dore RK

2013-05-01

Full Text Available Robin K DoreDavid Geffen School of Medicine, University of California, Los Angeles, CA, USAAbstract: Glucocorticoids are commonly prescribed medications to treat multiple diseases across many medical specialties. One of the most common yet largely unappreciated side effect of glucocorticoid use is increased risk of fracture. Many different therapies are indicated to prevent and treat this condition; many guidelines exist that suggest appropriate use of both glucocorticoids and the medications approved to prevent this common side effect of glucocorticoid therapy. Nevertheless, 30%–50% of patients on long-term glucocorticoid therapy sustain a fracture. Teriparatide, recombinant human parathyroid hormone (1–34, is a daily self-injectable therapy for 24 months approved for use in patients taking long-term glucocorticoids. Teriparatide has been shown to increase bone mineral density and reduce vertebral fracture risk in glucocorticoid-treated patients. Glucocorticoids have many adverse effects on bone that teriparatide has been shown to prevent or negate. Given the fact that preventive therapy for glucocorticoid-induced osteoporosis is often not prescribed, one wonders whether a daily self-injectable therapy for this condition would be prescribed by physicians and accepted by patients. This article reviews the epidemiology, pathophysiology, treatment, guidelines, and persistence data (when available for patients with glucocorticoid-induced osteoporosis treated with teriparatide.Keywords: glucocorticoid-induced osteoporosis, teriparatide, anabolic, PTH, parathyroid hormone

Asparaginase Potentiates Glucocorticoid-Induced Osteonecrosis in a Mouse Model.

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Chengcheng Liu

Full Text Available Osteonecrosis is a common dose-limiting toxicity of glucocorticoids. Data from clinical trials suggest that other medications can increase the risk of glucocorticoid-induced osteonecrosis. Here we utilized a mouse model to study the effect of asparaginase treatment on dexamethasone-induced osteonecrosis. Mice receiving asparaginase along with dexamethasone had a higher rate of osteonecrosis than those receiving only dexamethasone after 6 weeks of treatment (44% vs. 10%, P = 0.006. Similarly, epiphyseal arteriopathy, which we have shown to be an initiating event for osteonecrosis, was observed in 58% of mice receiving asparaginase and dexamethasone compared to 17% of mice receiving dexamethasone only (P = 0.007. As in the clinic, greater exposure to asparaginase was associated with greater plasma exposure to dexamethasone (P = 0.0001. This model also recapitulated other clinical risk factors for osteonecrosis, including age at start of treatment, and association with the systemic exposure to dexamethasone (P = 0.027 and asparaginase (P = 0.036. We conclude that asparaginase can potentiate the osteonecrotic effect of glucocorticoids.

Radiation-induced tetramer-to-dimer transition of Escherichia coli lactose repressor

International Nuclear Information System (INIS)

Goffinont, S.; Davidkova, M.; Spotheim-Maurizot, M.

2009-01-01

The wild type lactose repressor of Escherichia coli is a tetrameric protein formed by two identical dimers. They are associated via a C-terminal 4-helix bundle (called tetramerization domain) whose stability is ensured by the interaction of leucine zipper motifs. Upon in vitro γ-irradiation the repressor losses its ability to bind the operator DNA sequence due to damage of its DNA-binding domains. Using an engineered dimeric repressor for comparison, we show here that irradiation induces also the change of repressor oligomerisation state from tetramer to dimer. The splitting of the tetramer into dimers can result from the oxidation of the leucine residues of the tetramerization domain.

Glucocorticoids induce autophagy in rat bone marrow mesenchymal stem cells

DEFF Research Database (Denmark)

Wang, L.; Fan, J.; Lin, Y. S.

2015-01-01

Glucocorticoidinduced osteoporosis (GIOP) is a widespread clinical complication following glucocorticoid therapy. This irreversible damage to boneforming and resorbing cells is essential in the pathogenesis of osteoporosis. Autophagy is a physiological process involved in the regulation of cells...... and their responses to diverse stimuli, however, the role of autophagy in glucocorticoidinduced damage to bone marrow mesenchymal stem cells (BMSCs) remains unclear. The current study confirmed that glucocorticoid administration impaired the proliferation of BMSCs. Transmission electron microscopy...... that in response to glucocorticoid administration, induced autophagy aids to maintain proliferation and prevent apoptosis of BMSCs. Thus, it is hypothesized that autophagy may be a novel target in the treatment or prevention of osteoporosis....

The ontogeny of seizures induced by leucine-enkephalin and beta-endorphin.

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Snead, O C; Stephens, H

1984-06-01

Rats ranging in postnatal age from 6 hours to 28 days were implanted with cortical and depth electrodes as well as an indwelling cannula in the lateral ventricle. We then administered varying amounts of the opiate peptides leucine-enkephalin and beta-endorphin intracerebroventricularly with continuous electroencephalographic monitoring. Leucine-enkephalin produced electrical seizure activity in rats as young as 2 days. beta-Endorphin administration was associated with seizures at the fifth postnatal day, with a high incidence of apnea resulting in death in animals as young as 6 hours. An adult seizure response to beta-endorphin and leucine-enkephalin was seen at 15 and 28 days of age, respectively. Naloxone blocked the seizure produced by these opiate peptides in all age groups. The data indicate that the opiate peptides are potent epileptogenic compounds in developing brain, that seizures induced by leucine-enkephalin differ from those caused by beta-endorphin, and that petit mal-like seizure activity can be an adult response in the rodent.

Dexras1 mediates glucocorticoid-associated adipogenesis and diet-induced obesity

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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

Alanine Zipper-Like Coiled-Coil Domains Are Necessary for Homotypic Dimerization of Plant GAGA-Factors in the Nucleus and Nucleolus

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Bloss, Ulrich; Hecker, Andreas; Elgass, Kirstin; Hummel, Sabine; Hahn, Achim; Caesar, Katharina; Schleifenbaum, Frank; Harter, Klaus; Berendzen, Kenneth W.

2011-01-01

GAGA-motif binding proteins control transcriptional activation or repression of homeotic genes. Interestingly, there are no sequence similarities between animal and plant proteins. Plant BBR/BPC-proteins can be classified into two distinct groups: Previous studies have elaborated on group I members only and so little is known about group II proteins. Here, we focused on the initial characterization of AtBPC6, a group II protein from Arabidopsis thaliana. Comparison of orthologous BBR/BPC sequences disclosed two conserved signatures besides the DNA binding domain. A first peptide signature is essential and sufficient to target AtBPC6-GFP to the nucleus and nucleolus. A second domain is predicted to form a zipper-like coiled-coil structure. This novel type of domain is similar to Leucine zippers, but contains invariant alanine residues with a heptad spacing of 7 amino acids. By yeast-2-hybrid and BiFC-assays we could show that this Alanine zipper domain is essential for homotypic dimerization of group II proteins in vivo. Interhelical salt bridges and charge-stabilized hydrogen bonds between acidic and basic residues of the two monomers are predicted to form an interaction domain, which does not follow the classical knobs-into-holes zipper model. FRET-FLIM analysis of GFP/RFP-hybrid fusion proteins validates the formation of parallel dimers in planta. Sequence comparison uncovered that this type of domain is not restricted to BBR/BPC proteins, but is found in all kingdoms. PMID:21347358

Glucocorticoid effect on melphalan cytotoxicity, cell-cycle position, cell size, and [3H]uridine incorporation in one of three human melanoma cell lines

International Nuclear Information System (INIS)

Benckhuijsen, C.; Osman, A.M.; Hillebrand, M.J.; Smets, L.A.

1987-01-01

Three human melanoma cell lines of known content of specific glucocorticoid-binding sites were studied for colony formation after a microM dose of glucocorticoid combined with melphalan. In one of the three cell lines, M-5A, subcloned from M-5 (formerly designated RPMI 8322), the effect of combined treatment was markedly increased compared to that of melphalan even if the glucocorticoid was applied for 1 h only, 10 h before the melphalan. Semilogarithmic dose-effect plots for a reduction of final plating efficiency by glucocorticoid were curvilinear, according to a receptor-mediated process. The effects of glucocorticoid, melphalan, and their combination were linearized by bilogarithmic median-effect plotting which allowed the quantitation of a synergism which was more marked in case of glucocorticoid pretreatment, for 1 or 24 h, than on simultaneous exposure. According to sequential DNA per cell cytophotometry, melphalan abolished in M-5A a glucocorticoid-induced arrest in the G1 phase of the cell cycle. The cytotoxic synergism correlated with an apparent stimulation by glucocorticoid of the rate of acid-insoluble incorporation of [ 3 H]uridine and [ 14 C]leucine and an increase in cell size and protein content in M-5A cells but not in the other two cell lines. The way in which glucocorticoids induce an enhanced susceptibility to melphalan is not clear. Our results appear compatible with a hypothesis that chromatin in a transcriptionally activated state is more vulnerable to cytotoxic attack by an alkylating agent than under average conditions

Glucocorticoids and inhibition of bone formation induced by skeletal unloading

International Nuclear Information System (INIS)

Halloran, B.P.; Bikle, D.D.; Cone, C.M.; Morey-Holton, E.

1988-01-01

Skeletal unloading or loss of normal weight bearing in the growing animal inhibits bone formation and reduces bone calcium. To determine whether the inhibition of bone formation induced by skeletal unloading is a consequence of an increase in plasma glucocorticoids and/or an increase in bone sensitivity to glucocorticoids, the authors measured plasma corticosterone throughout the day in unloaded and normally loaded rats (hindlimb elevation model) and examined the effect of adrenalectomy on the response of bone to skeletal unloading. Plasma corticosterone levels were similar in normally loaded and unloaded rats at all times. Skeletal unloading in sham-adrenalectomized animals reduced tibial and vertebral calcium by 11.5 and 11.1%, respectively, and in adrenalectomized animals by 15.3 and 20.3%, respectively. Uptake of 45 Ca and [ 3 H]proline in the tibia was reduced by 8 and 14%, respectively, in the sham-adrenalectomized animals and by 13 and 19% in the adrenalectomized animals. Bone formation and apposition rates were reduced to the same level in sham- and adrenalectomized animals. These results suggest that the inhibition of bone formation induced by skeletal unloading is not a consequence of increased plasma glucocorticoids or an increase in bone sensitivity to the glucocorticoids but, rather, point to a local mediator in bone that senses mechanical load and transmits that information to the bone-forming cells directly

β-Adrenergic receptor antagonism prevents anxiety-like behavior and microglial reactivity induced by repeated social defeat.

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Wohleb, Eric S; Hanke, Mark L; Corona, Angela W; Powell, Nicole D; Stiner, La'Tonia M; Bailey, Michael T; Nelson, Randy J; Godbout, Jonathan P; Sheridan, John F

2011-04-27

Psychosocial stress is associated with altered immune function and development of psychological disorders including anxiety and depression. Here we show that repeated social defeat in mice increased c-Fos staining in brain regions associated with fear and threat appraisal and promoted anxiety-like behavior in a β-adrenergic receptor-dependent manner. Repeated social defeat also significantly increased the number of CD11b(+)/CD45(high)/Ly6C(high) macrophages that trafficked to the brain. In addition, several inflammatory markers were increased on the surface of microglia (CD14, CD86, and TLR4) and macrophages (CD14 and CD86) after social defeat. Repeated social defeat also increased the presence of deramified microglia in the medial amygdala, prefrontal cortex, and hippocampus. Moreover, mRNA analysis of microglia indicated that repeated social defeat increased levels of interleukin (IL)-1β and reduced levels of glucocorticoid responsive genes [glucocorticoid-induced leucine zipper (GILZ) and FK506 binding protein-51 (FKBP51)]. The stress-dependent changes in microglia and macrophages were prevented by propranolol, a β-adrenergic receptor antagonist. Microglia isolated from socially defeated mice and cultured ex vivo produced markedly higher levels of IL-6, tumor necrosis factor-α, and monocyte chemoattractant protein-1 after stimulation with lipopolysaccharide compared with microglia from control mice. Last, repeated social defeat increased c-Fos activation in IL-1 receptor type-1-deficient mice, but did not promote anxiety-like behavior or microglia activation in the absence of functional IL-1 receptor type-1. These findings indicate that repeated social defeat-induced anxiety-like behavior and enhanced reactivity of microglia was dependent on activation of β-adrenergic and IL-1 receptors.

Glucocorticoid Signaling and Bone Biology.

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Komori, T

2016-11-01

Since glucocorticoids remain an effective therapeutic option for the treatment of many inflammatory and autoimmune diseases, glucocorticoid-induced osteoporosis is the most common form of secondary osteoporosis. Fractures may occur in as many as 30-50% of patients receiving chronic glucocorticoid therapy. Under physiological conditions, glucocorticoids are required for normal bone development due to their regulation of osteoblast differentiation, possibly via the Wnt/β-catenin pathway and TSC22D3. However, serum levels of endogenous corticosterone are elevated in aged mice and glucocorticoids exert negative effects on the survival of osteoblasts and osteocytes as well as angiogenesis. Glucocorticoid treatments impair bone formation and enhance bone resorption. Excess glucocorticoids induce osteoblast and osteocyte apoptosis by increasing pro-apoptotic molecules, reactive oxygen species, and endoplasmic reticulum stress and suppressing the Wnt/β-catenin pathway. Autophagy protects osteocytes from glucocorticoid-induced apoptosis, but passed some threshold, the process of autophagy leads the cells to apoptosis. Excess glucocorticoids impair osteoblastogenesis by inducing Wnt antagonists, including Dkk1, Sost, and sFRP-1. However, the findings are controversial and the involvement of Wnt antagonists requires further study. Excess glucocorticoids reduce the phosphorylation of Akt and GSK3β, which enhances the degradation of β-catenin. Excess glucocorticoids have been shown to modulate the expression of miRNAs, including miR-29a, miR-34a-5p, and miR-199a-5p, which regulate the proliferation and differentiation of osteoblast lineage cells. Excess glucocorticoids also enhance bone resorption by reducing OPG expression, increasing Rankl expression and reactive oxygen species, and prolonging the life span of osteoclasts; however, they also suppress the bone-degrading capacity of osteoclasts by disturbing the organization of the cytoskeleton. © Georg Thieme Verlag KG

Myostatin Suppression of Akirin1 Mediates Glucocorticoid-Induced Satellite Cell Dysfunction

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Dong, Yanjun; Pan, Jenny S.; Zhang, Liping

2013-01-01

Glucocorticoids production is increased in many pathological conditions that are associated with muscle loss, but their role in causing muscle wasting is not fully understood. We have demonstrated a new mechanism of glucocorticoid-induced muscle atrophy: Dexamethasone (Dex) suppresses satellite cell function contributing to the development of muscle atrophy. Specifically, we found that Dex decreases satellite cell proliferation and differentiation in vitro and in vivo. The mechanism involved Dex-induced upregulation of myostatin and suppression of Akirin1, a promyogenic gene. When myostatin was inhibited in Dex-treated mice, Akirin1 expression increased as did satellite cell activity, muscle regeneration and muscle growth. In addition, silencing myostatin in myoblasts or satellite cells prevented Dex from suppressing Akirin1 expression and cellular proliferation and differentiation. Finally, overexpression of Akirin1 in myoblasts increased their expression of MyoD and myogenin and improved cellular proliferation and differentiation, theses improvements were no longer suppressed by Dex. We conclude that glucocorticoids stimulate myostatin which inhibits Akirin1 expression and the reparative functions of satellite cells. These responses attribute to muscle atrophy. Thus, inhibition of myostatin or increasing Akirin1 expression could lead to therapeutic strategies for improving satellite cell activation and enhancing muscle growth in diseases associated with increased glucocorticoid production. PMID:23516508

Myostatin suppression of Akirin1 mediates glucocorticoid-induced satellite cell dysfunction.

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Yanjun Dong

Full Text Available Glucocorticoids production is increased in many pathological conditions that are associated with muscle loss, but their role in causing muscle wasting is not fully understood. We have demonstrated a new mechanism of glucocorticoid-induced muscle atrophy: Dexamethasone (Dex suppresses satellite cell function contributing to the development of muscle atrophy. Specifically, we found that Dex decreases satellite cell proliferation and differentiation in vitro and in vivo. The mechanism involved Dex-induced upregulation of myostatin and suppression of Akirin1, a promyogenic gene. When myostatin was inhibited in Dex-treated mice, Akirin1 expression increased as did satellite cell activity, muscle regeneration and muscle growth. In addition, silencing myostatin in myoblasts or satellite cells prevented Dex from suppressing Akirin1 expression and cellular proliferation and differentiation. Finally, overexpression of Akirin1 in myoblasts increased their expression of MyoD and myogenin and improved cellular proliferation and differentiation, theses improvements were no longer suppressed by Dex. We conclude that glucocorticoids stimulate myostatin which inhibits Akirin1 expression and the reparative functions of satellite cells. These responses attribute to muscle atrophy. Thus, inhibition of myostatin or increasing Akirin1 expression could lead to therapeutic strategies for improving satellite cell activation and enhancing muscle growth in diseases associated with increased glucocorticoid production.

Surface properties of aqueous amino acid solutions II. Leucine-leucine hydrochloride and leucine-sodium leucinate mixtures.

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Matubayasi, Norihiro; Matsuyama, Shohei; Akizuki, Ryosuke

2005-08-15

To understand the distinction between the effects of zwitterionic, anionic, and cationic l-leucine upon adsorption and lateral interactions at air/water surface, the surface tensions of aqueous solutions of l-leucine-l-leucine hydrochloride and l-leucine-sodium l-leucinate mixtures were measured as a function of concentration and composition at 25 degrees C. The surface activity decreases in the order l-leucine >l-leucine hydrochloride > sodium l-leucinate. Both l-leucine hydrochloride and sodium l-leucinate form gaseous adsorbed films through the experimentally accessible concentration range, while the adsorbed film of zwitterionic l-leucine shows a transition between gaseous and expanded film.

CONTRIBUTIONS TO CLASSIFICATION ZIPPERS USED IN INDUSTRY FOOTWEAR AND LEATHER GOODS

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MALCOCI Marina

2016-05-01

Full Text Available Now customary accessory companies of all leather garments, zipper began to enjoy popularity only after 80 years of its invention. The first is considered the inventor of the zipper Elias Howe. Essentially involves fashion, change, innovation, originality, creativity and is defined as a succession of trends or fads, short. Create fashionable leather confections from home means accepting a contract with the producer and / or consumer, showing a profit motivating all at the right time. Continuous which require the exercise involves creative skills of fashion design, leading to a wide range of products. Current zipper is composed of: slider, teeth, strips shooter stops. Currently there is possibility to customize shooters to customer requirements, and even to form their own zippers. The present work presents the classification criteria zippers. They are after construction fastener after destination zippers, after the role they fulfill zippers, after the presentation at the procurement zippers, after finishing module of the metallic elements, as visibility zipper in the product, by type of teeth, by nature material strip zipper, after the type of materials they are made pullers, after the nature of the materials they are made of sliders and stops after the oxidation of metal components after finishing module teeth after shaped zipper, after slider type, by mode of ornamentation zippers. Knowing appearance zippers, elements of which it is composed, and their classification criteria allow us to correlate the shape of the product and destination.

Inhibition of glycogen synthase kinase-3β attenuates glucocorticoid-induced suppression of myogenic differentiation in vitro.

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Zhenyu Ma

Full Text Available Glucocorticoids are the only therapy that has been demonstrated to alter the progress of Duchenne muscular dystrophy (DMD, the most common muscular dystrophy in children. However, glucocorticoids disturb skeletal muscle metabolism and hamper myogenesis and muscle regeneration. The mechanisms involved in the glucocorticoid-mediated suppression of myogenic differentiation are not fully understood. Glycogen synthase kinase-3β (GSK-3β is considered to play a central role as a negative regulator in myogenic differentiation. Here, we showed that glucocorticoid treatment during the first 48 h in differentiation medium decreased the level of phosphorylated Ser9-GSK-3β, an inactive form of GSK-3β, suggesting that glucocorticoids affect GSK-3β activity. We then investigated whether GSK-3β inhibition could regulate glucocorticoid-mediated suppression of myogenic differentiation in vitro. Two methods were employed to inhibit GSK-3β: pharmacological inhibition with LiCl and GSK-3β gene knockdown. We found that both methods resulted in enhanced myotube formation and increased levels of muscle regulatory factors and muscle-specific protein expression. Importantly, GSK-3β inhibition attenuated glucocorticoid-induced suppression of myogenic differentiation. Collectively, these data suggest the involvement of GSK-3β in the glucocorticoid-mediated impairment of myogenic differentiation. Therefore, the inhibition of GSK-3β may be a strategy for preventing glucocorticoid-induced muscle degeneration.

Kinematics analysis of a robotic zipper prototype for miniaturisation

NARCIS (Netherlands)

Baharom, M.Z.; Delbressine, F.L.M.; Feijs, L.M.G.

2016-01-01

This paper presents the mechanism and kinematics analysis of a robotic zipper prototype. This generic version of the robotic zipper is dedicated to automatically open and close the zipper which could be beneficial to elderly, people with physical disability, upper limb reduction deficiencies (ULRD),

Experimental Study on the Effect of Calcitonin in Osteoporosis Induced by the Immobilization and Long-Term Glucocorticoid

International Nuclear Information System (INIS)

Park, Dong Jin; Lee, Sang Rae

1989-01-01

It is well known that the glucocorticoid induces osteoporosis by suppression of the osteoblast, but its effect on the osteoclast has some controversy whether it activates or suppresses the osteoclast. If the calcitonin, which is known to suppress the osteoclast, prevents the osteoporosis by glucocorticoid, then the suppression of the osteoclast by the glucocorticoid is not so significant. And if the calcitonin increases the osteoblastic activity, Tc-99m MDP uptake will be increased in spite of the glucocorticoid effect on the osteoblast. The immobilization operation was performed to the right leg of male Wistar rats weighing about 200 gm each. For 16 weeks after operation, rats were injected glucocorticoid alone or glucocorticoid and calcitonin. The bone density was measured by means of photodensitometry under reference aluminum step wedge and Tc-99m MDP uptake was available to the index of the osteoblastic activity. 1. The bone density of femoral head was markedly reduced than that of femoral shaft following ratio of cancellous and cortical components in both site. 2. glucocorticoid caused decrease in bone density of spine and femur, and there is significantly increase of it when medication of glucocorticoid and calcitonin injection simultaneously than that of glucocorticoid. 3. Tc-99m MDP uptake was revealed significant reduction in medication of glucocorticoid but increase in glucocorticoid and calcitonin injection simultaneously in later experimental period. 4. There was a slight reduction in plasma osteocalcin in medication of glucocorticoid through experimental periods and an increase in its value in case of giving glucocorticoid and calcitonin simultaneously in later experimental period. From these results, we suggest that osteoporosis by immobilization is more pronounced by glucocorticoid hormone and osteoporosis induced by immobilization and glucocorticoid use is prevented by calcitonin administration with increasing osteoblastic activity.

Adrenocorticotropic Hormone Secreting Pheochromocytoma Underlying Glucocorticoid Induced Pheochromocytoma Crisis

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Gil A. Geva

2018-01-01

Full Text Available Context. Pheochromocytomas are hormone secreting tumors of the medulla of the adrenal glands found in 0.1–0.5% of patients with hypertension. The vast majority of pheochromocytomas secrete catecholamines, but they have been occasionally shown to also secrete interleukins, calcitonin, testosterone, and in rare cases adrenocorticotropic hormone. Pheochromocytoma crisis is a life threatening event in which high levels of catecholamines cause a systemic reaction leading to organ failure. Case Description. A 70-year-old man was admitted with acute myocardial ischemia following glucocorticoid administration as part of an endocrine workup for an adrenal mass. Cardiac catheterization disclosed patent coronary arteries and he was discharged. A year later he returned with similar angina-like chest pain. During hospitalization, he suffered additional events of chest pain, shortness of breath, and palpitations following administration of glucocorticoids as preparation for intravenous contrast administration. Throughout his admission, the patient demonstrated both signs of Cushing’s syndrome and high catecholamine levels. Following stabilization of vital parameters and serum electrolytes, the adrenal mass was resected surgically and was found to harbor an adrenocorticotropic hormone secreting pheochromocytoma. This is the first documented case of adrenocorticotropic hormone secreting pheochromocytoma complicated by glucocorticoid induced pheochromocytoma crisis. Conclusion. Care should be taken when administering high doses of glucocorticoids to patients with suspected pheochromocytoma, even in a patient with concomitant Cushing’s syndrome.

Glucocorticoid-Induced Osteoporosis

Science.gov (United States)

... nervosa Cigarette smoking Alcohol abuse Low calcium and vitamin D, by low dietary intake or poor absorption in your gut Sedentary (inactive) lifestyle or immobility Certain medications besides glucocorticoids, including the following: excess thyroid hormone replacement the blood thinner heparin some ...

Burn-induced increase in atrogin-1 and MuRF-1 in skeletal muscle is glucocorticoid independent but downregulated by IGF-I.

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Lang, Charles H; Huber, Danuta; Frost, Robert A

2007-01-01

The present study determined whether thermal injury increases the expression of the ubiquitin (Ub) E3 ligases referred to as muscle ring finger (MuRF)-1 and muscle atrophy F-box (MAFbx; aka atrogin-1), which are muscle specific and responsible for the increased protein breakdown observed in other catabolic conditions. After 48 h of burn injury (40% total body surface area full-thickness scald burn) gastrocnemius weight was reduced, and this change was associated with an increased mRNA abundance for atrogin-1 and MuRF-1 (3.1- to 8-fold, respectively). Similarly, burn increased polyUb mRNA content in the gastrocnemius twofold. In contrast, there was no burn-induced atrophy of the soleus and no significant change in atrogin-1, MuRF-1, or polyUb mRNA. Burns also did not alter E3 ligase expression in heart. Four hours after administration of the anabolic agent insulin-like growth factor (IGF)-I to burned rats, the mRNA content of atrogin-1 and polyUb in gastrocnemius had returned to control values and the elevation in MuRF-1 was reduced 50%. In contrast, leucine did not alter E3 ligase expression. In a separate study, in vivo administration of the proteasome inhibitor Velcade prevented burn-induced loss of muscle mass determined at 48 h. Finally, administration of the glucocorticoid receptor antagonist RU-486 did not prevent burn-induced atrophy of the gastrocnemius or the associated elevation in atrogin-1, MuRF-1, or polyUb. In summary, the acute muscle wasting accompanying thermal injury is associated with a glucocorticoid-independent increase in the expression of several Ub E3 ligases that can be downregulated by IGF-I.

Glucocorticoid receptor modulators.

Science.gov (United States)

Meijer, Onno C; Koorneef, Lisa L; Kroon, Jan

2018-06-01

The glucocorticoid hormone cortisol acts throughout the body to support circadian processes and adaptation to stress. The glucocorticoid receptor is the target of cortisol and of synthetic glucocorticoids, which are used widely in the clinic. Both agonism and antagonism of the glucocorticoid receptor may be beneficial in disease, but given the wide expression of the receptor and involvement in various processes, beneficial effects are often accompanied by unwanted side effects. Selective glucocorticoid receptor modulators are ligands that induce a receptor conformation that allows activation of only a subset of downstream signaling pathways. Such molecules thereby combine agonistic and antagonistic properties. Here we discuss the mechanisms underlying selective receptor modulation and their promise in treating diseases in several organ systems where cortisol signaling plays a role. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

PPARβ/δ regulates glucocorticoid- and sepsis-induced FOXO1 activation and muscle wasting.

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Estibaliz Castillero

Full Text Available FOXO1 is involved in glucocorticoid- and sepsis-induced muscle wasting, in part reflecting regulation of atrogin-1 and MuRF1. Mechanisms influencing FOXO1 expression in muscle wasting are poorly understood. We hypothesized that the transcription factor peroxisome proliferator-activated receptor β/δ (PPARβ/δ upregulates muscle FOXO1 expression and activity with a downstream upregulation of atrogin-1 and MuRF1 expression during sepsis and glucocorticoid treatment and that inhibition of PPARβ/δ activity can prevent muscle wasting. We found that activation of PPARβ/δ in cultured myotubes increased FOXO1 activity, atrogin-1 and MuRF1 expression, protein degradation and myotube atrophy. Treatment of myotubes with dexamethasone increased PPARβ/δ expression and activity. Dexamethasone-induced FOXO1 activation and atrogin-1 and MuRF1 expression, protein degradation, and myotube atrophy were inhibited by PPARβ/δ blocker or siRNA. Importantly, muscle wasting induced in rats by dexamethasone or sepsis was prevented by treatment with a PPARβ/δ inhibitor. The present results suggest that PPARβ/δ regulates FOXO1 activation in glucocorticoid- and sepsis-induced muscle wasting and that treatment with a PPARβ/δ inhibitor may ameliorate loss of muscle mass in these conditions.

Leucine minimizes denervation-induced skeletal muscle atrophy of rats through akt/mtor signaling pathways

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Carolina Barbosa Ribeiro

2015-03-01

Full Text Available The aim of the present study was to evaluate the effect of leucine treatment (0.30 mM on muscle weight and signaling of myoproteins related to synthesis and degradation pathways of soleus muscle following seven days of complete sciatic nerve lesion.Wistar rats (n=24 of 3 to 4 months of age (192 ± 23 g were used. The animals were randomly distributed into four experimental groups (n=6/group: control, treated with leucine (L, denervated (D and denervated treated with leucine (DL.Dependent measures were proteins levels of AKT, AMPK, mTOR, and ACC performed by Western blot. Leucine induced a reduction in the phosphorylation of AMPK (p<0.05 by 16% in the L and by 68% in the DL groups as compared with control group. Denervation increased AMPK by 24% in the D group as compared with the control group (p<0.05. AKT was also modulated by denervation and leucine treatment, highlighted by the elevation of AKT phosphorylation in the D (65%, L (98% and DL (146% groups as compared with the control group (p<0.05. AKT phosphorylation was 49% higher in the D group as compared with the DL group.Furthermore, denervation decreased mTOR phosphorylation by 29% in the D group as compared with the control group. However, leucine treatment induced an increase of 49% in the phosphorylation of mTOR in the L group as compared with the control group, and an increase of 154% in the DL as compared with the D group ( p<0.05. ACC phosphorylation was 20% greater in the D group than the control group. Furthermore, ACC in the soleus was 22% lower in the in the L group and 50% lower in the DL group than the respective control group (p<0.05.In conclusion, leucine treatment minimized the deleterious effects of denervation on rat soleus muscle by increasing anabolic (AKT and mTOR and decreasing catabolic (AMPK pathways. These results may be interesting for muscle recovery following acute denervation, which may contribute to musculoskeletal rehabilitation after denervation.

Oral leucine supplementation is sensed by the brain but neither reduces food intake nor induces an anorectic pattern of gene expression in the hypothalamus.

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Thais T Zampieri

Full Text Available Leucine activates the intracellular mammalian target of the rapamycin (mTOR pathway, and hypothalamic mTOR signaling regulates food intake. Although central infusion of leucine reduces food intake, it is still uncertain whether oral leucine supplementation is able to affect the hypothalamic circuits that control energy balance. We observed increased phosphorylation of p70s6k in the mouse hypothalamus after an acute oral gavage of leucine. We then assessed whether acute oral gavage of leucine induces the activation of neurons in several hypothalamic nuclei and in the brainstem. Leucine did not induce the expression of Fos in hypothalamic nuclei, but it increased the number of Fos-immunoreactive neurons in the area postrema. In addition, oral gavage of leucine acutely increased the 24 h food intake of mice. Nonetheless, chronic leucine supplementation in the drinking water did not change the food intake and the weight gain of ob/ob mice and of wild-type mice consuming a low- or a high-fat diet. We assessed the hypothalamic gene expression and observed that leucine supplementation increased the expression of enzymes (BCAT1, BCAT2 and BCKDK that metabolize branched-chain amino acids. Despite these effects, leucine supplementation did not induce an anorectic pattern of gene expression in the hypothalamus. In conclusion, our data show that the brain is able to sense oral leucine intake. However, the food intake is not modified by chronic oral leucine supplementation. These results question the possible efficacy of leucine supplementation as an appetite suppressant to treat obesity.

In Planta Single-Molecule Pull-Down Reveals Tetrameric Stoichiometry of HD-ZIPIII:LITTLE ZIPPER Complexes.

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Husbands, Aman Y; Aggarwal, Vasudha; Ha, Taekjip; Timmermans, Marja C P

2016-08-01

Deciphering complex biological processes markedly benefits from approaches that directly assess the underlying biomolecular interactions. Most commonly used approaches to monitor protein-protein interactions typically provide nonquantitative readouts that lack statistical power and do not yield information on the heterogeneity or stoichiometry of protein complexes. Single-molecule pull-down (SiMPull) uses single-molecule fluorescence detection to mitigate these disadvantages and can quantitatively interrogate interactions between proteins and other compounds, such as nucleic acids, small molecule ligands, and lipids. Here, we establish SiMPull in plants using the HOMEODOMAIN LEUCINE ZIPPER III (HD-ZIPIII) and LITTLE ZIPPER (ZPR) interaction as proof-of-principle. Colocalization analysis of fluorophore-tagged HD-ZIPIII and ZPR proteins provides strong statistical evidence of complex formation. In addition, we use SiMPull to directly quantify YFP and mCherry maturation probabilities, showing these differ substantially from values obtained in mammalian systems. Leveraging these probabilities, in conjunction with fluorophore photobleaching assays on over 2000 individual complexes, we determined HD-ZIPIII:ZPR stoichiometry. Intriguingly, these complexes appear as heterotetramers, comprising two HD-ZIPIII and two ZPR molecules, rather than heterodimers as described in the current model. This surprising result raises new questions about the regulation of these key developmental factors and is illustrative of the unique contribution SiMPull is poised to make to in planta protein interaction studies. © 2016 American Society of Plant Biologists. All rights reserved.

11beta-hydroxysteroid dehydrogenase type 1 regulates glucocorticoid-induced insulin resistance in skeletal muscle.

LENUS (Irish Health Repository)

Morgan, Stuart A

2009-11-01

Glucocorticoid excess is characterized by increased adiposity, skeletal myopathy, and insulin resistance, but the precise molecular mechanisms are unknown. Within skeletal muscle, 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) converts cortisone (11-dehydrocorticosterone in rodents) to active cortisol (corticosterone in rodents). We aimed to determine the mechanisms underpinning glucocorticoid-induced insulin resistance in skeletal muscle and indentify how 11beta-HSD1 inhibitors improve insulin sensitivity.

Glucocorticoid-induced effects on the growth plate and the IGF system

NARCIS (Netherlands)

Smink, Jeske Johanna

2003-01-01

Glucocorticoids (GCs) are widely used as anti-inflammatory and immunosuppressive drugs. The use of these potent drugs, however, often results in side-effects, such as growth retardation in children. For already many years, this GC-induced growth retardation is suggested to involve impaired action of

Management of glucocorticoids-induced osteoporosis: role of teriparatide

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Silvia Migliaccio

2009-04-01

Full Text Available Silvia Migliaccio1, Marina Brama1, Nazzarena Malavolta21Dipartimento di Fisiopatologia Medica, Policlinico Umberto I, Università degli Studi Sapienza di Roma, Italy; 2Dipartimento di Medicina Interna, Policlinico S Orsola Malpighi, Bologna, ItalyAbstract: Glucocorticoids (GC-induced osteoporosis (GIOP is the most common cause of secondary osteoporosis, which leads to an increased fracture risk in patients. The normal bone turnover depends on a balance between osteoblasts and osteoclasts activity and GC can cause a rapid bone loss, decreasing bone formation and increasing bone resorption. The decreased bone formation is mainly due to the GC-induced apoptosis of both osteoblasts and osteocytes, while the increased bone resorption is due to the increased life-span of pre-existing osteoclasts. Bisphosphonates are clearly effective in preventing and treating GIOP but anabolic therapeutic strategies are the new promising therapeutic alternative. Experimental and clinical studies indicate that teriparatide, the active (1–34 parathyroid hormone (PTH molecule, is efficacious for the treatment of GIOP, being able to induce an increase in bone mass in these patients. Intermittent administration of human PTH (1–34 stimulates bone formation by increasing osteoblast number. Additionally, human PTH (1–34 modulates the level and/or activity of locally produced growth factors and cytokines. Teriparatide has been demonstrated in several clinical studies to significantly decrease the incidence of fractures in patients affected by GIOP. It has recently received an indication for GIOP and its label indication has also been expanded.Keywords: glucocorticoids, osteoblasts, osteoclasts, osteoporosis, teriparatide

A mechanistic study on the effect of dexamethasone in moderating cell death in Chinese Hamster Ovary cell cultures.

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Jing, Ying; Qian, Yueming; Ghandi, Mahmoud; He, Aiqing; Borys, Michael C; Pan, Shih-Hsie; Li, Zheng Jian

2012-01-01

Dexamethasone (DEX) was previously shown (Jing et al., Biotechnol Bioeng. 2010;107:488-496) to play a dual role in increasing sialylation of recombinant glycoproteins produced by Chinese Hamster Ovary (CHO) cells. DEX addition increased sialic acid levels of a recombinant fusion protein through increased expression of α2,3-sialyltransferase and β1,4-galactosyltransferase, but also decreased the sialidase-mediated, extracellular degradation of sialic acid through slowing cell death at the end of the culture period. This study examines the underlying mechanism for this cytoprotective action by studying the transcriptional response of the CHO cell genome upon DEX treatment using DNA microarrays and gene ontology term analysis. Many of those genes showing a significant transcriptional response were associated with the regulation of programmed cell death. The gene with the highest change in expression level, as validated by Quantitative PCR assays with TaqMan® probes and confirmed by Western Blot analysis, was the antiapoptotic gene Tsc22d3, also referred to as GILZ (glucocorticoid-induced leucine zipper). The pathway by which DEX suppressed cell death towards the end of the culture period was also confirmed by showing involvement of glucocorticoid receptors and GILZ through studies using the glucocorticoid antagonist mifepristone (RU-486). These findings advance the understanding of the mechanism by which DEX suppresses cell death in CHO cells and provide a rationale for the application of glucocorticoids in CHO cell culture processes. Copyright © 2011 American Institute of Chemical Engineers (AIChE).

The tobacco smoke component acrolein induces glucocorticoid resistant gene expression via inhibition of histone deacetylase.

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Randall, Matthew J; Haenen, Guido R M M; Bouwman, Freek G; van der Vliet, Albert; Bast, Aalt

2016-01-05

Chronic obstructive pulmonary disease (COPD) is the leading cause of cigarette smoke-related death worldwide. Acrolein, a crucial reactive electrophile found in cigarette smoke mimics many of the toxic effects of cigarette smoke-exposure in the lung. In macrophages, cigarette smoke is known to hinder histone deacetylases (HDACs), glucocorticoid-regulated enzymes that play an important role in the pathogenesis of glucocorticoid resistant inflammation, a common feature of COPD. Thus, we hypothesize that acrolein plays a role in COPD-associated glucocorticoid resistance. To examine the role of acrolein on glucocorticoid resistance, U937 monocytes, differentiated with PMA to macrophage-like cells were treated with acrolein for 0.5h followed by stimulation with hydrocortisone for 8h, or treated simultaneously with LPS and hydrocortisone for 8h without acrolein. GSH and nuclear HDAC activity were measured, or gene expression was analyzed by qPCR. Acrolein-mediated TNFα gene expression was not suppressed by hydrocortisone whereas LPS-induced TNFα expression was suppressed. Acrolein also significantly inhibited nuclear HDAC activity in macrophage-like cells. Incubation of recombinant HDAC2 with acrolein led to the formation of an HDAC2-acrolein adduct identified by mass spectrometry. Therefore, these results suggest that acrolein-induced inflammatory gene expression is resistant to suppression by the endogenous glucocorticoid, hydrocortisone. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Glucocorticoids, chronic stress, and obesity

NARCIS (Netherlands)

Dallman, Mary F.; Pecoraro, Norman C.; la Fleur, Susanne E.; Warne, James P.; Ginsberg, Abigail B.; Akana, Susan F.; Laugero, Kevin C.; Houshyar, Hani; Strack, Alison M.; Bhatnagar, Seema; Bell, Mary E.

2006-01-01

Glucocorticoids either inhibit or sensitize stress-induced activity in the hypothalamo-pituitary-adrenal (HPA) axis, depending on time after their administration, the concentration of the steroids, and whether there is a concurrent stressor input. When there are high glucocorticoids together with a

Effect of cAMP signaling on expression of glucocorticoid receptor, Bim and Bad in glucocorticoid-sensitive and resistant leukemic and multiple myeloma cells.

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Dong, Hongli; Carlton, Michael E; Lerner, Adam; Epstein, Paul M

2015-01-01

Stimulation of cAMP signaling induces apoptosis in glucocorticoid-sensitive and resistant CEM leukemic and MM.1 multiple myeloma cell lines, and this effect is enhanced by dexamethasone in both glucocorticoid-sensitive cell types and in glucocorticoid-resistant CEM cells. Expression of the mRNA for the glucocorticoid receptor alpha (GR) promoters 1A3, 1B and 1C, expression of mRNA and protein for GR, and the BH3-only proapoptotic proteins, Bim and Bad, and the phosphorylation state of Bad were examined following stimulation of the cAMP and glucocorticoid signaling pathways. Expression levels of GR promoters were increased by cAMP and glucocorticoid signaling, but GR protein expression was little changed in CEM and decreased in MM.1 cells. Stimulation of these two signaling pathways induced Bim in CEM cells, induced Bad in MM.1 cells, and activated Bad, as indicated by its dephosphorylation on ser112, in both cell types. This study shows that leukemic and multiple myeloma cells, including those resistant to glucocorticoids, can be induced to undergo apoptosis by stimulating the cAMP signaling pathway, with enhancement by glucocorticoids, and the mechanism by which this occurs may be related to changes in Bim and Bad expression, and in all cases, to activation of Bad.

NALP3 inflammasome up-regulation and CASP1 cleavage of the glucocorticoid receptor causes glucocorticoid resistance in leukemia cells

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Paugh, Steven W.; Bonten, Erik J.; Savic, Daniel; Ramsey, Laura B.; Thierfelder, William E.; Gurung, Prajwal; Malireddi, R. K. Subbarao; Actis, Marcelo; Mayasundari, Anand; Min, Jaeki; Coss, David R.; Laudermilk, Lucas T.; Panetta, John C.; McCorkle, J. Robert; Fan, Yiping; Crews, Kristine R.; Stocco, Gabriele; Wilkinson, Mark R.; Ferreira, Antonio M.; Cheng, Cheng; Yang, Wenjian; Karol, Seth E.; Fernandez, Christian A.; Diouf, Barthelemy; Smith, Colton; Hicks, J. Kevin; Zanut, Alessandra; Giordanengo, Audrey; Crona, Daniel; Bianchi, Joy J.; Holmfeldt, Linda; Mullighan, Charles G.; den Boer, Monique L.; Pieters, Rob; Jeha, Sima; Dunwell, Thomas L.; Latif, Farida; Bhojwani, Deepa; Carroll, William L.; Pui, Ching-Hon; Myers, Richard M.; Guy, R. Kiplin; Kanneganti, Thirumala-Devi; Relling, Mary V.; Evans, William E.

2015-01-01

Glucocorticoids are universally used in the treatment of acute lymphoblastic leukemia (ALL), and leukemia cell resistant to glucocorticoids confers a poor prognosis. To elucidate mechanisms of glucocorticoid resistance, we determined the sensitivity to prednisolone of primary leukemia cells from 444 newly diagnosed ALL patients, revealing significantly higher expression of caspase 1 (CASP1) and its activator NLRP3 in glucocorticoid resistant leukemia cells, due to significantly lower somatic methylation of CASP1 and NLRP3 promoters. Over-expression of CASP1 resulted in cleavage of the glucocorticoid receptor, diminished glucocorticoid-induced transcriptional response and increased glucocorticoid resistance. Knockdown or inhibition of CASP1 significantly increased glucocorticoid receptor levels and mitigated glucocorticoid resistance in CASP1 overexpressing ALL. Our findings establish a new mechanism by which the NLRP3/CASP1 inflammasome modulates cellular levels of the glucocorticoid receptor and diminishes cell sensitivity to glucocorticoids. The broad impact on glucocorticoid transcriptional response suggests this mechanism could also modify glucocorticoid effects in other diseases. PMID:25938942

Vitamin K2 Ameliorates Damage of Blood Vessels by Glucocorticoid: a Potential Mechanism for Its Protective Effects in Glucocorticoid-induced Osteonecrosis of the Femoral Head in a Rat Model.

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Zhang, Yuelei; Yin, Junhui; Ding, Hao; Zhang, Changqing; Gao, You-Shui

2016-01-01

Glucocorticoid has been reported to decrease blood vessel number and harm the blood supply in the femoral head, which is recognized to be an important mechanism of glucocorticoid-induced osteonecrosis of the femoral head (ONFH). To prevent glucocorticoid-induced ONFH, medication that promotes both bone formation and angiogenesis would be ideal. Vitamin K2 has been revealed to play an important role in bone metabolism; however, few studies have focused on the effect of Vitamin K2 on new vascular formation. Thus, this study aimed to investigate whether Vitamin K2 promoted new blood vessel formation in the presence of glucocorticoids, both in vitro and in vivo. The effect of Vitamin K2 on viability, migration, in vitro tube formation, and VEGF, vWF, CD31, KDR, Flt and PDGFB in EAhy926 incubated with or without dexamethasone were elucidated. VEGF, TGF-β and BMP-2, angiogenesis-related proteins secreted by osteoblasts, were also detected in the osteoblast-like cell line of MG63. In addition, blood vessels of the femoral head in rats administered with or without methylprednisolone and Vitamin K2 were evaluated using angiography and CD31 staining. In vitro studies showed that Vitamin K2 significantly protected endothelial cells from dexamethasone-induced apoptosis, promoted endothelial cell migration and in vitro tube formation. Angiogenesis-related proteins both in EAhy926 and MG63 were also upregulated by Vitamin K2 when cotreated with dexamethasone. In vivo studies showed enhanced blood vessel volume and CD31-positive staining cells in rats cotreated with VK2 and methylprednisolone compared to rats treated with methylprednisolone only. Collectively, Vitamin K2 has the ability to promote angiogenesis in vitro and to ameliorate vessels of the femoral head in glucocorticoid-treated rats in vivo, indicating that Vitamin K2 is a promising drug that may be used to prevent steroid-induced ONFH.

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

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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.

Journal of Biosciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

... identity to homeobox-leucine zipper protein HAHB-4. The analysis of proteome changes induced by N+ implantation could provid a new clue to studing mutation mechanism of ion implantation. To our knowledge, this is the first report about the analysis of proteome changes induced by N+ implantation in sunflower seeds.

SNARE zippering is hindered by polyphenols in the neuron

Energy Technology Data Exchange (ETDEWEB)

Yang, Yoosoo [Department of Genetic Engineering and Center for Human Interface Nanotechnology, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Biomedical Research Institute, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Kim, Se-Hyun; Heo, Paul; Kong, Byoungjae; Shin, Jonghyeok; Jung, Young-Hun; Yoon, Keejung; Chung, Woo-Jae [Department of Genetic Engineering and Center for Human Interface Nanotechnology, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Shin, Yeon-Kyun [Biomedical Research Institute, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA 50011 (United States); Kweon, Dae-Hyuk, E-mail: dhkweon@skku.edu [Department of Genetic Engineering and Center for Human Interface Nanotechnology, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

2014-07-18

Highlights: • Membrane fusion driven by SNARE complex is hindered by several polyphenols. • Distinctive inhibitory effect of each polyphenol on SNARE zippering in neuron was examined. • FRET between fluorescence protein-tagged SNAREs probed well SNARE zippering in PC12 cells. • Delphinidin and cyanidin inhibit N-terminal SNARE nucleation in Ca{sup 2+}-independent manner. • Myricetin inhibits Ca{sup 2+}-dependent transmembrane association of SNARE complex. - Abstract: Fusion of synaptic vesicles with the presynaptic plasma membrane in the neuron is mediated by soluble N-ethylmaleimide-sensitive fusion protein-attachment protein receptor (SNARE) proteins. SNARE complex formation is a zippering-like process which initiates at the N-terminus and proceeds to the C-terminal membrane-proximal region. Previously, we showed that this zippering-like process is regulated by several polyphenols, leading to the arrest of membrane fusion and the inhibition of neuroexocytosis. In vitro studies using purified SNARE proteins reconstituted in liposomes revealed that each polyphenol uniquely regulates SNARE zippering. However, the unique regulatory effect of each polyphenol in cells has not yet been examined. In the present study, we observed SNARE zippering in neuronal PC12 cells by measuring the fluorescence resonance energy transfer (FRET) changes of a cyan fluorescence protein (CFP) and a yellow fluorescence protein (YFP) fused to the N-termini or C-termini of SNARE proteins. We show that delphinidin and cyanidin inhibit the initial N-terminal nucleation of SNARE complex formation in a Ca{sup 2+}-independent manner, while myricetin inhibits Ca{sup 2+}-dependent transmembrane domain association of the SNARE complex in the cell. This result explains how polyphenols exhibit botulinum neurotoxin-like activity in vivo.

Assessment of the Prevalence and Risk Factors Associated With Glucocorticoid-Induced Diabetes Mellitus in Pemphigus Vulgaris Patients.

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Darjani, Abbas; Nickhah, Nahid; Hedayati Emami, Mohammad Hassan; Alizadeh, Narges; Rafiei, Rana; Eftekhari, Hojat; Gharaei Nejad, Kaveh

2017-06-01

Pemphigus vulgaris is a chronic autoimmune disease and glucocorticoids are one of the main treatments. Our study investigates the prevalence and associated factors of glucocorticoid-induced diabetes mellitus in these patients under different glucocorticoid regimens. 36 patients with first diagnosed Pemphigus vulgaris based on pathological and direct immunofluorescence findings who had received different glucocorticoid regimens (1-2 mg/kg oral or 1-2 mg/kg oral with 1g methylprednisolone pulse daily for 3 consecutive days with or without azathioprine) were evaluated during 2014-2016. Our study found that 22.2% of patients had impaired fasting glucose and incidence of corticosteroid-induced diabetes mellitus was 22.2% with no difference between oral and pulse therapy of corticosteroid. The first day after pulse therapy 19 patients of 21 had post bolus hyperglycemia that 36% of them became diabetic after 8 weeks. None of the variables, including age, BMI, HbA1c, LDL, HDL, TG, cholesterol, family history and blood pressure were associated with diabetes. Pretreatment FBS was the factor that would increase the likelihood of glucocorticoid-induced diabetes mellitus, 42.2% of patients with pretreatment FBS 100-126 developed diabetes in comparison with 17.2% in normal pretreatment FBS. Although the group who received azathioprine was associated with increased incidence of diabetes, the overall corticosteroid dose in this group was significantly higher than the other group (P=0.012), and controversy with other studies could be because of difference in corticosteroid dosage and small number of patients. The incidence of diabetes was not different between the group with glucocorticoid pulses and oral prednisolone without pulse therapy. Higher pretreatment FBS can be related to increased incidence of diabetes, but results from this study due to small number of patients are preliminary and multicenter studies are needed.

Glucocorticoid control of gene transcription in neural tissue

NARCIS (Netherlands)

Morsink, Maarten Christian

2007-01-01

Glucocorticoid hormones exert modulatory effects on neural function in a delayed genomic fashion. The two receptor types that can bind glucocorticoids, the mineralocorticoid receptor (MR) and the glucocorticoid receptor (GR), are ligand-inducible transcription factors. Therefore, changes in gene

Protective effect of dexamethasone on 5-FU-induced oral mucositis in hamsters.

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Ribeiro, Susana Barbosa; de Araújo, Aurigena Antunes; Araújo Júnior, Raimundo Fernandes de; Brito, Gerly Anne de Castro; Leitão, Renata Carvalho; Barbosa, Maisie Mitchele; Garcia, Vinicius Barreto; Medeiros, Aldo Cunha; Medeiros, Caroline Addison Carvalho Xavier de

2017-01-01

Oral mucositis (OM) is an important side effect of cancer treatment, characterized by ulcerative lesions in the mucosa of patients undergoing radiotherapy or chemotherapy, which has marked effects on patient quality of life and cancer therapy continuity. Considering that few protocols have demonstrated efficacy in preventing this side effect, the aim of this study was to examine the effect of dexamethasone (DEX) on OM induced by 5-fluorouracil (5-FU) in hamsters by studying signaling pathways. OM was induced in hamsters by 5-FU followed by mechanical trauma (MT) on day 4. On day 10, the animals were euthanized. The experimental groups included saline, MT, 5-FU, and DEX (0.25, 0.5, or 1 mg/kg). Macroscopic, histopathological, and immunohistochemical analyses as well as immunofluorescence experiments were performed on the oral mucosa of the animals. The oral mucosal samples were analyzed by enzyme-linked immunosorbent assays, and quantitative real-time polymerase chain reaction (qPCR). DEX (0.5 or 1 mg/kg) reduced inflammation and ulceration of the oral mucosa of hamsters. In addition, DEX (1 mg/kg) reduced the cytokine levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and macrophage migration inhibitory factor (MIF). DEX (1 mg/kg) also reduced the immunoexpression of cyclooxygenase (COX)-2, matrix metalloproteinase (MMP)-2, transforming growth factor (TGF)-β, MIF, Smad 2/3, Smad 2/3 phosphorylated and NFκB p65 in the jugal mucosa. Finally, DEX (1 mg/kg) increased interleukin-1 receptor-associated kinase 3 (IRAK-M), glucocorticoid-induced leucine zipper (GILZ), and mitogen-activated protein kinase (MKP1) gene expression and reduced NFκB p65 and serine threonine kinase (AKt) gene expression, relative to the 5-FU group. Thus, DEX improved OM induced by 5-FU in hamsters.

Protective effect of dexamethasone on 5-FU-induced oral mucositis in hamsters.

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Susana Barbosa Ribeiro

Full Text Available Oral mucositis (OM is an important side effect of cancer treatment, characterized by ulcerative lesions in the mucosa of patients undergoing radiotherapy or chemotherapy, which has marked effects on patient quality of life and cancer therapy continuity. Considering that few protocols have demonstrated efficacy in preventing this side effect, the aim of this study was to examine the effect of dexamethasone (DEX on OM induced by 5-fluorouracil (5-FU in hamsters by studying signaling pathways. OM was induced in hamsters by 5-FU followed by mechanical trauma (MT on day 4. On day 10, the animals were euthanized. The experimental groups included saline, MT, 5-FU, and DEX (0.25, 0.5, or 1 mg/kg. Macroscopic, histopathological, and immunohistochemical analyses as well as immunofluorescence experiments were performed on the oral mucosa of the animals. The oral mucosal samples were analyzed by enzyme-linked immunosorbent assays, and quantitative real-time polymerase chain reaction (qPCR. DEX (0.5 or 1 mg/kg reduced inflammation and ulceration of the oral mucosa of hamsters. In addition, DEX (1 mg/kg reduced the cytokine levels of tumor necrosis factor (TNF-α, interleukin (IL-1β, and macrophage migration inhibitory factor (MIF. DEX (1 mg/kg also reduced the immunoexpression of cyclooxygenase (COX-2, matrix metalloproteinase (MMP-2, transforming growth factor (TGF-β, MIF, Smad 2/3, Smad 2/3 phosphorylated and NFκB p65 in the jugal mucosa. Finally, DEX (1 mg/kg increased interleukin-1 receptor-associated kinase 3 (IRAK-M, glucocorticoid-induced leucine zipper (GILZ, and mitogen-activated protein kinase (MKP1 gene expression and reduced NFκB p65 and serine threonine kinase (AKt gene expression, relative to the 5-FU group. Thus, DEX improved OM induced by 5-FU in hamsters.

A novel variable antibody fragment dimerized by leucine zippers with enhanced neutralizing potency against rabies virus G protein compared to its corresponding single-chain variable antibody fragment.

Science.gov (United States)

Li, Zhuang; Cheng, Yue; Xi, Hualong; Gu, Tiejun; Yuan, Ruosen; Chen, Xiaoxu; Jiang, Chunlai; Kong, Wei; Wu, Yongge

2015-12-01

Fatal rabies can be prevented effectively by post-exposure prophylactic (PEP) with rabies immunoglobulin (RIG). Single-chain variable fragments (scFv), which are composed of a variable heavy chain (VH) and a variable light chain (VL) connected by a peptide linker, can potentially be used to replace RIG. However, in our previous study, a scFv (scFV57S) specific for the rabies virus (RV) G protein showed a lower neutralizing potency than that of its parent IgG due to lower stability and altered peptide assembly pattern. In monoclonal antibodies, the VH and VL interact non-covalently, while in scFvs the VH is connected covalently with the VL by the artificial linker. In this study, we constructed and expressed two peptides 57VL-JUN-HIS and 57VH-FOS-HA in Escherichia coli. The well-known Fos and Jun leucine zippers were utilized to dimerize VH and VL similarly to the IgG counterpart. The two peptides assembled to form zipFv57S in vitro. Due to the greater similarity in structure with IgG, the zipFv57S protein showed a higher binding ability and affinity resulting in notable improvement of in vitro neutralizing activity over its corresponding scFv. The zipFv57S protein was also found to be more stable and showed similar protective rate as RIG in mice challenged with a lethal dose of RV. Our results not only indicated zipFv57S as an ideal alternative for RIG in PEP but also offered a novel and efficient hetero-dimerization pattern of VH and VL leading to enhanced neutralizing potency. Copyright © 2015. Published by Elsevier Ltd.

Exenatide improves glucocorticoid-induced glucose intolerance in mice

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Ruiying Zhao

2011-01-01

Full Text Available Ruiying Zhao1,2*, Enrique Fuentes-Mattei1,2*, Guermarie Velazquez-Torres1,3, Chun-Hui Su1,2, Jian Chen1, Mong-Hong Lee1,2, Sai-Ching Jim Yeung4,51Department of Molecular and Cellular Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA; 2Program in Genes and Development, 3Program in Cancer Biology, Graduate School of Biomedical Sciences, University of Texas Health Science Center in Houston, Houston, TX, USA; 4Department of Endocrine Neoplasia and Hormonal Disorders, 5Department of Emergency Medicine, University of Texas MD Anderson Cancer Center, Houston, TX, USA *Both authors contributed equally.Abstract: Exenatide is an incretin mimetic that is recently available in the US for the treatment of diabetes. There is a paucity of information on the effects of exenatide in glucocorticoid (GC-induced diabetes. Although the effect of continuous intravenous infusion of exenatide on GC-induced glucose intolerance has been investigated before in healthy human males receiving oral prednisolone, we investigated the efficacy of a single subcutaneous dose of exenatide (3 µg/kg in lowering blood glucose in GC-induced glucose intolerance in C57BL/6 mice. In a longitudinal experiment, the area under the curve (AUC of oral glucose tolerance tests (OGTT significantly increased after dexamethasone (P = 0.004, which was subsequently decreased by exenatide (P < 0.001. A cross-sectional experiment showed that exenatide improved glucose tolerance compared with placebo in a mouse model of dexamethasone-induced glucose intolerance. AUC of OGTT in the exenatide group were significantly (P < 0.001 lower than in the placebo group. Insulin tolerance tests (ITT demonstrated that exenatide decreased the ability of the mice to tolerate insulin compared with placebo. The AUC of ITT in the exenatide group were also significantly (P = 0.006 lower than in the placebo group. In conclusion, a single dose of exenatide was able to decrease glucose intolerance and

Cliff : the automatized zipper

NARCIS (Netherlands)

Baharom, M.Z.; Toeters, M.J.; Delbressine, F.L.M.; Bangaru, C.; Feijs, L.M.G.

2016-01-01

It is our strong believe that fashion - more specifically apparel - can support us so much more in our daily life than it currently does. The Cliff project takes the opportunity to create a generic automatized zipper. It is a response to the struggle by elderly, people with physical disability, and

Glucocorticoids mediate stress-induced impairment of retrieval of stimulus-response memory.

Science.gov (United States)

Atsak, Piray; Guenzel, Friederike M; Kantar-Gok, Deniz; Zalachoras, Ioannis; Yargicoglu, Piraye; Meijer, Onno C; Quirarte, Gina L; Wolf, Oliver T; Schwabe, Lars; Roozendaal, Benno

2016-05-01

Acute stress and elevated glucocorticoid hormone levels are well known to impair the retrieval of hippocampus-dependent 'declarative' memory. Recent findings suggest that stress might also impair the retrieval of non-hippocampal memories. In particular, stress shortly before retention testing was shown to impair the retrieval of striatal stimulus-response associations in humans. However, the mechanism underlying this stress-induced retrieval impairment of non-hippocampal stimulus-response memory remains elusive. In the present study, we investigated whether an acute elevation in glucocorticoid levels mediates the impairing effects of stress on retrieval of stimulus-response memory. Male Sprague-Dawley rats were trained on a stimulus-response task in an eight-arm radial maze until they learned to associate a stimulus, i.e., cue, with a food reward in one of the arms. Twenty-four hours after successful acquisition, they received a systemic injection of vehicle, corticosterone (1mg/kg), the corticosterone-synthesis inhibitor metyrapone (35mg/kg) or were left untreated 1h before retention testing. We found that the corticosterone injection impaired the retrieval of stimulus-response memory. We further found that the systemic injection procedure per se was stressful as the vehicle administration also increased plasma corticosterone levels and impaired the retrieval of stimulus-response memory. However, memory retrieval was not impaired when rats were tested 2min after the systemic vehicle injection, before any stress-induced elevation in corticosterone levels had occurred. Moreover, metyrapone treatment blocked the effect of injection stress on both plasma corticosterone levels and memory retrieval impairment, indicating that the endogenous corticosterone response mediates the stress-induced memory retrieval impairment. None of the treatments affected rats' locomotor activity or motivation to search for the food reward within the maze. These findings show that stress

Rapid sensing of l-leucine by human and murine hypothalamic neurons: Neurochemical and mechanistic insights.

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Heeley, Nicholas; Kirwan, Peter; Darwish, Tamana; Arnaud, Marion; Evans, Mark L; Merkle, Florian T; Reimann, Frank; Gribble, Fiona M; Blouet, Clemence

2018-04-01

Dietary proteins are sensed by hypothalamic neurons and strongly influence multiple aspects of metabolic health, including appetite, weight gain, and adiposity. However, little is known about the mechanisms by which hypothalamic neural circuits controlling behavior and metabolism sense protein availability. The aim of this study is to characterize how neurons from the mediobasal hypothalamus respond to a signal of protein availability: the amino acid l-leucine. We used primary cultures of post-weaning murine mediobasal hypothalamic neurons, hypothalamic neurons derived from human induced pluripotent stem cells, and calcium imaging to characterize rapid neuronal responses to physiological changes in extracellular l-Leucine concentration. A neurochemically diverse subset of both mouse and human hypothalamic neurons responded rapidly to l-leucine. Consistent with l-leucine's anorexigenic role, we found that 25% of mouse MBH POMC neurons were activated by l-leucine. 10% of MBH NPY neurons were inhibited by l-leucine, and leucine rapidly reduced AGRP secretion, providing a mechanism for the rapid leucine-induced inhibition of foraging behavior in rodents. Surprisingly, none of the candidate mechanisms previously implicated in hypothalamic leucine sensing (K ATP channels, mTORC1 signaling, amino-acid decarboxylation) were involved in the acute activity changes produced by l-leucine. Instead, our data indicate that leucine-induced neuronal activation involves a plasma membrane Ca 2+ channel, whereas leucine-induced neuronal inhibition is mediated by inhibition of a store-operated Ca 2+ current. A subset of neurons in the mediobasal hypothalamus rapidly respond to physiological changes in extracellular leucine concentration. Leucine can produce both increases and decreases in neuronal Ca 2+ concentrations in a neurochemically-diverse group of neurons, including some POMC and NPY/AGRP neurons. Our data reveal that leucine can signal through novel mechanisms to rapidly

Peroxisome proliferator-activated receptor α agonist-induced down-regulation of hepatic glucocorticoid receptor expression in SD rats

International Nuclear Information System (INIS)

Chen Xiang; Li Ming; Sun Weiping; Bi Yan; Cai Mengyin; Liang Hua; Yu Qiuqiong; He Xiaoying; Weng Jianping

2008-01-01

It was reported that glucocorticoid production was inhibited by fenofibrate through suppression of type-1 11β-hydroxysteroid dehydrogenase gene expression in liver. The inhibition might be a negative-feedback regulation of glucocorticoid receptor (GR) activity by peroxisome proliferator-activated receptor alpha (PPARα), which is quickly induced by glucocorticoid in the liver. However, it is not clear if GR expression is changed by fenofibrate-induced PPARα activation. In this study, we tested this possibility in the liver of Sprague-Dawley rats. GR expression was reduced by fenofibrate in a time- and does-dependent manner. The inhibition was observed in liver, but not in fat and muscle. The corticosterone level in the blood was increased significantly by fenofibrate. These effects of fenofibrate were abolished by PPARα inhibitor MK886, suggesting that fenofibrate activated through PPARα. In conclusion, inhibition of GR expression may represent a new molecular mechanism for the negative feedback regulation of GR activity by PPARα

Melatonin protects chondrocytes from impairment induced by glucocorticoids via NAD+-dependent SIRT1.

Science.gov (United States)

Yang, Wei; Kang, Xiaomin; Qin, Na; Li, Feng; Jin, Xinxin; Ma, Zhengmin; Qian, Zhuang; Wu, Shufang

2017-10-01

Intra-articular injection of glucocorticoids is used to relieve pain and inflammation in osteoarthritis patients, which is occasionally accompanied with the serious side effects of glucocorticoids in collagen-producing tissue. Melatonin is the major hormone released from the pineal gland and its beneficial effects on cartilage has been suggested. In the present study, we investigated the protective role of melatonin on matrix degeneration in chondrocytes induced by dexamethasone (Dex). The chondrocytes isolated from mice knee joint were treated with Dex, melatonin, EX527 and siRNA targeted for SIRT6, respectively. Dex treatment induced the loss of the extracellular matrix, NAD + /NADH ratio and NADPH concentration in chondrocytes. Melatonin alone have no effect on the quantity of proteoglycans and collagen type IIa1, however, the pretreatment of melatonin reversed the negative effects induced by Dex. Meanwhile, the significant decrease in NAD + /NADH ratio and NADPH concentration in Dex group were up-regulated by pretreatment of melatonin. Furthermore, it was revealed that inhibition of SIRT1 blocked the protective effects of melatonin. The enhancement of NAD + -dependent SIRT1 activity contributes to the chondroprotecfive effects of melatonin, which has a great benefit to prevent dexamethasone-induced chondrocytes impairment. Copyright © 2017 Elsevier Inc. All rights reserved.

Glucocorticoid: A potential role in microgravity-induced bone loss

Science.gov (United States)

Yang, Jiancheng; Yang, Zhouqi; Li, Wenbin; Xue, Yanru; Xu, Huiyun; Li, Jingbao; Shang, Peng

2017-11-01

Exposure of animals and humans to conditions of microgravity, including actual spaceflight and simulated microgravity, results in numerous negative alterations to bone structure and mechanical properties. Although there are abundant researches on bone loss in microgravity, the explicit mechanism is not completely understood. At present, it is widely accepted that the absence of mechanical stimulus plays a predominant role in bone homeostasis disorders in conditions of weightlessness. However, aside from mechanical unloading, nonmechanical factors such as various hormones, cytokines, dietary nutrition, etc. are important as well in microgravity induced bone loss. The stress-induced increase in endogenous glucocorticoid (GC) levels is inevitable in microgravity environments. Moreover, it is well known that GCs have a detrimental effect to bone health at excess concentrations. Therefore, GC plays a potential role in microgravity-induced bone loss. This review summarizeds several studies and their prospective solutions to this hypothesis.

Expression of complement and pentraxin proteins in acute phase response elicited by tumor photodynamic therapy: the engagement of adrenal hormones.

Science.gov (United States)

Merchant, Soroush; Huang, Naiyan; Korbelik, Mladen

2010-12-01

Treatment of solid tumors by photodynamic therapy (PDT) was recently shown to trigger a strong acute phase response. Using the mouse Lewis lung carcinoma (LLC) model, the present study examined complement and pentraxin proteins as PDT-induced acute phase reactants. The results show a distinct pattern of changes in the expression of genes encoding these proteins in the tumor, as well as host liver and spleen, following PDT mediated by photosensitizer Photofrin™. These changes were influenced by glucocorticoid hormones, as evidenced by transcriptional activation of glucocorticoid receptor and the upregulation of gene encoding this receptor. The expression of gene for glucocorticoid-induced zipper (GILZ) protein, whose activity is particularly susceptible to glucocorticoid regulation, was also changed in PDT-treated tumors. A direct demonstration that tumor PDT induces glucocorticoid hormone upregulation is provided by documenting elevated levels of serum corticosterone in mice bearing PDT-treated LLC tumors. Tumor response to PDT was negatively affected by blocking glucocorticoid receptor activity, which suggests that glucocorticoid hormones have a positive impact on the therapeutic outcome with this therapy. Copyright © 2010 Elsevier B.V. All rights reserved.

Function of the HD-Zip I gene Oshox22 in ABA-mediated drought and salt tolerances in rice

NARCIS (Netherlands)

Zhang, S.; Kohlen, W.; Jiang, L.; Bouwmeester, H.J.; Meijer, A.H.; Schluepmann, H.; Liu, C.M.; Ouwerkerk, P.B.F.

2012-01-01

Oshox22 belongs to the homeodomain-leucine zipper (HD-Zip) family I of transcription factors, most of which have unknown functions. Here we show that the expression of Oshox22 is strongly induced by salt stress, abscisic acid (ABA), and polyethylene glycol treatment (PEG), and weakly by cold stress.

A leucine repeat motif in AbiA is required for resistance of Lactococcus lactis to phages representing three species.

Science.gov (United States)

Dinsmore, P K; O'Sullivan, D J; Klaenhammer, T R

1998-05-28

The abiA gene encodes an abortive bacteriophage infection mechanism that can protect Lactococcus species from infection by a variety of bacteriophages including three unrelated phage species. Five heptad leucine repeats suggestive of a leucine zipper motif were identified between residues 232 and 266 in the predicted amino acid sequence of the AbiA protein. The biological role of residues in the repeats was investigated by incorporating amino acid substitutions via site-directed mutagenesis. Each mutant was tested for phage resistance against three phages, phi 31, sk1, and c2, belonging to species P335, 936, and c2, respectively. The five residues that comprise the heptad repeats were designated L234, L242, A249, L256, and L263. Three single conservative mutations of leucine to valine in positions L235, L242, and L263 and a double mutation of two leucines (L235 and L242) to valines did not affect AbiA activity on any phages tested. Non-conservative single substitutions of charged amino acids for three of the leucines (L235, L242, and L256) virtually eliminated AbiA activity on all phages tested. Substitution of the alanine residue in the third repeat (A249) with a charged residue did not affect AbiA activity. Replacement of L242 with an alanine elimination phage resistance against phi 31, but partial resistance to sk1 and c2 remained. Two single proline substitutions for leucines L242 and L263 virtually eliminated AbiA activity against all phages, indicating that the predicted alpha-helical structure of this region is important. Mutations in an adjacent region of basic amino acids had various effects on phage resistance, suggesting that these basic residues are also important for AbiA activity. This directed mutagenesis analysis of AbiA indicated that the leucine repeat structure is essential for conferring phage resistance against three species of lactococcal bacteriophages.

A putative role for hypothalamic glucocorticoid receptors in hypertension induced by prenatal undernutrition in the rat.

Science.gov (United States)

Pérez, Hernán; Soto-Moyano, Rubén; Ruiz, Samuel; Hernández, Alejandro; Sierralta, Walter; Olivares, Ricardo; Núñez, Héctor; Flores, Osvaldo; Morgan, Carlos; Valladares, Luis; Gatica, Arnaldo; Flores, Francisco J

2010-10-08

Prenatal undernutrition induces hypertension later in life, possibly by disturbing the hypothalamo-pituitary-adrenal axis through programming decreased expression of hypothalamic glucocorticoid receptors. We examined the systolic blood pressure, heart rate and plasma corticosterone response to intra-paraventricular dexamethasone, mifepristone and corticosterone in eutrophic and prenatally undernourished young rats. Undernutrition was induced during fetal life by restricting the diet of pregnant mothers to 10 g daily (40% of diet consumed by well-nourished controls). At day 40 of postnatal life (i) intra-paraventricular administration of dexamethasone significantly reduced at least for 24h both the systolic pressure (-11.6%), the heart rate (-20.8%) and the plasma corticosterone (-40.0%) in normal animals, while producing lower effects (-5.5, -8.7, and -22.3%, respectively) on undernourished rats; (ii) intra-paraventricular administration of the antiglucocorticoid receptor ligand mifepristone to normal rats produced opposite effects (8.2, 20.3, and 48.0% increase, respectively) to those induced by dexamethasone, being these not significant in undernourished animals; (iii) intra-paraventricular corticosterone did not exert any significant effect. Results suggest that the low sensitivity of paraventricular neurons to glucocorticoid receptor ligands observed in prenatally undernourished rats could be due to the already reported glucocorticoid receptor expression, found in the hypothalamus of undernourished animals. Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.

Inhibition of dehydration-induced water intake by glucocorticoids is associated with activation of hypothalamic natriuretic peptide receptor-A in rat.

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Chao Liu

Full Text Available Atrial natriuretic peptide (ANP provides a potent defense mechanism against volume overload in mammals. Its primary receptor, natriuretic peptide receptor-A (NPR-A, is localized mostly in the kidney, but also is found in hypothalamic areas involved in body fluid volume regulation. Acute glucocorticoid administration produces potent diuresis and natriuresis, possibly by acting in the renal natriuretic peptide system. However, chronic glucocorticoid administration attenuates renal water and sodium excretion. The precise mechanism underlying this paradoxical phenomenon is unclear. We assume that chronic glucocorticoid administration may activate natriuretic peptide system in hypothalamus, and cause volume depletion by inhibiting dehydration-induced water intake. Volume depletion, in turn, compromises renal water excretion. To test this postulation, we determined the effect of dexamethasone on dehydration-induced water intake and assessed the expression of NPR-A in the hypothalamus. The rats were deprived of water for 24 hours to have dehydrated status. Prior to free access to water, the water-deprived rats were pretreated with dexamethasone or vehicle. Urinary volume and water intake were monitored. We found that dexamethasone pretreatment not only produced potent diuresis, but dramatically inhibited the dehydration-induced water intake. Western blotting analysis showed the expression of NPR-A in the hypothalamus was dramatically upregulated by dexamethasone. Consequently, cyclic guanosine monophosphate (the second messenger for the ANP content in the hypothalamus was remarkably increased. The inhibitory effect of dexamethasone on water intake presented in a time- and dose-dependent manner, which emerged at least after 18-hour dexamethasone pretreatment. This effect was glucocorticoid receptor (GR mediated and was abolished by GR antagonist RU486. These results indicated a possible physiologic role for glucocorticoids in the hypothalamic control of

Increased Dietary Leucine Reduces Doxorubicin-Associated Cardiac Dysfunction in Rats

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Thiago M. Fidale

2018-01-01

Full Text Available Cardiotoxicity is one of the most significant adverse effects of the oncologic treatment with doxorubicin, which is responsible for a substantial morbid and mortality. The occurrence of heart failure with ventricular dysfunction may lead to severe cardiomyopathy and ultimately to death. Studies have focused on the effects of leucine supplementation as a strategy to minimize or revert the clinical condition of induced proteolysis by several clinical onsets. However, the impact of leucine supplementation in heart failure induced by doxorubicin is unknown. Therefore, the objective of this work is to evaluate the effects of leucine supplementation on the cardiotoxicity in the heart of rats treated with doxorubicin. Rats treated with a 7.5 mg/kg cumulative dose of doxorubicin for 14 days presented a dilatation of the left ventricle (LV, and a reduction of the ejection fraction (FE. The 5% supplementation of leucine in the rats' food prevented the malfunctioning of the LV when administered with doxorubicin. Some alterations in the extracellular matrix remodeling were confirmed by the increase of collagen fibers in the doxorubicin group, which did not increase when the treatment was associated with leucine supplementation. Leucine attenuates heart failure in this experimental model with doxorubicin. Such protection is followed by the maintenance of interstitial collagen fibers.

Effects of proportions of dietary macronutrients on glucocorticoid metabolism in diet-induced obesity in rats.

Directory of Open Access Journals (Sweden)

Roland H Stimson

2010-01-01

Full Text Available Tissue glucocorticoid levels in the liver and adipose tissue are regulated by regeneration of inactive glucocorticoid by 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1 and inactivation by 5alpha- and 5beta-reductases. A low carbohydrate diet increases hepatic 11beta-HSD1 and reduces glucocorticoid metabolism during weight loss in obese humans. We hypothesized that similar variations in macronutrient proportions regulate glucocorticoid metabolism in obese rats. Male Lister Hooded rats were fed an obesity-inducing ad libitum 'Western' diet (37% fat, n = 36 for 22 weeks, then randomised to continue this diet (n = 12 or to switch to either a low carbohydrate (n = 12 or a moderate carbohydrate (n = 12 diet for the final 8 weeks. A parallel lean control group were fed an ad libitum control diet (10% fat, n = 12 throughout. The low and moderate carbohydrate diets decreased hepatic 11beta-HSD1 mRNA compared with the Western diet (both 0.7+/-0.0 vs 0.9+/-0.1 AU; p<0.01, but did not alter 11beta-HSD1 in adipose tissue. 5Alpha-reductase mRNA was increased on the low carbohydrate compared with the moderate carbohydrate diet. Compared with lean controls, the Western diet decreased 11beta-HSD1 activity (1.6+/-0.1 vs 2.8+/-0.1 nmol/mcg protein/hr; p<0.001 and increased 5alpha-reductase and 5beta-reductase mRNAs (1.9+/-0.3 vs 1.0+/-0.2 and 1.6+/-0.1 vs 1.0+/-0.1 AU respectively; p<0.01 in the liver, and reduced 11beta-HSD1 mRNA and activity (both p<0.01 in adipose tissue. Although an obesity-inducing high fat diet in rats recapitulates the abnormal glucocorticoid metabolism associated with human obesity in liver (but not in adipose tissue, a low carbohydrate diet does not increase hepatic 11beta-HSD1 in obese rats as occurs in humans.

Comparative analysis of pharmacological treatments with N-acetyl-DL-leucine (Tanganil) and its two isomers (N-acetyl-L-leucine and N-acetyl-D-leucine) on vestibular compensation: Behavioral investigation in the cat.

Science.gov (United States)

Tighilet, Brahim; Leonard, Jacques; Bernard-Demanze, Laurence; Lacour, Michel

2015-12-15

Head roll tilt, postural imbalance and spontaneous nystagmus are the main static vestibular deficits observed after an acute unilateral vestibular loss (UVL). In the UVL cat model, these deficits are fully compensated over 6 weeks as the result of central vestibular compensation. N-Acetyl-dl-leucine is a drug prescribed in clinical practice for the symptomatic treatment of acute UVL patients. The present study investigated the effects of N-acetyl-dl-leucine on the behavioral recovery after unilateral vestibular neurectomy (UVN) in the cat, and compared the effects of each of its two isomers N-acetyl-L-leucine and N-acetyl-D-leucine. Efficacy of these three drug treatments has been evaluated with respect to a placebo group (UVN+saline water) on the global sensorimotor activity (observation grids), the posture control (support surface measurement), the locomotor balance (maximum performance at the rotating beam test), and the spontaneous vestibular nystagmus (recorded in the light). Whatever the parameters tested, the behavioral recovery was strongly and significantly accelerated under pharmacological treatments with N-acetyl-dl-leucine and N-acetyl-L-leucine. In contrast, the N-acetyl-D-leucine isomer had no effect at all on the behavioral recovery, and animals of this group showed the same recovery profile as those receiving a placebo. It is concluded that the N-acetyl-L-leucine isomer is the active part of the racemate component since it induces a significant acceleration of the vestibular compensation process similar (and even better) to that observed under treatment with the racemate component only. Copyright © 2015 Elsevier B.V. All rights reserved.

Stress-induced enhancement of mouse amygdalar synaptic plasticity depends on glucocorticoid and ß-adrenergic activity.

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Ratna Angela Sarabdjitsingh

Full Text Available BACKGROUND: Glucocorticoid hormones, in interaction with noradrenaline, enable the consolidation of emotionally arousing and stressful experiences in rodents and humans. Such interaction is thought to occur at least partly in the basolateral nucleus of the amygdala (BLA which is crucially involved in emotional memory formation. Extensive evidence points to long-term synaptic potentiation (LTP as a mechanism contributing to memory formation. Here we determined in adolescent C57/Bl6 mice the effects of stress on LTP in the LA-BLA pathway and the specific roles of corticosteroid and β-adrenergic receptor activation in this process. PRINCIPAL FINDINGS: Exposure to 20 min of restraint stress (compared to control treatment prior to slice preparation enhanced subsequent LTP induction in vitro, without affecting baseline fEPSP responses. The role of glucocorticoid receptors, mineralocorticoid receptors and β2-adrenoceptors in the effects of stress was studied by treating mice with the antagonists mifepristone, spironolactone or propranolol respectively (or the corresponding vehicles prior to stress or control treatment. In undisturbed controls, mifepristone and propranolol administration in vivo did not influence LTP induced in vitro. By contrast, spironolactone caused a gradually attenuating form of LTP, both in unstressed and stressed mice. Mifepristone treatment prior to stress strongly reduced the ability to induce LTP in vitro. Propranolol normalized the stress-induced enhancement of LTP to control levels during the first 10 min after high frequency stimulation, after which synaptic responses further declined. CONCLUSIONS: Acute stress changes BLA electrical properties such that subsequent LTP induction is facilitated. Both β-adrenergic and glucocorticoid receptors are involved in the development of these changes. Mineralocorticoid receptors are important for the maintenance of LTP in the BLA, irrespective of stress-induced changes in the

L-leucine methyl ester stimulates insulin secretion and islet glutamate dehydrogenase

DEFF Research Database (Denmark)

Knudsen, P; Kofod, Hans; Lernmark, A

1983-01-01

Column perifusion of collagenase-isolated mouse pancreatic islets was used to study the dynamics of insulin release in experiments lasting for several hours. The methyl esters of L-leucine and L-arginine were synthesized. Whereas L-arginine methyl ester (L-arginine OMe) had no effect, L-leucine OMe...... stimulated the release of insulin. The effect of L-leucine OMe was maximal at 5 mmol/liter. Whereas the Km for glucose-stimulated insulin release was unaffected by 1 mmol/liter L-leucine OMe, the maximal release of D-glucose was increased by the amino acid derivative that appeared more effective than L......-leucine. L-Leucine OMe was also a potent stimulus of insulin release from the perfused mouse pancreas. In the presence of 10 mmol/liter L-glutamine, 1 mmol/liter L-leucine OMe induced a 50- to 75-fold increase in insulin release. A similar stimulatory effect was also observed in column-perifused RIN 5F cells...

Glucocorticoid programming of neuroimmune function.

Science.gov (United States)

Walker, David J; Spencer, Karen A

2018-01-15

Throughout life physiological systems strive to maintain homeostasis and these systems are susceptible to exposure to maternal or environmental perturbations, particularly during embryonic development. In some cases, these perturbations may influence genetic and physiological processes that permanently alter the functioning of these physiological systems; a process known as developmental programming. In recent years, the neuroimmune system has garnered attention for its fundamental interactions with key hormonal systems, such as the hypothalamic pituitary adrenal (HPA) axis. The ultimate product of this axis, the glucocorticoid hormones, play a key role in modulating immune responses within the periphery and the CNS as part of the physiological stress response. It is well-established that elevated glucocorticoids induced by developmental stress exert profound short and long-term physiological effects, yet there is relatively little information of how these effects are manifested within the neuroimmune system. Pre and post-natal periods are prime candidates for manipulation in order to uncover the physiological mechanisms that underlie glucocorticoid programming of neuroimmune responses. Understanding the potential programming role of glucocorticoids may be key in uncovering vulnerable windows of CNS susceptibility to stressful experiences during embryonic development and improve our use of glucocorticoids as therapeutics in the treatment of neurodegenerative diseases. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

Circumvention of glucocorticoid resistance in childhood leukemia.

Science.gov (United States)

Haarman, E G; Kaspers, G J L; Pieters, R; Rottier, M M A; Veerman, A J P

2008-09-01

In this study, we determined if in vitro resistance to prednisolone and dexamethasone could be circumvented by cortivazol or methylprednisolone, or reversed by meta-iodobenzylguanidine in pediatric lymphoblastic and myeloid leukemia. As there were strong correlations between the LC50 values (drug concentration inducing 50% leukemic cell kill, LCK) of the different glucocorticoids and median prednisolone/methylprednisolone, prednisolone/dexamethasone and prednisolone/cortivazol LC50 ratios did not differ between the leukemia subtypes, we conclude that none of the glucocorticoids had preferential anti-leukemic activity. Meta-iodobenzylguanidine however, partially reversed glucocorticoid resistance in 19% of the lymphoblastic leukemia samples.

Changes in leucine kinetics during meal absorption: effects of dietary leucine availability

International Nuclear Information System (INIS)

Nissen, S.; Haymond, M.W.

1986-01-01

Whole-body leucine and α/-ketoisocaproate (KIC) metabolism were estimated in mature dogs fed a complete meal, a meal devoid of branched-chain amino acids, and a meal devoid of all amino acids. Using a constant infusion of [4,5- 3 H]leucine and α-[1- 14 C]ketoisocaproate (KIC), combined with dietary [5,5,5- 2 H 3 ]leucine, the rate of whole-body proteolysis, protein synthesis, leucine oxidation, and interconversion leucine and KIC were estimated along with the rate of leucine absorption. Digestion of the complete meal resulted in a decrease in the rate of endogenous proteolysis, a small increase in the estimated rate of leucine entering protein, and a twofold increase in the rate of leucine oxidation. Ingestion of either the meal devoid of branched-chain amino acids or devoid of all amino acids resulted in a decrease in estimates of whole-body rates of proteolysis and protein synthesis, decreased leucine oxidation, and a decrease in the interconversion of leucine and KIC. The decrease in whole-body proteolysis was closely associated with the rise in plasma insulin concentrations following meal ingestion. Together these data suggest that the transition from tissue metabolism to anabolism is the result, at least in part, of decreased whole-body proteolysis. This meal-related decrease in proteolysis is independent of the dietary amino acid composition or content. In contrast, the rate of protein synthesis was sustained only when the meal complete in all amino acids was provided, indicating an overriding control of protein synthesis by amino acid availability

Chewing ameliorates stress-induced suppression of spatial memory by increasing glucocorticoid receptor expression in the hippocampus.

Science.gov (United States)

Miyake, Shinjiro; Yoshikawa, Gota; Yamada, Kentaro; Sasaguri, Ken-Ichi; Yamamoto, Toshiharu; Onozuka, Minoru; Sato, Sadao

2012-03-29

Chewing alters hypothalamic-pituitary-adrenal axis function and improves the ability to cope with stress in rodents. Given that stress negatively influences hippocampus-dependent learning and memory, we aimed to elucidate whether masticatory movements, namely chewing, improve the stress-induced impairment of spatial memory in conjunction with increased hippocampal glucocorticoid receptor expression. Male Sprague-Dawley rats were subjected to restraint stress by immobilization for 2h: the stress with chewing (SC) group were allowed to chew on a wooden stick during the latter half of the immobilization period, whereas the stress without chewing (ST) group were not allowed to do so. Performance in the Morris water maze test was significantly impaired in the ST group compared with the SC group. Further, the numbers of glucocorticoid receptor immunopositive neurons in the hippocampal cornu ammonis 1 region were significantly lower in the ST group than in the control and SC groups. The control and SC rats showed no significant differences in both the water maze performance and the numbers of glucocorticoid receptor-immunopositive neurons. The immunohistochemical finding correlated with the performance in the water maze test. These results suggest that chewing is a behavioral mechanism to cope with stress by increasing hippocampal glucocorticoid receptor expression. Copyright © 2012 Elsevier B.V. All rights reserved.

Testosterone supplementation, glucocorticoid milieu and bone homeostasis in the ageing male.

Science.gov (United States)

Ajdžanović, Vladimir Z; Filipović, Branko R; Šošić Jurjević, Branka T; Milošević, Verica Lj

2017-08-01

Male ageing is entwined with a continuous fall in free testosterone levels, which contributes to the pathogenesis of bone loss. Glucocorticoid excess, either dependent on the ageing process or iatrogenically induced, was found to additionally impair the bone structure and metabolism. Cautious testosterone supplementation in this respect may positively affect the glucocorticoid milieu and bone homeostasis, while testosterone-induced changes in the glucocorticoid output could serve as a determinant of bone-related therapeutic outcome. Namely, bone mineral content/density, the parameters of trabecular bone structure as well as bone strength are enhanced, serum calcitonin levels tend to increase, while serum osteocalcin, serum parathyroid hormone and urinary calcium decrease, all upon testosterone administration to the ageing male. In parallel, testosterone application decreases glucocorticoid secretion in the animal models of male ageing, while clinical data in this field are still inconsistent. Importantly, a physiological link exists between testosterone-induced changes in glucocorticoid levels and the tendency of bone status improvement in the ageing male. We believe that the assessment of circulating adrenocorticotropic hormone concentrations together with glucocorticoid levels, reflecting the hypothalamic-pituitary-adrenal axis feedback loop operativeness during testosterone supplementation, represents a well-balanced bone-related therapeutic update. © 2017 Société Française de Pharmacologie et de Thérapeutique.

CONTRIBUTIONS TO CLASSIFICATION ZIPPERS USED IN INDUSTRY FOOTWEAR AND LEATHER GOODS

OpenAIRE

MALCOCI Marina; PASCARI Ioana

2016-01-01

Now customary accessory companies of all leather garments, zipper began to enjoy popularity only after 80 years of its invention. The first is considered the inventor of the zipper Elias Howe. Essentially involves fashion, change, innovation, originality, creativity and is defined as a succession of trends or fads, short. Create fashionable leather confections from home means accepting a contract with the producer and / or consumer, showing a profit motivating all at the right time. Continuou...

Elucidation and modulation of glucocorticoid-induced apoptosis in acute lymphoblastic leukemia cells

International Nuclear Information System (INIS)

Eberhart, K.

2011-01-01

This thesis deals with the elucidation of the synergistic effect of the glucocorticoid dexamethasone and the metabolic modulator 2-deoxyglucose on apoptosis induction in two in vitro model systems of childhood acute lymphoblastic leukemia. 2-deoxyglucose accelerated the kinetics of, and increased the sensitivity to, glucocorticoid-induced apoptosis in two leukemia cell lines. In primary lymphocytes from healthy donors, in contrast, 2-deoxyglucose and dexamethasone did not act synergistically on apoptosis induction. To elucidate the molecular basis of the synergistic effect, glycolysis by means of glucose uptake, lactate production, ATP levels, glucose transporter and hexokinase expression and mitochondrial oxygen consumption was analyzed in treated vs. untreated cells. The study revealed a downregulation of gene expression of the glucose transporter GLUT1 and hexokinase 2 (HK2), release of HK2 from the outer mitochondrial membrane, as well as reduced glycolysis and mitochondrial respiration. Moreover, the analysis of the mitochondrial proteome by 2 dimensional differential gel electrophoresis after treatment with 2-deoxyglucose and dexamethasone revealed the regulation of several interesting candidate proteins involved in treatment related apoptosis. (author)

α-fetoprotein involvement during glucocorticoid-induced precocious maturation in rat colon.

Science.gov (United States)

Chen, Min; Sun, Peng; Liu, Xiao-Yan; Dong, Dan; Du, Jun; Gu, Luo; Ge, Ying-Bin

2011-06-28

To investigate the role of α-fetoprotein (AFP), a cancer-associated fetal glycoprotein, in glucocorticoid-induced precocious maturation in rat colon. Colons from suckling Sprague-Dawley rats were used in this study. Corticosterone acetate at a dose of 100 μg/g body weight was given to normal pups on days 7, 9 and 11 after birth to induce hypercorticoidism. Control animals were injected with identical volumes of normal saline. Some rats receiving corticosterone 7 d after birth were also treated with mifepristone (RU38486), a glucocorticoid cytoplasm receptor antagonist to investigate the effects of glucocorticoids (GCs). The morphological changes of the crypt depth and villous height of the villous zone in colon were observed as indices of colon maturation. Expression levels of AFP in colons were detected by reverse transcriptase polymerase chain reaction and Western blotting. To identify the cellular localization of AFP in developing rat colons, double-immunofluorescent staining was performed using antibodies to specific mesenchymal cell marker and AFP. Corticosterone increased the crypt depth and villous height in the colon of 8- and 10-d-old rats with hypercorticoidism compared with that in the control animals (120% in 8-d-old rats and 118% in 10-d-old rats in villous height, P = 0.021; 145% in 8-d-old rats and 124% in 10-d-old rats in crypt depth, P = 0.017). These increases were accompanied by an increase of AFP expression in both mRNA and protein (2.5-folds in 8-d-old and 2.5-folds in 10-d-old rats higher than in control animals, P = 0.035; 1.8-folds in 8-d-old and 1.3-folds in 10-d-old rats higher than in control animals, P = 0.023). Increased crypt depth and villous height and increased expression of AFP in the colon of rats with hypercorticoidism were blocked by mifepristone. Both had positive staining for AFP or vimentin, and overlapped in mesenchymal cells at each tested colon. GCs promote the development of rat colon. AFP appears to be involved, in

Variability in Zucker diabetic fatty rats: differences in disease progression in hyperglycemic and normoglycemic animals

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Wang X

2014-11-01

Full Text Available Xi Wang,1 Debra C DuBois,1,2 Siddharth Sukumaran,2 Vivaswath Ayyar,1 William J Jusko,2,3 Richard R Almon1–3 1Department of Biological Sciences, 2Department of Pharmaceutical Sciences, State University of New York at Buffalo, Buffalo, NY, USA; 3New York State Center of Excellence in Bioinformatics and Life Sciences, Buffalo, NY, USA Abstract: Both obesity and chronic inflammation are often associated with insulin resistance and type 2 diabetes. The Zucker diabetic fatty (ZDF rat (fa/fa is an obese animal model frequently used in type 2 diabetes research. The current study determines whether chronic administration (from 5 weeks of age through 24 weeks of age of salsalate, a salicylate with anti-inflammatory properties, would be effective in mitigating diabetes disease progression in ZDF rats. Although a trend existed for lower blood glucose in the salsalate-treated group, significant differences were obscured by high animal-level variability. However, even in the non-drug-treated group, not all ZDF rats became diabetic as expected. Therefore, animals were parsed into two groups, regardless of drug treatment: normoglycemic ZDF rats, which maintained blood glucose profiles identical to nondiabetic Zucker lean rats (ZLRs, and hyperglycemic ZDF rats, which exhibited progressive elevation in blood glucose. To ascertain the differences between ZDF rats that became hyperglycemic and those that did not, relevant physiological indices and expression levels of adiponectin, tumor necrosis factor-α, interleukin-6, and glucocorticoid-induced leucine zipper messenger RNAs in adipose tissue were measured at sacrifice. Plasma C-reactive protein concentrations and expression levels of cytokine and glucocorticoid-induced leucine zipper messenger RNAs suggested more prevalent chronic inflammation in hyperglycemic animals. Early elevation of the insulin-sensitizing adipokine, adiponectin, was present in both ZDF groups, with the rate of its age-related decline

Antioxidant treatment alters peripheral vascular dysfunction induced by postnatal glucocorticoid therapy in rats.

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Emilio A Herrera

2010-02-01

Full Text Available Postnatal glucocorticoid therapy in premature infants diminishes chronic lung disease, but it also increases the risk of hypertension in adulthood. Since glucocorticoid excess leads to overproduction of free radicals and endothelial dysfunction, this study tested the hypothesis that adverse effects on cardiovascular function of postnatal glucocorticoids are secondary to oxidative stress. Therefore, combined postnatal treatment of glucocorticoids with antioxidants may diminish unwanted effects.Male rat pups received a course of dexamethasone (Dex, or Dex with vitamins C and E (DexCE, on postnatal days 1-6 (P1-6. Controls received vehicle (Ctrl or vehicle with vitamins (CtrlCE. At P21, femoral vascular reactivity was determined via wire myography. Dex, but not DexCE or CtrlCE, increased mortality relative to Ctrl (81.3 versus 96.9 versus 90.6 versus 100% survival, respectively; P<0.05. Constrictor responses to phenylephrine (PE and thromboxane were enhanced in Dex relative to Ctrl (84.7+/-4.8 versus 67.5+/-5.7 and 132.7+/-4.9 versus 107.0+/-4.9% Kmax, respectively; P<0.05; effects that were diminished in DexCE (58.3+/-7.5 and 121.1+/-4.3% Kmax, respectively; P<0.05. Endothelium-dependent dilatation was depressed in Dex relative to Ctrl (115.3+/-11.9 versus 216.9+/-18.9, AUC; P<0.05; however, this effect was not restored in DexCE (68.3+/-8.3, AUC. Relative to Ctrl, CtrlCE alone diminished PE-induced constriction (43.4+/-3.7% Kmax and the endothelium-dependent dilatation (74.7+/-8.7 AUC; P<0.05.Treatment of newborn rats with dexamethasone has detrimental effects on survival and peripheral vasoconstrictor function. Coadministration of dexamethasone with antioxidant vitamins improves survival and partially restores vascular dysfunction. Antioxidant vitamins alone affect peripheral vascular function.

Leucine aminopeptidase blood test

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... medlineplus.gov/ency/article/003559.htm Leucine aminopeptidase blood test To use the sharing features on this page, ... Alternative Names Serum leucine aminopeptidase; LAP - serum Images Blood test References Chernecky CC, Berger BJ. Leucine aminopeptidase (LAP) - ...

Glucocorticoid-induced reversal of interleukin-1β-stimulated inflammatory gene expression in human oviductal cells.

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Stéphanie Backman

Full Text Available Studies indicate that high-grade serous ovarian carcinoma (HGSOC, the most common epithelial ovarian carcinoma histotype, originates from the fallopian tube epithelium (FTE. Risk factors for this cancer include reproductive parameters associated with lifetime ovulatory events. Ovulation is an acute inflammatory process during which the FTE is exposed to follicular fluid containing both pro- and anti-inflammatory molecules, such as interleukin-1 (IL1, tumor necrosis factor (TNF, and cortisol. Repeated exposure to inflammatory cytokines may contribute to transforming events in the FTE, with glucocorticoids exerting a protective effect. The global response of FTE cells to inflammatory cytokines or glucocorticoids has not been investigated. To examine the response of FTE cells and the ability of glucocorticoids to oppose this response, an immortalized human FTE cell line, OE-E6/E7, was treated with IL1β, dexamethasone (DEX, IL1β and DEX, or vehicle and genome-wide gene expression profiling was performed. IL1β altered the expression of 47 genes of which 17 were reversed by DEX. DEX treatment alone altered the expression of 590 genes, whereas combined DEX and IL1β treatment altered the expression of 784 genes. Network and pathway enrichment analysis indicated that many genes altered by DEX are involved in cytokine, chemokine, and cell cycle signaling, including NFκΒ target genes and interacting proteins. Quantitative real time RT-PCR studies validated the gene array data for IL8, IL23A, PI3 and TACC2 in OE-E6/E7 cells. Consistent with the array data, Western blot analysis showed increased levels of PTGS2 protein induced by IL1β that was blocked by DEX. A parallel experiment using primary cultured human FTE cells indicated similar effects on PTGS2, IL8, IL23A, PI3 and TACC2 transcripts. These findings support the hypothesis that pro-inflammatory signaling is induced in FTE cells by inflammatory mediators and raises the possibility that

Infralimbic dopamine D2 receptors mediate glucocorticoid-induced facilitation of auditory fear memory extinction in rats.

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Dadkhah, Masoumeh; Abdullahi, Payman Raise; Rashidy-Pour, Ali; Sameni, Hamid Reza; Vafaei, Abbas Ali

2018-03-01

The infralimbic (IL) cortex of the medial prefrontal cortex plays an important role in the extinction of fear memory. Also, it has been showed that both brain glucocorticoid and dopamine receptors are involved in many processes such as fear extinction that drive learning and memory; however, the interaction of these receptors in the IL cortex remains unclear. We examined a putative interaction between the effects of glucocorticoid and dopamine receptors stimulation in the IL cortex on fear memory extinction in an auditory fear conditioning paradigm in male rats. Corticosterone (the endogenous glucocorticoid receptor ligand), or RU38486 (the synthetic glucocorticoid receptor antagonist) microinfusion into the IL cortex 10 min before test 1 attenuated auditory fear expression at tests 1-3, suggesting as an enhancement of fear extinction. The effect of corticosterone, but not RU38486 was counteracted by the dopamine D2 receptor antagonist sulpiride pre-treatment administered into the IL (at a dose that failed to alter freezing behavior on its own). In contrast, intra-IL infusion of the dopamine D1 receptor antagonist SCH23390 pre-treatment failed to alter freezing behavior. These findings provide evidence for the involvement of the IL cortex D2 receptors in CORT-induced facilitation of fear memory extinction. Copyright © 2018 Elsevier B.V. All rights reserved.

Increase of glucocorticoids is not required for the acquisition, but hinders the extinction, of lithium-induced conditioned taste aversion.

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Kim, Kyu-Nam; Kim, Bom-Taeck; Kim, Young-Sang; Lee, Jong-Ho; Jahng, Jeong Won

2014-05-05

Lithium chloride at doses sufficient to induce conditioned taste aversion (CTA) causes c-Fos expression in the paraventricular nucleus and increases the plasma level of corticosterone with activation of the hypothalamic-pituitary-adrenal axis. This study was conducted to define the role of glucocorticoid in the acquisition and extinction of lithium-induced CTA. In experiment 1, Sprague-Dawley rats received dexamethasone (2mg/kg) or RU486 (20mg/kg) immediately after 5% sucrose access, and then an intraperitoneal injection of isotonic lithium chloride (12ml/kg) was followed with 30min interval. Rats had either 1 or 7 days of recovery period before the daily sucrose drinking tests. In experiment 2, rats were conditioned with the sucrose-lithium pairing, and then received dexamethasone or vehicle at 30min before each drinking test. In experiment 3, adrenalectomized (ADX or ADX+B) rats were subjected to sucrose drinking tests after the sucrose-lithium pairing. Dexamethasone, but not RU486, pretreatment blunted the formation of lithium-induced CTA memory. Dexamethasone prior to each drinking test suppressed sucrose consumption and prolonged the extinction of lithium-induced CTA. Sucrose consumption was significantly suppressed not only in ADX+B rats but also in ADX rats during the first drinking session; however, a significant decrease was found only in ADX rats on the fourth drinking session. These results reveal that glucocorticoid is not a necessary component in the acquisition, but an important player in the extinction, of lithium-induced CTA, and suggest that a pulse increase of glucocorticoid may hinder the extinction memory formation of lithium-induced CTA. Copyright © 2014 Elsevier B.V. All rights reserved.

Inhibitory effects of glucocorticoid on apoptosis and activation of NF-κB in P388 cells induced by radiation

International Nuclear Information System (INIS)

Shi Jianhui; Niu Yuhong; Ge Junbo; Xu Xiaoping; Cheng Wenying; Feng Xiao; Zhang Zongliang

2002-01-01

Objective: To explore effects of glucocorticoid on apoptosis and activation of NF-κB in P388 cells induced by radiation. Methods: Apoptosis in P388 cells induced by radiation treatment was detected by TUNEL assay. EMSA was used to detect the activation of NF-κB . Results: The apoptosis and activation of NF-κB in P388 cells could be induced by radiation. Dexamethasone (DXM) which could suppress activation of NF-κB of P388 cells increased significantly the apoptosis induced by radiation. Apoptosis rates in DXM-treated P388 cells after 2, 4, 6 and 8 Gy exposure increased by 60%, 100%, 129% and 67%, respectively. Activation rates of NF-κB in DXM-treated P388 cells after 2, 4, 6 and 8 Gy exposure decreased by 25%, 45%, 52% and 40%, respectively. Conclusion: Radiation induces apoptosis and activation of NF-κB in P388 cells simultaneously. Glucocorticoid enhances apoptosis in leukemic cells, which may be by means of suppressing activation of NF-κB

Why glucocorticoid withdrawal may sometimes be as dangerous as the treatment itself

DEFF Research Database (Denmark)

Dinsen, Stina; Baslund, Bo; Klose, Marianne

2013-01-01

Glucocorticoid therapy is widely used, but withdrawal from glucocorticoids comes with a potential life-threatening risk of adrenal insufficiency. Recent case reports document that adrenal crisis after glucocorticoid withdrawal remains a serious problem in clinical practice. Partly due...... to difficulties in inter-study comparison the true prevalence of glucocorticoid-induced adrenal insufficiency is unknown, but it might be somewhere between 46 and 100% 24h after glucocorticoid withdrawal, 26-49% after approximately one week, and some patients show prolonged suppression lasting months to years....... Adrenal insufficiency might therefore be underdiagnosed in clinical practice. Clinical data do not permit accurate estimates of a lower limit of glucocorticoid dose and duration of treatment, where adrenal insufficiency will not occur. Due to individual variation, neither the glucocorticoid dose nor...

An .I.ex vivo ./I.model to study v-Myb-induced leukemogenicity

Czech Academy of Sciences Publication Activity Database

Dvořáková, Marta; Králová, Jarmila; Karafiát, Vít; Bartůněk, Petr; Dvořák, Michal

2001-01-01

Roč. 27, č. 2 (2001), s. 437-445 ISSN 1079-9796 R&D Projects: GA ČR GV301/98/K042; GA ČR GA204/00/0554; GA AV ČR IPP2052002 Grant - others:HHMI(US) 75195-540401 Institutional research plan: CEZ:AV0Z5052915 Keywords : v-Myb oncoprotein * PEST domain * leucine zipper Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.703, year: 2001

The Regulation of Muscle Mass by Endogenous Glucocorticoids

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Daniel L Marks

2015-02-01

Full Text Available Glucocorticoids are highly conserved fundamental regulators of energy homeostasis. In response to stress in the form of perceived danger or acute inflammation, glucocorticoids are released from the adrenal gland, rapidly mobilizing energy from carbohydrate, fat and protein stores. In the case of inflammation, mobilized protein is critical for the rapid synthesis of acute phase reactants and an efficient immune response to infection. While adaptive in response to infection, chronic mobilization can lead to a p rofound depletion of energy stores. Skeletal muscle represents the major body store of protein, and can become substantially atrophied under conditions of chronic inflammation. Glucocorticoids elicit the atrophy of muscle by increasing the rate of protein degradation by the ubiquitin-proteasome system and autophagy lysosome system. Protein synthesis is also suppressed at the level of translational initiation, preventing the production of new myofibrillar protein. Glucocorticoids also antagonize the action of anabolic regulators such as insulin further exacerbating the loss of protein and muscle mass. The loss of muscle mass in the context of chronic disease is a key feature of cachexia and contributes substantially to morbidity and mortality. A growing body of evidence demonstrates that glucocorticoid signaling is a common mediator of wasting, irrespective of the underlying initiator or disease state. This review will highlight fundamental mechanisms of glucocorticoid signaling and detail the mechanisms of glucocorticoid-induced muscle atrophy. Additionally, the evidence for glucocorticoids as a driver of muscle wasting in numerous disease states will be discussed. Given the burden of wasting diseases and the nodal nature of glucocorticoid signaling, effective anti-glucocorticoid therapy would be a valuable clinical tool. Therefore, the progress and potential pitfalls in the development of glucocorticoid antagonists for muscle wasting will

Zipper plot: visualizing transcriptional activity of genomic regions.

Science.gov (United States)

Avila Cobos, Francisco; Anckaert, Jasper; Volders, Pieter-Jan; Everaert, Celine; Rombaut, Dries; Vandesompele, Jo; De Preter, Katleen; Mestdagh, Pieter

2017-05-02

Reconstructing transcript models from RNA-sequencing (RNA-seq) data and establishing these as independent transcriptional units can be a challenging task. Current state-of-the-art tools for long non-coding RNA (lncRNA) annotation are mainly based on evolutionary constraints, which may result in false negatives due to the overall limited conservation of lncRNAs. To tackle this problem we have developed the Zipper plot, a novel visualization and analysis method that enables users to simultaneously interrogate thousands of human putative transcription start sites (TSSs) in relation to various features that are indicative for transcriptional activity. These include publicly available CAGE-sequencing, ChIP-sequencing and DNase-sequencing datasets. Our method only requires three tab-separated fields (chromosome, genomic coordinate of the TSS and strand) as input and generates a report that includes a detailed summary table, a Zipper plot and several statistics derived from this plot. Using the Zipper plot, we found evidence of transcription for a set of well-characterized lncRNAs and observed that fewer mono-exonic lncRNAs have CAGE peaks overlapping with their TSSs compared to multi-exonic lncRNAs. Using publicly available RNA-seq data, we found more than one hundred cases where junction reads connected protein-coding gene exons with a downstream mono-exonic lncRNA, revealing the need for a careful evaluation of lncRNA 5'-boundaries. Our method is implemented using the statistical programming language R and is freely available as a webtool.

Glucocorticoids facilitate the retention of acquired immobility during forced swimming

NARCIS (Netherlands)

Veldhuis, H D; De Korte, C C; De Kloet, E R

1985-01-01

The adrenalectomy-induced decrease in the level of immobility during a 5 min retest period in the Porsolt swimming test could be reversed by glucocorticoids administered s.c. 15 min after the initial forced swimming exposure. The synthetic glucocorticoids dexamethasone and RU 28362 were active in

Prevention and treatment of glucocorticoid-induced osteoporosis in International and Italian scenarios

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A. Delle Sedie

2011-09-01

Full Text Available Osteoporosis (OP and increased risk of fracture (Fx associated with chronic glucocorticoid treatment pushed panels of experts and scientific societies to produce recommendations for both prevention and treatment of glucocorticoid-induced OP (GIO. Recently the American College of Rheumatology developed and/or endorsed their updated guidelines and recommendations for the prevention and treatment of GIO. In these recommendations the use of FRAX tool, for the 10-year probability of a major osteoporotic Fx, was integrated with other clinical risk factors to define low-, medium-, and high-risk patients. Updated approaches are delineated for post-menopausal women and men >50 years, pre-menopausal women not of childbearing potential, men 50 years, receiving >5 mg/day prednisone equivalent for >3 months; more recently teriparatide has also been included, only for those patients presenting ≥1 prevalent fragility Fx and receiving >5 mg/day prednisone equivalent for >12 months. Also zoledronic acid has been approved by Italian Agency of the Drug (AIFA, 30/08/10 for “… post-menopausal women and men chronically treated with GC ad high risk of Fx”, but the drug is dispensed exclusively at the hospital.

Acute stress-induced sensitization of the pituitary-adrenal response to heterotypic stressors: independence of glucocorticoid release and activation of CRH1 receptors.

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Belda, Xavier; Daviu, Núria; Nadal, Roser; Armario, Antonio

2012-09-01

A single exposure to some severe stressors causes sensitization of the hypothalamic-pituitary-adrenal (HPA) response to novel stressors. However, the putative factors involved in stress-induced sensitization are not known. In the present work we studied in adult male rats the possible role of glucocorticoids and CRH type 1 receptor (CRH-R1), using an inhibitor of glucocorticoid synthesis (metyrapone, MET), the glucocorticoid receptor (GR) antagonist RU38486 (mifepristone) and the non-peptide CRH-R1 antagonist R121919. In a first experiment we demonstrated with different doses of MET (40-150 mg/kg) that the highest dose acted as a pharmacological stressor greatly increasing ACTH release and altering the normal circadian pattern of HPA hormones, but no dose affected ACTH responsiveness to a novel environment as assessed 3 days after drug administration. In a second experiment, we found that MET, at a dose (75 mg/kg) that blocked the corticosterone response to immobilization (IMO), did not alter IMO-induced ACTH sensitization. Finally, neither the GR nor the CRH-R1 antagonists blocked IMO-induced ACTH sensitization on the day after IMO. Thus, a high dose of MET, in contrast to IMO, was unable to sensitize the HPA response to a novel environment despite the huge activation of the HPA axis caused by the drug. Neither a moderate dose of MET that markedly reduced corticosterone response to IMO, nor the blockade of GR or CRH-R1 receptors was able to alter stress-induced HPA sensitization. Therefore, stress-induced sensitization is not the mere consequence of a marked HPA activation and does not involve activation of glucocorticoid or CRH-R1 receptors. Copyright © 2012 Elsevier Inc. All rights reserved.

Activated Glucocorticoid Receptor Interacts with the INHAT Component Set/TAF-Iβ and Releases it from a Glucocorticoid-responsive Gene Promoter, Relieving Repression: Implications for the Pathogenesis of Glucocorticoid Resistance in Acute Undifferentiated Leukemia with Set-Can Translocation

Science.gov (United States)

Ichijo, Takamasa; Chrousos, George P.; Kino, Tomoshige

2008-01-01

SUMMARY Set/template-activating factor (TAF)-Iβ, part of the Set-Can oncogene product found in acute undifferentiated leukemia, is a component of the inhibitor of acetyltransferases (INHAT) complex. Set/TAF-Iβ interacted with the DNA-binding domain of the glucocorticoid receptor (GR) in yeast two-hybrid screening, and repressed GR-induced transcriptional activity of a chromatin-integrated glucocorticoid-responsive and a natural promoter. Set/TAF-Iβ was co-precipitated with glucocorticoid response elements (GREs) of these promoters in the absence of dexamethasone, while addition of the hormone caused dissociation of Set/TAF-Iβ from and attraction of the p160-type coactivator GRIP1 to the promoter GREs. Set-Can fusion protein, on the other hand, did not interact with GR, was constitutively co-precipitated with GREs and suppressed GRIP1-induced enhancement of GR transcriptional activity and histone acetylation. Thus, Set/TAF-Iβ acts as a ligand-activated GR-responsive transcriptional repressor, while Set-Can does not retain physiologic responsiveness to ligand-bound GR, possibly contributing to the poor responsiveness of Set-Can-harboring leukemic cells to glucocorticoids. PMID:18096310

Activated glucocorticoid receptor interacts with the INHAT component Set/TAF-Ibeta and releases it from a glucocorticoid-responsive gene promoter, relieving repression: implications for the pathogenesis of glucocorticoid resistance in acute undifferentiated leukemia with Set-Can translocation.

Science.gov (United States)

Ichijo, Takamasa; Chrousos, George P; Kino, Tomoshige

2008-02-13

Set/template-activating factor (TAF)-Ibeta, part of the Set-Can oncogene product found in acute undifferentiated leukemia, is a component of the inhibitor of acetyltransferases (INHAT) complex. Set/TAF-Ibeta interacted with the DNA-binding domain of the glucocorticoid receptor (GR) in yeast two-hybrid screening, and repressed GR-induced transcriptional activity of a chromatin-integrated glucocorticoid-responsive and a natural promoter. Set/TAF-Ibeta was co-precipitated with glucocorticoid response elements (GREs) of these promoters in the absence of dexamethasone, while addition of the hormone caused dissociation of Set/TAF-Ibeta from and attraction of the p160-type coactivator GRIP1 to the promoter GREs. Set-Can fusion protein, on the other hand, did not interact with GR, was constitutively co-precipitated with GREs and suppressed GRIP1-induced enhancement of GR transcriptional activity and histone acetylation. Thus, Set/TAF-Ibeta acts as a ligand-activated GR-responsive transcriptional repressor, while Set-Can does not retain physiologic responsiveness to ligand-bound GR, possibly contributing to the poor responsiveness of Set-Can-harboring leukemic cells to glucocorticoids.

The obesity-associated transcription factor ETV5 modulates circulating glucocorticoids

Science.gov (United States)

Gutierrez-Aguilar, Ruth; Thompson, Abigail; Marchand, Nathalie; Dumont, Patrick; Woods, Stephen C.; de Launoit, Yvan; Seeley, Randy J.; Ulrich-Lai, Yvonne M.

2015-01-01

The transcription factor E-twenty-six version 5 (ETV5) has been linked with obesity in genome-wide association studies. Moreover, ETV5-deficient mice (knockout; KO) have reduced body weight, lower fat mass, and are resistant to diet-induced obesity, directly linking ETV5 to the regulation of energy balance and metabolism. ETV5 is expressed in hypothalamic brain regions that regulate both metabolism and HPA axis activity, suggesting that ETV5 may also modulate HPA axis function. In order to test this possibility, plasma corticosterone levels were measured in ETV5 KO and wildtype (WT) mice before (pre-stress) and after (post-stress) a mild stressor (intraperitoneal injection). ETV5 deficiency increased both pre- and post-stress plasma corticosterone, suggesting that loss of ETV5 elevated glucocorticoid tone. Consistent with this idea, ETV5 KO mice have reduced thymus weight, suggestive of increased glucocorticoid-induced thymic involution. ETV5 deficiency also decreased the mRNA expression of glucocorticoid receptor (GR), mineralocorticoid receptor (MR), and vasopressin receptor 1A in the hypothalamus, without altering vasopressin, corticotropin-releasing hormone, or oxytocin mRNA expression. In order to test whether reduced MR and GR expression affected glucocorticoid negative feedback, a dexamethasone suppression test was performed. Dexamethasone reduced plasma corticosterone in both ETV5 KO and WT mice, suggesting that glucocorticoid negative feedback was unaltered by ETV5 deficiency. In summary, these data suggest that the obesity-associated transcription factor ETV5 normally acts to diminish circulating glucocorticoids. This might occur directly via ETV5 actions on HPA-regulatory brain circuitry, and/or indirectly via ETV5-induced alterations in metabolic factors that then influence the HPA axis. PMID:25813907

The leucine-rich repeat structure.

Science.gov (United States)

Bella, J; Hindle, K L; McEwan, P A; Lovell, S C

2008-08-01

The leucine-rich repeat is a widespread structural motif of 20-30 amino acids with a characteristic repetitive sequence pattern rich in leucines. Leucine-rich repeat domains are built from tandems of two or more repeats and form curved solenoid structures that are particularly suitable for protein-protein interactions. Thousands of protein sequences containing leucine-rich repeats have been identified by automatic annotation methods. Three-dimensional structures of leucine-rich repeat domains determined to date reveal a degree of structural variability that translates into the considerable functional versatility of this protein superfamily. As the essential structural principles become well established, the leucine-rich repeat architecture is emerging as an attractive framework for structural prediction and protein engineering. This review presents an update of the current understanding of leucine-rich repeat structure at the primary, secondary, tertiary and quaternary levels and discusses specific examples from recently determined three-dimensional structures.

Leucine Supplementation Accelerates Connective Tissue Repair of Injured Tibialis Anterior Muscle

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Marcelo G. Pereira

2014-09-01

Full Text Available This study investigated the effect of leucine supplementation on the skeletal muscle regenerative process, focusing on the remodeling of connective tissue of the fast twitch muscle tibialis anterior (TA. Young male Wistar rats were supplemented with leucine (1.35 g/kg per day; then, TA muscles from the left hind limb were cryolesioned and examined after 10 days. Although leucine supplementation induced increased protein synthesis, it was not sufficient to promote an increase in the cross-sectional area (CSA of regenerating myofibers (p > 0.05 from TA muscles. However, leucine supplementation reduced the amount of collagen and the activation of phosphorylated transforming growth factor-β receptor type I (TβR-I and Smad2/3 in regenerating muscles (p < 0.05. Leucine also reduced neonatal myosin heavy chain (MyHC-n (p < 0.05, increased adult MyHC-II expression (p < 0.05 and prevented the decrease in maximum tetanic strength in regenerating TA muscles (p < 0.05. Our results suggest that leucine supplementation accelerates connective tissue repair and consequent function of regenerating TA through the attenuation of TβR-I and Smad2/3 activation. Therefore, future studies are warranted to investigate leucine supplementation as a nutritional strategy to prevent or attenuate muscle fibrosis in patients with several muscle diseases.

Leucine signaling in the pathogenesis of type 2 diabetes and obesity.

Science.gov (United States)

Melnik, Bodo C

2012-03-15

Epidemiological evidence points to increased dairy and meat consumption, staples of the Western diet, as major risk factors for the development of type 2 diabetes (T2D). This paper presents a new concept and comprehensive review of leucine-mediated cell signaling explaining the pathogenesis of T2D and obesity by leucine-induced over-stimulation of mammalian target of rapamycin complex 1 (mTORC1). mTORC1, a pivotal nutrient-sensitive kinase, promotes growth and cell proliferation in response to glucose, energy, growth factors and amino acids. Dairy proteins and meat stimulate insulin/insulin-like growth factor 1 signaling and provide high amounts of leucine, a primary and independent stimulator for mTORC1 activation. The downstream target of mTORC1, the kinase S6K1, induces insulin resistance by phosphorylation of insulin receptor substrate-1, thereby increasing the metabolic burden of β-cells. Moreover, leucine-mediated mTORC1-S6K1-signaling plays an important role in adipogenesis, thus increasing the risk of obesity-mediated insulin resistance. High consumption of leucine-rich proteins explains exaggerated mTORC1-dependent insulin secretion, increased β-cell growth and β-cell proliferation promoting an early onset of replicative β-cell senescence with subsequent β-cell apoptosis. Disturbances of β-cell mass regulation with increased β-cell proliferation and apoptosis as well as insulin resistance are hallmarks of T2D, which are all associated with hyperactivation of mTORC1. In contrast, the anti-diabetic drug metformin antagonizes leucine-mediated mTORC1 signaling. Plant-derived polyphenols and flavonoids are identified as natural inhibitors of mTORC1 and exert anti-diabetic and anti-obesity effects. Furthermore, bariatric surgery in obesity reduces increased plasma levels of leucine and other branched-chain amino acids. Attenuation of leucine-mediated mTORC1 signaling by defining appropriate upper limits of the daily intake of leucine-rich animal and dairy

Molecular characterisation of two novel maize LRR receptor-like kinases, which belong to the SERK gene family

NARCIS (Netherlands)

Baudino, S.; Hansen, S.; Brettschneider, R.; Hecht, V.F.G.; Dresselhaus, T.; Lörz, H.; Dumas, C.; Rogowsky, P.M.

2001-01-01

Genes encoding two novel members of the leucine-rich repeat receptor-like kinase (LRR-RLK) superfamily have been isolated from maize (Zea mays L.). These genes have been named ZmSERK1 and ZmSERK2 since features such as a putative leucine zipper (ZIP) and five leucine rich repeats in the

Effect of Rituximab in Patients With Leucine-Rich, Glioma-Inactivated 1 Antibody–Associated Encephalopathy

Science.gov (United States)

Irani, Sarosh R.; Gelfand, Jeffrey M.; Bettcher, Brianne M.; Singhal, Neel S.; Geschwind, Michael D.

2015-01-01

IMPORTANCE This observational study describes the efficacy and safety of rituximab in 5 patients with voltage-gated potassium channel (VGKC)–complex/leucine-rich, glioma-inactivated 1 (LGI1) antibody–associated encephalopathy. Rituximab is a monoclonal antibody that targets CD20 and is used to treat other neurologic and nonneurologic diseases. OBSERVATIONS This case series reports sequential seizure frequencies, modified Rankin Scale scores, and VGKC-complex antibody titers in 5 adult patients (median age, 65 years; range, 48–73 years) treated with rituximab. Median time from symptom onset to rituximab initiation was 414 days (range, 312–851 days). One patient showed a rapid clinical improvement after treatment with rituximab alone and experienced a rituximab-responsive clinical relapse. Another showed possible improvement on neuropsychometric memory indexes after rituximab therapy. In contrast, all patients showed robust responses to treatment with glucocorticoids, intravenous immunoglobulins, and/or plasma exchange at some point in their illness. Treatment with glucocorticoids—less so with intravenous immunoglobulins and plasma exchange—was associated with the most marked reductions in VGKC-complex antibodies. The only patient who did not receive glucocorticoids showed the poorest clinical and serologic responses. CONCLUSIONS AND RELEVANCE Rituximab was well tolerated in this predominantly older adult patient population and may be an effective option for some patients with LGI1 antibody–associated encephalopathy. Glucocorticoid therapy appears particularly efficacious. Earlier rituximab administration and randomized trials are required to formally assess efficacy. PMID:24842754

Glucocorticoid metabolites in newborns: A marker for traffic noise related stress?

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Lech Cantuaria, Manuella; Usermann, Jakob; Proietti, Elena

2018-01-01

Traffic noise has been associated with an increased risk for several non-auditory health effects, which may be explained by a noise-induced release of stress hormones (e.g. glucocorticoids). Although several studies in children and adults have indicated an increased secretion of glucocorticoids...

Leucine supplementation protects from insulin resistance by regulating adiposity levels.

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Elke Binder

Full Text Available BACKGROUND: Leucine supplementation might have therapeutic potential in preventing diet-induced obesity and improving insulin sensitivity. However, the underlying mechanisms are at present unclear. Additionally, it is unclear whether leucine supplementation might be equally efficacious once obesity has developed. METHODOLOGY/PRINCIPAL FINDINGS: Male C57BL/6J mice were fed chow or a high-fat diet (HFD, supplemented or not with leucine for 17 weeks. Another group of HFD-fed mice (HFD-pairfat group was food restricted in order to reach an adiposity level comparable to that of HFD-Leu mice. Finally, a third group of mice was exposed to HFD for 12 weeks before being chronically supplemented with leucine. Leucine supplementation in HFD-fed mice decreased body weight and fat mass by increasing energy expenditure, fatty acid oxidation and locomotor activity in vivo. The decreased adiposity in HFD-Leu mice was associated with increased expression of uncoupling protein 3 (UCP-3 in the brown adipose tissue, better insulin sensitivity, increased intestinal gluconeogenesis and preservation of islets of Langerhans histomorphology and function. HFD-pairfat mice had a comparable improvement in insulin sensitivity, without changes in islets physiology or intestinal gluconeogenesis. Remarkably, both HFD-Leu and HFD-pairfat mice had decreased hepatic lipid content, which likely helped improve insulin sensitivity. In contrast, when leucine was supplemented to already obese animals, no changes in body weight, body composition or glucose metabolism were observed. CONCLUSIONS/SIGNIFICANCE: These findings suggest that leucine improves insulin sensitivity in HFD-fed mice by primarily decreasing adiposity, rather than directly acting on peripheral target organs. However, beneficial effects of leucine on intestinal gluconeogenesis and islets of Langerhans's physiology might help prevent type 2 diabetes development. Differently, metabolic benefit of leucine supplementation

Temporary abdominal closure with zipper-mesh device for management of intra-abdominal sepsis

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Edivaldo Massazo Utiyama

Full Text Available OBJECTIVE: to present our experience with scheduled reoperations in 15 patients with intra-abdominal sepsis. METHODS: we have applied a more effective technique consisting of temporary abdominal closure with a nylon mesh sheet containing a zipper. We performed reoperations in the operating room under general anesthesia at an average interval of 84 hours. The revision consisted of debridement of necrotic material and vigorous lavage of the involved peritoneal area. The mean age of patients was 38.7 years (range, 15 to 72 years; 11 patients were male, and four were female. RESULTS: forty percent of infections were due to necrotizing pancreatitis. Sixty percent were due to perforation of the intestinal viscus secondary to inflammation, vascular occlusion or trauma. We performed a total of 48 reoperations, an average of 3.2 surgeries per patient. The mesh-zipper device was left in place for an average of 13 days. An intestinal ostomy was present adjacent to the zipper in four patients and did not present a problem for patient management. Mortality was 26.6%. No fistulas resulted from this technique. When intra-abdominal disease was under control, the mesh-zipper device was removed, and the fascia was closed in all patients. In three patients, the wound was closed primarily, and in 12 it was allowed to close by secondary intent. Two patients developed hernia; one was incisional and one was in the drain incision. CONCLUSION: the planned reoperation for manual lavage and debridement of the abdomen through a nylon mesh-zipper combination was rapid, simple, and well-tolerated. It permitted effective management of severe septic peritonitis, easy wound care and primary closure of the abdominal wall.

Leucine Modulates Mitochondrial Biogenesis and SIRT1-AMPK Signaling in C2C12 Myotubes

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Chunzi Liang

2014-01-01

Full Text Available Previous studies from this laboratory demonstrate that dietary leucine protects against high fat diet-induced mitochondrial impairments and stimulates mitochondrial biogenesis and energy partitioning from adipocytes to muscle cells through SIRT1-mediated mechanisms. Moreover, β-hydroxy-β-methyl butyrate (HMB, a metabolite of leucine, has been reported to activate AMPK synergistically with resveratrol in C2C12 myotubes. Therefore, we hypothesize that leucine-induced activation of SIRT1 and AMPK is the central event that links the upregulated mitochondrial biogenesis and fatty acid oxidation in skeletal muscle. Thus, C2C12 myotubes were treated with leucine (0.5 mM, alanine (0.5 mM, valine (0.5 mM, EX527 (SIRT1 inhibitor, 25 μM, and Compound C (AMPK inhibitor, 25 μM alone or in combination to determine the roles of AMPK and SIRT1 in leucine-modulation of energy metabolism. Leucine significantly increased mitochondrial content, mitochondrial biogenesis-related genes expression, fatty acid oxidation, SIRT1 activity and gene expression, and AMPK phosphorylation in C2C12 myotubes compared to the controls, while EX527 and Compound C markedly attenuated these effects. Furthermore, leucine treatment for 24 hours resulted in time-dependent increases in cellular NAD+, SIRT1 activity, and p-AMPK level, with SIRT1 activation preceding that of AMPK, indicating that leucine activation of SIRT1, rather than AMPK, is the primary event.

Current smoking is an independent risk factor for new-onset diabetes mellitus during highdose glucocorticoid treatment.

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Sugiyama, Takao; Sugimoto, Toyohiko; Suzuki, Sawako; Sato, Yuta; Tanaka, Tomoaki; Tatsuno, Ichiro

2015-08-01

Although high-dose glucocorticoids have been reported to cause new-onset diabetes mellitus (glucocorticoid-induced diabetes mellitus), its risk factors have remained to be determined. We investigated the risk factors related to glucocorticoid-induced diabetes mellitus diagnosed within 2 months after the high-dose treatment (newly treated with an initial high dose of > 20 mg prednisolone (PSL) equivalent per day for at least more than 6 months) in collagen vascular diseases. A total of 2,631 patients with collagen vascular diseases was registered between 1986 and 2006 in the Chiba-Shimoshizu Rheumatic Cohort. We analyzed 681 patients newly treated with high-dose glucocorticoid who did not have diabetes mellitus and/or its previous diagnosis (age: 46.3 ± 16.7 years, PSL dose: 40.0 ± 14.1 mg/day). Glucocorticoid-induced diabetes mellitus was diagnosed by two or more glucose measurements in patients with fasting glycaemia ≥ 7 mmol/L and 120 minutes post-load glycaemia ≥ 11.1 mmol/L. Glucocorticoid-induced diabetes mellitus was observed in 26.3% of patients, and the glucocorticoid-induced diabetes mellitus group had higher age, higher BMI, lower rates of females and systemic lupus erythematosus, higher rates of smoking, alcohol use, and microscopic polyangiitis. Multivariate logistic regression analysis demonstrated that the risk of glucocorticoid-induced diabetes mellitus was independently higher in every 10-year increment of initial age with adjusted odds ratio (OR) 1.556 (95% confidence interval: 1.359 - 1.783), in every 1 kg/m2 increment of BMI with OR 1.062 (1.002 - 1.124), in current smoking with OR 1.664 (1.057 - 2.622), and in every 10 mg increment of initial dose of prednisolone with OR 1.250 (1.074 - 1.454). High-dose glucocorticoids caused diabetes mellitus with high prevalence within a short period, and current smokers should be considered at higher risk of glucocorticoidinduced diabetes mellitus in addition to age, BMI, and initial dose.

Syntheses and Self-assembling Behaviors of Pentagonal Conjugates of Tryptophane Zipper-Forming Peptide

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Nobuo Kimizuka

2011-08-01

Full Text Available Pentagonal conjugates of tryptophane zipper-forming peptide (CKTWTWTE with a pentaazacyclopentadecane core (Pentagonal-Gly-Trpzip and Pentagonal-Ala-Trpzip were synthesized and their self-assembling behaviors were investigated in water. Pentagonal-Gly-Trpzip self-assembled into nanofibers with the width of about 5 nm in neutral water (pH 7 via formation of tryptophane zipper, which irreversibly converted to nanoribbons by heating. In contrast, Pentagonal-Ala-Trpzip formed irregular aggregates in water.

The Role of (99m)Tc-Annexin V Apoptosis Scintigraphy in Visualizing Early Stage Glucocorticoid-Induced Femoral Head Osteonecrosis in the Rabbit.

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Wang, Xiaolong; Liu, Yu; Wang, Xuemei; Liu, Rui; Li, Jianbo; Zhang, Guoliang; Li, Qiang; Wang, Lei; Bai, Zhigang; Zhao, Jianmin

2016-01-01

To validate the ability of (99m)Tc-Annexin V to visualize early stage of glucocorticoid-induced femoral head necrosis by comparing with (99m)Tc-MDP bone scanning. Femoral head necrosis was induced in adult New Zealand white rabbits by intramuscular injection of methylprednisolone. (99m)Tc-Annexin scintigraphy and (99m)Tc-MDP scans were performed before and 5, 6, and 8 weeks after methylprednisolone administration. Rabbits were sacrificed at various time points and conducted for TUNEL and H&E staining. All methylprednisolone treated animals developed femoral head necrosis; at 8 weeks postinjection, destruction of bone structure was evident in H&E staining, and apoptosis was confirmed by the TUNEL assay. This was matched by (99m)Tc-Annexin V images, which showed a significant increase in signal over baseline. Serial (99m)Tc-Annexin V scans revealed that increased (99m)Tc-Annexin V uptake could be observed in 5 weeks. In contrast, there was no effect on (99m)Tc-MDP signal until 8 weeks. The TUNEL assay revealed that bone cell apoptosis occurred at 5 weeks. (99m)Tc-Annexin V is superior to (99m)Tc-MDP for the early detection of glucocorticoid-induced femoral head necrosis in the rabbit and may be a better strategy for the early detection of glucocorticoid-induced femoral head necrosis in patients.

Glucocorticoid inhibition of leptin- and lipopolysaccharide-induced interleukin-6 production in obesity.

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Huang, Chun-Jung; Acevedo, Edmund O; Mari, David C; Randazzo, Christopher; Shibata, Yoshimi

2014-01-01

Obesity is considered a chronic inflammatory condition that enhances the risk of numerous inflammatory diseases, including diabetes and cardiovascular disease. Glucocorticoids (GCs) and synthetic therapeutic GCs are anti-inflammatory agents, but the exact functions of GCs in obesity-related inflammation are unknown. Therefore, the objective of this study was to examine the inhibitory effect of an exogenous GC (dexamethasone, DEX) on leptin- and lipopolysaccharide (LPS)-induced IL-6 production by peripheral blood mononuclear cells (PBMCs) ex vivo in obese subjects compared to normal-weight subjects. Blood samples were drawn from 14 obese (BMI>30 kg/m(2)) and 14 normal-weight (BMIobese subjects showed greater leptin- and LPS-induced IL-6 production compared to normal-weight subjects. The suppressive effect of DEX on leptin- and LPS-induced IL-6 production (IC50) was not different between the two groups. However, the IC50 of DEX for LPS-induced was correlated with BMI, waist circumference, and hip circumference. These findings suggest that reduced GC sensitivity may be an important mechanism in the up-regulation of selected obese inflammation. Published by Elsevier Inc.

Glucose-induced serum- and glucocorticoid-regulated kinase activation in oncofetal fibronectin expression

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Khan, Zia A.; Barbin, Yousef P.; Farhangkhoee, Hana; Beier, Norbert; Scholz, Wolfgang; Chakrabarti, Subrata

2005-01-01

Preferential expression of oncofetal extra domain-B fibronectin (EDB + FN), a proposed angiogenic marker, has been shown in proliferative diabetic retinopathy. High levels of glucose also increase EDB + FN expression in endothelial cells (ECs) via transforming growth factor-β1 (TGF-β1) and endothelin-1 (ET-1). The present study was aimed at elucidating the role of serum- and glucocorticoid-regulated kinase (SGK-1) in glucose-induced EDB + FN expression. Using human macro- and microvascular ECs, we show that high levels of glucose, TGF-β1, and ET-1 increase the EDB + FN expression via SGK-1 alteration at the mRNA, protein, and activity levels. Inhibition of TGF-β1 and ET-1 prevented glucose-induced SGK-1 activation and the EDB + FN expression. Furthermore, using siRNA-mediated SGK-1 gene silencing, we show that glucose-induced EDB + FN expression can be completely prevented. These findings provide first evidence of glucose-induced SGK-1 activation in altered EDB + FN expression and provide novel avenues for therapeutic modalities

Glucocorticoids maintain human osteoclasts in the active mode of their resorption cycle

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Søe, Kent; Delaissé, Jean-Marie

2010-01-01

that glucocorticoids deeply modify this resorptive behavior. First, glucocorticoids gradually induce excavations with a trenchlike morphology while reducing the time-dependent increase in excavation numbers. This indicates that glucocorticoids make osteoclasts elongate the excavations they initiated rather than...... migrating to a new resorption site, as in control conditions. Second, the round excavations in control conditions contain undegraded demineralized collagen as repeatedly reported earlier, whereas the excavations with a trenchlike morphology generated under glucocorticoid exposure appear devoid of leftovers...... of demineralized collagen. This indicates that collagenolysis proceeds generally at a lower rate than demineralization under control conditions, whereas collagenolysis rates are increased up to the level of demineralization rates in the presence of glucocorticoids. Taking these observations together leads...

On the retinal toxicity of intraocular glucocorticoids.

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Torriglia, Alicia; Valamanesh, Fatemeh; Behar-Cohen, Francine

2010-12-15

Corticosteroids are hormones involved in many physiological responses such as stress, immune modulation, protein catabolism and water homeostasis. The subfamily of glucocorticoids is used systemically in the treatment of inflammatory diseases or allergic reactions. In the eye, glucocorticoides are used to treat macular edema, inflammation and neovascularization. The most commonly used glucocorticoid is triamcinolone acetonide (TA). The pharmaceutical formulation of TA is not adapted for intravitreal administration but has been selected by ophthalmologists because its very low intraocular solubility provides sustained effect. Visual benefits of intraocular TA do not clearly correlate with morpho-anatomical improvements, suggesting potential toxicity. We therefore studied, non-common, but deleterious effects of glucocorticoids on the retina. We found that the intravitreal administration of TA is beneficial in the treatment of neovascularization because it triggers cell death of endothelial cells of neovessels by a caspase-independent mechanism. However, this treatment is toxic for the retina because it induces a non-apoptotic, caspase-independent cell death related to paraptosis, mostly in the retinal pigmented epithelium cells and the Müller cells. Copyright © 2010 Elsevier Inc. All rights reserved.

Piper sarmentosum Effects on 11β-Hydroxysteroid Dehydrogenase Type 1 Enzyme in Serum and Bone in Rat Model of Glucocorticoid-Induced Osteoporosis.

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Mohamad Asri, Siti Fadziyah; Mohd Ramli, Elvy Suhana; Soelaiman, Ima Nirwana; Mat Noh, Muhamad Alfakry; Abdul Rashid, Abdul Hamid; Suhaimi, Farihah

2016-11-15

Glucocorticoid-induced osteoporosis is one of the common causes of secondary osteoporosis. Piper sarmentosum ( Ps ) extract possesses antioxidant and anti-inflammatory activities. In this study, we determined the correlation between the effects of Ps leaf water extract with the regulation of 11β-hydroxysteroid dehydrogenase (HSD) type 1 enzyme activity in serum and bone of glucocorticoid-induced osteoporotic rats. Twenty-four Sprague-Dawley rats were grouped into following: G1: sham-operated group administered with intramuscular vehicle olive oil and vehicle normal saline orally; G2: adrenalectomized (adrx) control group given intramuscular dexamethasone (120 μg/kg/day) and vehicle normal saline orally; G3: adrx group given intramuscular dexamethasone (120 μg/kg/day) and water extract of Piper sarmentosum (125 mg/kg/day) orally. After two months, the femur and serum were taken for ELISA analysis. Results showed that Ps leaf water extract significantly reduced the femur corticosterone concentration ( p < 0.05). This suggests that Ps leaf water extract was able to prevent bone loss due to long-term glucocorticoid therapy by acting locally on the bone cells by increasing the dehydrogenase action of 11β-HSD type 1. Thus, Ps may have the potential to be used as an alternative medicine against osteoporosis and osteoporotic fracture in patients on long-term glucocorticoid treatment.

Overexpression of Glucocorticoid Receptor β Enhances Myogenesis and Reduces Catabolic Gene Expression.

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Hinds, Terry D; Peck, Bailey; Shek, Evan; Stroup, Steven; Hinson, Jennifer; Arthur, Susan; Marino, Joseph S

2016-02-11

Unlike the glucocorticoid receptor α (GRα), GR β (GRβ) has a truncated ligand-binding domain that prevents glucocorticoid binding, implicating GRα as the mediator of glucocorticoid-induced skeletal muscle loss. Because GRβ causes glucocorticoid resistance, targeting GRβ may be beneficial in impairing muscle loss as a result of GRα activity. The purpose of this study was to determine how the overexpression of GRβ affects myotube formation and dexamethasone (Dex) responsiveness. We measured GR isoform expression in C₂C12 muscle cells in response to Dex and insulin, and through four days of myotube formation. Next, lentiviral-mediated overexpression of GRβ in C₂C12 was performed, and these cells were characterized for cell fusion and myotube formation, as well as sensitivity to Dex via the expression of ubiquitin ligases. GRβ overexpression increased mRNA levels of muscle regulatory factors and enhanced proliferation in myoblasts. GRβ overexpressing myotubes had an increased fusion index. Myotubes overexpressing GRβ had lower forkhead box O3 (Foxo3a) mRNA levels and a blunted muscle atrophy F-box/Atrogen-1 (MAFbx) and muscle ring finger 1 (MuRF1) response to Dex. We showed that GRβ may serve as a pharmacological target for skeletal muscle growth and protection from glucocorticoid-induced catabolic signaling. Increasing GRβ levels in skeletal muscle may cause a state of glucocorticoid resistance, stabilizing muscle mass during exposure to high doses of glucocorticoids.

Overexpression of Glucocorticoid Receptor β Enhances Myogenesis and Reduces Catabolic Gene Expression

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Terry D. Hinds

2016-02-01

Full Text Available Unlike the glucocorticoid receptor α (GRα, GR β (GRβ has a truncated ligand-binding domain that prevents glucocorticoid binding, implicating GRα as the mediator of glucocorticoid-induced skeletal muscle loss. Because GRβ causes glucocorticoid resistance, targeting GRβ may be beneficial in impairing muscle loss as a result of GRα activity. The purpose of this study was to determine how the overexpression of GRβ affects myotube formation and dexamethasone (Dex responsiveness. We measured GR isoform expression in C2C12 muscle cells in response to Dex and insulin, and through four days of myotube formation. Next, lentiviral-mediated overexpression of GRβ in C2C12 was performed, and these cells were characterized for cell fusion and myotube formation, as well as sensitivity to Dex via the expression of ubiquitin ligases. GRβ overexpression increased mRNA levels of muscle regulatory factors and enhanced proliferation in myoblasts. GRβ overexpressing myotubes had an increased fusion index. Myotubes overexpressing GRβ had lower forkhead box O3 (Foxo3a mRNA levels and a blunted muscle atrophy F-box/Atrogen-1 (MAFbx and muscle ring finger 1 (MuRF1 response to Dex. We showed that GRβ may serve as a pharmacological target for skeletal muscle growth and protection from glucocorticoid-induced catabolic signaling. Increasing GRβ levels in skeletal muscle may cause a state of glucocorticoid resistance, stabilizing muscle mass during exposure to high doses of glucocorticoids.

Caffeic acid phenethyl ester protects against glucocorticoid-induced osteoporosis in vivo: Impact on oxidative stress and RANKL/OPG signals

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Tolba, Mai F.; El-Serafi, Ahmed T.; Omar, Hany A.

2017-01-01

Glucocorticoid-induced osteoporosis (GIO) is one of the most common causes of secondary osteoporosis. Given that glucocorticoids are considered as a main component of the treatment protocols for a variety of inflammation and immune-mediated diseases besides its use as adjuvant to several chemotherapeutic agents, it is crucial to find ways to overcome this critical adverse effect. Caffeic acid phenethyl ester (CAPE), which is a natural compound derived from honeybee propolis displayed promising antiosteoporotic effects against mechanical bone injury in various studies. The current work aimed at investigating the potential protective effect of CAPE against GIO in vivo with emphasis on the modulation of oxidative status and receptor activator of NF-kB ligand (RANKL)/osteoprotegrin (OPG) signaling. The results showed that CAPE opposed dexamethasone (DEX)-mediated alterations in bone histology and tartarate-resistant acid phosphatase (TRAP) activity. In addition, CAPE restored oxidative balance, Runt-related transcription factor 2 (RunX2) expression and reduced caspase-3 activity in femur tissues. Co-administration of CAPE with DEX normalized RANKL/OPG ratio and Akt activation indicating a reduction in DEX-osteoclastogenesis. In conclusion, concurrent treatment of CAPE with DEX exhibited promising effects in the protection against DEX-induced osteoporosis through opposing osteoclastogenesis and protecting osteoblasts. The potent antioxidant activity of CAPE is, at least in part, involved in its anti-apoptotic effects and modulation of RunX2 and RANKL/OPG signals. The use of CAPE-enriched propolis formulas is strongly recommended for patients on chronic glucocorticoid therapy to help in the attenuation of GIO. - Highlights: • Caffeic acid phenethyl ester (CAPE) counteracts DEX-induced osteoporosis. • CAPE hinders DEX-induced alterations in oxidation parameters as GSH, SOD and MDA. • CAPE opposes osteoclastogenesis via suppressing RANL/OPG ratio and Akt signals. �

Caffeic acid phenethyl ester protects against glucocorticoid-induced osteoporosis in vivo: Impact on oxidative stress and RANKL/OPG signals

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Tolba, Mai F. [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ain Shams University, Cairo 11566 (Egypt); Chapman University, Irvine 92618, CA (United States); El-Serafi, Ahmed T. [Sharjah Institute for Medical Research, University of Sharjah, Sharjah 27272 (United Arab Emirates); Department of Medical Biochemistry, Faculty of Medicine, Suez Canal University, Ismailia (Egypt); Omar, Hany A., E-mail: hanyomar@sharjah.ac.ae [Sharjah Institute for Medical Research, University of Sharjah, Sharjah 27272 (United Arab Emirates); Department of Pharmacology, Faculty of Pharmacy, Beni-Suef University, Beni-Suef 62514 (Egypt)

2017-06-01

Glucocorticoid-induced osteoporosis (GIO) is one of the most common causes of secondary osteoporosis. Given that glucocorticoids are considered as a main component of the treatment protocols for a variety of inflammation and immune-mediated diseases besides its use as adjuvant to several chemotherapeutic agents, it is crucial to find ways to overcome this critical adverse effect. Caffeic acid phenethyl ester (CAPE), which is a natural compound derived from honeybee propolis displayed promising antiosteoporotic effects against mechanical bone injury in various studies. The current work aimed at investigating the potential protective effect of CAPE against GIO in vivo with emphasis on the modulation of oxidative status and receptor activator of NF-kB ligand (RANKL)/osteoprotegrin (OPG) signaling. The results showed that CAPE opposed dexamethasone (DEX)-mediated alterations in bone histology and tartarate-resistant acid phosphatase (TRAP) activity. In addition, CAPE restored oxidative balance, Runt-related transcription factor 2 (RunX2) expression and reduced caspase-3 activity in femur tissues. Co-administration of CAPE with DEX normalized RANKL/OPG ratio and Akt activation indicating a reduction in DEX-osteoclastogenesis. In conclusion, concurrent treatment of CAPE with DEX exhibited promising effects in the protection against DEX-induced osteoporosis through opposing osteoclastogenesis and protecting osteoblasts. The potent antioxidant activity of CAPE is, at least in part, involved in its anti-apoptotic effects and modulation of RunX2 and RANKL/OPG signals. The use of CAPE-enriched propolis formulas is strongly recommended for patients on chronic glucocorticoid therapy to help in the attenuation of GIO. - Highlights: • Caffeic acid phenethyl ester (CAPE) counteracts DEX-induced osteoporosis. • CAPE hinders DEX-induced alterations in oxidation parameters as GSH, SOD and MDA. • CAPE opposes osteoclastogenesis via suppressing RANL/OPG ratio and Akt signals. �

SDF-1 improves wound healing ability of glucocorticoid-treated adipose tissue-derived mesenchymal stem cells.

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Kato, Toshiki; Khanh, Vuong Cat; Sato, Kazutoshi; Takeuchi, Kosuke; Carolina, Erica; Yamashita, Toshiharu; Sugaya, Hisashi; Yoshioka, Tomokazu; Mishima, Hajime; Ohneda, Osamu

2017-11-18

Glucocorticoids cause the delayed wound healing by suppressing inflammation that is required for wound healing process. Adipose tissue-derived mesenchymal stem cells (AT-MSCs) play an important role for wound healing by their cytokine productions including stromal derived factor 1 (SDF-1). However, it has not been clear how glucocorticoids affect the wound healing ability of AT-MSCs. In this study, we found that glucocorticoid downregulated SDF-1 expression in AT-MSCs. In addition, glucocorticoid-treated AT-MSCs induced less migration of inflammatory cells and impaired wound healing capacity compared with glucocorticoid-untreated AT-MSCs. Of note, prostaglandin E2 (PGE2) synthesis-related gene expression was downregulated by glucocorticoid and PGE2 treatment rescued not only SDF-1 expression in the presence of glucocorticoid but also their wound healing capacity in vivo. Furthermore, we found SDF-1-overexpressed AT-MSCs restored wound healing capacity even after treatment of glucocorticoid. Consistent with the results obtained from glucocorticoid-treated AT-MSCs, we found that AT-MSCs isolated from steroidal osteonecrosis donors (sAT-MSCs) who received chronic glucocorticoid therapy showed less SDF-1 expression and impaired wound healing capacity compared with traumatic osteonecrosis donor-derived AT-MSCs (nAT-MSCs). Moreover, the SDF-1 level was also reduced in plasma derived from steroidal osteonecrosis donors compared with traumatic osteonecrosis donors. These results provide the evidence that concomitant application of AT-MSCs with glucocorticoid shows impaired biological modulatory effects that induce impaired wound healing. Copyright © 2017 Elsevier Inc. All rights reserved.

Glucocorticoids Enhance Muscle Proteolysis through a Myostatin-Dependent Pathway at the Early Stage.

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Wang, Ruxia; Jiao, Hongchao; Zhao, Jingpeng; Wang, Xiaojuan; Lin, Hai

2016-01-01

Myostatin, a member of the TGF-β superfamily of secreted proteins, is expressed primarily in skeletal muscle. It negatively regulates muscle mass and is associated with glucocorticoid-induced muscle atrophy. However, it remains unclear whether myostatin is involved in glucocorticoid-induced muscle protein turnover. The aim of the present study was to investigate the role of myostatin in protein metabolism during dexamethasone (DEX) treatment. Protein synthesis rates and the expression of the genes for myostatin, ubiquitin-proteasome atrogin-1, MuRF1, FoxO1/3a and mTOR/p70S6K were determined. The results show that DEX decreased (Pmyostatin. DEX increased (P0.05). The phosphorylation levels of mTOR and p70S6K were decreased by DEX treatment (Pmyostatin (P 0.05). In conclusion, the present study suggests that the myostatin signalling pathway is associated with glucocorticoid-induced muscle protein catabolism at the beginning of exposure. Myostatin is not a main pathway associated with the suppression of muscle protein synthesis by glucocorticoids.

Effects of leucine supplemented diet on intestinal absorption in tumor bearing pregnant rats

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de Mello Maria

2002-04-01

Full Text Available Abstract Background It is known that amino acid oxidation is increased in tumor-bearing rat muscles and that leucine is an important ketogenic amino acid that provides energy to the skeletal muscle. Methods To evaluate the effects of a leucine supplemented diet on the intestinal absorption alterations produced by Walker 256, growing pregnant rats were distributed into six groups. Three pregnant groups received a normal protein diet (18% protein: pregnant (N, tumor-bearing (WN, pair-fed rats (Np. Three other pregnant groups were fed a diet supplemented with 3% leucine (15% protein plus 3% leucine: leucine (L, tumor-bearing (WL and pair-fed with leucine (Lp. Non pregnant rats (C, which received a normal protein diet, were used as a control group. After 20 days, the animals were submitted to intestinal perfusion to measure leucine, methionine and glucose absorption. Results Tumor-bearing pregnant rats showed impairment in food intake, body weight gain and muscle protein content, which were less accentuated in WL than in WN rats. These metabolic changes led to reduction in both fetal and tumor development. Leucine absorption slightly increased in WN group. In spite of having a significant decrease in leucine and methionine absorption compared to L, the WL group has shown a higher absorption rate of methionine than WN group, probably due to the ingestion of the leucine supplemented diet inducing this amino acid uptake. Glucose absorption was reduced in both tumor-bearing groups. Conclusions Leucine supplementation during pregnancy in tumor-bearing rats promoted high leucine absorption, increasing the availability of the amino acid for neoplasic cells and, mainly, for fetus and host utilization. This may have contributed to the better preservation of body weight gain, food intake and muscle protein observed in the supplemented rats in relation to the non-supplemented ones.

Effects of leucine supplemented diet on intestinal absorption in tumor bearing pregnant rats

International Nuclear Information System (INIS)

Ventrucci, Gislaine; Mello, Maria Alice Roston de; Gomes-Marcondes, Maria Cristina Cintra

2002-01-01

It is known that amino acid oxidation is increased in tumor-bearing rat muscles and that leucine is an important ketogenic amino acid that provides energy to the skeletal muscle. To evaluate the effects of a leucine supplemented diet on the intestinal absorption alterations produced by Walker 256, growing pregnant rats were distributed into six groups. Three pregnant groups received a normal protein diet (18% protein): pregnant (N), tumor-bearing (WN), pair-fed rats (Np). Three other pregnant groups were fed a diet supplemented with 3% leucine (15% protein plus 3% leucine): leucine (L), tumor-bearing (WL) and pair-fed with leucine (Lp). Non pregnant rats (C), which received a normal protein diet, were used as a control group. After 20 days, the animals were submitted to intestinal perfusion to measure leucine, methionine and glucose absorption. Tumor-bearing pregnant rats showed impairment in food intake, body weight gain and muscle protein content, which were less accentuated in WL than in WN rats. These metabolic changes led to reduction in both fetal and tumor development. Leucine absorption slightly increased in WN group. In spite of having a significant decrease in leucine and methionine absorption compared to L, the WL group has shown a higher absorption rate of methionine than WN group, probably due to the ingestion of the leucine supplemented diet inducing this amino acid uptake. Glucose absorption was reduced in both tumor-bearing groups. Leucine supplementation during pregnancy in tumor-bearing rats promoted high leucine absorption, increasing the availability of the amino acid for neoplasic cells and, mainly, for fetus and host utilization. This may have contributed to the better preservation of body weight gain, food intake and muscle protein observed in the supplemented rats in relation to the non-supplemented ones

Glucocorticoid programming of intrauterine development.

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Fowden, A L; Valenzuela, O A; Vaughan, O R; Jellyman, J K; Forhead, A J

2016-07-01

Glucocorticoids (GCs) are important environmental and maturational signals during intrauterine development. Toward term, the maturational rise in fetal glucocorticoid receptor concentrations decreases fetal growth and induces differentiation of key tissues essential for neonatal survival. When cortisol levels rise earlier in gestation as a result of suboptimal conditions for fetal growth, the switch from tissue accretion to differentiation is initiated prematurely, which alters the phenotype that develops from the genotype inherited at conception. Although this improves the chances of survival should delivery occur, it also has functional consequences for the offspring long after birth. Glucocorticoids are, therefore, also programming signals that permanently alter tissue structure and function during intrauterine development to optimize offspring fitness. However, if the postnatal environmental conditions differ from those signaled in utero, the phenotypical outcome of early-life glucocorticoid receptor overexposure may become maladaptive and lead to physiological dysfunction in the adult. This review focuses on the role of GCs in developmental programming, primarily in farm species. It examines the factors influencing GC bioavailability in utero and the effects that GCs have on the development of fetal tissues and organ systems, both at term and earlier in gestation. It also discusses the windows of susceptibility to GC overexposure in early life together with the molecular mechanisms and long-term consequences of GC programming with particular emphasis on the cardiovascular, metabolic, and endocrine phenotype of the offspring. Copyright © 2016 Elsevier Inc. All rights reserved.

Leucine elicits myotube hypertrophy and enhances maximal contractile force in tissue engineered skeletal muscle in vitro.

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Martin, Neil R W; Turner, Mark C; Farrington, Robert; Player, Darren J; Lewis, Mark P

2017-10-01

The amino acid leucine is thought to be important for skeletal muscle growth by virtue of its ability to acutely activate mTORC1 and enhance muscle protein synthesis, yet little data exist regarding its impact on skeletal muscle size and its ability to produce force. We utilized a tissue engineering approach in order to test whether supplementing culture medium with leucine could enhance mTORC1 signaling, myotube growth, and muscle function. Phosphorylation of the mTORC1 target proteins 4EBP-1 and rpS6 and myotube hypertrophy appeared to occur in a dose dependent manner, with 5 and 20 mM of leucine inducing similar effects, which were greater than those seen with 1 mM. Maximal contractile force was also elevated with leucine supplementation; however, although this did not appear to be enhanced with increasing leucine doses, this effect was completely ablated by co-incubation with the mTOR inhibitor rapamycin, showing that the augmented force production in the presence of leucine was mTOR sensitive. Finally, by using electrical stimulation to induce chronic (24 hr) contraction of engineered skeletal muscle constructs, we were able to show that the effects of leucine and muscle contraction are additive, since the two stimuli had cumulative effects on maximal contractile force production. These results extend our current knowledge of the efficacy of leucine as an anabolic nutritional aid showing for the first time that leucine supplementation may augment skeletal muscle functional capacity, and furthermore validates the use of engineered skeletal muscle for highly-controlled investigations into nutritional regulation of muscle physiology. © 2017 The Authors. Journal of Cellular Physiology Published by wiley periodicals, Inc.

Leucine signaling in the pathogenesis of type 2 diabetes and obesity

OpenAIRE

Melnik, Bodo C

2012-01-01

Epidemiological evidence points to increased dairy and meat consumption, staples of the Western diet, as major risk factors for the development of type 2 diabetes (T2D). This paper presents a new concept and comprehensive review of leucine-mediated cell signaling explaining the pathogenesis of T2D and obesity by leucine-induced over-stimulation of mammalian target of rapamycin complex 1 (mTORC1). mTORC1, a pivotal nutrient-sensitive kinase, promotes growth and cell proliferation in response t...

LY294002 inhibits glucocorticoid-induced COX-2 gene expression in cardiomyocytes through a phosphatidylinositol 3 kinase-independent mechanism

International Nuclear Information System (INIS)

Sun Haipeng; Xu Beibei; Sheveleva, Elena; Chen, Qin M.

2008-01-01

Glucocorticoids induce COX-2 expression in rat cardiomyocytes. While investigating whether phosphatidylinositol 3 kinase (PI3K) plays a role in corticosterone (CT)-induced COX-2, we found that LY294002 (LY29) but not wortmannin (WM) attenuates CT from inducing COX-2 gene expression. Expression of a dominant-negative mutant of p85 subunit of PI3K failed to inhibit CT from inducing COX-2 expression. CT did not activate PI3K/AKT signaling pathway whereas LY29 and WM decreased the activity of PI3K. LY303511 (LY30), a structural analogue and a negative control for PI3K inhibitory activity of LY29, also suppressed COX-2 induction. These data suggest PI3K-independent mechanisms in regulating CT-induced COX-2 expression. LY29 and LY30 do not inhibit glucocorticoid receptor transactivity. Both compounds have been reported to inhibit Casein Kinase 2 activity and modulate potassium and calcium levels independent of PI3K, while LY29 has been reported to inhibit mammalian Target of Rapamycin (mTOR), and DNA-dependent Protein Kinase (DNA-PK). Inhibitor of Casein Kinase 2 (CK2), mTOR or DNA-PK failed to prevent CT from inducing COX-2 expression. Tetraethylammonium (TEA), a potassium channel blocker, and nimodipine, a calcium channel blocker, both attenuated CT from inducing COX-2 gene expression. CT was found to increase intracellular Ca 2+ concentration, which can be inhibited by LY29, TEA or nimodipine. These data suggest a possible role of calcium instead of PI3K in CT-induced COX-2 expression in cardiomyocytes

Syntheses of DL-[2-13C]leucine and its use in the preparation of [3-DL-[2-13C]leucine]oxytocin and [8-DL-[2-13C]leucine]oxytocin

International Nuclear Information System (INIS)

Viswanatha, V.; Larsen, B.; Hruby, V.J.

1979-01-01

DL-[2- 13 C]Leucine was prepared by condensing the sodium salt of ethyl acetamido-[2- 13 C]cyanoacetate with isobutylbromide in hexamethylphosphoroustriamide followed by acid hydrolysis. N-BOC-DL-[2- 13 C]Leucine was prepared and incorporated into [8-DL-[2- 13 C]leucine]oxytocin by total synthesis. The 13 C-labeled hormone derivative [8-[2- 13 C]leucine]oxytocin was separated from its 8-position diastereoisomer by partition chromatography. The specifically 13 C-labeled peptide hormone diastereoisomeric analog [3-DL-[2- 13 C]leucine]oxytocin also was prepared by solid phase peptide synthesis. No suitable solvent system for partition chromatography separation of the latter diastereoisomeric peptide mixture could be found. However an excellent preparative separation of the diastereoisomers could be obtained by reverse phase high pressure liquid chromatography on a partisil 10 M9 ODS column using the solvent system 0.05 M ammonium acetate (pH 4.0), acetonitrile (81:19, v/v) to give pure [3-[2- 13 C]leucine]oxytocin and [3-D-[2- 13 C]leucine]oxytocin. An excellent separation of [8-[2- 13 C]leucine]oxytocin and the corresponding delata-D-leucine diastereoisomer derivative could also be accomplished by high pressure liquid chromatography. (author)

SPILANTHES ACMELLA AND PHYSICAL EXERCISE INCREASED TESTOSTERONE LEVELS AND OSTEOBLAST CELLS IN GLUCOCORTICOID-INDUCED OSTEOPOROSIS MALE MICE

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Hening Laswati

2015-08-01

Full Text Available Background: Glucocorticoid-induced osteoporosis is leading cause of secondary osteoporosis by decreasing formation activity and increasing resorption activity. Spilanthes acmella, is one of Indonesia medicinal plants that contain of polyphenol and flavonoids. Previously in vitro study showed that buthanol and water fraction from this plant have increased alkaline phosphatase that known as marker of bone formation. The objective of this study to analyze the effect of Spilanthes acmella  and physical exercise in increasing testosterone and  osteoblast cells of femoral’s trabecular glucocorticoid-induced osteoporosis male mice. Method: This study using a posttest control group design, 36 male healthy mice (5 months old  were randomizely devided into 6 groups, there are : 1.Healthy control group (without induction dexamethaxone, 2.Osteoporosis groups (induction with dexamethaxone without treatment, 3.Positive control receive suspension alendronat, 4.70% Ethanol extract of Spilanthes acmella group, 5.Combination group of 70% extract ethanol of Spilanthes acmella and exercise, and 6.Exercise group  (walking using mice treadmill 10m/minute, 5-12 minutes 3 times a week. All of the intervention were given for 4 weeks. The serum levels of testosterone were determined using  immunoserology (ELISA and osteoblast cells were determined histomorphometry by light microscopy.  All statistical test were carried out using SPSS 23 and statistical significance was  set at p<0.05 for all analysis. The testosterone levels  between group were compared using Mann-Whitney test and osteoblast cells between group were compared with multiple comparison. Results: It showed that the alendronate group, combination group and the exercise group increasing testosterone level (p<0.05 from that osteoporotic group. There were also increasing osteoblast cells (p<0.05 in the alendronate group and combination group. There was no correlation between testosterone level and

Membrane-Associated Effects of Glucocorticoid on BACE1 Upregulation and Aβ Generation: Involvement of Lipid Raft-Mediated CREB Activation.

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Choi, Gee Euhn; Lee, Sei-Jung; Lee, Hyun Jik; Ko, So Hee; Chae, Chang Woo; Han, Ho Jae

2017-08-30

Glucocorticoid has been widely accepted to induce Alzheimer's disease, but the nongenomic effect of glucocorticoid on amyloid β (Aβ) generation has yet to be studied. Here, we investigated the effect of the nongenomic pathway induced by glucocorticoid on amyloid precursor protein processing enzymes as well as Aβ production using male ICR mice and human neuroblastoma SK-N-MC cells. Mice groups exposed to restraint stress or intracerebroventricular injection of Aβ showed impaired cognition, decreased intracellular glucocorticoid receptor (GR) level, but elevated level of membrane GR (mGR). In this respect, we identified the mGR-dependent pathway evoked by glucocorticoid using impermeable cortisol conjugated to BSA (cortisol-BSA) on SK-N-MC cells. Cortisol-BSA augmented the expression of β-site amyloid precursor protein cleaving enzyme 1 (BACE1), the level of C-terminal fragment β of amyloid precursor protein (C99) and Aβ production, which were maintained even after blocking intracellular GR. We also found that cortisol-BSA enhanced the interaction between mGR and Gαs, which colocalized in the lipid raft. The subsequently activated CREB by cortisol-BSA bound to the CRE site of the BACE1 promoter increasing its expression, which was downregulated by inhibiting CBP. Consistently, blocking CBP attenuated cognitive impairment and Aβ production induced by corticosterone treatment or intracerebroventricular injection of Aβ more efficiently than inhibiting intracellular GR in mice. In conclusion, glucocorticoid couples mGR with Gαs and triggers cAMP-PKA-CREB axis dependent on the lipid raft to stimulate BACE1 upregulation and Aβ generation. SIGNIFICANCE STATEMENT Patients with Alzheimer's disease (AD) have been growing sharply and stress is considered as the major environment factor of AD. Glucocorticoid is the primarily responsive factor to stress and is widely known to induce AD. However, most AD patients usually have impaired genomic pathway of glucocorticoid

Sulforaphane reverses glucocorticoid-induced apoptosis in osteoblastic cells through regulation of the Nrf2 pathway

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Lin H

2014-07-01

Full Text Available Hao Lin,1,* Bo Wei,1,* Guangsheng Li,1 Jinchang Zheng,1 Jiecong Sun,1 Jiaqi Chu,2 Rong Zeng,1 Yanru Niu21Department of Spinal Surgery, Affiliated Hospital of Guangdong Medical College, Zhanjiang, People’s Republic of China; 2Laboratory Institute of Minimally Invasive Orthopedic Surgery, Affiliated Hospital of Guangdong Medical College, Zhanjiang, People’s Republic of China *These authors contributed equally to this work Abstract: Apoptosis of osteoblasts triggered by high-dose glucocorticoids (GCs has been identified as a major cause of osteoporosis. However, the underlying molecular mechanisms accounting for this action remain elusive, which has impeded the prevention and cure of this side effect. Sulforaphane (SFP is a naturally occurring isothiocyanate that has huge health benefits for humans. In this study, by using osteoblastic MC3T3-E1 cells as a model, we demonstrate the protective effects of SFP against dexamethasone (Dex-induced apoptosis and elucidate the underlying molecular mechanisms. The results show that SFP could effectively inhibit the Dex-induced growth inhibition and release of lactate dehydrogenase in MC3T3-E1 cells. Treatment with Dex induced caspase-dependent apoptosis in MC3T3-E1 cells, as evidenced by an increase in the Sub-G1 phase, chromatin condensation, and deoxyribonucleic acid fragmentation, which were significantly suppressed by coincubation with SFP. Mitochondria-mediated apoptosis pathway contributed importantly to Dex-induced apoptosis, as revealed by the activation of caspase-3/-9 and subsequent cleavage of poly adenosine diphosphate ribose polymerase, which was also effectively blocked by SFP. Moreover, treatments of Dex strongly induced overproduction of reactive oxygen species and inhibited the expression of nuclear factor erythroid 2-related factor 2 (Nrf2 and the downstream effectors HO1 and NQO1. However, cotreatment with SFP effectively reversed this action of Dex. Furthermore, silencing of Nrf2 by

Genome wide identification and expression analysis of Homeodomain leucine zipper subfamily IV (HDZ IV gene family from Musa accuminata

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Ashutosh ePandey

2016-02-01

Full Text Available The homedodomain zipper family (HD-ZIP of transcription factors is present only in plants and plays important role in the regulation of plant-specific processes. The subfamily IV of HDZ transcription factors (HD-ZIP IV has primarily been implicated in the regulation of epidermal structure development. Though this gene family is present in all lineages of land plants, members of this gene family have not been identified in banana, which is one of the major staple fruit crops. In the present work, we identified 21 HDZIV genes in banana by the computational analysis of banana genome resource. Our analysis suggested that these genes putatively encode proteins having all the characteristic domains of HDZIV transcription factors. The phylogenetic analysis of the banana HDZIV family genes further confirmed that after separation from a common ancestor, the banana and poales lineages might have followed distinct evolutionary paths. Further, we conclude that segmental duplication played a major role in the evolution of banana HDZIV genes. All the identified banana HDZIV genes expresses in different banana tissue, however at varying levels. The transcript levels of some of the banana HDZIV genes were also detected in banana fruit pulp, suggesting their putative role in fruit attributes. A large number of genes of this family showed modulated expression under drought and salinity stress. Taken together, the present work lays a foundation for elucidation of functional aspects of the banana HDZIV genes and for their possible use in the banana improvement programs.

The Single Needle Lockstitch Machine. [Setting Zippers.] Module 8.

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South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

This module on setting zippers, one in a series on the single needle lockstitch sewing machine for student self-study, contains five sections. Each section includes the following parts: an introduction, directions, an objective, learning activities, student information, student self-check, check-out activities, and an instructor's final checklist.…

Glucocorticoid effects on object recognition memory require training-associated emotional arousal

OpenAIRE

Okuda, Shoki; Roozendaal, Benno; McGaugh, James L.

2004-01-01

Considerable evidence implicates glucocorticoid hormones in the regulation of memory consolidation and memory retrieval. The present experiments investigated whether the influence of these hormones on memory depends on the level of emotional arousal induced by the training experience. We investigated this issue in male Sprague–Dawley rats by examining the effects of immediate posttraining systemic injections of the glucocorticoid corticosterone on object recognition memory under two condition...

Resistance of Type 5 chemical protective clothing against nanometric airborne particles: Behavior of seams and zipper.

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Vinches, Ludwig; Hallé, Stéphane

2017-12-01

In the field of dermal protection, the use of chemical protective clothing (CPC) (including coveralls) are considered as the last barrier against airborne engineered nanomaterials (ENM). In the majority of cases, Type 5 CPC, used against solid particles (ISO 13982-1), perform well against ENM. But in a recent study, a penetration level (PL) of up to 8.5% of polydisperse sodium chloride airborne nanoparticles has been measured. Moreover, in all the previous studies, tests were performed on a sample of protective clothing material without seams or zippers. Thus, the potential for permeation through a zipper or seams has not yet been determined, even though these areas would be privileged entry points for airborne ENM. This work was designed to evaluate the PL of airborne ENM through coveralls and specifically the PL through the seams on different parts of the CPC and the zipper. Eight current models of CPC (Type 5) were selected. The samples were taken from places with and without seams and with a zipper. In some cases, a cover strip can be added to the zipper to enhance its sealing. Polydisperse nanoparticles were generated by nebulization of a sodium chloride solution. A penetration cell was developed to expose the sample to airborne nanometric particles. The NaCl particle concentration in number was measured with an ultrafine particle counter and the PL was defined as the downstream concentration divided by the upstream concentration. The results obtained show that the PL increased significantly in the presence of seams and could reach up to 90% depending on the seam's design. Moreover, this study classifies the different types of seams by their resistance against airborne ENM. As for the penetration of airborne NaCl particles through the zipper, the PL was greatly attenuated by the presence of a cover strip, but only for certain models of coveralls. Finally, the values of the pressure drop were directly linked to the type of seam. All of these conclusions provide

Ursodeoxycholic acid attenuates experimental autoimmune arthritis by targeting Th17 and inducing pAMPK and transcriptional corepressor SMILE.

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Lee, Eun-Jung; Kwon, Jeong-Eun; Park, Min-Jung; Jung, Kyung-Ah; Kim, Da-Som; Kim, Eun-Kyung; Lee, Seung Hoon; Choi, Jong Young; Park, Sung-Hwan; Cho, Mi-La

2017-08-01

Ursodeoxycholic acid (UDCA) has been known that UDCA has prominent effects on liver, however, there is little known about its influence on autoimmune disease. Here, the benefit of UDCA on arthritis rheumatoid (RA) in vivo was tested. RA mouse were induced using collagen II (CIA, collagen induced arthritis) where the disease severity or UDCA-related signaling pathway such as AMP-activated protein kinase (AMPK) or small heterodimer partner interacting leucine zipper protein (SMILE) was evaluated by westerblot and immunohistochemical staining. Gene expression was measured by realtime-polymerase chain reaction (PCR). The administration of UDCA effectively alleviated the arthritic score and incidence with decreased cartilage damage and lipid metabolic parameters. UDCA also suppressed the secretion of pro-inflammatory cytokines. It was confirmed that UDCA upregulated the expression of SMILE and transcriptional activity of PPARγ via controlling AMPK or p38 activity. In the present study, the therapeutic effect of UDCA inducing SMILE through AMPK activation in rheumatoid arthritis mouse as well as other autoimmune disease was proposed. Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

Hypersensitivity Reactions from Excipients in Systemic Glucocorticoid Formulations

DEFF Research Database (Denmark)

Calogiuri, Gianfranco; Garvey, Lene H; Romita, Paolo

2016-01-01

Glucocorticoids are the most widely used drugs for the treatment of hypersensitivity, however these drugs themselves and the excipients contained in commercial corticosteroid formulations are able to induce severe immediate-type hypersensitivity reactions. Reactions involving excipients have been...

Leucine stimulates protein synthesis in skeletal muscle of neonatal pigs by enhancing mTORC1 activation.

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Suryawan, Agus; Jeyapalan, Asumthia S; Orellana, Renan A; Wilson, Fiona A; Nguyen, Hanh V; Davis, Teresa A

2008-10-01

Skeletal muscle in the neonate grows at a rapid rate due in part to an enhanced sensitivity to the postprandial rise in amino acids, particularly leucine. To elucidate the molecular mechanism by which leucine stimulates protein synthesis in neonatal muscle, overnight-fasted 7-day-old piglets were treated with rapamycin [an inhibitor of mammalian target of rapamycin (mTOR) complex (mTORC)1] for 1 h and then infused with leucine for 1 h. Fractional rates of protein synthesis and activation of signaling components that lead to mRNA translation were determined in skeletal muscle. Rapamycin completely blocked leucine-induced muscle protein synthesis. Rapamycin markedly reduced raptor-mTOR association, an indicator of mTORC1 activation. Rapamycin blocked the leucine-induced phosphorylation of mTOR, S6 kinase 1 (S6K1), and eukaryotic initiation factor (eIF)4E-binding protein-1 (4E-BP1) and formation of the eIF4E.eIF4G complex and increased eIF4E.4E-BP1 complex abundance. Rapamycin had no effect on the association of mTOR with rictor, a crucial component for mTORC2 activation, or G protein beta-subunit-like protein (GbetaL), a component of mTORC1 and mTORC2. Neither leucine nor rapamycin affected the phosphorylation of AMP-activated protein kinase (AMPK), PKB, or tuberous sclerosis complex (TSC)2, signaling components that reside upstream of mTOR. Eukaryotic elongation factor (eEF)2 phosphorylation was not affected by leucine or rapamycin, although current dogma indicates that eEF2 phosphorylation is mTOR dependent. Together, these in vivo data suggest that leucine stimulates muscle protein synthesis in neonates by enhancing mTORC1 activation and its downstream effectors.

Alterations in the Helicoverpa armigera midgut digestive physiology after ingestion of pigeon pea inducible leucine aminopeptidase.

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Purushottam R Lomate

Full Text Available Jasmonate inducible plant leucine aminopeptidase (LAP is proposed to serve as direct defense in the insect midgut. However, exact functions of inducible plant LAPs in the insect midgut remain to be estimated. In the present investigation, we report the direct defensive role of pigeon pea inducible LAP in the midgut of Helicoverpa armigera (Lepidoptera: Noctuidae and responses of midgut soluble aminopeptidases and serine proteinases upon LAP ingestion. Larval growth and survival was significantly reduced on the diets supplemented with pigeon pea LAP. Aminopeptidase activities in larvae remain unaltered in presence or absence of inducible LAP in the diet. On the contrary, serine proteinase activities were significantly decreased in the larvae reared on pigeon pea LAP containing diet as compared to larvae fed on diet without LAP. Our data suggest that pigeon pea inducible LAP is responsible for the degradation of midgut serine proteinases upon ingestion. Reduction in the aminopeptidase activity with LpNA in the H. armigera larvae was compensated with an induction of aminopeptidase activity with ApNA. Our findings could be helpful to further dissect the roles of plant inducible LAPs in the direct plant defense against herbivory.

Investigation of radioprotective properties of synthetic antagonist of glucocorticoids RU 38 486

International Nuclear Information System (INIS)

Sejliev, A.A.; Zvonareva, N.B.; Zhivotovskij, B.D.; Khanson, K.P.; Akademiya Meditsinskikh Nauk SSSR, Leningrad

1992-01-01

Radioprotective properties of synthetic antiglucocorticoid RU 38 486 were investigated. It was demonstrated that this antigonist of glucocorticoids possesses radioprotective effect in vitro and in vivo systems. Radioprotective properties at molecular level exhibited in inhibition of postirradiation endonuclease activation and in prevention of internucleosome chromatin degradation. Involvement of cytosol glucocorticoid receptors in initiation of radiation-induced programmed cell death is discussed

Adenosine Receptor Stimulation Improves Glucocorticoid-Induced Osteoporosis in a Rat Model

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Gabriele Pizzino

2017-09-01

Full Text Available Glucocorticoid-induced osteoporosis (GIO is a secondary cause of bone loss. Bisphosphonates approved for GIO, might induce jaw osteonecrosis; thus additional therapeutics are required. Adenosine receptor agonists are positive regulators of bone remodeling, thus the efficacy of adenosine receptor stimulation for treating GIO was tested. In a preventive study GIO was induced in Sprague-Dawley rats by methylprednisolone (MP for 60 days. Animals were randomly assigned to receive polydeoxyribonucleotide (PDRN, an adenosine A2 receptor agonist, or PDRN and DMPX (3,7-dimethyl-1-propargylxanthine, an A2 antagonist, or vehicle (0.9% NaCl. Another set of animals was used for a treatment study, following the 60 days of MP-induction rats were randomized to receive (for additional 60 days PDRN, or PDRN and DMPX (an adenosine A2 receptor antagonist, or zoledronate (as control for gold standard treatment, or vehicle. Control animals were administered with vehicle for either 60 or 120 days. Femurs were analyzed after treatments for histology, imaging, and breaking strength analysis. MP treatment induced severe bone loss, the concomitant use of PDRN prevented the developing of osteoporosis. In rats treated for 120 days, PDRN restored bone architecture and bone strength; increased b-ALP, osteocalcin, osteoprotegerin and stimulated the Wnt canonical and non-canonical pathway. Zoledronate reduced bone resorption and ameliorated the histological features, without significant effects on bone formation. Our results suggest that adenosine receptor stimulation might be useful for preventing and treating GIO.

Excessive Leucine-mTORC1-Signalling of Cow Milk-Based Infant Formula: The Missing Link to Understand Early Childhood Obesity.

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Melnik, Bodo C

2012-01-01

Increased protein supply by feeding cow-milk-based infant formula in comparison to lower protein content of human milk is a well-recognized major risk factor of childhood obesity. However, there is yet no conclusive biochemical concept explaining the mechanisms of formula-induced childhood obesity. It is the intention of this article to provide the biochemical link between leucine-mediated signalling of mammalian milk proteins and adipogenesis as well as early adipogenic programming. Leucine has been identified as the predominant signal transducer of mammalian milk, which stimulates the nutrient-sensitive kinase mammalian target of rapamycin complex 1 (mTORC1). Leucine thus functions as a maternal-neonatal relay for mTORC1-dependent neonatal β-cell proliferation and insulin secretion. The mTORC1 target S6K1 plays a pivotal role in stimulation of mesenchymal stem cells to differentiate into adipocytes and to induce insulin resistance. It is of most critical concern that infant formulas provide higher amounts of leucine in comparison to human milk. Exaggerated leucine-mediated mTORC1-S6K1 signalling induced by infant formulas may thus explain increased adipogenesis and generation of lifelong elevated adipocyte numbers. Attenuation of mTORC1 signalling of infant formula by leucine restriction to physiologic lower levels of human milk offers a great chance for the prevention of childhood obesity and obesity-related metabolic diseases.

Stress- and glucocorticoid-induced priming of neuroinflammatory responses: potential mechanisms of stress-induced vulnerability to drugs of abuse.

Science.gov (United States)

Frank, Matthew G; Watkins, Linda R; Maier, Steven F

2011-06-01

Stress and stress-induced glucocorticoids (GCs) sensitize drug abuse behavior as well as the neuroinflammatory response to a subsequent pro-inflammatory challenge. Stress also predisposes or sensitizes individuals to develop substance abuse. There is an emerging evidence that glia and glia-derived neuroinflammatory mediators play key roles in the development of drug abuse. Drugs of abuse such as opioids, psychostimulants, and alcohol induce neuroinflammatory mediators such as pro-inflammatory cytokines (e.g. interleukin (IL)-1β), which modulate drug reward, dependence, and tolerance as well as analgesic properties. Drugs of abuse may directly activate microglial and astroglial cells via ligation of Toll-like receptors (TLRs), which mediate the innate immune response to pathogens as well as xenobiotic agents (e.g. drugs of abuse). The present review focuses on understanding the immunologic mechanism(s) whereby stress primes or sensitizes the neuroinflammatory response to drugs of abuse and explores whether stress- and GC-induced sensitization of neuroimmune processes predisposes individuals to drug abuse liability and the role of neuroinflammatory mediators in the development of drug addiction. Copyright © 2011 Elsevier Inc. All rights reserved.

Ultradian hormone stimulation induces glucocorticoid receptor-mediated pulses of gene transcription.

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Stavreva, Diana A; Wiench, Malgorzata; John, Sam; Conway-Campbell, Becky L; McKenna, Mervyn A; Pooley, John R; Johnson, Thomas A; Voss, Ty C; Lightman, Stafford L; Hager, Gordon L

2009-09-01

Studies on glucocorticoid receptor (GR) action typically assess gene responses by long-term stimulation with synthetic hormones. As corticosteroids are released from adrenal glands in a circadian and high-frequency (ultradian) mode, such treatments may not provide an accurate assessment of physiological hormone action. Here we demonstrate that ultradian hormone stimulation induces cyclic GR-mediated transcriptional regulation, or gene pulsing, both in cultured cells and in animal models. Equilibrium receptor-occupancy of regulatory elements precisely tracks the ligand pulses. Nascent RNA transcripts from GR-regulated genes are released in distinct quanta, demonstrating a profound difference between the transcriptional programs induced by ultradian and constant stimulation. Gene pulsing is driven by rapid GR exchange with response elements and by GR recycling through the chaperone machinery, which promotes GR activation and reactivation in response to the ultradian hormone release, thus coupling promoter activity to the naturally occurring fluctuations in hormone levels. The GR signalling pathway has been optimized for a prompt and timely response to fluctuations in hormone levels, indicating that biologically accurate regulation of gene targets by GR requires an ultradian mode of hormone stimulation.

Insulin-Inducible SMILE Inhibits Hepatic Gluconeogenesis.

Science.gov (United States)

Lee, Ji-Min; Seo, Woo-Young; Han, Hye-Sook; Oh, Kyoung-Jin; Lee, Yong-Soo; Kim, Don-Kyu; Choi, Seri; Choi, Byeong Hun; Harris, Robert A; Lee, Chul-Ho; Koo, Seung-Hoi; Choi, Hueng-Sik

2016-01-01

The role of a glucagon/cAMP-dependent protein kinase-inducible coactivator PGC-1α signaling pathway is well characterized in hepatic gluconeogenesis. However, an opposing protein kinase B (PKB)/Akt-inducible corepressor signaling pathway is unknown. A previous report has demonstrated that small heterodimer partner-interacting leucine zipper protein (SMILE) regulates the nuclear receptors and transcriptional factors that control hepatic gluconeogenesis. Here, we show that hepatic SMILE expression was induced by feeding in normal mice but not in db/db and high-fat diet (HFD)-fed mice. Interestingly, SMILE expression was induced by insulin in mouse primary hepatocyte and liver. Hepatic SMILE expression was not altered by refeeding in liver-specific insulin receptor knockout (LIRKO) or PKB β-deficient (PKBβ(-/-)) mice. At the molecular level, SMILE inhibited hepatocyte nuclear factor 4-mediated transcriptional activity via direct competition with PGC-1α. Moreover, ablation of SMILE augmented gluconeogenesis and increased blood glucose levels in mice. Conversely, overexpression of SMILE reduced hepatic gluconeogenic gene expression and ameliorated hyperglycemia and glucose intolerance in db/db and HFD-fed mice. Therefore, SMILE is an insulin-inducible corepressor that suppresses hepatic gluconeogenesis. Small molecules that enhance SMILE expression would have potential for treating hyperglycemia in diabetes. © 2016 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.

Glucocorticoid Regulation of the Vitamin D Receptor

Science.gov (United States)

Hidalgo, Alejandro A.; Trump, Donald L.; Johnson, Candace S.

2010-01-01

Many studies indicate calcitriol has potent anti-tumor activity in different types of cancers. However, high levels of vitamin D can produce hypercalcemia in some patients. Glucocorticoids are used to ameliorate hypercalcemia and to enhance calcitriol anti-tumor activity. Calcitriol in combination with the glucocorticoid dexamethasone (Dex) increased vitamin D receptor (VDR) protein levels and ligand binding in squamous cell carcinoma VII (SCC). In this study we found that both calcitriol and Dex induce VDR- and glucocorticoid receptor (GR)-mediated transcription respectively, indicating both hormone receptors are active in SCC. Pre-treatment with Dex increases VDR-mediated transcription at the human CYP24A1 promoter. Whereas, pre-treatment with other steroid hormones, including dihydrotestosterone and R1881, has no effect on VDR-mediated transcription. Real-time PCR indicates treatment with Dex increases Vdr transcripts in a time-dependent manner, suggesting Dex may directly regulate expression of Vdr. Numerous putative glucocorticoid response elements (GREs) were found in the Vdr gene. Chromatin immunoprecipitation (ChIP) assay demonstrated GR binding at several putative GREs located within the mouse Vdr gene. However, none of the putative GREs studied increase GR-mediated transcription in luciferase reporter assays. In an attempt to identify the response element responsible for Vdr transcript regulation, future studies will continue to analyze newly identified GREs more distal from the Vdr gene promoter. PMID:20398752

Endogenous glucocorticoids exacerbate cholestasis-associated liver injury and hypercholesterolemia in mice.

Science.gov (United States)

van der Geest, Rick; Ouweneel, Amber B; van der Sluis, Ronald J; Groen, Albert K; Van Eck, Miranda; Hoekstra, Menno

2016-09-01

Cholestatic liver disease is characterized by a disruption of bile flow, bile acid toxicity, liver injury, and hypercholesterolemia. Relatively high secretion of glucocorticoids by the adrenals has been observed under cholestatic conditions. Here we investigated a contribution of the rise in endogenous glucocorticoids to initial stage cholestasis pathology. Adrenalectomized or sham-operated control C57BL/6 mice were given an oral dose of alpha-naphthylisothiocyanate to induce cholestasis. Adrenalectomy effectively lowered plasma corticosterone levels (18±5ng/ml vs 472±58ng/ml; Phypercholesterolemia. In conclusion, we have shown that endogenous glucocorticoids exacerbate the liver injury and hypercholesterolemia associated with acute cholestasis in mice. Copyright © 2016 Elsevier Inc. All rights reserved.

Prevention of Glucocorticoid-Induced Osteoporosis: Clinical audit to evaluate the implementation of National Osteoporosis Guideline Group 2017 guidelines in a primary care setting.

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Carter, Matthew

2018-04-12

Treatment with glucocorticoids is the leading cause of drug-induced osteoporosis. National Osteoporosis Guideline Group (NOGG) 2017 guidelines advise a case-finding strategy for patients at risk. The aims of the audit were to evaluate the implementation of the NOGG 2017 guidelines for patients receiving long-term glucocorticoid therapy in a suburban general practice, to instigate changes to ensure 90% of patients are investigated and treated appropriately, and to evaluate impact at a 6-mo re-audit. Reporting Analysis and Intelligence Delivering Results (RAIDR) is a health-care intelligence tool accessing primary care clinical data. Using RAIDR, data on relevant osteoporotic risk factors were combined to produce FRAX scores for patients who had been prescribed glucocorticoids 3 or more times in the past 12 months. FRAX data were displayed in a NOGG guidance graph for major osteoporotic fracture probability. Patients were assessed as high, intermediate, or low risk. High- and intermediate-risk patients above the NOGG threshold were recommended to start bisphosphonates; these patients were sent a prescription for alendronate and a letter of explanation. There were no intermediate patients below the NOGG threshold. Low-risk patients were recommended to have lifestyle advice; a leaflet was produced and sent to these patients. Initial results showed that only 25% of patients recommended to be on bisphosphonates were taking them. Steps were taken to educate the general practitioners in the FRAX tool and NOGG guidelines; the chronic obstructive pulmonary disease annual template was amended to aid adherence by alerting the nurse to the number of glucocorticoid courses prescribed, with additional boxes for prescribing alendronate and printing the lifestyle leaflet; and 2-monthly RAIDR searches by the practice pharmacist were started. A re-audit 6 mo later showed improvement to 92%. This audit showed that education, reminders, and simple computer prompts can greatly improve

Ex vivo stimulation of whole blood as a means to determine glucocorticoid sensitivity

Directory of Open Access Journals (Sweden)

Burnsides C

2012-08-01

Full Text Available Christopher Burnsides,1,* Jacqueline Corry,1,* Jacob Alexander,1 Catherine Balint,1 David Cosmar,1 Gary Phillips,2 Jeanette I Webster Marketon1,31Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Internal Medicine, 2Center for Biostatistics, 3Institute for Behavioral Medicine Research, Wexner Medical Center at The Ohio State University, Columbus, OH, USA*JC and CB have equally contributed to this workPurpose: Glucocorticoids are commonly prescribed to treat a number of diseases including the majority of inflammatory diseases. Despite considerable interpersonal variability in response to glucocorticoids, an insensitivity rate of about 30%, and the risk of adverse side effects of glucocorticoid therapy, currently no assay is performed to determine sensitivity.Patients and methods: Here we propose a whole blood ex vivo stimulation assay to interrogate known glucocorticoid receptor (GR up- and downregulated genes to indicate glucocorticoid sensitivity. We have chosen to employ real-time PCR in order to provide a relatively fast and inexpensive assay.Results: We show that the GR-regulated genes, GILZ and FKBP51, are upregulated in whole blood by treatment with dexamethasone and that LPS-induction of cytokines (IL-6 and TNFα are repressed by dexamethasone in a dose responsive manner. There is considerable interpersonal variability in the maximum induction of these genes but little variation in the EC50 and IC50 concentrations. The regulation of the GR-induced genes differs throughout the day whereas the suppression of LPS-induced cytokines is not as sensitive to time of day.Conclusion: In all, this assay would provide a method to determine glucocorticoid receptor responsiveness in whole blood.Keywords: glucocorticoid responsiveness, gene regulation, nuclear receptor, GILZ, FKBP51, cytokines

Peripheral mechanisms contributing to the glucocorticoid hypersensitivity in proopiomelanocortin null mice treated with corticosterone

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Michailidou, Zoi; Coll, Anthony P; Kenyon, Christopher J; Morton, Nicholas M; O'Rahilly, Stephen; Seckl, Jonathan R; Chapman, Karen E

2007-01-01

Proopiomelanocortin (POMC) deficiency causes severe obesity through hyperphagia of hypothalamic origin. However, low glucocorticoid levels caused by adrenal insufficiency mitigate against insulin resistance, hyperphagia and fat accretion in Pomc−/− mice. Upon exogenous glucocorticoid replacement, corticosterone-supplemented (CORT) Pomc−/− mice show exaggerated responses, including excessive fat accumulation, hyperleptinaemia and insulin resistance. To investigate the peripheral mechanisms underlying this glucocorticoid hypersensitivity, we examined the expression levels of key determinants and targets of glucocorticoid action in adipose tissue and liver. Despite lower basal expression of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), which generates active glucocorticoids within cells, CORT-mediated induction of 11β-HSD1 mRNA levels was more pronounced in adipose tissues of Pomc−/− mice. Similarly, CORT treatment increased lipoprotein lipase mRNA levels in all fat depots in Pomc−/− mice, consistent with exaggerated fat accumulation. Glucocorticoid receptor (GR) mRNA levels were selectively elevated in liver and retroperitoneal fat of Pomc−/− mice but were corrected by CORT in the latter depot. In liver, CORT increased phosphoenolpyruvate carboxykinase mRNA levels specifically in Pomc−/− mice, consistent with their insulin-resistant phenotype. Furthermore, CORT induced hypertension in Pomc−/− mice, independently of adipose or liver renin–angiotensin system activation. These data suggest that CORT-inducible 11β-HSD1 expression in fat contributes to the adverse cardiometabolic effects of CORT in POMC deficiency, whereas higher GR levels may be more important in liver. PMID:17592030

A reversal phase arrest uncoupling the bone formation and resorption contributes to the bone loss in glucocorticoid treated ovariectomised aged sheep

DEFF Research Database (Denmark)

Andreasen, Christina Møller; Ding, Ming; Overgaard, Søren

2015-01-01

Large animals as sheep are often used as models for human osteoporosis. Our aim was therefore to determine how glucocorticoid treatment of ovariectomised sheep affects the cancellous bone, determining the cellular events within the bone remodelling process that contributes to their bone loss...... in postmenopausal women with glucocorticoid-induced osteoporosis. This supports the relevance of the sheep model to the pathophysiology of glucocorticoid-induced osteoporosis in postmenopausal women, making it a relevant preclinical model for orthopaedic implant and biomaterial research........ Twenty female sheep were assigned for two groups; an untreated control group and an ovariectomised group treated with glucocorticoids (0.6mg/kg/day, 5 times weekly) for 7months. At 7months the glucocorticoid-treated ovariectomised sheep showed a significant change in the bone microstructure revealed...

Paired hormone response elements predict caveolin-1 as a glucocorticoid target gene.

Directory of Open Access Journals (Sweden)

Marinus F van Batenburg

2010-01-01

Full Text Available Glucocorticoids act in part via glucocorticoid receptor binding to hormone response elements (HREs, but their direct target genes in vivo are still largely unknown. We developed the criterion that genomic occurrence of paired HREs at an inter-HRE distance less than 200 bp predicts hormone responsiveness, based on synergy of multiple HREs, and HRE information from known target genes. This criterion predicts a substantial number of novel responsive genes, when applied to genomic regions 10 kb upstream of genes. Multiple-tissue in situ hybridization showed that mRNA expression of 6 out of 10 selected genes was induced in a tissue-specific manner in mice treated with a single dose of corticosterone, with the spleen being the most responsive organ. Caveolin-1 was strongly responsive in several organs, and the HRE pair in its upstream region showed increased occupancy by glucocorticoid receptor in response to corticosterone. Our approach allowed for discovery of novel tissue specific glucocorticoid target genes, which may exemplify responses underlying the permissive actions of glucocorticoids.

Biochemical endpoints of glucocorticoid hormone action

Energy Technology Data Exchange (ETDEWEB)

Young, D.A.; Nicholson, M.L.; Guyette, W.A.; Giddings, S.J.; Mendelsohn, S.L.; Nordeen, S.K.; Lyons, R.T.

1978-01-01

Both the rapidly evolving metabolic effects of glucocorticoids and the more slowly developing lethal actions appear to be initiated via the synthesis of new mRNAs and proteins. The chronic suppression of cell growth may be the consequence of suppression of overall rates of protein synthesis (and probably RNA and DNA synthesis as well) that in turn may represent the cellular response to the small changes in ratios of adenine nucleotides that result from the suppression of oxidative ATP production. The inhibition of glucose transport may also play a role here to prevent a compensatory increase in glycolytic ATP production. Some other hormone actions, the decrease in the ability of cells to concentrate AIB and the increase in nuclear fragility are unrelated to, and evolve separately from, the hormonal inhibitions on energy production. Cell killing is not the result of suppression of protein synthesis, nor of hormone-induced increases in calcium uptake. While the mechanisms are unknown, the increase in nuclear fragility appears to be the earliest measure of their operation. In tumor cells resistance to lethal actions of glucocorticoids may emerge via the selection of cells with hardier membranes, that are better able to withstand the intracellular destructive events set in motion by high levels of glucocorticoids.

Leucine metabolism in patients with Hepatic Encephalopathy

International Nuclear Information System (INIS)

McGhee, A.S.; Kassouny, M.E.; Matthews, D.E.; Millikan, W.

1986-01-01

A primed continuous infusion of [ 15 N, 1- 13 C]leucine was used to determine whether increased oxidation and/or protein synthesis of leucine occurs in patients with cirrhosis. Five controls and patients were equilibrated on a metabolic balance diet [0.6 g protein per kg ideal body weight (IBW)]. An additional four patients were equilibrated in the same manner with the same type of diet with a protein level of 0.75 g per kg IBW. Plasma leucine and breath CO 2 enrichments were measured by mass spectrometry. Protein synthesis and leucine metabolism were identical in controls and patients when both were fed a diet with 0.6 g protein/kg IBW. Results indicate that systemic derangements of leucine metabolism are not the cause of Hepatic Encephalopathy

Glucocorticoid effects on object recognition memory require training-associated emotional arousal.

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Okuda, Shoki; Roozendaal, Benno; McGaugh, James L

2004-01-20

Considerable evidence implicates glucocorticoid hormones in the regulation of memory consolidation and memory retrieval. The present experiments investigated whether the influence of these hormones on memory depends on the level of emotional arousal induced by the training experience. We investigated this issue in male Sprague-Dawley rats by examining the effects of immediate posttraining systemic injections of the glucocorticoid corticosterone on object recognition memory under two conditions that differed in their training-associated emotional arousal. In rats that were not previously habituated to the experimental context, corticosterone (0.3, 1.0, or 3.0 mg/kg, s.c.) administered immediately after a 3-min training trial enhanced 24-hr retention performance in an inverted-U shaped dose-response relationship. In contrast, corticosterone did not affect 24-hr retention of rats that received extensive prior habituation to the experimental context and, thus, had decreased novelty-induced emotional arousal during training. Additionally, immediate posttraining administration of corticosterone to nonhabituated rats, in doses that enhanced 24-hr retention, impaired object recognition performance at a 1-hr retention interval whereas corticosterone administered after training to well-habituated rats did not impair 1-hr retention. Thus, the present findings suggest that training-induced emotional arousal may be essential for glucocorticoid effects on object recognition memory.

DNA sequence of 15 base pairs is sufficient to mediate both glucocorticoid and progesterone induction of gene expression

International Nuclear Information System (INIS)

Straehle, U.; Klock, G.; Schuetz, G.

1987-01-01

To define the recognition sequence of the glucocorticoid receptor and its relationship with that of the progesterone receptor, oligonucleotides derived from the glucocorticoid response element of the tyrosine aminotransferase gene were tested upstream of a heterologous promoter for their capacity to mediate effects of these two steroids. The authors show that a 15-base-pair sequence with partial symmetry is sufficient to confer glucocorticoid inducibility on the promoter of the herpes simplex virus thymidine kinase gene. The same 15-base-pair sequence mediates induction by progesterone. Point mutations in the recognition sequence affect inducibility by glucocorticoids and progesterone similarly. Together with the strong conservation of the sequence of the DNA-binding domain of the two receptors, these data suggest that both proteins recognize a sequence that is similar, if not the same

Synovial DKK1 expression is regulated by local glucocorticoid metabolism in inflammatory arthritis.

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Hardy, Rowan; Juarez, Maria; Naylor, Amy; Tu, Jinwen; Rabbitt, Elizabeth H; Filer, Andrew; Stewart, Paul M; Buckley, Christopher D; Raza, Karim; Cooper, Mark S

2012-10-18

Inflammatory arthritis is associated with increased bone resorption and suppressed bone formation. The Wnt antagonist dickkopf-1 (DKK1) is secreted by synovial fibroblasts in response to inflammation and this protein has been proposed to be a master regulator of bone remodelling in inflammatory arthritis. Local glucocorticoid production is also significantly increased during joint inflammation. Therefore, we investigated how locally derived glucocorticoids and inflammatory cytokines regulate DKK1 synthesis in synovial fibroblasts during inflammatory arthritis. We examined expression and regulation of DKK1 in primary cultures of human synovial fibroblasts isolated from patients with inflammatory arthritis. The effect of TNFα, IL-1β and glucocorticoids on DKK1 mRNA and protein expression was examined by real-time PCR and ELISA. The ability of inflammatory cytokine-induced expression of the glucocorticoid-activating enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11β-HSD1) to sensitise fibroblasts to endogenous glucocorticoids was explored. Global expression of Wnt signalling and target genes in response to TNFα and glucocorticoids was assessed using a custom array. DKK1 expression in human synovial fibroblasts was directly regulated by glucocorticoids but not proinflammatory cytokines. Glucocorticoids, but not TNFα, regulated expression of multiple Wnt agonists and antagonists in favour of inhibition of Wnt signalling. However, TNFα and IL-1β indirectly stimulated DKK1 production through increased expression of 11β-HSD1. These results demonstrate that in rheumatoid arthritis synovial fibroblasts, DKK1 expression is directly regulated by glucocorticoids rather than TNFα. Consequently, the links between synovial inflammation, altered Wnt signalling and bone remodelling are not direct but are dependent on local activation of endogenous glucocorticoids.

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

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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.

Glucocorticoid receptors on leukemic cells as evidenced by dexamethasone-induced cytolysis and /sup 3/H-dexamethasone binding

Energy Technology Data Exchange (ETDEWEB)

Thraenhardt, H; Haefer, R; Zintl, F

1987-01-01

The presence of glucocorticoid receptors on the leukemic cells of 33 patients affected with acute lymphatic leukemia (ALL) and 6 patients affected with acute myeloic leukemia (AML) was investigated by dexamethasone-induced cytolysis and (/sup 3/H)-dexamethasone binding. The tests undertaken proved that after 20 hours of incubation 9 of 26 non-T-non-B-ALL (c-ALL and unclassified ALL) and 2 of AML were lysed with dexamethasone; blood lymphocytes and bone marrow leukocytes of healthy donors, however, were not affected. Non-T-non-B-ALL and AML were able to bind essentially more (/sup 3/H)-dexamethasone than T-ALL. There existed no correlation between dexamethasone binding and dexamethasone-induced cytolysis.

Xenobiotics and the Glucocorticoid Receptor

International Nuclear Information System (INIS)

Gulliver, Linda S M

2017-01-01

Glucocorticoid Receptor (GR) is present in virtually every human cell type. Representing a nuclear receptor superfamily, GR has several different isoforms essentially acting as ligand-dependent transcription factors, regulating glucocorticoid-responsive gene expression in both a positive and a negative manner. Although the natural ligand of the Glucocorticoid Receptor, glucocorticoids (GC) represent only some of the multiple ligands for GR. Xenobiotics, ubiquitous in the environment, bind to GR and are also capable of activating or repressing GR gene expression, thereby modulating GR cell and tissue-specific downstream effects in a multitude of ways that include responses to inflammatory, allergic, metabolic, neoplastic and autoimmune processes. Many xenobiotics, if inadequately metabolized by xenobiotic metabolizing enzymes and not wholly eliminated, could have deleterious toxic effects with potentially lethal consequences. This review examines GR, the genomic and non-genomic actions of natural and synthetic GC and the body's handling of xenobiotic compounds, before reviewing what is presently known about GR's interactions with many of the more commonly encountered and some of the less well known GR-associated xenobiotics. GR promiscuity and crosstalk with other signaling pathways is discussed, alongside novel roles for GR that include mood disorder and addiction. A knowledge of GR interactions with xenobiotics is increasingly relevant when considering aging populations and the related prevalence of neoplastic disease, together with growing concerns around human exposure to mixtures of chemicals in the environment. Furthermore, escalating rates of obesity, Type 2 diabetes; autoimmune, allergy, addiction and mood disorder-related pathologies, require novel targeted interventions and GR appears a promising pharmacological candidate. - Highlights: • Biological impact of xenobiotics acting through Glucocorticoid Receptor. • Promiscuity of Glucocorticoid

Xenobiotics and the Glucocorticoid Receptor

Energy Technology Data Exchange (ETDEWEB)

Gulliver, Linda S M, E-mail: linda.gulliver@otago.ac.nz

2017-03-15

Glucocorticoid Receptor (GR) is present in virtually every human cell type. Representing a nuclear receptor superfamily, GR has several different isoforms essentially acting as ligand-dependent transcription factors, regulating glucocorticoid-responsive gene expression in both a positive and a negative manner. Although the natural ligand of the Glucocorticoid Receptor, glucocorticoids (GC) represent only some of the multiple ligands for GR. Xenobiotics, ubiquitous in the environment, bind to GR and are also capable of activating or repressing GR gene expression, thereby modulating GR cell and tissue-specific downstream effects in a multitude of ways that include responses to inflammatory, allergic, metabolic, neoplastic and autoimmune processes. Many xenobiotics, if inadequately metabolized by xenobiotic metabolizing enzymes and not wholly eliminated, could have deleterious toxic effects with potentially lethal consequences. This review examines GR, the genomic and non-genomic actions of natural and synthetic GC and the body's handling of xenobiotic compounds, before reviewing what is presently known about GR's interactions with many of the more commonly encountered and some of the less well known GR-associated xenobiotics. GR promiscuity and crosstalk with other signaling pathways is discussed, alongside novel roles for GR that include mood disorder and addiction. A knowledge of GR interactions with xenobiotics is increasingly relevant when considering aging populations and the related prevalence of neoplastic disease, together with growing concerns around human exposure to mixtures of chemicals in the environment. Furthermore, escalating rates of obesity, Type 2 diabetes; autoimmune, allergy, addiction and mood disorder-related pathologies, require novel targeted interventions and GR appears a promising pharmacological candidate. - Highlights: • Biological impact of xenobiotics acting through Glucocorticoid Receptor. • Promiscuity of Glucocorticoid

Differential effects of the new glucocorticoid receptor antagonist ORG 34517 and RU486 (mifepristone) on glucocorticoid receptor nuclear translocation in the AtT20 cell line.

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Peeters, B W M M; Ruigt, G S F; Craighead, M; Kitchener, P

2008-12-01

Glucocorticoid agonists bind to cytoplasmic glucocorticoid receptors (GRs) and subsequently translocate as an agonist-GR complex into the nucleus. In the nucleus the complex regulates the transcription of target genes. A number of GR antagonists (RU486, progesterone, RU40555) have also been shown to induce receptor translocation. These compounds should be regarded as partial agonists. For the nonselective progesterone receptor antagonists, RTI3021-012 and RTI3021-022, it was shown that GR antagonism is possible without the induction of GR translocation. In the present studies, the new GR antagonist, ORG 34517, was investigated for its potential to induce GR translocation and to antagonize corticosterone-induced GR translocation in the AtT20 (mouse pituitary) cell line. ORG 34517 was compared to RU486. In contrast to RU486, ORG 34517 (at doses up to 3 x 10(-7) M) did not induce GR translocation, but was able to block corticosterone (3 x 10(-8) M) induced GR translocation. ORG 34517 can be regarded as a true competitive GR antagonist without partial agonistic activities.

Dietary flavonoid kaempferol inhibits glucocorticoid-induced bone loss by promoting osteoblast survival.

Science.gov (United States)

Adhikary, Sulekha; Choudhary, Dharmendra; Ahmad, Naseer; Karvande, Anirudha; Kumar, Avinash; Banala, Venkatesh Teja; Mishra, Prabhat Ranjan; Trivedi, Ritu

2018-02-13

Kaempferol, a dietary flavonoid found in fruits and vegetables, has been reported to reverse osteopenic condition in ovariectomized rats. Because kaempferol is endowed with osteogenic activity, the aim of this study was to determine whether it has a beneficial effect on glucocorticoid (GC)-induced bone loss. Adult female rats were divided into four groups as control (vehicle; distilled water), methylprednisolone (MP; 5 mg•kg•d, subcutaneously), MP + kaempferol (5 mg•kg•d, oral), and MP + human parathyroid 1-34 (30 µg/kg, 5 times/wk, subcutaneously) and treated for 4 wk. To study the antagonizing effect of kaempferol on GC-induced inhibition of fracture healing, drill-hole injury was performed on control and GC-treated rats. An oral dose of kaempferol was given for 14 d to observe the effect on callus formation at the site of injury. After treatment, bones were collected for further analysis. GC was associated with a decreased bone mineral density and impaired bone microarchitecture parameters. Consumption of kaempferol induced bone-sparing effects in GC-induced osteopenic condition. Additionally, improved callus formation at site of drill injury in femur diaphysis was observed with kaempferol consumption in animals on GC. Consistent with the in vivo data, kaempferol elicited a higher expression of osteogenic markers in vitro and antagonized the apoptotic effect of dexamethasone on calvarial osteoblasts. These results suggested that kaempferol reduced GC-induced bone loss and enhanced bone regeneration at fractured site, thus emphasizing the positive role of flavonoids on bone health. Copyright © 2018 Elsevier Inc. All rights reserved.

Relationship between plasma and tissue parameters of leucine metabolism

International Nuclear Information System (INIS)

Vazquez, J.A.; Paul, H.S.; Adibi, S.A.

1986-01-01

Using a primed continuous infusion of [1- 14 C] leucine, the authors investigated parameters of leucine metabolism in plasma, expired air, and tissues of fed and 48-hour starved rats. The ratios of muscle/plasma specific activity of α-ketoisocaproate (KIC) in fed and starved rats, respectively were not significantly different from one (1.07 +/- 0.14 and 0.97 +/- 0.10, mean +/- SE, 7 rats). The ratio of muscle/plasma specific activity of leucine was also not significantly different from one (0.86 +/- 0.11) in fed rats, but was significantly lower than one (0.80 +/- 0.07) in starved rats. The rate of leucine oxidation was approximately 32% higher when calculated based on plasma KIC rather than leucine specific activity. However, starvation significantly increased the rate of leucine oxidation with either specific activity. The rate of leucine incorporation into whole body protein was unaffected by starvation (32.7 +/- 3.5 vs 36.1 +/- 2.5 μmol/100 g/h), but the incorporation into total protein of liver (1350 +/- 140 vs 780 +/- 33 nmol) and of skeletal muscle (1940 +/- 220 vs 820 +/- 60 nmol) was significantly decreased. The authors conclude that a) leucine or KIC specific activity in muscle is better predicted by plasma KIC than leucine specific activity, and b) the tracer infusion technique is valid for the study of leucine oxidation but not for leucine incorporation into whole body protein

Protein and leucine metabolism in maple syrup urine disease

International Nuclear Information System (INIS)

Thompson, G.N.; Bresson, J.L.; Pacy, P.J.; Bonnefont, J.P.; Walter, J.H.; Leonard, J.V.; Saudubray, J.M.; Halliday, D.

1990-01-01

Constant infusions of [13C]leucine and [2H5]phenylalanine were used to trace leucine and protein kinetics, respectively, in seven children with maple syrup urine disease (MSUD) and eleven controls matched for age and dietary protein intake. Despite significant elevations of plasma leucine (mean 351 mumol/l, range 224-477) in MSUD subjects, mean whole body protein synthesis [3.78 +/- 0.42 (SD) g.kg-1. 24 h-1] and catabolism (4.07 +/- 0.46) were similar to control values (3.69 +/- 0.50 and 4.09 +/- 0.50, respectively). The relationship between phenylalanine and leucine fluxes was also similar in MSUD subjects (mean phenylalanine-leucine flux ratio 0.35 +/- 0.07) and previously reported adult controls (0.33 +/- 0.02). Leucine oxidation was undetectable in four of the MSUD subjects and very low in the other three (less than 4 mumol.kg-1.h-1; controls 13-20). These results show that persistent elevation in leucine concentration has no effect on protein synthesis. The marked disturbance in leucine metabolism in MSUD did not alter the relationship between rates of catabolism of protein to phenylalanine and leucine, which provides further support for the validity of the use of a single amino acid to trace whole body protein metabolism. The minimal leucine oxidation in MSUD differs from findings in other inborn metabolic errors and indicates that in patients with classical MSUD there is no significant route of leucine disposal other than through protein synthesis

Distinct cytoplasmic domains of the growth hormone receptor are required for glucocorticoid- and phorbol ester-induced decreases in growth hormone (GH) binding. These domains are different from that reported for GH-induced receptor internalization

DEFF Research Database (Denmark)

King, A P; Tseng, M J; Logsdon, C D

1996-01-01

Glucocorticoids inhibit growth in children and antagonize the growth-promoting action of GH in peripheral tissues. Recently, they have been shown to decrease GH binding. In this study we examine the molecular mechanisms by which the glucocorticoid dexamethasone (DEX) and the phorbol ester phorbol...... of GH binding are also observed in a Chinese hamster ovary (CHO) cell line stably transfected with a rat liver GHR cDNA, further arguing that DEX and PMA act post-translationally on GHR. Using mutant GHRs stably expressed in CHO cells, amino acids 455-506 and tyrosines 333 and/or 338 of GHR were shown...... to be required for maximal DEX-induced inhibition of GH binding. DEX decreased GH binding to a GHR mutant F346A, which is reported to be deficient in ligand-induced internalization, suggesting that DEX decreases GH binding by a mechanism distinct from that of ligand-induced GHR internalization. PMA reduced GH...

Glucocorticoids interact with the hippocampal endocannabinoid system in impairing retrieval of contextual fear memory

Science.gov (United States)

Atsak, Piray; Hauer, Daniela; Campolongo, Patrizia; Schelling, Gustav; McGaugh, James L.; Roozendaal, Benno

2012-01-01

There is extensive evidence that glucocorticoid hormones impair the retrieval of memory of emotionally arousing experiences. Although it is known that glucocorticoid effects on memory retrieval impairment depend on rapid interactions with arousal-induced noradrenergic activity, the exact mechanism underlying this presumably nongenomically mediated glucocorticoid action remains to be elucidated. Here, we show that the hippocampal endocannabinoid system, a rapidly activated retrograde messenger system, is involved in mediating glucocorticoid effects on retrieval of contextual fear memory. Systemic administration of corticosterone (0.3–3 mg/kg) to male Sprague–Dawley rats 1 h before retention testing impaired the retrieval of contextual fear memory without impairing the retrieval of auditory fear memory or directly affecting the expression of freezing behavior. Importantly, a blockade of hippocampal CB1 receptors with AM251 prevented the impairing effect of corticosterone on retrieval of contextual fear memory, whereas the same impairing dose of corticosterone increased hippocampal levels of the endocannabinoid 2-arachidonoylglycerol. We also found that antagonism of hippocampal β-adrenoceptor activity with local infusions of propranolol blocked the memory retrieval impairment induced by the CB receptor agonist WIN55,212–2. Thus, these findings strongly suggest that the endocannabinoid system plays an intermediary role in regulating rapid glucocorticoid effects on noradrenergic activity in impairing memory retrieval of emotionally arousing experiences. PMID:22331883

[Role of the Periaqueductal Gray Matter of the Midbrain in Regulation of Somatic Pain Sensitivity During Stress: Participation of Corticotropin-Releasing Factor and Glucocorticoid Hormones].

Science.gov (United States)

Yarushkina, N I; Filaretova, L P

2015-01-01

Periaqueductal gray matter of the midbrain (PAGM) plays a crucial role in the regulation of pain sensitivity under stress, involving in the stress-induced analgesia. A key hormonal system of adaptation under stress is the hypothalamic-pituitary-adrenocortical (HPA) axis. HPA axis's hormones, corticotropin-releasing factor (CRF) and glucocorticoids, are involved in stress-induced analgesia. Exogenous hormones of the HPA axis, similarly to the hormones produced under stress, may cause an analgesic effect. CRF-induced analgesia may be provided by glucocorticoid hormones. CRF and glucocorticoids-induced effects on somatic pain sensitivity may be mediated by PAGM. The aim of the review was to analyze the data of literature on the role of PAGM in the regulation of somatic pain sensitivity under stress and in providing of CRF and glucocorticoid-induced analgesia.

Microarray-based screening of differentially expressed genes in glucocorticoid-induced avascular necrosis

Science.gov (United States)

Huang, Gangyong; Wei, Yibing; Zhao, Guanglei; Xia, Jun; Wang, Siqun; Wu, Jianguo; Chen, Feiyan; Chen, Jie; Shi, Jingshen

2017-01-01

The underlying mechanisms of glucocorticoid (GC)-induced avascular necrosis of the femoral head (ANFH) have yet to be fully understood, in particular the mechanisms associated with the change of gene expression pattern. The present study aimed to identify key genes with a differential expression pattern in GC-induced ANFH. E-MEXP-2751 microarray data were downloaded from the ArrayExpress database. Differentially expressed genes (DEGs) were identified in 5 femoral head samples of steroid-induced ANFH rats compared with 5 placebo-treated rat samples. Gene Ontology (GO) and pathway enrichment analyses were performed upon these DEGs. A total 93 DEGs (46 upregulated and 47 downregulated genes) were identified in GC-induced ANFH samples. These DEGs were enriched in different GO terms and pathways, including chondrocyte differentiation and detection of chemical stimuli. The enrichment map revealed that skeletal system development was interconnected with several other GO terms by gene overlap. The literature mined network analysis revealed that 5 upregulated genes were associated with femoral necrosis, including parathyroid hormone receptor 1 (PTHR1), vitamin D (1,25-Dihydroxyvitamin D3) receptor (VDR), collagen, type II, α1, proprotein convertase subtilisin/kexin type 6 and zinc finger protein 354C (ZFP354C). In addition, ZFP354C and VDR were identified to transcription factors. Furthermore, PTHR1 was revealed to interact with VDR, and α-2-macroglobulin (A2M) interacted with fibronectin 1 (FN1) in the PPI network. PTHR1 may be involved in GC-induced ANFH via interacting with VDR. A2M may also be involved in the development of GC-induced ANFH through interacting with FN1. An improved understanding of the molecular mechanisms underlying GC-induced ANFH may provide novel targets for diagnostics and therapeutic treatment. PMID:28393228

Impact of glucocorticoid on neurogenesis

Directory of Open Access Journals (Sweden)

Haruki Odaka

2017-01-01

Full Text Available Neurogenesis is currently an area of great interest in neuroscience. It is closely linked to brain diseases, including mental disorders and neurodevelopmental disease. Both embryonic and adult neurogeneses are influenced by glucocorticoids secreted from the adrenal glands in response to a variety of stressors. Moreover, proliferation/differentiation of the neural stem/progenitor cells (NSPCs is affected by glucocorticoids through intracellular signaling pathways such as phosphoinositide 3-kinase (PI3K/Akt, hedgehog, and Wnt. Our review presents recent evidence of the impact of glucocorticoids on NSPC behaviors and the underlying molecular mechanisms; this provides important information for understanding the pathological role of glucocorticoids on neurogenesis-associated brain diseases.

DNA hybridization kinetics: zippering, internal displacement and sequence dependence.

Science.gov (United States)

Ouldridge, Thomas E; Sulc, Petr; Romano, Flavio; Doye, Jonathan P K; Louis, Ard A

2013-10-01

Although the thermodynamics of DNA hybridization is generally well established, the kinetics of this classic transition is less well understood. Providing such understanding has new urgency because DNA nanotechnology often depends critically on binding rates. Here, we explore DNA oligomer hybridization kinetics using a coarse-grained model. Strand association proceeds through a complex set of intermediate states, with successful binding events initiated by a few metastable base-pairing interactions, followed by zippering of the remaining bonds. But despite reasonably strong interstrand interactions, initial contacts frequently dissociate because typical configurations in which they form differ from typical states of similar enthalpy in the double-stranded equilibrium ensemble. Initial contacts must be stabilized by two or three base pairs before full zippering is likely, resulting in negative effective activation enthalpies. Non-Arrhenius behavior arises because the number of base pairs required for nucleation increases with temperature. In addition, we observe two alternative pathways-pseudoknot and inchworm internal displacement-through which misaligned duplexes can rearrange to form duplexes. These pathways accelerate hybridization. Our results explain why experimentally observed association rates of GC-rich oligomers are higher than rates of AT- rich equivalents, and more generally demonstrate how association rates can be modulated by sequence choice.

Synergistic effects of leucine and resveratrol on insulin sensitivity and fat metabolism in adipocytes and mice

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Bruckbauer Antje

2012-08-01

Full Text Available Abstract Background Sirtuins are important regulators of glucose and fat metabolism, and sirtuin activation has been proposed as a therapeutic target for insulin resistance and diabetes. We have shown leucine to increase mitochondrial biogenesis and fat oxidation via Sirt1 dependent pathways. Resveratrol is a widely recognized activator of Sirt; however, the biologically-effective high concentrations used in cell and animal studies are generally impractical or difficult to achieve in humans. Accordingly, we sought to determine whether leucine would exhibit synergy with low levels of resveratrol on sirtuin-dependent outcomes in adipocytes and in diet-induced obese (DIO mice. Methods 3T3-L1 mouse adipocytes were treated with Leucine (0.5 mM, β-hydroxy-β-methyl butyrate (HMB (5 μM or Resveratrol (200 nM alone or in combination. In addition, diet-induced obese mice were treated for 6-weeks with low (2 g/kg diet or high (10 g/kg diet dose HMB, Leucine (24 g/kg diet; 200% of normal level or low (12.5 mg/kg diet or high (225 mg/kg diet dose resveratrol, alone or as combination with leucine-resveratrol or HMB-resveratrol. Results Fatty acid oxidation, AMPK, Sirt1 and Sirt3 activity in 3T3-L1 adipocytes and in muscle cells, were significantly increased by the combinations compared to the individual treatments. Similarly, 6-week feeding of low-dose resveratrol combined with either leucine or its metabolite HMB to DIO mice increased adipose Sirt1 activity, muscle glucose and palmitate uptake (measured via PET/CT, insulin sensitivity (HOMAIR, improved inflammatory stress biomarkers (CRP, IL-6, MCP-1, adiponectin and reduced adiposity comparable to the effects of high dose resveratrol, while low-dose resveratrol exerted no independent effect. Conclusion These data demonstrate that either leucine or its metabolite HMB may be combined with a low concentration of resveratrol to exert synergistic effects on Sirt1-dependent outcomes; this may result in more

Glucocorticoids Inhibit Basal and Hormone-Induced Serotonin Synthesis in Pancreatic Beta Cells.

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Moina Hasni Ebou

Full Text Available Diabetes is a major complication of chronic Glucocorticoids (GCs treatment. GCs induce insulin resistance and also inhibit insulin secretion from pancreatic beta cells. Yet, a full understanding of this negative regulation remains to be deciphered. In the present study, we investigated whether GCs could inhibit serotonin synthesis in beta cell since this neurotransmitter has been shown to be involved in the regulation of insulin secretion. To this aim, serotonin synthesis was evaluated in vitro after treatment with GCs of either islets from CD1 mice or MIN6 cells, a beta-cell line. We also explored the effect of GCs on the stimulation of serotonin synthesis by several hormones such as prolactin and GLP 1. We finally studied this regulation in islet in two in vivo models: mice treated with GCs and with liraglutide, a GLP1 analog, and mice deleted for the glucocorticoid receptor in the pancreas. We showed in isolated islets and MIN6 cells that GCs decreased expression and activity of the two key enzymes of serotonin synthesis, Tryptophan Hydroxylase 1 (Tph1 and 2 (Tph2, leading to reduced serotonin contents. GCs also blocked the induction of serotonin synthesis by prolactin or by a previously unknown serotonin activator, the GLP-1 analog exendin-4. In vivo, activation of the Glucagon-like-Peptide-1 receptor with liraglutide during 4 weeks increased islet serotonin contents and GCs treatment prevented this increase. Finally, islets from mice deleted for the GR in the pancreas displayed an increased expression of Tph1 and Tph2 and a strong increased serotonin content per islet. In conclusion, our results demonstrate an original inhibition of serotonin synthesis by GCs, both in basal condition and after stimulation by prolactin or activators of the GLP-1 receptor. This regulation may contribute to the deleterious effects of GCs on beta cells.

The Ste20 Family Kinases MAP4K4, MINK1, and TNIK Converge to Regulate Stress-Induced JNK Signaling in Neurons.

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Larhammar, Martin; Huntwork-Rodriguez, Sarah; Rudhard, York; Sengupta-Ghosh, Arundhati; Lewcock, Joseph W

2017-11-15

The c-Jun- N -terminal kinase (JNK) signaling pathway regulates nervous system development, axon regeneration, and neuronal degeneration after acute injury or in chronic neurodegenerative disease. Dual leucine zipper kinase (DLK) is required for stress-induced JNK signaling in neurons, yet the factors that initiate DLK/JNK pathway activity remain poorly defined. In the present study, we identify the Ste20 kinases MAP4K4, misshapen-like kinase 1 (MINK1 or MAP4K6) and TNIK Traf2- and Nck-interacting kinase (TNIK or MAP4K7), as upstream regulators of DLK/JNK signaling in neurons. Using a trophic factor withdrawal-based model of neurodegeneration in both male and female embryonic mouse dorsal root ganglion neurons, we show that MAP4K4, MINK1, and TNIK act redundantly to regulate DLK activation and downstream JNK-dependent phosphorylation of c-Jun in response to stress. Targeting MAP4K4, MINK1, and TNIK, but not any of these kinases individually, is sufficient to protect neurons potently from degeneration. Pharmacological inhibition of MAP4Ks blocks stabilization and phosphorylation of DLK within axons and subsequent retrograde translocation of the JNK signaling complex to the nucleus. These results position MAP4Ks as important regulators of the DLK/JNK signaling pathway. SIGNIFICANCE STATEMENT Neuronal degeneration occurs in disparate circumstances: during development to refine neuronal connections, after injury to clear damaged neurons, or pathologically during disease. The dual leucine zipper kinase (DLK)/c-Jun- N -terminal kinase (JNK) pathway represents a conserved regulator of neuronal injury signaling that drives both neurodegeneration and axon regeneration, yet little is known about the factors that initiate DLK activity. Here, we uncover a novel role for a subfamily of MAP4 kinases consisting of MAP4K4, Traf2- and Nck-interacting kinase (TNIK or MAP4K7), and misshapen-like kinase 1 (MINK1 or MAP4K6) in regulating DLK/JNK signaling in neurons. Inhibition of

NALP3 inflammasome upregulation and CASP1 cleavage of the glucocorticoid receptor cause glucocorticoid resistance in leukemia cells

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S.W. Paugh (Steven); E.J. Bonten (Erik J.); D. Savic (Daniel); L.B. Ramsey (Laura B.); W.E. Thierfelder (William E.); P. Gurung (Prajwal); R.K.S. Malireddi (R. K. Subbarao); M. Actis (Marcelo); A. Mayasundari (Anand); J. Min (Jaeki); D.R. Coss (David R.); L.T. Laudermilk (Lucas T.); J.C. Panetta (John); J.R. McCorkle (J. Robert); Y. Fan (Yiping); K.R. Crews (Kristine R.); G. Stocco (Gabriele); M.R. Wilkinson (Mark R.); A.M. Ferreira (Antonio M.); C. Cheng (Cheng); W. Yang (Wenjian); S.E. Karol (Seth E.); C.A. Fernandez (Christian A.); B. Diouf (Barthelemy); C. Smith (Colton); J.K. Hicks (J Kevin); A. Zanut (Alessandra); A. Giordanengo (Audrey); D.J. Crona; J.J. Bianchi (Joy J.); L. Holmfeldt (Linda); C.G. Mullighan (Charles); M.L. den Boer (Monique); R. Pieters (Rob); S. Jeha (Sima); T.L. Dunwell (Thomas L.); F. Latif (Farida); D. Bhojwani (Deepa); W.L. Carroll (William L.); C.-H. Pui (Ching-Hon); R.M. Myers (Richard M.); R.K. Guy (R Kiplin); T.-D. Kanneganti (Thirumala-Devi); M.V. Relling (Mary); W.E. Evans (William)

2015-01-01

textabstractGlucocorticoids are universally used in the treatment of acute lymphoblastic leukemia (ALL), and resistance to glucocorticoids in leukemia cells confers poor prognosis. To elucidate mechanisms of glucocorticoid resistance, we determined the prednisolone sensitivity of primary leukemia

Efficacy of Vitamin K2 for Glucocorticoid-induced Osteoporosis in Patients with Systemic Autoimmune Diseases.

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Shikano, Kotaro; Kaneko, Kaichi; Kawazoe, Mai; Kaburaki, Makoto; Hasunuma, Tomoko; Kawai, Shinichi

2016-01-01

Objective Vitamin K2 (menatetrenone) is an effective treatment for patients with postmenopausal osteoporosis. We herein performed a subanalysis of patients with systemic autoimmune diseases undergoing glucocorticoid therapy in our previous prospective study. Methods Sixty patients were categorized into a group with vitamin K2 treatment (n=20, Group A) and a group without vitamin K2 treatment (n=40, Group B). All patients were treated with bisphosphonates. Results Serum levels of osteocalcin and undercarboxylated osteocalcin decreased significantly after the start of glucocorticoid therapy in both groups, while the serum osteocalcin level was significantly higher in Group A than Group B during the third (p=0.0250) and fourth weeks (p=0.0155). The serum level of the N-terminal peptide of type I procollagen, a bone formation marker, decreased during glucocorticoid therapy, but was significantly higher in Group A than Group B during the fourth week (p=0.0400). The bone mineral density and fracture rate showed no significant differences between the two groups. Conclusion Although vitamin K2 improves bone turnover markers in patients with osteoporosis on glucocorticoid therapy, it has no significant effect on the bone mineral density and fracture rate after 1.5 years of treatment.

[Effect of glucocorticoides on the release of amino acids in the perfused rat hindquarter (author's transl)].

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Thienhaus, R; Tharandt, L; Zais, U; Staib, W

1975-06-01

The release of amino acids by skeletal muscle was studied in the isolated perfused rat hindquarter. Adrenalectomy depressed the formation of glutamine and alanine as well as the efflux of all other amino acids measured. Betamethasone--a synthetic glucocorticoid--caused a significant increase in the efflux of nearly all amino acids up to the level of normal controls. The release of amino acids was also increased in perfused hindquarters of diabetic rats. On the other hand, insulin exhibited a depressing effect on the release of amino acids by hindquarters of normal rats. The metabolic integrity of the muscle tissue was proved by measuring creatine phosphate, ATP, ADP and water content as well as by the significant insulin effect on glucose uptake and on [14C]leucine incorporation into muscle proteins.

Glucocorticoid receptor signaling in health and disease

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Kadmiel, Mahita; Cidlowski, John A.

2013-01-01

Glucocorticoids are steroid hormones regulated in a circadian and stres-associated manner to maintain various metabolic and homeostatic functions that are necessary for life. Synthetic glucocorticoids are widely prescribed drugs for many conditions including asthma, chronic obstructive pulmonary disease (COPD), and inflammatory disorders of the eye. Research in the last few years has begun to unravel the profound complexity of glucocorticoid signaling and has contributed remarkably to improved therapeutic strategies. Glucocorticoids signal through the glucocorticoid receptor, a member of the superfamily of nuclear receptors, in both genomic and non-genomic ways in almost every tissue in the human body. In this review, we will provide an update on glucocorticoid receptor signaling and highlight the role of GR signaling in physiological and pathophysiological conditions in the major organ systems in the human body. PMID:23953592

Effect of a Herbal-Leucine mix on the IL-1β-induced cartilage degradation and inflammatory gene expression in human chondrocytes

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Haqqi Tariq M

2011-08-01

Full Text Available Abstract Background Conventional treatments for the articular diseases are often effective for symptom relief, but can also cause significant side effects and do not slow the progression of the disease. Several natural substances have been shown to be effective at relieving the symptoms of osteoarthritis (OA, and preliminary evidence suggests that some of these compounds may exert a favorable influence on the course of the disease. The objective of this study was to investigate the anti-inflammatory/chondroprotective potential of a Herbal and amino acid mixture containing extract of the Uncaria tomentosa, Boswellia spp., Lepidium meyenii and L-Leucine on the IL-1β-induced production of nitric oxide (NO, glycosaminoglycan (GAG, matrix metalloproteinases (MMPs, aggrecan (ACAN and type II collagen (COL2A1 in human OA chondrocytes and OA cartilage explants. Methods Primary OA chondrocytes or OA cartilage explants were pretreated with Herbal-Leucine mixture (HLM, 1-10 μg/ml and then stimulated with IL-1β (5 ng/ml. Effect of HLM on IL-1β-induced gene expression of iNOS, MMP-9, MMP-13, ACAN and COL2A1 was verified by real time-PCR. Estimation of NO and GAG release in culture supernatant was done using commercially available kits. Results HLM tested in these in vitro studies was found to be an effective anti-inflammatory agent, as evidenced by strong inhibition of iNOS, MMP-9 and MMP-13 expression and NO production in IL-1β-stimulated OA chondrocytes (p Leucine mixture (HLM up-regulation of ACAN and COL2A1 expression in IL-1β-stimulated OA chondrocytes was also noted (p Conclusion Our data suggests that HLM could be chondroprotective and anti-inflammatory agent in arthritis, switching chondrocyte gene expression from catabolic direction towards anabolic and regenerative, and consequently this approach may be potentially useful as a new adjunct therapeutic/preventive agent for OA or injury recovery.

Chronic leucine supplementation improves glycemic control in etiologically distinct mouse models of obesity and diabetes mellitus

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Hou Jue

2010-07-01

Full Text Available Abstract Background Leucine may function as a signaling molecule to regulate metabolism. We have previously shown that dietary leucine supplementation significantly improves glucose and energy metabolism in diet-induced obese mice, suggesting that leucine supplementation could potentially be a useful adjuvant therapy for obesity and type 2 diabetes. Since the underlying cause for obesity and type 2 diabetes is multifold, we further investigated metabolic effects of leucine supplementation in obese/diabetes mouse models with different etiologies, and explored the underlying molecular mechanisms. Methods Leucine supplementation was carried out in NONcNZO10/LtJ (RCS10 - a polygenic model predisposed to beta cell failure and type 2 diabetes, and in B6.Cg-Ay/J (Ay - a monogenic model for impaired central melanocortin receptor signaling, obesity, and severe insulin resistance. Mice in the treatment group received the drinking water containing 1.5% leucine for up to 8 months; control mice received the tap water. Body weight, body composition, blood HbA1c levels, and plasma glucose and insulin levels were monitored throughout and/or at the end of the study period. Indirect calorimetry, skeletal muscle gene expression, and adipose tissue inflammation were also assessed in Ay mice. Results Leucine supplementation significantly reduced HbA1c levels throughout the study period in both RCS10 and Ay mice. However, the treatment had no long term effect on body weight or adiposity. The improvement in glycemic control was associated with an increased insulin response to food challenge in RCS10 mice and decreased plasma insulin levels in Ay mice. In leucine-treated Ay mice, energy expenditure was increased by ~10% (p y mice whereas the expression levels of MCP-1 and TNF-alpha and macrophage infiltration in adipose tissue were significantly reduced. Conclusions Chronic leucine supplementation significantly improves glycemic control in multiple mouse models of

Optimal glucocorticoid replacement in adrenal insufficiency.

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Øksnes, Marianne; Ross, Richard; Løvås, Kristian

2015-01-01

Adrenal insufficiency (glucocorticoid deficiency) comprises a group of rare diseases, including primary adrenal insufficiency, secondary adrenal insufficiency and congenital adrenal hyperplasia. Lifesaving glucocorticoid therapy was introduced over 60 years ago, but since then a number of advances in treatment have taken place. Specifically, little is known about short- and long-term treatment effects, and morbidity and mortality. Over the past decade, systematic cohort and registry studies have described reduced health-related quality of life, an unfavourable metabolic profile and increased mortality in patients with adrenal insufficiency, which may relate to unphysiological glucocorticoid replacement. This has led to the development of new modes of replacement that aim to mimic normal glucocorticoid physiology. Here, evidence for the inadequacy of conventional glucocorticoid therapy and recent developments in treatment are reviewed, with an emphasis on primary adrenal insufficiency. Copyright © 2014 Elsevier Ltd. All rights reserved.

Anabolic effects of leucine-rich whey protein, carbohydrate, and soy protein with and without β-hydroxy-β-methylbutyrate (HMB) during fasting-induced catabolism: A human randomized crossover trial.

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Rittig, Nikolaj; Bach, Ermina; Thomsen, Henrik H; Møller, Andreas B; Hansen, Jakob; Johannsen, Mogens; Jensen, Erik; Serena, Anja; Jørgensen, Jens O; Richelsen, Bjørn; Jessen, Niels; Møller, Niels

2017-06-01

Protein-rich beverages are widely used clinically to preserve muscle protein and improve physical performance. Beverages with high contents of leucine or its keto-metabolite β-hydroxy-β-methylbutyrate (HMB) are especially anabolic in muscle, but it is uncertain whether this also applies to catabolic conditions such as fasting and whether common or separate intracellular signaling cascades are involved. To compare a specific leucine-rich whey protein beverage (LWH) with isocaloric carbohydrate- (CHO), soy protein (SOY), and soy protein +3 g HMB (HMB) during fasting-induced catabolic conditions. Eight healthy lean male subjects underwent four interventions (LWH, CHO, SOY, and HMB) using a randomized crossover design. Each trial included a 36 h fast and consisted of a 3 h basal fasting period and a 4 h 'sipping' period. Forearm net balances of phenylalanine (NB phe , measure of net protein loss) improved for all groups (p HMB compared with SOY (p HMB have superior anabolic effects on muscle protein kinetics after 36 h of fasting, and LWH distinctly activates the mTOR pathway. These novel findings suggest that leucine-rich whey protein and/or HMB are specifically beneficial during fasting-induced catabolic conditions. Copyright © 2016 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Overexpression and characterization of an extracellular leucine aminopeptidase from Aspergillus oryzae.

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Matsushita-Morita, Mayumi; Tada, Sawaki; Suzuki, Satoshi; Hattori, Ryota; Marui, Junichiro; Furukawa, Ikuyo; Yamagata, Youhei; Amano, Hitoshi; Ishida, Hiroki; Takeuchi, Michio; Kashiwagi, Yutaka; Kusumoto, Ken-Ichi

2011-02-01

Leucine aminopeptidase (LAP), an enzyme used in the food industry, is an exopeptidase that removes an amino acid residue, primarily leucine (Leu), from the N-terminus of peptides and protein substrates. In this study, we focused on the leucine aminopeptidase A (lapA) gene from Aspergillus oryzae RIB40. To purify and characterize the LapA, lapA was overexpressed in A. oryzae RIB40 using the amyB promoter. LAP activity in the culture supernatant of one transformant harboring the lapA expression plasmid was 33 times that of the host strain. LapA was purified from the culture supernatant of this lapA-overexpressing strain by column chromatography. The purified recombinant LapA had a molecular mass of 33 kDa, and its N-terminal amino acid was the tyrosine at position 80 of the deduced amino acid sequence. Optimal enzyme activity was observed at 60°C and pH 8.5, and the enzyme was stable at temperatures up to 60°C and in the pH range 7.5-11. In transcriptional analysis, lapA was induced under alkaline conditions and expressed at a relatively low level under normal conditions. LapA showed maximum hydrolyzing activity for the substrate leucine para-nitroanilide (Leu-pNA), followed by substrates Phe-pNA (39% activity compared with Leu-pNA), Met-pNA, Lys-pNA, and Arg-pNA. In addition, LapA preferentially hydrolyzed peptides longer than tripeptides.

Kidney tissue targeted metabolic profiling of glucocorticoid-induced osteoporosis and the proposed therapeutic effects of Rhizoma Drynariae studied using UHPLC/MS/MS.

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Huang, Yue; Liu, Xinyu; Zhao, Longshan; Li, Famei; Xiong, Zhili

2014-06-01

Traditional Chinese medicine and modern science have indicated that there is a close relationship between bone and kidney. In light of this, this project was designed to study the metabolic profiling by UHPLC/MS/MS of glucocorticoid-induced osteoporosis in kidney tissue and the possible therapeutic effects of Rhizoma Drynariae (RD), a classic traditional Chinese medicine, in improving the kidney function and strengthening bone. Twenty-one Wistar rats were divided into three groups: control group (rats before prednisolone inducing), a model group (prednisolone-induced group) and a treatment group (prednisolone-induced rats that were then administered RD ethanol extracts). By using pattern recognition analysis, a significant change in the metabolic profile of kidney tissue samples was observed in the model group and restoration of the profile was observed after the administration of RD ethanol extracts. Some significantly changed biomarkers related to osteoporosis such as sphingolipids (C16 dihydrosphingosine, C18 dihydrosphingosine, C18 phytosphingosine, C20 phytosphingosine), lysophosphatidycholines (C16:0 LPC, C18:0 LPC) and phenylalanine were identified. As a complement to the metabolic profiling of RD in plasma, these biomarkers suggest that kidney damage, cell cytotoxicity and apoptosis exist in osteoporosis rats, which is helpful in further understanding the underlying process of glucocorticoid-induced osetoporosis and the suggested therapeutic effects of RD. The method shows that tissue target metabonomics might provide a powerful tool to further understand the process of disease and the mechanism of therapeutic effect of Chinese medicines. Copyright © 2014 John Wiley & Sons, Ltd.

Corticosterone induces rapid spinogenesis via synaptic glucocorticoid receptors and kinase networks in hippocampus.

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Yoshimasa Komatsuzaki

Full Text Available BACKGROUND: Modulation of dendritic spines under acute stress is attracting much attention. Exposure to acute stress induces corticosterone (CORT secretion from the adrenal cortex, resulting in rapid increase of CORT levels in plasma and the hippocampus. METHODOLOGY/PRINCIPAL FINDINGS: Here we demonstrated the mechanisms of rapid effect (∼1 h of CORT on the density and morphology of spines by imaging neurons in adult male rat hippocampal slices. The application of CORT at 100-1000 nM induced a rapid increase in the density of spines of CA1 pyramidal neurons. The density of small-head spines (0.2-0.4 µm was increased even at low CORT levels (100-200 nM. The density of middle-head spines (0.4-0.5 µm was increased at high CORT levels between 400-1000 nM. The density of large-head spines (0.5-1.0 µm was increased only at 1000 nM CORT. Co-administration of RU486, an antagonist of glucocorticoid receptor (GR, abolished the effect of CORT. Blocking a single kinase, such as MAPK, PKA, PKC or PI3K, suppressed CORT-induced enhancement of spinogenesis. Blocking NMDA receptors suppressed the CORT effect. CONCLUSIONS/SIGNIFICANCE: These results imply that stress levels of CORT (100-1000 nM drive the spinogenesis via synaptic GR and multiple kinase pathways.

Additive insulinogenic action of Opuntia ficus-indica cladode and fruit skin extract and leucine after exercise in healthy males

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2013-01-01

Background Oral intake of a specific extract of Opuntia ficus-indica cladode and fruit skin (OpunDia™) (OFI) has been shown to increase serum insulin concentration while reducing blood glucose level for a given amount of glucose ingestion after an endurance exercise bout in healthy young volunteers. However, it is unknown whether OFI-induced insulin stimulation after exercise is of the same magnitude than the stimulation by other insulinogenic agents like leucine as well as whether OFI can interact with those agents. Therefore, the aims of the present study were: 1) to compare the degree of insulin stimulation by OFI with the effect of leucine administration; 2) to determine whether OFI and leucine have an additive action on insulin stimulation post-exercise. Methods Eleven subjects participated in a randomized double-blind cross-over study involving four experimental sessions. In each session the subjects successively underwent a 2-h oral glucose tolerance test (OGTT) after a 30-min cycling bout at ~70% VO2max. At t0 and t60 during the OGTT, subjects ingested 75 g glucose and capsules containing either 1) a placebo; 2) 1000 mg OFI; 3) 3 g leucine; 4) 1000 mg OFI + 3 g leucine. Blood samples were collected before and at 30-min intervals during the OGTT for determination of blood glucose and serum insulin. Results Whereas no effect of leucine was measured, OFI reduced blood glucose at t90 by ~7% and the area under the glucose curve by ~15% and increased serum insulin concentration at t90 by ~35% compared to placebo (P<0.05). From t60 to the end of the OGTT, serum insulin concentration was higher in OFI+leucine than in placebo which resulted in a higher area under the insulin curve (+40%, P<0.05). Conclusion Carbohydrate-induced insulin stimulation post-exercise can be further increased by the combination of OFI with leucine. OFI and leucine could be interesting ingredients to include together in recovery drinks to resynthesize muscle glycogen faster post

The effects of glucocorticoid on microarchitecture, collagen, mineral and mechanical properties of sheep femur cortical bone

DEFF Research Database (Denmark)

Ding, Ming; Danielsen, Carl C; Overgaard, Søren

2010-01-01

The effects of glucocorticoid on microarchitecture, collagen, mineral and mechanical properties of sheep femur cortical bone – Validation of large animal model for tissue engineering and biomaterial research Ming Ding,1* Carl Christian Danielsen,2 Søren Overgaard1 1Orthopaedic Research Laboratory......, Department of Orthopaedics and Traumatology, Odense University Hospital, Institute of Clinical Research, University of Southern Denmark, Odense C, Denmark 2Department of Connective Tissue Biology, Institute of Anatomy, University of Aarhus, Aarhus C, Denmark Osteopenia in sheep has been successfully induced...... by glucocorticoid treatment and the changes in properties of cancellous bone were comparable with those observed in humans after long-term glucocorticoid treatment. However, the influence on cortical bone has not been thoroughly elucidated. This study aimed to investigate the influence of glucocorticoid on sheep...

Sex-Specificity of Mineralocorticoid Target Gene Expression during Renal Development, and Long-Term Consequences

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Dumeige, Laurence; Storey, Caroline; Decourtye, Lyvianne; Nehlich, Melanie; Lhadj, Christophe; Viengchareun, Say; Kappeler, Laurent; Lombès, Marc; Martinerie, Laetitia

2017-01-01

Sex differences have been identified in various biological processes, including hypertension. The mineralocorticoid signaling pathway is an important contributor to early arterial hypertension, however its sex-specific expression has been scarcely studied, particularly with respect to the kidney. Basal systolic blood pressure (SBP) and heart rate (HR) were measured in adult male and female mice. Renal gene expression studies of major players of mineralocorticoid signaling were performed at different developmental stages in male and female mice using reverse transcription quantitative PCR (RT-qPCR), and were compared to those of the same genes in the lung, another mineralocorticoid epithelial target tissue that regulates ion exchange and electrolyte balance. The role of sex hormones in the regulation of these genes was also investigated in differentiated KC3AC1 renal cells. Additionally, renal expression of the 11 β-hydroxysteroid dehydrogenase type 2 (11βHSD2) protein, a regulator of mineralocorticoid specificity, was measured by immunoblotting and its activity was indirectly assessed in the plasma using liquid-chromatography coupled to mass spectrometry in tandem (LC-MSMS) method. SBP and HR were found to be significantly lower in females compared to males. This was accompanied by a sex- and tissue-specific expression profile throughout renal development of the mineralocorticoid target genes serum and glucocorticoid-regulated kinase 1 (Sgk1) and glucocorticoid-induced leucine zipper protein (Gilz), together with Hsd11b2, Finally, the implication of sex hormones in this sex-specific expression profile was demonstrated in vitro, most notably for Gilz mRNA expression. We demonstrate a tissue-specific, sex-dependent and developmentally-regulated pattern of expression of the mineralocorticoid pathway that could have important implications in physiology and pathology. PMID:28230786

Leucine stimulation of skeletal muscle protein synthesis

International Nuclear Information System (INIS)

Layman, D.K.; Grogan, C.K.

1986-01-01

Previous work in this laboratory has demonstrated a stimulatory effect of leucine on skeletal muscle protein synthesis measured in vitro during catabolic conditions. Studies in other laboratories have consistently found this effect in diaphragm muscle, however, studies examining effects on nitrogen balance or with in vivo protein synthesis in skeletal muscle are equivocal. This experiment was designed to determine the potential of leucine to stimulate skeletal muscle protein synthesis in vivo. Male Sprague-Dawley rats weighing 200 g were fasted for 12 hrs, anesthetized, a jugular cannula inserted, and protein synthesis measured using a primed continuous infusion of 14 C-tyrosine. A plateau in specific activity was reached after 30 to 60 min and maintained for 3 hrs. The leucine dose consisted of a 240 umole priming dose followed by a continuous infusion of 160 umoles/hr. Leucine infusion stimulated protein synthesis in the soleus muscle (28%) and in the red (28%) and white portions (12%) of the gastrocnemius muscle compared with controls infused with only tyrosine. The increased rates of protein synthesis were due to increased incorporation of tyrosine into protein and to decreased specific activity of the free tyrosine pool. These data indicate that infusion of leucine has the potential to stimulate in vivo protein synthesis in skeletal muscles

Regulation of NAD(P)H:quininone oxidoreductase by glucocorticoids

International Nuclear Information System (INIS)

Pinaire, J.A.; Xiao, G.-H.; Falkner, K.C.; Prough, R.A.

2004-01-01

Previous studies in neonatal and adolescent rats as well as adrenalectomized rats have demonstrated that glucocorticoids regulate the expression of the rat NAD(P)H:quinone oxidoreductase gene (QOR). We used primary cultures of rat adult hepatocytes to document that added glucorticoids repress both the basal and 1,2-benzanthracene-induced expression of QOR mRNA by 65-70%. QOR enzyme activity and protein were concomitantly suppressed as well. The monotonic concentration response for repression of QOR gene products up to 100 μM DEX concentration demonstrated that the glucocorticoid receptor (GR) was most likely involved in this process. The lack of effect at higher concentration rules out a role for the Pregnane X receptor in this regulation by DEX. In addition, the anti-glucorticoid RU38486 blocked this negative regulation and the protein synthesis inhibitor cycloheximide had no effect on this repression process. Similar results of GR dependence were observed using a luciferase reporter construct containing the 5'-flanking region of the human QOR gene using HepG2 cells. Collectively, these results demonstrate that GR must directly participate in the negative regulation of QOR gene expression by dexamethasone and other glucocorticoids in vivo

Interaction between leucine and phosphodiesterase 5 inhibition in modulating insulin sensitivity and lipid metabolism

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Fu L

2015-05-01

Full Text Available Lizhi Fu,1 Fenfen Li,1 Antje Bruckbauer,2 Qiang Cao,1 Xin Cui,1 Rui Wu,1 Hang Shi,1 Bingzhong Xue,1 Michael B Zemel21Department of Biology, Center for Obesity Reversal, Georgia State University, Atlanta, GA, 2NuSirt Biopharma Inc., Nashville, TN, USA Purpose: Leucine activates SIRT1/AMP-activated protein kinase (AMPK signaling and markedly potentiates the effects of other sirtuin and AMPK activators on insulin signaling and lipid metabolism. Phosphodiesterase 5 inhibition increases nitric oxide–cGMP signaling, which in turn exhibits a positive feedback loop with both SIRT1 and AMPK, thus amplifying peroxisome proliferator-activated receptor γ co-activator α (PGC1α-mediated effects. Methods: We evaluated potential synergy between leucine and PDE5i on insulin sensitivity and lipid metabolism in vitro and in diet-induced obese (DIO mice. Results: Leucine (0.5 mM exhibited significant synergy with subtherapeutic doses (0.1–10 nM of PDE5-inhibitors (sildenafil and icariin on fat oxidation, nitric oxide production, and mitochondrial biogenesis in hepatocytes, adipocytes, and myotubes. Effects on insulin sensitivity, glycemic control, and lipid metabolism were then assessed in DIO-mice. DIO-mice exhibited fasting and postprandial hyperglycemia, insulin resistance, and hepatic steatosis, which were not affected by the addition of leucine (24 g/kg diet. However, the combination of leucine and a subtherapeutic dose of icariin (25 mg/kg diet for 6 weeks reduced fasting glucose (38%, P<0.002, insulin (37%, P<0.05, area under the glucose tolerance curve (20%, P<0.01, and fully restored glucose response to exogenous insulin challenge. The combination also inhibited hepatic lipogenesis, stimulated hepatic and muscle fatty acid oxidation, suppressed hepatic inflammation, and reversed high-fat diet-induced steatosis. Conclusion: These robust improvements in insulin sensitivity, glycemic control, and lipid metabolism indicate therapeutic potential for

Role of the hinge region of glucocorticoid receptor for HEXIM1-mediated transcriptional repression

International Nuclear Information System (INIS)

Yoshikawa, Noritada; Shimizu, Noriaki; Sano, Motoaki; Ohnuma, Kei; Iwata, Satoshi; Hosono, Osamu; Fukuda, Keiichi; Morimoto, Chikao

2008-01-01

We previously reported that HEXIM1 (hexamethylene bisacetamide-inducible protein 1), which suppresses transcription elongation via sequestration of positive transcription elongation factor b (P-TEFb) using 7SK RNA as a scaffold, directly associates with glucocorticoid receptor (GR) to suppress glucocorticoid-inducible gene activation. Here, we revealed that the hinge region of GR is essential for its interaction with HEXIM1, and that oxosteroid receptors including GR show sequence homology in their hinge region and interact with HEXIM1, whereas the other members of nuclear receptors do not. We also showed that HEXIM1 suppresses GR-mediated transcription in two ways: sequestration of P-TEFb by HEXIM1 and direct interaction between GR and HEXIM1. In contrast, peroxisome proliferator-activated receptor γ-dependent gene expression is negatively modulated by HEXIM1 solely via sequestration of P-TEFb. We, therefore, conclude that HEXIM1 may act as a gene-selective transcriptional regulator via direct interaction with certain transcriptional regulators including GR and contribute to fine-tuning of, for example, glucocorticoid-mediated biological responses

Behavioral neuroadaptation to alcohol : from glucocorticoids to histone acetylation

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Daniel Beracochea

2016-10-01

Full Text Available A prime mechanism that contributes to the development and maintenance of alcoholism is the dysregulation of the hypothalamic-pituitary-adrenal (HPA axis activity and the release of glucocorticoids (cortisol in humans and primates, corticosterone in rodents from the adrenal glands. In the brain, sustained, local elevation of glucocorticoid concentration even long after cessation of chronic alcohol consumption compromises functional integrity of a circuit including the prefrontal cortex, the hippocampus and the amygdala. These structures are implicated in learning and memory processes as well as in orchestrating neuroadaptive responses to stress and anxiety responses. Thus, potentiation of anxiety-related neuroadaptation by alcohol is characterized by an abnormally amygdala hyperactivity coupled with a hypofunction of the prefrontal cortex and the hippocampus. This review describes research on molecular and epigenetic mechanisms by which alcohol causes distinct region-specific adaptive changes in gene expression patterns and ultimately, leads to a variety of cognitive and behavioral impairments on prefrontal- and hippocampal-based tasks. Alcohol-induced neuroadaptations involve the dysregulation of numerous signaling cascades, leading to long-term changes in transcriptional profiles of genes, through the actions of transcription factors such as CREB (cAMP response element binding protein and chromatin remodeling due to post-translational modifications of histone proteins. We describe the role of prefrontal-hippocampus-amygdala circuit in mediating the effects of acute and chronic alcohol on learning and memory, and region-specific molecular and epigenetic mechanisms involved in this process. This review first discusses the importance of brain region-specific dysregulation of glucocorticoid concentration in the development of alcohol dependence and describes on how persistently increased glucocorticoid levels in prefrontal cortex may be involved in

Fine-tuning of T-cell development by the CD3γ di-leucine-based TCR-sorting motif

DEFF Research Database (Denmark)

Lauritsen, Jens Peter Holst; Boding, Lasse; Buus, Terkild B

2015-01-01

The CD3γ di-leucine-based (diL) receptor-sorting motif plays a central role in TCR down-regulation and in clonal expansion of virus-specific T cells. However, the role of the CD3γ diL motif in T-cell development is not known. In this study, we show that protein kinase C-induced TCR down-regulatio......The CD3γ di-leucine-based (diL) receptor-sorting motif plays a central role in TCR down-regulation and in clonal expansion of virus-specific T cells. However, the role of the CD3γ diL motif in T-cell development is not known. In this study, we show that protein kinase C-induced TCR down...

The aryl hydrocarbon receptor and glucocorticoid receptor interact to activate human metallothionein 2A

Energy Technology Data Exchange (ETDEWEB)

Sato, Shoko, E-mail: satosho@rs.tus.ac.jp [Laboratory of Nutrition, Graduate School of Agricultural Science, Tohoku University, Sendai 981-8555 (Japan); Shirakawa, Hitoshi, E-mail: shirakah@m.tohoku.ac.jp [Laboratory of Nutrition, Graduate School of Agricultural Science, Tohoku University, Sendai 981-8555 (Japan); Tomita, Shuhei, E-mail: tomita@med.tottori-u.ac.jp [Division of Molecular Pharmacology, Department of Pathophysiological and Therapeutic Science, Yonago 683-8503 (Japan); Tohkin, Masahiro, E-mail: tohkin@phar.nagoya-cu.ac.jp [Department of Medical Safety Science, Graduate School of Pharmaceutical Science, Nagoya City University, Nagoya 267-8603 (Japan); Gonzalez, Frank J., E-mail: gonzalef@mail.nih.gov [Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 (United States); Komai, Michio, E-mail: mkomai@m.tohoku.ac.jp [Laboratory of Nutrition, Graduate School of Agricultural Science, Tohoku University, Sendai 981-8555 (Japan)

2013-11-15

Although the aryl hydrocarbon receptor (AHR) and glucocorticoid receptor (GR) play essential roles in mammalian development, stress responses, and other physiological events, crosstalk between these receptors has been the subject of much debate. Metallothioneins are classic glucocorticoid-inducible genes that were reported to increase upon treatment with AHR agonists in rodent tissues and cultured human cells. In this study, the mechanism of human metallothionein 2A (MT2A) gene transcription activation by AHR was investigated. Cotreatment with 3-methylcholanthrene and dexamethasone, agonists of AHR and GR respectively, synergistically increased MT2A mRNA levels in HepG2 cells. MT2A induction was suppressed by RNA interference against AHR or GR. Coimmunoprecipitation experiments revealed a physical interaction between AHR and GR proteins. Moreover, chromatin immunoprecipitation assays indicated that AHR was recruited to the glucocorticoid response element in the MT2A promoter. Thus, we provide a novel mechanism whereby AHR modulates expression of human MT2A via the glucocorticoid response element and protein–protein interactions with GR. - Highlights: • Aryl hydrocarbon receptor forms a complex with glucocorticoid receptor in cells. • Human metallothionein gene is regulated by the AHR and GR interaction. • AHR–GR complex binds to glucocorticoid response element in metallothionein gene. • We demonstrated a novel transcriptional mechanism via AHR and GR interaction.

The aryl hydrocarbon receptor and glucocorticoid receptor interact to activate human metallothionein 2A

International Nuclear Information System (INIS)

Sato, Shoko; Shirakawa, Hitoshi; Tomita, Shuhei; Tohkin, Masahiro; Gonzalez, Frank J.; Komai, Michio

2013-01-01

Although the aryl hydrocarbon receptor (AHR) and glucocorticoid receptor (GR) play essential roles in mammalian development, stress responses, and other physiological events, crosstalk between these receptors has been the subject of much debate. Metallothioneins are classic glucocorticoid-inducible genes that were reported to increase upon treatment with AHR agonists in rodent tissues and cultured human cells. In this study, the mechanism of human metallothionein 2A (MT2A) gene transcription activation by AHR was investigated. Cotreatment with 3-methylcholanthrene and dexamethasone, agonists of AHR and GR respectively, synergistically increased MT2A mRNA levels in HepG2 cells. MT2A induction was suppressed by RNA interference against AHR or GR. Coimmunoprecipitation experiments revealed a physical interaction between AHR and GR proteins. Moreover, chromatin immunoprecipitation assays indicated that AHR was recruited to the glucocorticoid response element in the MT2A promoter. Thus, we provide a novel mechanism whereby AHR modulates expression of human MT2A via the glucocorticoid response element and protein–protein interactions with GR. - Highlights: • Aryl hydrocarbon receptor forms a complex with glucocorticoid receptor in cells. • Human metallothionein gene is regulated by the AHR and GR interaction. • AHR–GR complex binds to glucocorticoid response element in metallothionein gene. • We demonstrated a novel transcriptional mechanism via AHR and GR interaction

Efficacy and Safety of Leucine Supplementation in the Elderly.

Science.gov (United States)

Borack, Michael S; Volpi, Elena

2016-12-01

Leucine supplementation has grown in popularity due to the discovery of its anabolic effects on cell signaling and protein synthesis in muscle. The current recommendation is a minimum intake of 55 mg ⋅ kg -1 . d -1 Leucine acutely stimulates skeletal muscle anabolism and can overcome the anabolic resistance of aging. The value of chronic leucine ingestion for muscle growth is still unclear. Most of the research into leucine consumption has focused on efficacy. To our knowledge, very few studies have sought to determine the maximum safe level of intake. Limited evidence suggests that intakes of ≤1250 mg ⋅ kg -1 . d -1 do not appear to have any health consequences other than short-term elevated plasma ammonia concentrations. Similarly, no adverse events have been reported for the leucine metabolite β-hydroxy-β-methylbutyrate (HMB), although no studies have tested HMB toxicity in humans. Therefore, future research is needed to evaluate leucine and HMB toxicity in the elderly and in specific health conditions. © 2016 American Society for Nutrition.

Endogenous glucocorticoids exacerbate cholestasis-associated liver injury and hypercholesterolemia in mice

International Nuclear Information System (INIS)

Geest, Rick van der; Ouweneel, Amber B.; Sluis, Ronald J. van der; Groen, Albert K.; Van Eck, Miranda; Hoekstra, Menno

2016-01-01

Cholestatic liver disease is characterized by a disruption of bile flow, bile acid toxicity, liver injury, and hypercholesterolemia. Relatively high secretion of glucocorticoids by the adrenals has been observed under cholestatic conditions. Here we investigated a contribution of the rise in endogenous glucocorticoids to initial stage cholestasis pathology. Adrenalectomized or sham-operated control C57BL/6 mice were given an oral dose of alpha-naphthylisothiocyanate to induce cholestasis. Adrenalectomy effectively lowered plasma corticosterone levels (18 ± 5 ng/ml vs 472 ± 58 ng/ml; P < 0.001) and disrupted the metabolic and anti-inflammatory glucocorticoid function. Adrenal removal did not exacerbate the cholestasis extent. In contrast, the cholestasis-associated liver injury was markedly lower in adrenalectomized mice as compared to controls as evidenced by a 84%–93% decrease in liver necrosis and plasma alanine aminotransferase and bile acid levels (P < 0.001 for all). Gene expression analysis on livers from adrenalectomized mice suggested the absence of bile acid toxicity-associated farnesoid X receptor signaling in the context of a 44% (P < 0.01) and 82% (P < 0.001) reduction in sodium/bile acid cotransporter member 1 transcript level as compared to respectively control and non-diseased mice. Adrenalectomy reduced the expression of the cholesterol synthesis gene HMG-CoA reductase by 70% (P < 0.05), which translated into a 73% lower plasma total cholesterol level (P < 0.05). Treatment of C57BL/6 mice with the glucocorticoid receptor antagonist RU-486 recapitulated the protective effect of adrenalectomy on indices of liver injury and hypercholesterolemia. In conclusion, we have shown that endogenous glucocorticoids exacerbate the liver injury and hypercholesterolemia associated with acute cholestasis in mice. - Highlights: • Cholestasis is associated with increased plasma glucocorticoid levels in mice. • Adrenalectomy lowers cholestasis-associated liver

Endogenous glucocorticoids exacerbate cholestasis-associated liver injury and hypercholesterolemia in mice

Energy Technology Data Exchange (ETDEWEB)

Geest, Rick van der, E-mail: r.van.der.geest@lacdr.leidenuniv.nl [Leiden Academic Centre for Drug Research (Netherlands); Ouweneel, Amber B., E-mail: a.b.ouweneel@lacdr.leidenuniv.nl [Leiden Academic Centre for Drug Research (Netherlands); Sluis, Ronald J. van der, E-mail: r.vandersluis@lacdr.leidenuniv.nl [Leiden Academic Centre for Drug Research (Netherlands); Groen, Albert K., E-mail: a.k.groen@umcg.nl [University Medical Center Groningen (Netherlands); Van Eck, Miranda, E-mail: m.eck@lacdr.leidenuniv.nl [Leiden Academic Centre for Drug Research (Netherlands); Hoekstra, Menno, E-mail: hoekstra@lacdr.leidenuniv.nl [Leiden Academic Centre for Drug Research (Netherlands)

2016-09-01

Cholestatic liver disease is characterized by a disruption of bile flow, bile acid toxicity, liver injury, and hypercholesterolemia. Relatively high secretion of glucocorticoids by the adrenals has been observed under cholestatic conditions. Here we investigated a contribution of the rise in endogenous glucocorticoids to initial stage cholestasis pathology. Adrenalectomized or sham-operated control C57BL/6 mice were given an oral dose of alpha-naphthylisothiocyanate to induce cholestasis. Adrenalectomy effectively lowered plasma corticosterone levels (18 ± 5 ng/ml vs 472 ± 58 ng/ml; P < 0.001) and disrupted the metabolic and anti-inflammatory glucocorticoid function. Adrenal removal did not exacerbate the cholestasis extent. In contrast, the cholestasis-associated liver injury was markedly lower in adrenalectomized mice as compared to controls as evidenced by a 84%–93% decrease in liver necrosis and plasma alanine aminotransferase and bile acid levels (P < 0.001 for all). Gene expression analysis on livers from adrenalectomized mice suggested the absence of bile acid toxicity-associated farnesoid X receptor signaling in the context of a 44% (P < 0.01) and 82% (P < 0.001) reduction in sodium/bile acid cotransporter member 1 transcript level as compared to respectively control and non-diseased mice. Adrenalectomy reduced the expression of the cholesterol synthesis gene HMG-CoA reductase by 70% (P < 0.05), which translated into a 73% lower plasma total cholesterol level (P < 0.05). Treatment of C57BL/6 mice with the glucocorticoid receptor antagonist RU-486 recapitulated the protective effect of adrenalectomy on indices of liver injury and hypercholesterolemia. In conclusion, we have shown that endogenous glucocorticoids exacerbate the liver injury and hypercholesterolemia associated with acute cholestasis in mice. - Highlights: • Cholestasis is associated with increased plasma glucocorticoid levels in mice. • Adrenalectomy lowers cholestasis-associated liver

Transcriptional regulation of the tyrosine hydroxylase gene by glucocorticoid and cyclic AMP

International Nuclear Information System (INIS)

Lewis, E.J.; Harrington, C.A.; Chikaraishi, D.M.

1987-01-01

Glucocorticoid and cyclic AMP increase tyrosine hydroxylase (TH) activity and mRNA levels in pheochromocytoma cultures. The transcriptional activity of the TH gene, as measured by nuclear run-on assay, is also increased when cultures are treated with the synthetic glucocorticoid dexamethasone or agents that increase intracellular cyclic AMP, such as forskolin and 8-BrcAMP. Both inducers effect transcriptional changes within 10 min after treatment and are maximal after 30 min for forskolin and after 60 min for dexamethasone. The 5' flanking sequences of the TH gene were fused to the bacterial gene chloramphenicol acetyltransferase (CAT), and the hybrid gene was transfected into pheochromocytoma cultures and GH 4 pituitary cells. In both cell lines, a region of the TH gene containing bases -272 to +27 conferred induction of CAT by cyclic AMP, but not by glucocorticoid. The same results were found when a region of the TH gene containing -773 to + 27 was used. Thus, the sequences required for induction of TH by cyclic AMP are contained within 272 bases of 5' flanking sequence, but sequences sufficient for glucocorticoid regulation are not contained with 773 bases

Application of zipper-fracturing of horizontal cluster wells in the Changning shale gas pilot zone, Sichuan Basin

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Bin Qian

2015-03-01

Full Text Available After several years of exploration practices in the Changning-Weiyuan national shale gas pilot zone, the industrial production has been achieved in a number of vertical and horizontal wells completed by SRV fracturing, and a series of independent shale gas reservoir stimulation technologies have come into being. Next, it is necessary to consider how to enhance the efficiency of fracturing by a factory-mode operation. This paper presents the deployment of Changning Well Pad A, the first cluster horizontal shale gas well group, and proposes the optimal design for the factory operation mode of this Pad according to the requirements of wellpad fracturing stimulation technologies and the mountainous landform in the Sichuan Basin. Accordingly, a zipper-fracturing mode was firstly adopted in the factory fracturing on wellpad. With the application of standardized field process, zipper operation, assembly line work, staggered placement of downhole fractures, and microseismic monitoring in real time, the speed of fracturing reached 3.16 stages a day on average, and the stimulated reservoir volume was maximized, which has fully revealed how the factory operation mode contributes to the large-scale SRV fracturing of horizontal shale gas cluster wells on wellpads in the aspect of speed and efficiency. Moreover, the fracturing process, operation mode, surface facilities and post-fracturing preliminary evaluation of the zipper-fracturing in the well group were examined comprehensively. It is concluded from the practice that the zipper-fracturing in the two wells enhanced the efficiency by 78% and stimulated reservoir volume by 50% compared with the single-well fracturing at the preliminary stage in this area.

Glucocorticoid cell reception in mice of different strains with natural killer cell activity depressed during immobilization stress

International Nuclear Information System (INIS)

Lyashko, V.N.; Sukhikh, G.T.

1987-01-01

The authors study differences in stress-induced depression of natural killer cell activity in mice of different inbred lines, depending on parameters of glucocorticoid binding with glucorticoid receptors of spleen cells and on the hormonal status of the animals. In determining the parameters of glucocorticoid binding on intact splenocytes, aliquots of a suspension of washed splenocytes were incubated with tritium-labeled dexamethasone

Leucine and valine requirements of the growing germfree chicks

International Nuclear Information System (INIS)

Ishibashi, Teru; Kametaka, Masao; Ozaki, Akira; Yamamoto, Tetsuzo; Mitsuoka, Tomotari.

1977-01-01

To compare the requirements of leucine and valine of the growing germfree and conventional chicks, 7-day-old chicks were fed a diet with graded levels of leucine or valine for 7 days. Daily gains of body weight of the germfree chicks were greater than those of the conventional chicks when the dietary leucine or valine level was higher than the requirement level. Adversely, daily gains of body weight of the germfree chicks were less than those of the conventional chicks when the dietary leucine or valine level was very low. Leucine and valine requirements for maximum growth, however, was the same and estimated to be 0.95 and 0.78%, repectively, of the diet for both groups. After the feeding test, the chicks were injected with L-leucine- and L-valine-U- 14 C and expired carbon dioxide was collected for 2 and 3 hours, respectively. From the percentage of recovery of 14 C in the expired carbon dioxide, the leucine and valine requirements were found to be 0.80 and 0.53% of the diet for both groups, respectively. Three hours after feeding test, the plasma free valine concentration was estimated in the chicks which was not injected the isotope. The requirement of valine was estimated to be 0.59% for the germfree chicks and 0.54% for the conventional chicks. From the above data, it may be concluded that no difference, or very small if any, is found in the requirements of leucine and valine between the germfree chicks and those of the conventional chicks. (auth.)

Non-Ligand-Induced Dimerization is Sufficient to Initiate the Signalling and Endocytosis of EGF Receptor

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George Kourouniotis

2016-07-01

Full Text Available The binding of epidermal growth factor (EGF to EGF receptor (EGFR stimulates cell mitogenesis and survival through various signalling cascades. EGF also stimulates rapid EGFR endocytosis and its eventual degradation in lysosomes. The immediate events induced by ligand binding include receptor dimerization, activation of intrinsic tyrosine kinase and autophosphorylation. However, in spite of intensified efforts, the results regarding the roles of these events in EGFR signalling and internalization is still very controversial. In this study, we constructed a chimeric EGFR by replacing its extracellular domain with leucine zipper (LZ and tagged a green fluorescent protein (GFP at its C-terminus. We showed that the chimeric LZ-EGFR-GFP was constitutively dimerized. The LZ-EGFR-GFP dimer autophosphorylated each of its five well-defined C-terminal tyrosine residues as the ligand-induced EGFR dimer does. Phosphorylated LZ-EGFR-GFP was localized to both the plasma membrane and endosomes, suggesting it is capable of endocytosis. We also showed that LZ-EGFR-GFP activated major signalling proteins including Src homology collagen-like (Shc, extracellular signal-regulated kinase (ERK and Akt. Moreover, LZ-EGFR-GFP was able to stimulate cell proliferation. These results indicate that non-ligand induced dimerization is sufficient to activate EGFR and initiate cell signalling and EGFR endocytosis. We conclude that receptor dimerization is a critical event in EGF-induced cell signalling and EGFR endocytosis.

Leucine-induced activation of translational initiation is partly regulated by the branched-chain α-keto acid dehydrogenase complex in C2C12 cells

International Nuclear Information System (INIS)

Nakai, Naoya; Shimomura, Yoshiharu; Tamura, Tomohiro; Tamura, Noriko; Hamada, Koichiro; Kawano, Fuminori; Ohira, Yoshinobu

2006-01-01

Branched-chain amino acid leucine has been shown to activate the translational regulators through the mammalian target of rapamycin. However, the leucine's effects are self-limiting because leucine promotes its own disposal by an oxidative pathway. The irreversible and rate-limiting step in the leucine oxidation pathway is catalyzed by the branched-chain α-keto acid dehydrogenase (BCKDH) complex. The complex contains E1 (α2β2), E2, and E3 subunits, and its activity is abolished by phosphorylation of the E1α subunit by BCKDH kinase. The relationship between the activity of BCKDH complex and leucine-mediated activation of the protein translation was investigated using the technique of RNA interference. The activity of BCKDH complex in C2C12 cell was modulated by transfection of small interfering RNA (siRNA) for BCKDH E2 subunit or BCKDH kinase. Transfection of siRNAs decreased the mRNA expression and protein amount of corresponding gene. Suppression of either E2 subunit or kinase produced opposite effects on the cell proliferation and the activation of translational regulators by leucine. Suppression of BCKDH kinase for 48 h resulted in decreasing cell proliferation. In contrast, E2 suppression led to increased amount of total cellular protein. The phosphorylation of p70 S6 kinase by leucine was increased in E2-siRNA transfected C2C12 cells, whereas the leucine's effect was diminished in kinase-siRNA transfected cells. These results suggest that the activation of the translational regulators by leucine was partly regulated by the activity of BCKDH complex

Novel tumor suppressor function of glucocorticoid-induced TNF receptor GITR in multiple myeloma.

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Yang Liu

Full Text Available Glucocorticoid-induced TNF receptor (GITR plays a crucial role in modulating immune response and inflammation, however the role of GITR in human cancers is poorly understood. In this study, we demonstrated that GITR is inactivated during tumor progression in Multiple Myeloma (MM through promoter CpG island methylation, mediating gene silencing in primary MM plasma cells and MM cell lines. Restoration of GITR expression in GITR deficient MM cells led to inhibition of MM proliferation in vitro and in vivo and induction of apoptosis. These findings were supported by the presence of induction of p21 and PUMA, two direct downstream targets of p53, together with modulation of NF-κB in GITR-overexpressing MM cells. Moreover, the unbalanced expression of GITR in clonal plasma cells correlated with MM disease progression, poor prognosis and survival. These findings provide novel insights into the pivotal role of GITR in MM pathogenesis and disease progression.

Chronic stress accelerates ligature-induced periodontitis by suppressing glucocorticoid receptor-α signaling.

Science.gov (United States)

Lu, Huaixiu; Xu, Minguang; Wang, Feng; Liu, Shisen; Gu, Jing; Lin, Songshan; Zhao, Lisheng

2016-03-25

Periodontitis is a common chronic inflammatory disease. Recent studies have shown that chronic stress (CS) might modulate periodontal disease, but there are few models of CS-induced periodontitis, and the underlying mechanisms are unclear. The present study established a rat model of periodontitis associated with CS induced by nylon thread ligatures. The severity of periodontitis was evaluated in this model by radiographic and pathological examination. The inflammatory reaction indicated by the elevated serum levels of interleukin (IL)-1β, IL-6 and IL-8 was assessed by enzyme-linked immunosorbent assay. Toll-like receptor-4 (TLR4) and glucocorticoid receptor-α (GR-α) expressions were detected by reverse transcriptase-PCR and western blotting. Open-field tests and serum corticosterone were used to evaluate CS. The results showed that CS induced behavioral changes and increased corticosterone levels of the animals with periodontitis. CS stimulation markedly increased alveolar bone loss, periodontal pocket depth and the number of plaques. It also enhanced the inflammatory reaction. These results suggest that CS accelerated the ligature-induced pathological changes associated with periodontitis. Further analysis of the mechanisms involved showed that GR-α expression was significantly downregulated in periodontal tissues of the animals undergoing CS. Blocking GR-α signaling in lipopolysaccharide and corticosteroid-treated human periodontal ligament fibroblast cells in vitro significantly upregulated the expression of p-Akt (protein kinase B) and TLR4, promoted nuclear factor-κB activity and increased levels of IL-1β, IL-6 and IL-8. This research suggests that CS might accelerate the pathological progression of periodontitis by a GR-α signaling-mediated inflammatory response and that this may be a potential therapeutic target for the treatment of periodontal disease, particularly in patients with CS.

Glucocorticoids are ineffective in alcoholic hepatitis

DEFF Research Database (Denmark)

Christensen, E; Gluud, C

1995-01-01

The aim of this study was to perform a meta-analysis of controlled clinical trials of glucocorticoid treatment in clinical alcoholic hepatitis, adjusting for prognostic variables and their possible interaction with therapy, because these trials have given appreciably different results. Weighted...... logistic regression analysis was applied using the summarised descriptive data (for example, % with encephalopathy, mean bilirubin value) of the treatment and control groups of 12 controlled trials that gave this information. Despite evidence of publication bias favouring glucocorticoid treatment, its...... overall effect on mortality was not statistically significant (p = 0.20)--the relative risk (steroid/control) was 0.78 (95% confidence intervals 0.51, 1.18). There was indication of interaction between glucocorticoid therapy and gender, but not encephalopathy. Thus, the effect of glucocorticoid treatment...

Independent association of glucocorticoids with damage accrual in SLE.

Science.gov (United States)

Apostolopoulos, Diane; Kandane-Rathnayake, Rangi; Raghunath, Sudha; Hoi, Alberta; Nikpour, Mandana; Morand, Eric F

2016-01-01

To determine factors associated with damage accrual in a prospective cohort of patients with SLE. Patients with SLE who attended the Lupus Clinic at Monash Health, Australia, between 2007 and 2013 were studied. Clinical variables included disease activity (Systemic Lupus Erythematosus Disease Activity Index-2K, SLEDAI-2K), time-adjusted mean SLEDAI, cumulative glucocorticoid dose and organ damage (Systemic Lupus International Collaborating Clinics Damage Index (SDI)). Multivariate logistic regression analyses were performed to identify factors associated with damage accrual. A total of 162 patients were observed over a median (IQR) 3.6 (2.0-4.7) years. Seventy-five per cent (n=121) of patients received glucocorticoids. Damage accrual was significantly more frequent in glucocorticoid-exposed patients (42% vs 15%, p<0.01). Higher glucocorticoid exposure was independently associated with overall damage accrual after controlling for factors including ethnicity and disease activity and was significant at time-adjusted mean doses above 4.42 mg prednisolone/day; the OR of damage accrual in patients in the highest quartile of cumulative glucocorticoid exposure was over 10. Glucocorticoid exposure was independently associated with damage accrual in glucocorticoid-related and non-glucocorticoid related domains of the SDI. Glucocorticoid use is independently associated with the accrual of damage in SLE, including in non-glucocorticoid related domains.

Leucine kinetics from [2H3]- and [13C]leucine infused simultaneously by gut and vein

International Nuclear Information System (INIS)

Hoerr, R.A.; Matthews, D.E.; Bier, D.M.; Young, V.R.

1991-01-01

In amino acid tracer kinetic studies of the fed state, ingested amino acid may be taken up during its initial transit through splanchnic tissues and thus not enter the plasma compartment where tracer is infused. To investigate this possibility, adult human subjects received simultaneous intravenous (iv) and intragastric (ig) leucine tracer infusions, first during a postabsorptive (PA) 4-h primed continuous ig infusion of L-[1-13C]-leucine and L-[5,5,5-2H3]leucine iv, followed on a separate day by a fed infusion, in which an ig infusion of a liquid formula was started 2 h before the tracer infusion and continued throughout the tracer study. Subjects were accustomed to a constant experimental diet supplying 1.5 g protein.kg-1.day-1 and 41-45 kcal.kg-1.day-1 for 7 and 12 days before the PA and fed studies, respectively. For the PA study, plasma enrichment for the ig tracer was 3.34 +/- 0.27 (SE) mol + excess and for the iv tracer it was 4.18 +/- 0.10 (P less than 0.02). Enrichments of alpha-keto-isocaproic acid (KIC) were 3.24 +/- 0.16 (ig) and 3.02 +/- 0.14 (iv), respectively [not significant (NS)]. For the fed study, plasma leucine enrichment for the ig tracer was 2.15 +/- 0.14 and for the iv tracer was 2.84 +/- 0.09 (P less than 0.02). KIC enrichments were 2.02 +/- 0.08 (ig) and 2.24 +/- 0.08 (iv), respectively (NS). In the PA study, the ratio of the plasma leucine enrichments for the ig and iv tracers was 0.80 +/- 0.06 and in the fed experiment, 0.76 +/- 0.05, respectively

Leucine-rich diet alters the eukaryotic translation initiation factors expression in skeletal muscle of tumour-bearing rats

Directory of Open Access Journals (Sweden)

Mello Maria

2007-03-01

Full Text Available Abstract Background Cancer-cachexia induces a variety of metabolic disorders on protein turnorver, decreasing protein synthesis and increasing protein degradation. Controversly, insulin, other hormones, and branched-chain amino acids, especially leucine, stimulate protein synthesis and modulate the activity of translation initiation factors involved in protein synthesis. Since the tumour effects are more pronounced when associated with pregnancy, ehancing muscle-wasting proteolysis, in this study, the influence of a leucine-rich diet on the protein synthesis caused by cancer were investigated. Methods Pregnant rats with or without Walker 256 tumour were distributed into six groups. During 20 days of experiment, three groups were fed with a control diet: C – pregnant control, W – tumour-bearing, and P – pair-fed, which received the same amount of food as ingested by the W group; three other groups of pregnant rats were fed a leucine-rich diet: L – pregnant leucine, WL – tumour-bearing, and PL – pair-fed, which received the same amount of food as ingested by the WL group. Results The gastrocnemius muscle of WL rats showed increased incorporation of leucine in protein compared to W rats; the leucine-rich diet also prevented the decrease in plasma insulin normally seen in W. The expression of translation initiation factors increased when tumour-bearing rats fed leucine-rich diet, with increase of ~35% for eIF2α and eIF5, ~17% for eIF4E and 20% for eIF4G; the expression of protein kinase S6K1 and protein kinase C was also highly enhanced. Conclusion The results suggest that a leucine-rich diet increased the protein synthesis in skeletal muscle in tumour-bearing rats possibly through the activation of eIF factors and/or the S6kinase pathway.

Leucine-rich diet alters the eukaryotic translation initiation factors expression in skeletal muscle of tumour-bearing rats

International Nuclear Information System (INIS)

Ventrucci, Gislaine; Mello, Maria Alice R; Gomes-Marcondes, Maria Cristina C

2007-01-01

Cancer-cachexia induces a variety of metabolic disorders on protein turnorver, decreasing protein synthesis and increasing protein degradation. Controversly, insulin, other hormones, and branched-chain amino acids, especially leucine, stimulate protein synthesis and modulate the activity of translation initiation factors involved in protein synthesis. Since the tumour effects are more pronounced when associated with pregnancy, ehancing muscle-wasting proteolysis, in this study, the influence of a leucine-rich diet on the protein synthesis caused by cancer were investigated. Pregnant rats with or without Walker 256 tumour were distributed into six groups. During 20 days of experiment, three groups were fed with a control diet: C – pregnant control, W – tumour-bearing, and P – pair-fed, which received the same amount of food as ingested by the W group; three other groups of pregnant rats were fed a leucine-rich diet: L – pregnant leucine, WL – tumour-bearing, and PL – pair-fed, which received the same amount of food as ingested by the WL group. The gastrocnemius muscle of WL rats showed increased incorporation of leucine in protein compared to W rats; the leucine-rich diet also prevented the decrease in plasma insulin normally seen in W. The expression of translation initiation factors increased when tumour-bearing rats fed leucine-rich diet, with increase of ~35% for eIF2α and eIF5, ~17% for eIF4E and 20% for eIF4G; the expression of protein kinase S6K1 and protein kinase C was also highly enhanced. The results suggest that a leucine-rich diet increased the protein synthesis in skeletal muscle in tumour-bearing rats possibly through the activation of eIF factors and/or the S6kinase pathway

Leucine-rich diet alters the eukaryotic translation initiation factors expression in skeletal muscle of tumour-bearing rats

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Ventrucci, Gislaine [Laboratório de Nutrição e Câncer, Departamento de Fisiologia e Biofísica, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, 13083-970, São Paulo (Brazil); Mello, Maria Alice R [Departamento de Fisiologia e Biofísica, Instituto Biociências, Universidade Estadual de São Paulo, UNESP, Rio Claro, 13506-900, São Paulo (Brazil); Gomes-Marcondes, Maria Cristina C [Laboratório de Nutrição e Câncer, Departamento de Fisiologia e Biofísica, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, 13083-970, São Paulo (Brazil)

2007-03-06

Cancer-cachexia induces a variety of metabolic disorders on protein turnorver, decreasing protein synthesis and increasing protein degradation. Controversly, insulin, other hormones, and branched-chain amino acids, especially leucine, stimulate protein synthesis and modulate the activity of translation initiation factors involved in protein synthesis. Since the tumour effects are more pronounced when associated with pregnancy, ehancing muscle-wasting proteolysis, in this study, the influence of a leucine-rich diet on the protein synthesis caused by cancer were investigated. Pregnant rats with or without Walker 256 tumour were distributed into six groups. During 20 days of experiment, three groups were fed with a control diet: C – pregnant control, W – tumour-bearing, and P – pair-fed, which received the same amount of food as ingested by the W group; three other groups of pregnant rats were fed a leucine-rich diet: L – pregnant leucine, WL – tumour-bearing, and PL – pair-fed, which received the same amount of food as ingested by the WL group. The gastrocnemius muscle of WL rats showed increased incorporation of leucine in protein compared to W rats; the leucine-rich diet also prevented the decrease in plasma insulin normally seen in W. The expression of translation initiation factors increased when tumour-bearing rats fed leucine-rich diet, with increase of ~35% for eIF2α and eIF5, ~17% for eIF4E and 20% for eIF4G; the expression of protein kinase S6K1 and protein kinase C was also highly enhanced. The results suggest that a leucine-rich diet increased the protein synthesis in skeletal muscle in tumour-bearing rats possibly through the activation of eIF factors and/or the S6kinase pathway.

ABI-like transcription factor gene TaABL1 from wheat improves multiple abiotic stress tolerances in transgenic plants.

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Xu, Dong-Bei; Gao, Shi-Qing; Ma, You-Zhi; Xu, Zhao-Shi; Zhao, Chang-Ping; Tang, Yi-Miao; Li, Xue-Yin; Li, Lian-Cheng; Chen, Yao-Feng; Chen, Ming

2014-12-01

The phytohormone abscisic acid (ABA) plays crucial roles in adaptive responses of plants to abiotic stresses. ABA-responsive element binding proteins (AREBs) are basic leucine zipper transcription factors that regulate the expression of downstream genes containing ABA-responsive elements (ABREs) in promoter regions. A novel ABI-like (ABA-insensitive) transcription factor gene, named TaABL1, containing a conserved basic leucine zipper (bZIP) domain was cloned from wheat. Southern blotting showed that three copies were present in the wheat genome. Phylogenetic analyses indicated that TaABL1 belonged to the AREB subfamily of the bZIP transcription factor family and was most closely related to ZmABI5 in maize and OsAREB2 in rice. Expression of TaABL1 was highly induced in wheat roots, stems, and leaves by ABA, drought, high salt, and low temperature stresses. TaABL1 was localized inside the nuclei of transformed wheat mesophyll protoplast. Overexpression of TaABL1 enhanced responses of transgenic plants to ABA and hastened stomatal closure under stress, thereby improving tolerance to multiple abiotic stresses. Furthermore, overexpression of TaABL1 upregulated or downregulated the expression of some stress-related genes controlling stomatal closure in transgenic plants under ABA and drought stress conditions, suggesting that TaABL1 might be a valuable genetic resource for transgenic molecular breeding.

Influence of postnatal glucocorticoids on hippocampal-dependent learning varies with elevation patterns and administration methods.

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Claflin, Dragana I; Schmidt, Kevin D; Vallandingham, Zachary D; Kraszpulski, Michal; Hennessy, Michael B

2017-09-01

Recent interest in the lasting effects of early-life stress has expanded to include effects on cognitive performance. An increase in circulating glucocorticoids is induced by stress exposure and glucocorticoid effects on the hippocampus likely underlie many of the cognitive consequences. Here we review studies showing that corticosterone administered to young rats at the conclusion of the stress-hyporesponsiveness period affects later performance in hippocampally-mediated trace eyeblink conditioning. The nature and even direction of these effects varies with the elevation patterns (level, duration, temporal fluctuation) achieved by different administration methods. We present new time course data indicating that constant glucocorticoid elevations generally corresponded with hippocampus-mediated learning deficits, whereas acute, cyclical elevations corresponded with improved initial acquisition. Sensitivity was greater for males than for females. Further, changes in hippocampal neurogenesis paralleled some but not all effects. The findings demonstrate that specific patterns of glucocorticoid elevation produced by different drug administration procedures can have markedly different, sex-specific consequences on basic cognitive performance and underlying hippocampal physiology. Implications of these findings for glucocorticoid medications prescribed in childhood are discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

Do the interactions between glucocorticoids and sex hormones regulate the development of the Metabolic Syndrome?

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Marià eAlemany

2012-02-01

Full Text Available The metabolic syndrome is basically a maturity-onset disease. Typically, its manifestations begin to flourish years after the initial dietary or environmental aggression began. Since most hormonal, metabolic or defense responses are practically immediate, the procrastinated response don't seem justified. Only in childhood, the damages of the metabolic syndrome appear with minimal delay. Sex affects the incidence of the metabolic syndrome, but this is more an effect of timing than absolute gender differences, females holding better than males up to menopause, when the differences between sexes tend to disappear. The metabolic syndrome is related to an immune response, countered by a permanent increase in glucocorticoids, which keep the immune system at bay but also induce insulin resistance, alter the lipid metabolism, favor fat deposition, mobilize protein and decrease androgen synthesis. Androgens limit the operation of glucocorticoids, which is also partly blocked by estrogens, since they decrease inflammation (which enhances glucocorticoid release. These facts suggest that the appearance of the metabolic syndrome symptoms depends on the strength (i.e. levels of androgens and estrogens. The predominance of glucocorticoids and the full manifestation of the syndrome in men are favored by decreased androgen activity. Low androgens can be found in infancy, maturity, advanced age, or because of their inhibition by glucocorticoids (inflammation, stress, medical treatment. Estrogens decrease inflammation and reduce the glucocorticoid response. Low estrogen (infancy, menopause again allow the predominance of glucocorticoids and the manifestation of the metabolic syndrome. It is postulated that the equilibrium between sex hormones and glucocorticoids may be a critical element in the timing of the manifestation of metabolic syndrome-related pathologies.

Exogenous glucocorticoids and adverse cerebral effects in children

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Damsted, Sara K.; Born, A P; Paulson, Olaf B

2011-01-01

of the glucocorticoid receptor, which is associated with unfavorable cellular outcomes. Prenatal treatment with glucocorticoids can compromise brain growth and is associated with periventricular leukomalacia, attentions deficits and poorer cognitive performance. In the neonatal period exposure to glucocorticoids....... Glucocortioids affect several cellular structures and functions, which may explain the observed adverse effects. Glucocorticoids can impair neuronal glucose uptake, decrease excitability, cause atrophy of dendrites, compromise development of myelin-producing oligodendrocytes and disturb important cellular...

Electroconvulsive stimulations normalizes stress-induced changes in the glucocorticoid receptor and behaviour

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Hageman, Ida; Nielsen, Marianne; Wörtwein, Gitta

2009-01-01

Animal models of chronic stress, such as 21 days of 6h/daily restraint stress cause changes in neuronal morphology in the hippocampus and alter behaviour. These changes are partly mediated by the glucocorticoids. The objective of this study was threefold: (1) to study how this particular chronic ...

Impaired glucocorticoid-mediated HPA axis negative feedback induced by juvenile social isolation in male rats.

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Boero, Giorgia; Pisu, Maria Giuseppina; Biggio, Francesca; Muredda, Laura; Carta, Gianfranca; Banni, Sebastiano; Paci, Elena; Follesa, Paolo; Concas, Alessandra; Porcu, Patrizia; Serra, Mariangela

2018-05-01

We previously demonstrated that socially isolated rats at weaning showed a significant decrease in corticosterone and adrenocorticotropic hormone (ACTH) levels, associated with an enhanced response to acute stressful stimuli. Here we shown that social isolation decreased levels of total corticosterone and of its carrier corticosteroid-binding globulin, but did not influence the availability of the free active fraction of corticosterone, both under basal conditions and after acute stress exposure. Under basal conditions, social isolation increased the abundance of glucocorticoid receptors, while it decreased that of mineralocorticoid receptors. After acute stress exposure, socially isolated rats showed long-lasting corticosterone, ACTH and corticotrophin releasing hormone responses. Moreover, while in the hippocampus and hypothalamus of group-housed rats glucocorticoid receptors expression increased with time and reached a peak when corticosterone levels returned to basal values, in socially isolated rats expression of glucocorticoid receptors did not change. Finally, social isolation also affected the hypothalamic endocannabinoid system: compared to group-housed rats, basal levels of anandamide and cannabinoid receptor type 1 were increased, while basal levels of 2-arachidonoylglycerol were decreased in socially isolated rats and did not change after acute stress exposure. The present results show that social isolation in male rats alters basal HPA axis activity and impairs glucocorticoid-mediated negative feedback after acute stress. Given that social isolation is considered an animal model of several neuropsychiatric disorders, such as generalized anxiety disorder, depression, post-traumatic stress disorder and schizophrenia, these data could contribute to better understand the alterations in HPA axis activity observed in these disorders. Copyright © 2018 Elsevier Ltd. All rights reserved.

Adrenal Insufficiency Caused by Locally Applied Glucocorticoids-Myth or Fact?

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Dinsen, Stina; Klose, Marianne; Rasmussen, Åse Krogh

2015-01-01

Case-reports have made it evident that both inhaled, percutaneous, intranasal, intraarticular and ophthalmic administered glucocorticoids have the potential to cause life threatening adrenal insufficiency. With few and sometimes conflicting data and study methodology the prevalence of adrenal...... insufficiency secondary to locally applied glucocorticoids is not clear. Adrenal insufficiency can only be correctly evaluated by a stimulation test, and has by this procedure been reported in up to 40-50% of patients treated with high-dose inhaled glucocorticoids. Medium- to low-dose inhaled glucocorticoids...... have been shown to cause adrenal suppression in 0-16% of patients. Glucocorticoid creams and nasal glucocorticoids can cause adrenal insufficiency, also when used within prescribed doses, but the frequency seems to be less than with inhaled glucocorticoids. Intraarticularly administered glucocorticoids...

Circadian secretion patterns of ß-endorphin and leucine enkephalin

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E. H. de Wet

1992-07-01

Full Text Available ß-endorphin and leucine enkephalin are neuropeptides with potent opioid activity. In a study to investigate the circadian secretion patterns of the above-mentioned, blood samples were collected hourly from 12 healthy males who were subjected to the experiment for 24 hours. Radioimmunoassays were used in the analysis of plasma samples for ß-endorphin and leucine enkephalin. Peak concentrations of ß-endorphin were demonstrated from 08:00-09:00, while peak concentrations of leucine enkephalin occured from 23:00-07:00. Trough concentrations of ß-endorphin occurred from 24:00-05:00, while trough con­centrations of leucine enkephalin were demonstrated from 09:00-12:00. The illustrated circadian secretion pattern for ß-endorphin simulates the well-known circadian rhythm of cortisol. The answer to this may be in the fact that ß-endorphin and corticotropin stem from the same precursor. The illustrated circadian secretion pattern for leucine enkephalin simulates that of melatonin. The reason for this is unclear.

The structural determinants responsible for c-Fos protein proteasomal degradation differ according to the conditions of expression.

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Ferrara, Patrizia; Andermarcher, Elisabetta; Bossis, Guillaume; Acquaviva, Claire; Brockly, Frédérique; Jariel-Encontre, Isabelle; Piechaczyk, Marc

2003-03-13

c-fos gene is expressed constitutively in a number of tissues as well as in certain tumor cells and is inducible, in general rapidly and transiently, in virtually all other cell types by a variety of stimuli. Its protein product, c-Fos, is a short-lived transcription factor that heterodimerizes with various protein partners within the AP-1 transcription complex via leucine zipper/leucine zipper interactions for binding to specific DNA sequences. It is mostly, if not exclusively, degraded by the proteasome. To localize the determinant(s) responsible for its instability, we have conducted a genetic analysis in which the half-lives of c-Fos mutants and chimeras made with the stable EGFP reporter protein were compared under two experimental conditions taken as example of continous and inducible expression. Those were constitutive expression in asynchronously growing Balb/C 3T3 mouse embryo fibroblasts and transient induction in the same cells undergoing the G0/G1 phase transition upon stimulation by serum. Our work shows that c-Fos is degraded faster in synchronous- than in asynchronous cells. This difference in turnover is primarily accounted for by several mechanisms. First, in asynchronous cells, a unique C-terminal destabilizer is active whereas, in serum-stimulated cells two destabilizers located at both extremities of the protein are functional. Second, heterodimerization and/or binding to DNA accelerates protein degradation only during the G0/G1 phase transition. Adding another level of complexity to turnover control, phosphorylation at serines 362 and 374, which are c-Fos phosphorylation sites largely modified during the G0/G1 phase transition, stabilizes c-Fos much more efficiently in asynchronous than in serum-stimulated cells. In both cases, the reduced degradation rate is due to inhibition of the activity of the C-terminal destabilizer. However, in serum-stimulated cells, this effect is partially masked by the activation of the N-terminal destabilizer and

Glucocorticoids and fetal programming part 2: Mechanisms.

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Moisiadis, Vasilis G; Matthews, Stephen G

2014-07-01

The lifelong health of an individual is shaped during critical periods of development. The fetus is particularly susceptible to internal and external stimuli, many of which can alter developmental trajectories and subsequent susceptibility to disease. Glucocorticoids are critical in normal development of the fetus, as they are involved in the growth and maturation of many organ systems. The surge in fetal glucocorticoid levels that occurs in most mammalian species over the last few days of pregnancy is an important developmental switch leading to fundamental changes in gene regulation in many organs, including the brain. These changes are important for the transition to postnatal life. Exposure of the fetus to increased levels of glucocorticoids, resulting from maternal stress or treatment with synthetic glucocorticoids, can lead to long-term 'programming' of hypothalamic-pituitary-adrenal function and behaviours. Glucocorticoids act at multiple levels within the fetal brain. Growing evidence indicates that they can exert powerful effects on the epigenome, including on DNA methylation, histone acetylation and microRNA, to influence gene expression. Such influences probably represent a critical component of the 'programming' process, and might be partly responsible for the transgenerational effects of antenatal glucocorticoid exposure on neurologic, cardiovascular and metabolic function.

Glucocorticoids as mediators of developmental programming effects.

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Khulan, Batbayar; Drake, Amanda J

2012-10-01

Epidemiological evidence suggests that exposure to an adverse environment in early life is associated with an increased risk of cardio-metabolic and behavioral disorders in adulthood, a phenomenon termed 'early life programming'. One major hypothesis for early life programming is fetal glucocorticoid overexposure. In animal studies, prenatal glucocorticoid excess as a consequence of maternal stress or through exogenous administration to the mother or fetus is associated with programming effects on cardiovascular and metabolic systems and on the brain. These effects can be transmitted to subsequent generations. Studies in humans provide some evidence that prenatal glucocorticoid exposure may exert similar programming effects on glucose/insulin homeostasis, blood pressure and neurodevelopment. The mechanisms by which glucocorticoids mediate these effects are unclear but may include a role for epigenetic modifications. This review discusses the evidence for glucocorticoid programming in animal models and in humans. Copyright © 2012 Elsevier Ltd. All rights reserved.

Exogenous glucocorticoids and adverse cerebral effects in children

DEFF Research Database (Denmark)

Damsted, Sara K.; Born, A P; Paulson, Olaf B

2011-01-01

of the glucocorticoid receptor, which is associated with unfavorable cellular outcomes. Prenatal treatment with glucocorticoids can compromise brain growth and is associated with periventricular leukomalacia, attentions deficits and poorer cognitive performance. In the neonatal period exposure to glucocorticoids...... reduces neurogenesis and cerebral volume, impairs memory and increases the incidence of cerebral palsy. Cerebral effects of glucocorticoids in later childhood have been less thoroughly studied, but apparent brain atrophy, reduced size of limbic structures and neuropsychiatric symptoms have been reported....... Glucocortioids affect several cellular structures and functions, which may explain the observed adverse effects. Glucocorticoids can impair neuronal glucose uptake, decrease excitability, cause atrophy of dendrites, compromise development of myelin-producing oligodendrocytes and disturb important cellular...

Prophylactic pamidronate partially protects from glucocorticoid-induced bone loss in the mdx mouse model of Duchenne muscular dystrophy.

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Yoon, Sung-Hee; Chen, Jinghan; Grynpas, Marc D; Mitchell, Jane

2016-09-01

Glucocorticoids are extensively used to treat patients with Duchenne muscular dystrophy because of their ability to delay muscle damage, prolong ambulation and extend life. However, use of glucocorticoids significantly increases bone loss, fragility and fractures. To determine if antiresorptive bisphosphonates could prevent the effects of glucocorticoids on bone quality, we used dystrophic mdx mice treated with the glucocorticoid prednisone during 8weeks of rapid bone growth from 5 to 13weeks of age and treated some mice with the bisphosphonate pamidronate during the first two weeks of prednisone administration. Prednisone reduced long bone growth, decreased cortical bone thickness and area and decreased the strength of the femurs. Pamidronate treatment protected mice from cortical bone loss but did not increase bone strength. The combination of prednisone and pamidronate inhibited remodeling of metaphyseal trabecular bone with large numbers of trabeculae containing remnants of calcified cartilage. Prednisone improved muscle strength in the mdx mice and decreased serum creatine kinase with evidence of improved muscle histology and these effects were maintained in mice treated with pamidronate. Copyright © 2016. Published by Elsevier Inc.

Perioperative glucocorticoids in hip and knee surgery - benefit vs. harm?

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Lunn, T H; Kehlet, H

2013-01-01

with systemic glucocorticoid. Pain was reduced with high-dose systemic and local glucocorticoid, but not with low-dose systemic glucocorticoid. Systemic inflammatory markers were reduced with low-dose and high-dose systemic glucocorticoid, and with local glucocorticoid. Functional recovery was improved...... with local glucocorticoid. All studies were small-sized and none sufficiently powered to meaningfully evaluate uncommon adverse events. Most of the local administration studies had poor scientific quality (high risk of bias). Due to clinical heterogeneity and poor scientific quality, no meta......-analysis was performed. In conclusion, in addition to PONV reduction with low-dose systemic glucocorticoid, this review supports high-dose systemic glucocorticoid to ameliorate post-operative pain after hip and knee surgery. However, large-scale safety and dose-finding studies are warranted before final recommendations....

Comprehensive characterization and RNA-Seq profiling of the HD-Zip transcription factor family in soybean (Glycine max) during dehydration and salt stress

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The homeodomain leucine zipper (HD-Zip) transcription factor family is one of the largest plant specific superfamilies, and includes genes with roles in modulation of plant growth and response to environmental stresses. Many HD-Zip genes are well characterized in Arabidopsis (Arabidopsis thaliana), ...

Effect of glucocorticoids and gamma radiation on epidermal Langerhans cells

International Nuclear Information System (INIS)

Belsito, D.V.; Baer, R.L.; Thorbecke, G.J.; Gigli, I.

1984-01-01

The effect of 750 rads of gamma radiation on the rate of return of epidermal Langerhans cells (LC) following suppressive doses of topical glucorticoids was studied in guinea pigs. Gamma radiation alone had no effect on the LC as assessed by staining for cell membrane ATPase activity and Ia antigen. It did, however, delay the expected return of Ia but not ATPase surface markers on the LC after perturbation with glucocorticoids. The delayed return of surface Ia antigen is possibly related to a radiation-induced defect in the production of a required lymphokine and/or in intracellular Ia transport. Although our data do not rule out a cytolytic effect of steroids on the LC, they do strongly suggest that, at least in part, glucocorticoids act on the LC by altering cell surface characteristics

Leucine kinetics from (2H3)- and ( sup 13 C)leucine infused simultaneously by gut and vein

Energy Technology Data Exchange (ETDEWEB)

Hoerr, R.A.; Matthews, D.E.; Bier, D.M.; Young, V.R. (Massachusetts Institute of Technology, Cambridge (USA))

1991-01-01

In amino acid tracer kinetic studies of the fed state, ingested amino acid may be taken up during its initial transit through splanchnic tissues and thus not enter the plasma compartment where tracer is infused. To investigate this possibility, adult human subjects received simultaneous intravenous (iv) and intragastric (ig) leucine tracer infusions, first during a postabsorptive (PA) 4-h primed continuous ig infusion of L-(1-13C)-leucine and L-(5,5,5-2H3)leucine iv, followed on a separate day by a fed infusion, in which an ig infusion of a liquid formula was started 2 h before the tracer infusion and continued throughout the tracer study. Subjects were accustomed to a constant experimental diet supplying 1.5 g protein.kg-1.day-1 and 41-45 kcal.kg-1.day-1 for 7 and 12 days before the PA and fed studies, respectively. For the PA study, plasma enrichment for the ig tracer was 3.34 +/- 0.27 (SE) mol + excess and for the iv tracer it was 4.18 +/- 0.10 (P less than 0.02). Enrichments of alpha-keto-isocaproic acid (KIC) were 3.24 +/- 0.16 (ig) and 3.02 +/- 0.14 (iv), respectively (not significant (NS)). For the fed study, plasma leucine enrichment for the ig tracer was 2.15 +/- 0.14 and for the iv tracer was 2.84 +/- 0.09 (P less than 0.02). KIC enrichments were 2.02 +/- 0.08 (ig) and 2.24 +/- 0.08 (iv), respectively (NS). In the PA study, the ratio of the plasma leucine enrichments for the ig and iv tracers was 0.80 +/- 0.06 and in the fed experiment, 0.76 +/- 0.05, respectively.

Participation of ATM in cellular response to DNA damage induced by ionizing radiation

International Nuclear Information System (INIS)

Meng Xiangbing; Song Yi; Mao Jianping; Gong Bo; Dong Yan; Liu Bin; Sun Zhixian

2000-01-01

Objective: To clone ATM full length cDNA and cDNA fragments containing some functional domains and to identify proteins that interact with ATM and mediate DNA damage signal transduction in cellular response to DNA damage. Methods: ATM cDNA was amplified from MarthomTM-Ready cDNA kit of human leukocytes by LD-PCR. ATM-interacting proteins were screened by yeast two hybrid system. Results: ATM full-length cDNA and cDNA fragments containing PI3K kinase domain, leucine zipper and proline rich region were amplified from human cDNAs. Several candidate clones that interacted with ATM PI3K domain were identified. Conclusion: ATM mediates DNA damage signal transduction by interacting with many proteins

Altered lipid partitioning and glucocorticoid availability in CBG-deficient male mice with diet-induced obesity.

Science.gov (United States)

Gulfo, José; Ledda, Angelo; Serra, Elisabet; Cabot, Cristina; Esteve, Montserrat; Grasa, Mar

2016-08-01

To evaluate how deficiency in corticosteroid-binding globulin (CBG), the specific carrier of glucocorticoids, affects glucocorticoid availability and adipose tissue in obesity. C57BL/6 (WT) and CBG-deficient (KO) male mice were fed during 12 weeks with standard or hyperlipidic diet (HL). Glucocorticoid availability and metabolic parameters were assessed. Body weight and food intake were increased in KO compared with WT mice fed a standard diet and were similar when fed a HL diet. Expression of CBG was found in white adipose tissue by immunochemistry, real-time PCR, and Western blot. In obesity, the subcutaneous depot developed less in KO mice compared with WT, which was associated with a minor adipocyte area and peroxisome proliferator-activated receptor-γ expression. Conversely, the epididymal depot displayed higher weight and adipocyte area in KO than in WT mice. CBG deficiency caused a fall of hepatic 11β-hydroxysteroid dehydrogenase type 2 expression and an increase in epidymal adipose tissue, particularly in HL mice. Deficiency in CBG drives lipid partitioning from subcutaneous to visceral adipose depot under a context of lipid excess and differentially modulates 11β-hydroxysteroid dehydrogenase type 2 expression. © 2016 The Obesity Society.

Molecular mechanisms of glucocorticoid receptor signaling

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Marta Labeur

2010-10-01

Full Text Available This review highlights the most recent findings on the molecular mechanisms of the glucocorticoid receptor (GR. Most effects of glucocorticoids are mediated by the intracellular GR which is present in almost every tissue and controls transcriptional activation via direct and indirect mechanisms. Nevertheless the glucocorticoid responses are tissue -and gene- specific. GR associates selectively with corticosteroid ligands produced in the adrenal gland in response to changes of humoral homeostasis. Ligand interaction with GR promotes either GR binding to genomic glucocorticoid response elements, in turn modulating gene transcription, or interaction of GR monomers with other transcription factors activated by other signalling pathways leading to transrepression. The GR regulates a broad spectrum of physiological functions, including cell differentiation, metabolism and inflammatory responses. Thus, disruption or dysregulation of GR function will result in severe impairments in the maintenance of homeostasis and the control of adaptation to stress.

Using fecal glucocorticoids for stress assessment in Mourning Doves

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Washburn, Brian E.; Millspaugh, Joshua J.; Schulz, John H.; Jones, Susan B.; Mong, T.

2003-01-01

Fecal glucocorticoid assays provide a potentially useful, noninvasive means to study physiological responses of wildlife to various stressors. The objective of our study was to validate a method for measuring glucocorticoid metabolites in Mourning Dove (Zenaida macroura) feces. We validated the assay using standard procedures (e.g., parallelism, recovery of exogenous corticosterone) to demonstrate that the assay accurately and precisely measured glucocorticoid metabolites in Mourning Dove fecal extracts. We conducted adrenocorticotropin (ACTH) challenge experiments to validate the assay's ability to determine biologically important changes in fecal glucocorticoids. Fecal glucocorticoid levels increased significantly approximately 2-3 hr after administration of ACTH at 50 IU per kg body mass to wild Mourning Doves held in captivity. In contrast, fecal glucocorticoid metabolites did not increase in control birds, birds that received saline injections, or a lower dose of ACTH (1 IU per kg body mass). Variation in overall fecal glucocorticoid metabolite levels may have been influenced by season and the length of time birds were held in captivity. Non-invasive fecal glucocorticoid metabolite analyses, in combination with demographic information, may have considerable utility for monitoring the effects of natural and anthropogenic disturbances on Mourning Dove populations.

Excessive Leucine-mTORC1-Signalling of Cow Milk-Based Infant Formula: The Missing Link to Understand Early Childhood Obesity

OpenAIRE

Melnik, Bodo C.

2012-01-01

Increased protein supply by feeding cow-milk-based infant formula in comparison to lower protein content of human milk is a well-recognized major risk factor of childhood obesity. However, there is yet no conclusive biochemical concept explaining the mechanisms of formula-induced childhood obesity. It is the intention of this article to provide the biochemical link between leucine-mediated signalling of mammalian milk proteins and adipogenesis as well as early adipogenic programming. Leucine ...

Small leucine-rich proteoglycans in the aging skeleton

DEFF Research Database (Denmark)

Young, M F; Bi, Y; Ameye, L

2006-01-01

Small Leucine-Rich Proteoglyans (SLRPs) are major skeletal extracellular matrix (ECM) components that comprise a family of 13 members containing repeats of a leucine-rich motif. To examine SLRP function, we generated mice deficient in one or more member and analyzed them at the tissue, cell...

Systematic review of the clinical effect of glucocorticoids on nonhematologic malignancy

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Keith Bruce D

2008-03-01

Full Text Available Abstract Background Glucocorticoids are often used in the treatment of nonhematologic malignancy. This review summarizes the clinical evidence of the effect of glucocorticoid therapy on nonhematologic malignancy. Methods A systematic review of clinical studies of glucocorticoid therapy in patients with nonhematologic malignancy was undertaken. Only studies having endpoints of tumor response or tumor control or survival were included. PubMed, EMBASE, the Cochrane Register/Databases, conference proceedings (ASCO, AACR, ASTRO/ASTR, ESMO, ECCO and other resources were used. Data was extracted using a standard form. There was quality assessment of each study. There was a narrative synthesis of information, with presentation of results in tables. Where appropriate, meta-analyses were performed using data from published reports and a fixed effect model. Results Fifty four randomized controlled trials (RCTs, one meta-analysis, four phase l/ll trials and four case series met the eligibility criteria. Clinical trials of glucocorticoid monotherapy in breast and prostate cancer showed modest response rates. In advanced breast cancer meta-analyses, the addition of glucocorticoids to either chemotherapy or other endocrine therapy resulted in increased response rate, but not increased survival. In GI cancer, there was one RCT each of glucocorticoids vs. supportive care and chemotherapy +/- glucocorticoids; glucocorticoid effect was neutral. The only RCT found of chemotherapy +/- glucocorticoids, in which the glucocorticoid arm did worse, was in lung cancer. In glucocorticoid monotherapy, meta-analysis found that continuous high dose glucocorticoids had a detrimental effect on survival. The only other evidence, for a detrimental effect of glucocorticoid monotherapy, was in one of the two trials in lung cancer. Conclusion Glucocorticoid monotherapy has some benefit in breast and prostate cancer. In advanced breast cancer, the addition of glucocorticoids to other

Neutrophils are not less sensitive than other blood leukocytes to the genomic effects of glucocorticoids.

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Gaelle Hirsch

Full Text Available Neutrophils are generally considered less responsive to glucocorticoids compared to other inflammatory cells. The reported increase in human neutrophil survival mediated by these drugs partly supports this assertion. However, it was recently shown that dexamethasone exerts potent anti-inflammatory effects in equine peripheral blood neutrophils. Few comparative studies of glucocorticoid effects in neutrophils and other leukocytes have been reported and a relative insensitivity of neutrophils to these drugs could not be ruled out.We assessed glucocorticoid-responsiveness in equine and human peripheral blood neutrophils and neutrophil-depleted leukocytes.Blood neutrophils and neutrophil-depleted leukocytes were isolated from 6 healthy horses and 4 human healthy subjects. Cells were incubated for 5 h with or without LPS (100 ng/mL alone or combined with hydrocortisone, prednisolone or dexamethasone (10(-8 M and 10(-6 M. IL-1β, TNF-α, IL-8, glutamine synthetase and GR-α mRNA expression was quantified by qPCR. Equine neutrophils were also incubated for 20 h with or without the three glucocorticoids and cell survival was assessed by flow cytometry and light microscopy on cytospin preparations.We found that glucocorticoids down-regulated LPS-induced pro-inflammatory mRNA expression in both cell populations and species. These drugs also significantly increased glutamine synthetase gene expression in both equine cell populations. The magnitude of glucocorticoid response between cell populations was generally similar in both species. We also showed that dexamethasone had a comparable inhibitory effect on pro-inflammatory gene expression in both human and equine neutrophils. As reported in other species, glucocorticoids significantly increase the survival in equine neutrophils.Glucocorticoids exert genomic effects of similar magnitude on neutrophils and on other blood leukocytes. We speculate that the poor response to glucocorticoids observed in some

Neutrophils Are Not Less Sensitive Than Other Blood Leukocytes to the Genomic Effects of Glucocorticoids

Science.gov (United States)

Hirsch, Gaelle; Lavoie-Lamoureux, Anouk; Beauchamp, Guy; Lavoie, Jean-Pierre

2012-01-01

Background Neutrophils are generally considered less responsive to glucocorticoids compared to other inflammatory cells. The reported increase in human neutrophil survival mediated by these drugs partly supports this assertion. However, it was recently shown that dexamethasone exerts potent anti-inflammatory effects in equine peripheral blood neutrophils. Few comparative studies of glucocorticoid effects in neutrophils and other leukocytes have been reported and a relative insensitivity of neutrophils to these drugs could not be ruled out. Objective We assessed glucocorticoid-responsiveness in equine and human peripheral blood neutrophils and neutrophil-depleted leukocytes. Methods Blood neutrophils and neutrophil-depleted leukocytes were isolated from 6 healthy horses and 4 human healthy subjects. Cells were incubated for 5 h with or without LPS (100 ng/mL) alone or combined with hydrocortisone, prednisolone or dexamethasone (10−8 M and 10−6 M). IL-1β, TNF-α, IL-8, glutamine synthetase and GR-α mRNA expression was quantified by qPCR. Equine neutrophils were also incubated for 20 h with or without the three glucocorticoids and cell survival was assessed by flow cytometry and light microscopy on cytospin preparations. Results We found that glucocorticoids down-regulated LPS-induced pro-inflammatory mRNA expression in both cell populations and species. These drugs also significantly increased glutamine synthetase gene expression in both equine cell populations. The magnitude of glucocorticoid response between cell populations was generally similar in both species. We also showed that dexamethasone had a comparable inhibitory effect on pro-inflammatory gene expression in both human and equine neutrophils. As reported in other species, glucocorticoids significantly increase the survival in equine neutrophils. Conclusions Glucocorticoids exert genomic effects of similar magnitude on neutrophils and on other blood leukocytes. We speculate that the poor response to

Chronic Stress and Glucocorticoids: From Neuronal Plasticity to Neurodegeneration

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Sheela Vyas

2016-01-01

Full Text Available Stress and stress hormones, glucocorticoids (GCs, exert widespread actions in central nervous system, ranging from the regulation of gene transcription, cellular signaling, modulation of synaptic structure, and transmission and glial function to behavior. Their actions are mediated by glucocorticoid and mineralocorticoid receptors which are nuclear receptors/transcription factors. While GCs primarily act to maintain homeostasis by inducing physiological and behavioral adaptation, prolonged exposure to stress and elevated GC levels may result in neuro- and psychopathology. There is now ample evidence for cause-effect relationships between prolonged stress, elevated GC levels, and cognitive and mood disorders while the evidence for a link between chronic stress/GC and neurodegenerative disorders such as Alzheimer’s (AD and Parkinson’s (PD diseases is growing. This brief review considers some of the cellular mechanisms through which stress and GC may contribute to the pathogenesis of AD and PD.

Expression analysis of OsbZIP transcription factors in resistance ...

African Journals Online (AJOL)

zino

2013-08-21

Aug 21, 2013 ... Plant basic leucine zipper (bZIP) proteins play an essential role in the genes expression and regulation in higher plants. They have been shown to regulate diverse plant specific phenomena, including germination, floral induction and development, seed maturation, photomorphogenesis, biotic and.

Sequence Classification: 889214 [

Lifescience Database Archive (English)

Full Text Available elix-leucine zipper (bHLH/Zip) transcription factor that forms a complex with another bHLH/Zip protein, Rtg1p, to activate the retrog...rade (RTG) and TOR pathways; Rtg3p || http://www.ncbi.nlm.nih.gov/protein/6319365 ...

A p300 and SIRT1 Regulated Acetylation Switch of C/EBPα Controls Mitochondrial Function

NARCIS (Netherlands)

Zaini, Mohamad A; Müller, Christine; de Jong, Tristan V; Ackermann, Tobias; Hartleben, Götz; Kortman, Gertrud; Gührs, Karl-Heinz; Fusetti, Fabrizia; Krämer, Oliver H; Guryev, Victor; Calkhoven, Cornelis F

2018-01-01

Cellular metabolism is a tightly controlled process in which the cell adapts fluxes through metabolic pathways in response to changes in nutrient supply. Among the transcription factors that regulate gene expression and thereby cause changes in cellular metabolism is the basic leucine-zipper (bZIP)

Leucine metabolism in cirrhotic patients with hepatic encephalopathy

International Nuclear Information System (INIS)

McGhee, A.S.

1985-01-01

The purpose of this study was to determine whether increased oxidation of or protein synthesis requiring leucine occurs in cirrhotic patients. Five control subjects and four subjects with cirrhosis were equilibrated on a baseline diet (0.6 g protein per kg ideal body weight [IBW]) with sufficient nonprotein calories to preclude negative nitrogen balance. An additional four patients were equilibrated on the same type of diet with a higher protein level (0.75 g per kg IBW). Control subjects and the patients were then studied during continuous infusion of L-[ 15 N, 1- 13 C] leucine in the fasted state and, in the fed state, with a Propac diet which had the same distribution of energy nutrients as the baseline diets. Plasma levels of L-[ 15 N, 1- 13 C], L-[1- 13 C] and L-[ 15 N] leucine were measured during isotopic steady state by gas chromatography-mass spectrometry and fractional excretion of 13 CO 2 in breath samples were analyzed by isotopic ratio mass spectrometry. During the fasted and fed states leucine metabolism was measured to quantitate rates of nitrogen flux (Q/sub N/), carbon flux (Q/sub c/) and oxidation to carbon dioxide and water (C). From these measured values, proteins breakdown (B), protein synthesis (S), deamination (X 0 ) and reamination (X/sub N/) were calculated. The results showed that protein synthesis and leucine metabolism were identical in controls and patients when both were fed a diet with 0.6 g protein/kg IBW and maintenance level of nonprotein calories. The data also showed that leucine metabolism can be quantitatively and reproducibly measured in subjects with cirrhosis

Molecular Integration of Incretin and Glucocorticoid Action Reverses Immunometabolic Dysfunction and Obesity.

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Quarta, Carmelo; Clemmensen, Christoffer; Zhu, Zhimeng; Yang, Bin; Joseph, Sini S; Lutter, Dominik; Yi, Chun-Xia; Graf, Elisabeth; García-Cáceres, Cristina; Legutko, Beata; Fischer, Katrin; Brommage, Robert; Zizzari, Philippe; Franklin, Bernardo S; Krueger, Martin; Koch, Marco; Vettorazzi, Sabine; Li, Pengyun; Hofmann, Susanna M; Bakhti, Mostafa; Bastidas-Ponce, Aimée; Lickert, Heiko; Strom, Tim M; Gailus-Durner, Valerie; Bechmann, Ingo; Perez-Tilve, Diego; Tuckermann, Jan; Hrabě de Angelis, Martin; Sandoval, Darleen; Cota, Daniela; Latz, Eicke; Seeley, Randy J; Müller, Timo D; DiMarchi, Richard D; Finan, Brian; Tschöp, Matthias H

2017-10-03

Chronic inflammation has been proposed to contribute to the pathogenesis of diet-induced obesity. However, scarce therapeutic options are available to treat obesity and the associated immunometabolic complications. Glucocorticoids are routinely employed for the management of inflammatory diseases, but their pleiotropic nature leads to detrimental metabolic side effects. We developed a glucagon-like peptide-1 (GLP-1)-dexamethasone co-agonist in which GLP-1 selectively delivers dexamethasone to GLP-1 receptor-expressing cells. GLP-1-dexamethasone lowers body weight up to 25% in obese mice by targeting the hypothalamic control of feeding and by increasing energy expenditure. This strategy reverses hypothalamic and systemic inflammation while improving glucose tolerance and insulin sensitivity. The selective preference for GLP-1 receptor bypasses deleterious effects of dexamethasone on glucose handling, bone integrity, and hypothalamus-pituitary-adrenal axis activity. Thus, GLP-1-directed glucocorticoid pharmacology represents a safe and efficacious therapy option for diet-induced immunometabolic derangements and the resulting obesity. Copyright © 2017 Elsevier Inc. All rights reserved.

Nutritional efficiency of alpha-ketoisocaproate relative to leucine, assessed isotopically

International Nuclear Information System (INIS)

Kang, C.W.; Walser, M.

1985-01-01

The efficiency of alpha-ketoisocaproate as a dietary substitute for leucine was assessed in rats by two techniques: first, the minimal dose of alpha-ketoisocaproate required, as a supplement to a leucine-free diet, to achieve a growth rate as great as animals receiving leucine was found to be between 2.2 and 4.4 times larger. Therefore the nutritional efficiency of alpha-ketoisocaproate lies between 0.23 and 0.46. Second, alpha-[1- 14 C]-ketoisocaproate and [ 3 H]leucine were administered orally and the ratio of 14 C/ 3 H incorporated into the leucine of whole-body protein and fibrin was measured. This ratio, divided by the ratio 14 C/ 3 H injected, was the same in fibrin as in whole-body protein and averaged 0.39. Thus both techniques yield the same value, within the error of measurement, for the relative nutritional efficiency of alpha-ketoisocaproate. The authors also found that alpha-ketoisocaproate feeding at varying dosage did not alter this ratio in whole-body protein, suggesting that neither wide variations in growth rate nor exposure for 10 days to alpha-ketoisocaproate alters the relative rates of utilization (or oxidation) of alpha-ketoisocaproate vs. leucine

Nutritional efficiency of alpha-ketoisocaproate relative to leucine, assessed isotopically

Energy Technology Data Exchange (ETDEWEB)

Kang, C.W.; Walser, M.

1985-10-01

The efficiency of alpha-ketoisocaproate as a dietary substitute for leucine was assessed in rats by two techniques: first, the minimal dose of alpha-ketoisocaproate required, as a supplement to a leucine-free diet, to achieve a growth rate as great as animals receiving leucine was found to be between 2.2 and 4.4 times larger. Therefore the nutritional efficiency of alpha-ketoisocaproate lies between 0.23 and 0.46. Second, alpha-(1- UC)-ketoisocaproate and (TH)leucine were administered orally and the ratio of UC/TH incorporated into the leucine of whole-body protein and fibrin was measured. This ratio, divided by the ratio UC/TH injected, was the same in fibrin as in whole-body protein and averaged 0.39. Thus both techniques yield the same value, within the error of measurement, for the relative nutritional efficiency of alpha-ketoisocaproate. The authors also found that alpha-ketoisocaproate feeding at varying dosage did not alter this ratio in whole-body protein, suggesting that neither wide variations in growth rate nor exposure for 10 days to alpha-ketoisocaproate alters the relative rates of utilization (or oxidation) of alpha-ketoisocaproate vs. leucine.

Leucine supplementation in the management of protein energy ...

African Journals Online (AJOL)

Objective: To establish if leucine could be used as a therapeutic agent in the treatment of protein energy malnutrition. Study selection: Based on defined key words a search was carried out on Pubmed to retrieve all publications on leucine supplementation and muscle protein synthesis. Only studies that met the search ...

Glucocorticoids for the treatment of post-traumatic stress disorder and phobias: a novel therapeutic approach.

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de Quervain, Dominique J-F; Margraf, Jürgen

2008-04-07

Post-traumatic stress disorder (PTSD) and phobias belong to the most common anxiety disorders and to the most common psychiatric illnesses in general. In both disorders, aversive memories are thought to play an important role in the pathogenesis and symptomatology. Previously, we have reported that elevated glucocorticoid levels inhibit memory retrieval in animals and healthy humans. We therefore hypothesized that the administration of glucocorticoids might also inhibit the retrieval of aversive memory, thereby reducing symptoms in patients with PTSD and phobias. In recent clinical studies, we found first evidence to support this hypothesis. In patients with PTSD, low-dose cortisol treatment for one month reduced symptoms of traumatic memories without causing adverse side effects. Furthermore, we found evidence for a prolonged effect of the cortisol treatment. Persistent retrieval and reconsolidation of traumatic memories is a process that keeps these memories vivid and thereby the disorder alive. By inhibiting memory retrieval, cortisol may weaken the traumatic memory trace, and thus reduce symptoms even beyond the treatment period. In patients with social phobia, we found that a single oral administration of cortisone 1 h before a socio-evaluative stressor significantly reduced self-reported fear during the anticipation-, exposure-, and recovery phase of the stressor. In subjects with spider phobia, repeated oral administration of cortisol 1 h before exposure to a spider photograph induced a progressive reduction of stimulus-induced fear. This effect was maintained when subjects were exposed to the stimulus again two days after the last cortisol administration, indicating that cortisol facilitated the extinction of phobic fear. In conclusion, by a common mechanism of reducing the retrieval of aversive memories, glucocorticoids may be suited for the treatment of PTSD as well as phobias. More studies are needed to further evaluate the therapeutic efficacy of

Diretrizes para prevenção e tratamento da osteoporose induzida por glicocorticoide Guidelines for the prevention and treatment of glucocorticoid-induced osteoporosis

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Rosa Maria Rodrigues Pereira

2012-08-01

Full Text Available Os glicocorticoides (GC são prescritos por praticamente todas as especialidades médicas, e cerca de 0,5% da população geral do Reino Unido utiliza esses medicamentos. Com o aumento da sobrevida dos pacientes com doenças reumatológicas, a morbidade secundária ao uso dessa medicação representa um aspecto importante que deve ser considerado no manejo de nossos pacientes. As incidências de fraturas vertebrais e não vertebrais são elevadas, variando de 30%-50% em pessoas que usam GC por mais de três meses. Assim, a osteoporose e as fraturas por fragilidade devem ser prevenidas e tratadas em todos os pacientes que iniciarão ou que já estejam em uso desses esteroides. Diversas recomendações elaboradas por várias sociedades internacionais têm sido descritas na literatura, porém não há consenso entre elas. Recentemente, o Americam College of Rheumatology publicou novas recomendações, porém elas são fundamentadas na FRAX (WHO Fracture Risk Assessment Tool para analisar o risco de cada indivíduo e, dessa maneira, não podem ser completamente utilizadas pela população brasileira. Dessa forma, a Comissão de Osteoporose e Doenças Osteometabólicas da Sociedade Brasileira de Reumatologia, em conjunto com a Associação Médica Brasileira e a Associação Brasileira de Medicina Física e Reabilitação, implementou as diretrizes brasileiras de osteoporose induzida por glicocorticoide (OPIG, baseando-se na melhor evidência científica disponível e/ou experiência de experts. DESCRIÇÃO DO MÉTODO DE COLETA DE EVIDÊNCIA: A revisão bibliográfica de artigos científicos desta diretriz foi realizada na base de dados MEDLINE. A busca de evidência partiu de cenários clínicos reais, e utilizou as seguintes palavras-chave (MeSH terms: Osteoporosis, Osteoporosis/chemically induced*= (Glucocorticoids= Adrenal Cortex Hormones, Steroids, Glucocorticoids, Glucocorticoids/administration and dosage, Glucocorticoids/therapeutic use

Sestrin regulation of TORC1: Is Sestrin a leucine sensor?

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Lee, Jun Hee; Cho, Uhn-Soo; Karin, Michael (Michigan); (UCSD)

2016-06-07

Sestrins are highly conserved, stress-inducible proteins that inhibit target of rapamycin complex 1 (TORC1) signaling. After their transcriptional induction, both vertebrate and invertebrate Sestrins turn on the adenosine monophosphate (AMP)–activated protein kinase (AMPK), which activates the tuberous sclerosis complex (TSC), a key inhibitor of TORC1 activation. However, Sestrin overexpression, on occasion, can result in TORC1 inhibition even in AMPK-deficient cells. This effect has been attributed to Sestrin’s ability to bind the TORC1-regulating GATOR2 protein complex, which was postulated to control trafficking of TORC1 to lysosomes. How the binding of Sestrins to GATOR2 is regulated and how it contributes to TORC1 inhibition are unknown. New findings suggest that the amino acid leucine specifically disrupts the association of Sestrin2 with GATOR2, thus explaining how leucine and related amino acids stimulate TORC1 activity. We discuss whether and how these findings fit what has already been learned about Sestrin-mediated TORC1 inhibition from genetic studies conducted in fruit flies and mammals.

Differentiating leucine incorporation of

NARCIS (Netherlands)

Yokokawa, T.; Sintes, E.; de Corte, D.; Olbrich, K.; Herndl, G.J.

2012-01-01

The abundance (based on catalyzed reporter deposition-fluorescence in situ hybrid ization, CARD-FISH) and leucine incorporation rates of Archaea and Bacteria were determined throughout the water column in the eastern Atlantic. Bacteria dominated throughout the water column, although their

Model of how plants sense zinc deficiency

DEFF Research Database (Denmark)

Assuncao, Ana G.L.; Persson, Daniel Olof; Husted, Søren

2013-01-01

to develop plant-based solutions addressing nutrient-use-efficiency and adaptation to nutrient-limited or -toxic soils. Recently two transcription factors of the bZIP family (basic-region leucine zipper) have been identified in Arabidopsis and shown to be pivotal in the adaptation response to zinc deficiency...

Molecular mechanisms of glucocorticoid receptor signaling Mecanismos moleculares de señalización del receptor de glucocorticoides

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Marta Labeur

2010-10-01

Full Text Available This review highlights the most recent findings on the molecular mechanisms of the glucocorticoid receptor (GR. Most effects of glucocorticoids are mediated by the intracellular GR which is present in almost every tissue and controls transcriptional activation via direct and indirect mechanisms. Nevertheless the glucocorticoid responses are tissue -and gene- specific. GR associates selectively with corticosteroid ligands produced in the adrenal gland in response to changes of humoral homeostasis. Ligand interaction with GR promotes either GR binding to genomic glucocorticoid response elements, in turn modulating gene transcription, or interaction of GR monomers with other transcription factors activated by other signalling pathways leading to transrepression. The GR regulates a broad spectrum of physiological functions, including cell differentiation, metabolism and inflammatory responses. Thus, disruption or dysregulation of GR function will result in severe impairments in the maintenance of homeostasis and the control of adaptation to stress.Esta revisión destaca los más recientes hallazgos sobre los mecanismos moleculares del receptor de glucocorticoides (GR. La mayoría de los efectos de los glucocorticoides son mediados por los GR intracelulares presentes en casi todos los tejidos y controlan la activación transcripcional por mecanismos directos e indirectos. Las respuestas a los glucocorticoides son específicas para cada gen y tejido. Los GR se asocian en forma selectiva con ligandos producidos en la glándula adrenal, corticosteroides, en respuesta a cambios neuroendocrinos. La interacción del ligando con el GR promueve: a la unión del GR a elementos genómicos de respuesta a glucocorticoides, modulando la transcripción; b la interacción de monómeros del GR con otros factores de transcripción activados por otras vías, llevando a la transrepresión. El GR regula un amplio espectro de funciones fisiológicas, incluyendo la

Dominance rank causally affects personality and glucocorticoid regulation in female rhesus macaques

Science.gov (United States)

Kohn, Jordan N.; Snyder-Mackler, Noah; Barreiro, Luis B.; Johnson, Zachary P.; Tung, Jenny; Wilson, Mark E.

2017-01-01

Low social status is frequently associated with heightened exposure to social stressors and altered glucocorticoid regulation by the hypothalamic-pituitary-adrenal (HPA) axis. Additionally, personality differences can affect how individuals behave in response to social conditions, and thus may aggravate or protect against the effects of low status on HPA function. Disentangling the relative importance of personality from the effects of the social environment on the HPA axis has been challenging, since social status can predict aspects of behavior, and both can remain stable across the lifespan. To do so here, we studied an animal model of social status and social behavior, the rhesus macaque (Macaca mulatta). We performed two sequential experimental manipulations of dominance rank (i.e., social status) in 45 adult females, allowing us to characterize personality and glucocorticoid regulation (based on sensitivity to the exogenous glucocorticoid dexamethasone) in each individual while she occupied two different dominance ranks. We identified two behavioral characteristics, termed ‘social approachability’ and ‘boldness,’ which were highly social status-dependent. Social approachability and a third dimension, anxiousness, were also associated with cortisol dynamics in low status females, suggesting that behavioral tendencies may sensitize individuals to the effects of low status on HPA axis function. Finally, we found that improvements in dominance rank increased dexamethasone-induced acute cortisol suppression and glucocorticoid negative feedback. Our findings indicate that social status causally affects both behavioral tendencies and glucocorticoid regulation, and that some behavioral tendencies also independently affect cortisol levels, beyond the effects of rank. Together, they highlight the importance of considering personality and social status together when investigating their effects on HPA axis function. PMID:27639059

Autophagy and leucine promote chronological longevity and respiration proficiency during calorie restriction in yeast.

Science.gov (United States)

Aris, John P; Alvers, Ashley L; Ferraiuolo, Roy A; Fishwick, Laura K; Hanvivatpong, Amanda; Hu, Doreen; Kirlew, Christine; Leonard, Michael T; Losin, Kyle J; Marraffini, Michelle; Seo, Arnold Y; Swanberg, Veronica; Westcott, Jennifer L; Wood, Michael S; Leeuwenburgh, Christiaan; Dunn, William A

2013-10-01

We have previously shown that autophagy is required for chronological longevity in the budding yeast Saccharomyces cerevisiae. Here we examine the requirements for autophagy during extension of chronological life span (CLS) by calorie restriction (CR). We find that autophagy is upregulated by two CR interventions that extend CLS: water wash CR and low glucose CR. Autophagy is required for full extension of CLS during water wash CR under all growth conditions tested. In contrast, autophagy was not uniformly required for full extension of CLS during low glucose CR, depending on the atg allele and strain genetic background. Leucine status influenced CLS during CR. Eliminating the leucine requirement in yeast strains or adding supplemental leucine to growth media extended CLS during CR. In addition, we observed that both water wash and low glucose CR promote mitochondrial respiration proficiency during aging of autophagy-deficient yeast. In general, the extension of CLS by water wash or low glucose CR was inversely related to respiration deficiency in autophagy-deficient cells. Also, autophagy is required for full extension of CLS under non-CR conditions in buffered media, suggesting that extension of CLS during CR is not solely due to reduced medium acidity. Thus, our findings show that autophagy is: (1) induced by CR, (2) required for full extension of CLS by CR in most cases (depending on atg allele, strain, and leucine availability) and, (3) promotes mitochondrial respiration proficiency during aging under CR conditions. Copyright © 2013 Elsevier Inc. All rights reserved.

Dietary leucine--an environmental modifier of insulin resistance acting on multiple levels of metabolism.

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Yazmin Macotela

Full Text Available Environmental factors, such as the macronutrient composition of the diet, can have a profound impact on risk of diabetes and metabolic syndrome. In the present study we demonstrate how a single, simple dietary factor--leucine--can modify insulin resistance by acting on multiple tissues and at multiple levels of metabolism. Mice were placed on a normal or high fat diet (HFD. Dietary leucine was doubled by addition to the drinking water. mRNA, protein and complete metabolomic profiles were assessed in the major insulin sensitive tissues and serum, and correlated with changes in glucose homeostasis and insulin signaling. After 8 weeks on HFD, mice developed obesity, fatty liver, inflammatory changes in adipose tissue and insulin resistance at the level of IRS-1 phosphorylation, as well as alterations in metabolomic profile of amino acid metabolites, TCA cycle intermediates, glucose and cholesterol metabolites, and fatty acids in liver, muscle, fat and serum. Doubling dietary leucine reversed many of the metabolite abnormalities and caused a marked improvement in glucose tolerance and insulin signaling without altering food intake or weight gain. Increased dietary leucine was also associated with a decrease in hepatic steatosis and a decrease in inflammation in adipose tissue. These changes occurred despite an increase in insulin-stimulated phosphorylation of p70S6 kinase indicating enhanced activation of mTOR, a phenomenon normally associated with insulin resistance. These data indicate that modest changes in a single environmental/nutrient factor can modify multiple metabolic and signaling pathways and modify HFD induced metabolic syndrome by acting at a systemic level on multiple tissues. These data also suggest that increasing dietary leucine may provide an adjunct in the management of obesity-related insulin resistance.

A leucine-supplemented diet improved protein content of skeletal muscle in young tumor-bearing rats

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Gomes-Marcondes M.C.C.

2003-01-01

Full Text Available Cancer cachexia induces host protein wastage but the mechanisms are poorly understood. Branched-chain amino acids play a regulatory role in the modulation of both protein synthesis and degradation in host tissues. Leucine, an important amino acid in skeletal muscle, is higher oxidized in tumor-bearing animals. A leucine-supplemented diet was used to analyze the effects of Walker 256 tumor growth on body composition in young weanling Wistar rats divided into two main dietary groups: normal diet (N, 18% protein and leucine-rich diet (L, 15% protein plus 3% leucine, which were further subdivided into control (N or L or tumor-bearing (W or LW subgroups. After 12 days, the animals were sacrificed and their carcass analyzed. The tumor-bearing groups showed a decrease in body weight and fat content. Lean carcass mass was lower in the W and LW groups (W = 19.9 ± 0.6, LW = 23.1 ± 1.0 g vs N = 29.4 ± 1.3, L = 28.1 ± 1.9 g, P < 0.05. Tumor weight was similar in both tumor-bearing groups fed either diet. Western blot analysis showed that myosin protein content in gastrocnemius muscle was reduced in tumor-bearing animals (W = 0.234 ± 0.033 vs LW = 0.598 ± 0.036, N = 0.623 ± 0.062, L = 0.697 ± 0.065 arbitrary intensity, P < 0.05. Despite accelerated tumor growth, LW animals exhibited a smaller reduction in lean carcass mass and muscle myosin maintenance, suggesting that excess leucine in the diet could counteract, at least in part, the high host protein wasting in weanling tumor-bearing rats.

Interaction of basal forebrain cholinergic neurons with the glucocorticoid system in stress regulation and cognitive impairment

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Saswati ePaul

2015-04-01

Full Text Available A substantial number of studies on basal forebrain cholinergic neurons (BFCN have provided compelling evidence for their role in the etiology of stress, cognitive aging, Alzheimer’s disease (AD, and other neurodegenerative diseases. BFCN project to a broad range of cortical sites and limbic structures, including the hippocampus, and are involved in stress and cognition. In particular, the hippocampus, the primary target tissue of the glucocorticoid stress hormones, is associated with cognitive function in tandem with hypothalamic-pituitary-adrenal (HPA axis modulation. The present review summarizes glucocorticoid and HPA axis research to date in an effort to establish the manner in which stress affects the release of acetylcholine, glucocorticoids, and their receptor in the context of cognitive processes. We attempt to provide the molecular interactive link between the glucocorticoids and cholinergic system that contributes to BFCN degeneration in stress-induced acceleration of cognitive decline in aging and AD. We also discuss the importance of animal models in facilitating such studies for pharmacological use, which could help decipher disease states and propose leads for pharmacological intervention.

At same leucine intake, a whey/plant protein blend is not as effective as whey to initiate a transient post prandial muscle anabolic response during a catabolic state in mini pigs.

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Aurélia Revel

Full Text Available Muscle atrophy has been explained by an anabolic resistance following food intake and an increase of dietary protein intake is recommended. To be optimal, a dietary protein has to be effective not only to initiate but also to prolong a muscle anabolic response in a catabolic state. To our knowledge, whether or not a dairy or a dairy/plant protein blend fulfills these criterions is unknown in a muscle wasting situation.Our aim was, in a control and a catabolic state, to measure continuously muscle anabolism in term of intensity and duration in response to a meal containing casein (CAS, whey (WHEY or a whey/ plant protein blend (BLEND and to evaluate the best protein source to elicit the best post prandial anabolism according to the physio-pathological state.Adult male Yucatan mini pigs were infused with U-13C-Phenylalanine and fed either CAS, WHEY or BLEND. A catabolic state was induced by a glucocorticoid treatment for 8 days (DEX. Muscle protein synthesis, proteolysis and balance were measured with the hind limb arterio-venous differences technique. Repeated time variance analysis were used to assess significant differences.In a catabolic situation, whey proteins were able to initiate muscle anabolism which remained transient in contrast to the stimulated muscle protein accretion with WHEY, CAS or BLEND in healthy conditions. Despite the same leucine intake compared to WHEY, BLEND did not restore a positive protein balance in DEX animals.Even with WHEY, the duration of the anabolic response was not optimal and has to be improved in a catabolic state. The use of BLEND remained of lower efficiency even at same leucine intake than whey.

Cloaked similarity between HIV-1 and SARS-CoV suggests an anti-SARS strategy

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Kliger Yossef

2003-09-01

Full Text Available Abstract Background Severe acute respiratory syndrome (SARS is a febrile respiratory illness. The disease has been etiologically linked to a novel coronavirus that has been named the SARS-associated coronavirus (SARS-CoV, whose genome was recently sequenced. Since it is a member of the Coronaviridae, its spike protein (S2 is believed to play a central role in viral entry by facilitating fusion between the viral and host cell membranes. The protein responsible for viral-induced membrane fusion of HIV-1 (gp41 differs in length, and has no sequence homology with S2. Results Sequence analysis reveals that the two viral proteins share the sequence motifs that construct their active conformation. These include (1 an N-terminal leucine/isoleucine zipper-like sequence, and (2 a C-terminal heptad repeat located upstream of (3 an aromatic residue-rich region juxtaposed to the (4 transmembrane segment. Conclusions This study points to a similar mode of action for the two viral proteins, suggesting that anti-viral strategy that targets the viral-induced membrane fusion step can be adopted from HIV-1 to SARS-CoV. Recently the FDA approved Enfuvirtide, a synthetic peptide corresponding to the C-terminal heptad repeat of HIV-1 gp41, as an anti-AIDS agent. Enfuvirtide and C34, another anti HIV-1 peptide, exert their inhibitory activity by binding to a leucine/isoleucine zipper-like sequence in gp41, thus inhibiting a conformational change of gp41 required for its activation. We suggest that peptides corresponding to the C-terminal heptad repeat of the S2 protein may serve as inhibitors for SARS-CoV entry.

Midlife stress alters memory and mood-related behaviors in old age: Role of locally activated glucocorticoids.

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Wheelan, Nicola; Kenyon, Christopher J; Harris, Anjanette P; Cairns, Carolynn; Al Dujaili, Emad; Seckl, Jonathan R; Yau, Joyce L W

2018-03-01

Chronic exposure to stress during midlife associates with subsequent age-related cognitive decline and may increase the vulnerability to develop psychiatric conditions. Increased hypothalamic-pituitary-adrenal (HPA) axis activity has been implicated in pathogenesis though any causative role for glucocorticoids is unestablished. This study investigated the contribution of local glucocorticoid regeneration by the intracellular enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), in persisting midlife stress-induced behavioral effects in mice. Middle-aged (10 months old) 11β-HSD1-deficient mice and wild-type congenic controls were randomly assigned to 28 days of chronic unpredictable stress or left undisturbed (non-stressed). All mice underwent behavioral testing at the end of the stress/non-stress period and again 6-7 months later. Chronic stress impaired spatial memory in middle-aged wild-type mice. The effects, involving a wide spectrum of behavioral modalities, persisted for 6-7 months after cessation of stress into early senescence. Enduring effects after midlife stress included impaired spatial memory, enhanced contextual fear memory, impaired fear extinction, heightened anxiety, depressive-like behavior, as well as reduced hippocampal glucocorticoid receptor mRNA expression. In contrast, 11β-HSD1 deficient mice resisted both immediate and enduring effects of chronic stress, despite similar stress-induced increases in systemic glucocorticoid activity during midlife stress. In conclusion, chronic stress in midlife exerts persisting effects leading to cognitive and affective dysfunction in old age via mechanisms that depend, at least in part, on brain glucocorticoids generated locally by 11β-HSD1. This finding supports selective 11β-HSD1 inhibition as a novel therapeutic target to ameliorate the long-term consequences of stress-related psychiatric disorders in midlife. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Prostate Cancer Cells in Different Androgen Receptor Status Employ Different Leucine Transporters.

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Otsuki, Hideo; Kimura, Toru; Yamaga, Takashi; Kosaka, Takeo; Suehiro, Jun-Ichi; Sakurai, Hiroyuki

2017-02-01

Leucine stimulates cancer cell proliferation through the mTOR pathway, therefore, inhibiting leucine transporters may be a novel therapeutic target for cancer. L-type amino acid transporter (LAT) 1, a Na + -independent amino acid transporter, is highly expressed in many tumor cells. However, leucine transporter(s) in different stages of prostate cancer, particularly in the stages of castration resistance with androgen receptor (AR) expression, is unclear. LNCaP and DU145 and PC-3 cell lines were used as a model of androgen dependent, and metastatic prostate cancer. A new "LN-cr" cell line was established after culturing LNCaP cells for 6 months under androgen-free conditions, which is considered a model of castration resistant prostate cancer (CRPC) with androgen AR expression. The expression of leucine transporters was investigated with quantitative PCR and immunofluorescence. Uptake of 14 C Leucine was examined in the presence or absence of BCH (a pan-LAT inhibitor), JPH203 (an LAT1-specific inhibitor), or Na + . Cell growth was assessed with MTT assay. siRNA studies were performed to evaluate the indispensability of y + LAT2 on leucine uptake and cell viability in LN-cr. Cell viability showed a 90% decrease in the absence of leucine in all four cell lines. LNCaP cells principally expressed LAT3, and their leucine uptake was more than 90% Na + -independent. BCH, but not JPH203, inhibited leucine uptake, and cell proliferation (IC 50BCH :15 mM). DU145 and PC-3 cells predominantly expressed LAT1. Leucine uptake and cell growth were suppressed by BCH or JPH203 in a dose-dependent manner (IC 50BCH : ∼20 mM, IC 50JPH203 : ∼5 µM). In LN-cr cells, Na + -dependent uptake of leucine was 3.8 pmol/mgprotein/min, while, Na + -independent uptake was only 0.52 (P prostate cancer. Prostate 77:222-233, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Alcohol dysregulates corticotropin-releasing-hormone (CRH promoter activity by interfering with the negative glucocorticoid response element (nGRE.

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Magdalena M Przybycien-Szymanska

Full Text Available EtOH exposure in male rats increases corticotropin-releasing hormone (CRH mRNA in the paraventricular nucleus of the hypothalamus (PVN, a brain region responsible for coordinating stress and anxiety responses. In this study we identified the molecular mechanisms involved in mediating these effects by examining the direct effects of EtOH on CRH promoter activity in a neuronal cell line derived from the PVN (IVB. In addition, we investigated the potential interactions of EtOH and glucocorticoids on the CRH promoter by concomitantly treating cells with EtOH and the glucocorticoid receptor (GR antagonist RU486, and by sequentially deleting GR binding sites within glucocorticoid response element (GRE on the CRH promoter. Cells were transiently transfected with a firefly luciferase reporter construct containing 2.5 kb of the rat wild type (WT or mutated CRH promoter. Our results showed that EtOH treatment induced a biphasic response in CRH promoter activity. EtOH exposure for 0.5 h significantly decreased promoter activity compared to vehicle treated controls, whereas promoter activity was significantly increased after 2.0 h of EtOH exposure. Treatment with RU486, or deletion of the GR binding sites 1 and 2 within the GRE, abolished the EtOH-induced increase in the promoter activity, however did not affect EtOH-induced decrease in CRH promoter activity at an earlier time point. Overall, our data suggest that alcohol exposure directly regulates CRH promoter activity by interfering with the normal feedback mechanisms of glucocorticoids mediated by GR signaling at the GRE site of the CRH promoter.

Proliferation related acidic leucine-rich protein PAL31 functions as a caspase-3 inhibitor

International Nuclear Information System (INIS)

Sun Weiyong; Kimura, Hiromichi; Hattori, Naka; Tanaka, Satoshi; Matsuyama, Shigemi; Shiota, Kunio

2006-01-01

Proliferation related acidic leucine-rich protein PAL31 (PAL31) is expressed in proliferating cells and consists of 272 amino acids with a tandem structure of leucine-rich repeats in the N-terminus and a highly acidic region with a putative nuclear localization signal in the C-terminus. We previously reported that PAL31 is required for cell cycle progression. In the present study, we found that the antisense oligonucleotide of PAL31 induced apoptosis to the transfected Nb2 cells. Stable transfectants, in which PAL31 was regulated by an inducible promoter, were generated to gain further insight into the signaling role of PAL31 in the regulation of apoptosis. Expression of PAL31 resulted in the marked rescue of Rat1 cells from etoposide and UV radiation-induced apoptosis and the cytoprotection was correlated with the levels of PAL31 protein. Thus, cytoprotection from apoptosis is a physiological function of PAL31. PAL31 can suppress caspase-3 activity but not cytochrome c release in vitro, indicating that PAL31 is a direct caspase-3 inhibitor. In conclusion, PAL31 is a multifunctional protein working as a cell cycle progression factor as well as a cell survival factor

The Effect of Oral Leucine on Protein Metabolism in Adolescents with Type 1 Diabetes Mellitus

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Wilson ThomasA

2010-11-01

Full Text Available Lack of insulin results in a catabolic state in subjects with insulin-dependent diabetes mellitus which is reversed by insulin treatment. Amino acid supply, especially branched chain amino acids such as leucine, enhances protein synthesis in both animal and human studies. This small study was undertaken to assess the acute effect of supplemental leucine on protein metabolism in adolescents with type 1 diabetes. L-[1-13C] Leucine was used to assess whole-body protein metabolism in six adolescent females (16–18 yrs with type 1 diabetes during consumption of a basal diet (containing 58 μmoles leucine/kg/h and the basal diet with supplemental leucine (232 μmoles leucine/kg/h. Net leucine balance was significantly higher with supplemental leucine ( μmoles leucine/kg body weight/hr than with the basal diet (, due to reduced protein degradation ( μmoles leucine/kg body weight/hr compared to the basal diet (, .

N-myristoylated ubiquitin ligase Cbl-b inhibitor prevents on glucocorticoid-induced atrophy in mouse skeletal muscle.

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Ochi, Arisa; Abe, Tomoki; Nakao, Reiko; Yamamoto, Yoriko; Kitahata, Kanako; Takagi, Marina; Hirasaka, Katsuya; Ohno, Ayako; Teshima-Kondo, Shigetada; Taesik, Gwag; Choi, Inho; Kawamura, Tomoyuki; Nemoto, Hisao; Mukai, Rie; Terao, Junji; Nikawa, Takeshi

2015-03-15

A DGpYMP peptide mimetic of tyrosine(608)-phosphorylated insulin receptor substrate-1 (IRS-1), named Cblin, was previously shown to significantly inhibit Cbl-b-mediated IRS-1 ubiquitination. In the present study, we developed N-myristoylated Cblin and investigated whether it was effective in preventing glucocorticoid-induced muscle atrophy. Using HEK293 cells overexpressing Cbl-b, IRS-1 and ubiquitin, we showed that the 50% inhibitory concentrations of Cbl-b-mediated IRS-1 ubiquitination by N-myristoylated Cblin and Cblin were 30 and 120 μM, respectively. Regarding the DEX-induced atrophy of C2C12 myotubes, N-myristoylated Cblin was more effective than Cblin for inhibiting the DEX-induced decreases in C2C12 myotube diameter and IRS-1 degradation. The inhibitory efficacy of N-myristoylated Cblin on IRS-1 ubiquitination in C2C12 myotubes was approximately fourfold larger than that of Cblin. Furthermore, N-myristoylation increased the incorporation of Cblin into HEK293 cells approximately 10-folds. Finally, we demonstrated that N-myristoylated Cblin prevented the wet weight loss, IRS-1 degradation, and MAFbx/atrogin-1 and MuRF-1 expression in gastrocnemius muscle of DEX-treated mice approximately fourfold more effectively than Cblin. Taken together, these results suggest that N-myristoylated Cblin prevents DEX-induced skeletal muscle atrophy in vitro and in vivo, and that N-myristoylated Cblin more effectively prevents muscle atrophy than unmodified Cblin. Copyright © 2015 Elsevier Inc. All rights reserved.

Conformational composition of neutral leucine. Matrix isolation infrared and ab initio study

International Nuclear Information System (INIS)

Stepanian, Stepan G.; Ivanov, Alexander Yu.; Adamowicz, Ludwik

2013-01-01

Highlights: • FTIR spectra of leucine isolated in argon, neon and xenon matrices are obtained. • UV irradiation is used to separate bands of the leucine conformers. • Populations of the leucine conformers is determined. - Abstract: Low-temperature matrix-isolation FTIR spectroscopy and ab initio calculations are employed to determine conformational composition of neutral leucine. The presence of three leucine conformers in the matrices is revealed. This is in agreement with the results of a detailed study of the potential energy surface of leucine which demonstrates that only five out of 105 possible conformers should have populations in the matrices larger than 2% and only three conformers, which are the ones detected in the experiment, should have populations larger than 10%. UV irradiation of the matrix samples are used to separate bands of the different conformers. We also show that the populations of the leucine conformers in the gas phase at 440 K are significantly different from the ones in matrices. The population of the lowest energy conformer in the gas phase being approximately 23% in the gas phase increases to over 64% in matrices

A zipper network model of the failure mechanics of extracellular matrices.

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Ritter, Michael C; Jesudason, Rajiv; Majumdar, Arnab; Stamenovic, Dimitrije; Buczek-Thomas, Jo Ann; Stone, Phillip J; Nugent, Matthew A; Suki, Béla

2009-01-27

Mechanical failure of soft tissues is characteristic of life-threatening diseases, including capillary stress failure, pulmonary emphysema, and vessel wall aneurysms. Failure occurs when mechanical forces are sufficiently high to rupture the enzymatically weakened extracellular matrix (ECM). Elastin, an important structural ECM protein, is known to stretch beyond 200% strain before failing. However, ECM constructs and native vessel walls composed primarily of elastin and proteoglycans (PGs) have been found to fail at much lower strains. In this study, we hypothesized that PGs significantly contribute to tissue failure. To test this, we developed a zipper network model (ZNM), in which springs representing elastin are organized into long wavy fibers in a zipper-like formation and placed within a network of springs mimicking PGs. Elastin and PG springs possessed distinct mechanical and failure properties. Simulations using the ZNM showed that the failure of PGs alone reduces the global failure strain of the ECM well below that of elastin, and hence, digestion of elastin does not influence the failure strain. Network analysis suggested that whereas PGs drive the failure process and define the failure strain, elastin determines the peak and failure stresses. Predictions of the ZNM were experimentally confirmed by measuring the failure properties of engineered elastin-rich ECM constructs before and after digestion with trypsin, which cleaves the core protein of PGs without affecting elastin. This study reveals a role for PGs in the failure properties of engineered and native ECM with implications for the design of engineered tissues.

Acetone Formation in the Vibrio Family: a New Pathway for Bacterial Leucine Catabolism

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Nemecek-Marshall, Michele; Wojciechowski, Cheryl; Wagner, William P.; Fall, Ray

1999-01-01

There is current interest in biological sources of acetone, a volatile organic compound that impacts atmospheric chemistry. Here, we determined that leucine-dependent acetone formation is widespread in the Vibrionaceae. Sixteen Vibrio isolates, two Listonella species, and two Photobacterium angustum isolates produced acetone in the presence of l-leucine. Shewanella isolates produced much less acetone. Growth of Vibrio splendidus and P. angustum in a fermentor with controlled aeration revealed that acetone was produced after a lag in late logarithmic or stationary phase of growth, depending on the medium, and was not derived from acetoacetate by nonenzymatic decarboxylation in the medium. l-Leucine, but not d-leucine, was converted to acetone with a stoichiometry of approximately 0.61 mol of acetone per mol of l-leucine. Testing various potential leucine catabolites as precursors of acetone showed that only α-ketoisocaproate was efficiently converted by whole cells to acetone. Acetone production was blocked by a nitrogen atmosphere but not by electron transport inhibitors, suggesting that an oxygen-dependent reaction is required for leucine catabolism. Metabolic labeling with deuterated (isopropyl-d7)-l-leucine revealed that the isopropyl carbons give rise to acetone with full retention of deuterium in each methyl group. These results suggest the operation of a new catabolic pathway for leucine in vibrios that is distinct from the 3-hydroxy-3-methylglutaryl-coenzyme A pathway seen in pseudomonads. PMID:10601206

Leucine zipper transcription factor-like 1 expression in gastric ...

African Journals Online (AJOL)

the gastric cancer tissues, and its relationship to cellular adhesion protein. ... related to cellular adhesion protein, but not to mRNA level. ... malignant tumors, and is correlated with gastric, ... The present study was aimed at investigating the.

Are BDNF and glucocorticoid activities calibrated?

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Jeanneteau, Freddy; Chao, Moses V.

2012-01-01

One hypothesis to account for the onset and severity of neurological disorders is the loss of trophic support. Indeed, changes in the levels and activities of brain-derived neurotrophic factor (BDNF) occur in numerous neurodegenerative and neuropsychiatric diseases. A deficit promotes vulnerability whereas a gain of function facilitates recovery by enhancing survival, synapse formation and synaptic plasticity. Implementation of ‘BDNF therapies’, however, faces numerous methodological and pharmacokinetic issues. Identifying BDNF mimetics that activate the BDNF receptor or downstream targets of BDNF signaling represent an alternative approach. One mechanism that shows great promise is to study the interplay of BDNF and glucocorticoid hormones, a major class of natural steroid secreted during stress reactions and in synchrony with circadian rhythms. While small amounts of glucocorticoids support normal brain function, excess stimulation by these steroid hormones precipitate stress-related affective disorders. To date, however, because of the paucity of knowledge of underlying cellular mechanisms, deleterious effects of glucocorticoids are not prevented following extreme stress. In the present review, we will discuss the complementary roles share by BDNF and glucocorticoids in synaptic plasticity, and delineate possible signaling mechanisms mediating these effects. PMID:23022538

The role of glucocorticoids in emotional memory reconsolidation.

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Meir Drexler, Shira; Wolf, Oliver T

2017-07-01

Glucocorticoids are secreted following exposure to stressful events. Their modulating role on memory reconsolidation, a post-retrieval process of re-stabilization, has been investigated only recently, at times with conflicting results. The goal of this review is twofold. First, to establish the modulating role of glucocorticoids on memory reconsolidation. Second, to point the potential factors and confounds that might explain the seemingly paradoxical findings. Here we review recent pharmacological studies, conducted in rodents and humans, which suggest a critical role of glucocorticoids in this post-retrieval process. In particular, the activation of glucocorticoid receptors in the amygdala and hippocampus is suggested to be involved in emotional memories reconsolidation, pointing to a similarity between post-retrieval reconsolidation and initial memory consolidation. In addition, based on the general reconsolidation literature, we suggest several factors that might play a role in determining the direction and strength of the reconsolidation effect following glucocorticoids treatment: memory-related factors, manipulation-related factors, and individual differences. We conclude that only when taking these additional factors into account can the paradox be resolved. Copyright © 2016 Elsevier Inc. All rights reserved.

Clinical and Genomic Crosstalk between Glucocorticoid Receptor and Estrogen Receptor α In Endometrial Cancer

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Jeffery M. Vahrenkamp

2018-03-01

Full Text Available Summary: Steroid hormone receptors are simultaneously active in many tissues and are capable of altering each other’s function. Estrogen receptor α (ER and glucocorticoid receptor (GR are expressed in the uterus, and their ligands have opposing effects on uterine growth. In endometrial tumors with high ER expression, we surprisingly found that expression of GR is associated with poor prognosis. Dexamethasone reduced normal uterine growth in vivo; however, this growth inhibition was abolished in estrogen-induced endometrial hyperplasia. We observed low genomic-binding site overlap when ER and GR are induced with their respective ligands; however, upon simultaneous induction they co-occupy more sites. GR binding is altered significantly by estradiol with GR recruited to ER-bound loci that become more accessible upon estradiol induction. Gene expression responses to co-treatment were more similar to estradiol but with additional regulated genes. Our results suggest phenotypic and molecular interplay between ER and GR in endometrial cancer. : Estrogen receptor α (ER and glucocorticoid receptor (GR are expressed in the uterus and have differential effects on growth. Vahrenkamp et al. find that expression of both receptors is associated with poor outcome in endometrial cancer and that simultaneous induction of ER and GR leads to molecular interplay between the receptors. Keywords: estrogen receptor, glucocorticoid receptor, endometrial cancer

The ability of H1 or H2 receptor antagonists or their combination in counteracting the glucocorticoid-induced alveolar bone loss in rats.

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Ezzat, Bassant A; Abbass, Marwa M S

2014-02-01

The aim of the present study was to compare between three possible osteoporotic treatments in prevention of glucocorticoid-induced alveolar bone loss. Fifty adult female Wistar rats with an average weight 150-200 g were randomized into five groups: group I (control) was intraperitoneally injected with saline. The other experimental groups (II & III, IV & V) were intraperitoneally injected with 200 µg/100 g body weight dexamethasone. The experimental groups III, IV and V received intraperitoneal injection of 10 mg/kg/day pheniramine maleate (H1 receptor antagonist), ranitidine hydrochloride (H2 receptor antagonist) and concomitant doses of both H1 & H2 receptor antagonists respectively. After 30 days, the rats have been sacrificed. The mandibles were examined histologically, histochemically and histomorphometrically. The bone mineral density was measured using dual-energy X-ray absorptiometry (DEXA). Histopathologically the glucocorticoid group showed wide medullary cavities with wide osteocytic lacunae. These marrow cavities were reduced in the prophylactic groups (III, IV) but increased in group V. Bone histomorphometric analysis revealed improvement in static bone parameters in groups III and IV and deterioration in group V in comparison to group II. The DEXA revealed significant reduction in the bone mineral density in all experimental groups compared to the control group. In a rat model, the administration of H1 or H2 receptor antagonists separately could minimize the alveolar bone loss caused by the administration of glucocorticoids while concomitant administration of both H1 and H2 receptor antagonists deteriorated the bone condition. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Pathophysiology of Glucocorticoid Signaling.

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Vitellius, Géraldine; Trabado, Séverine; Bouligand, Jérôme; Delemer, Brigitte; Lombès, Marc

2018-06-01

Glucocorticoids (GC), such as cortisol or dexamethasone, control various physiological functions, notably those involved in development, metabolism, inflammatory processes and stress, and exert most of their effects upon binding to the glucocorticoid receptor (GR, encoded by NR3C1 gene). GC signaling follows several consecutive steps leading to target gene transactivation, including ligand binding, nuclear translocation of ligand-activated GR complexes, DNA binding, coactivator interaction and recruitment of functional transcriptional machinery. Any step may be impaired and may account for altered GC signaling. Partial or generalized glucocorticoid resistance syndrome may result in a reduced level of functional GR, a decreased hormone affinity and binding, a defect in nuclear GR translocation, a decrease or lack of DNA binding and/or post-transcriptional GR modifications. To date, 26 loss-of-function NR3C1 mutations have been reported in the context of hypertension, hirsutism, adrenal hyperplasia or metabolic disorders. These clinical signs are generally associated with biological features including hypercortisolism without negative regulatory feedback loop on the hypothalamic-pituitary-adrenal axis. Patients had often low plasma aldosterone and renin levels despite hypertension. Only one GR gain-of-function mutation has been described associating Cushing's syndrome phenotype with normal urinary-free cortisol. Some GR polymorphisms (ER22/23EK, GR-9β) have been linked to glucocorticoid resistance and a healthier metabolic profile whereas some others seemed to be associated with GC hypersensitivity (N363S, BclI), increasing cardiovascular risk (diabetes type 2, visceral obesity). This review focuses on the earlier findings on the pathophysiology of GR signaling and presents criteria facilitating identification of novel NR3C1 mutations in selected patients. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Characterization of a novel non-steroidal glucocorticoid receptor antagonist

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Li, Qun-Yi; Zhang, Meng [The National Center for Drug Screening, Shanghai (China); State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai (China); Hallis, Tina M.; DeRosier, Therese A. [Cell Systems Division, Invitrogen, Madison, WI (United States); Yue, Jian-Min; Ye, Yang [State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai (China); Mais, Dale E. [The National Center for Drug Screening, Shanghai (China); MPI Research, Mattawan, MI (United States); Wang, Ming-Wei, E-mail: wangmw@mail.shcnc.ac.cn [The National Center for Drug Screening, Shanghai (China); State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai (China)

2010-01-15

Selective antagonists of the glucocorticoid receptor (GR) are desirable for the treatment of hypercortisolemia associated with Cushing's syndrome, psychic depression, obesity, diabetes, neurodegenerative diseases, and glaucoma. NC3327, a non-steroidal small molecule with potent binding affinity to GR (K{sub i} = 13.2 nM), was identified in a high-throughput screening effort. As a full GR antagonist, NC3327 greatly inhibits the dexamethasone (Dex) induction of marker genes involved in hepatic gluconeogenesis, but has a minimal effect on matrix metalloproteinase 9 (MMP-9), a GR responsive pro-inflammatory gene. Interestingly, the compound recruits neither coactivators nor corepressors to the GR complex but competes with glucocorticoids for the interaction between GR and a coactivator peptide. Moreover, NC3327 does not trigger GR nuclear translocation, but significantly blocks Dex-induced GR transportation to the nucleus, and thus appears to be a 'competitive' GR antagonist. Therefore, the non-steroidal compound, NC3327, may represent a new class of GR antagonists as potential therapeutics for a variety of cortisol-related endocrine disorders.

Characterization of a novel non-steroidal glucocorticoid receptor antagonist

International Nuclear Information System (INIS)

Li, Qun-Yi; Zhang, Meng; Hallis, Tina M.; DeRosier, Therese A.; Yue, Jian-Min; Ye, Yang; Mais, Dale E.; Wang, Ming-Wei

2010-01-01

Selective antagonists of the glucocorticoid receptor (GR) are desirable for the treatment of hypercortisolemia associated with Cushing's syndrome, psychic depression, obesity, diabetes, neurodegenerative diseases, and glaucoma. NC3327, a non-steroidal small molecule with potent binding affinity to GR (K i = 13.2 nM), was identified in a high-throughput screening effort. As a full GR antagonist, NC3327 greatly inhibits the dexamethasone (Dex) induction of marker genes involved in hepatic gluconeogenesis, but has a minimal effect on matrix metalloproteinase 9 (MMP-9), a GR responsive pro-inflammatory gene. Interestingly, the compound recruits neither coactivators nor corepressors to the GR complex but competes with glucocorticoids for the interaction between GR and a coactivator peptide. Moreover, NC3327 does not trigger GR nuclear translocation, but significantly blocks Dex-induced GR transportation to the nucleus, and thus appears to be a 'competitive' GR antagonist. Therefore, the non-steroidal compound, NC3327, may represent a new class of GR antagonists as potential therapeutics for a variety of cortisol-related endocrine disorders.

Interactions between the metabolism of L-leucine and D-glucose in the pancreatic. beta. -cells

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Gylfe, E; Sehlin, J [Umeaa Univ. (Sweden). Dept. of Histology

1976-01-01

..beta..-cell-rich pancreatic islets microdissected from obese-hyperglycemic mice were used to study interactions between the metabolism of L-leucine and D-glucose. L-leucine reduced the islet content of aspartic acid whereas D-glucose, when added to L-leucine-incubated islets, increased the contents of aspartic acid and ..gamma..-aminobutyric acid (GABA). D-glucose also increased the incorporation of L-leucine carbon into aspartic acid, GABA and glutamic acid, suggesting stimulation of a malate shuttle mechanism. When expressed per mole of the individual amino acids, the incorporation of L-leucine carbon into GABA was 2.5 - 4 times higher than into glutamic acid indicating intracellular compartmentation of the latter amino acid. Both L-leucine and D-leucine stimulated /sup 14/CO/sub 2/ production from /sup 14/C-labelled D-glucose. L-leucine did not affect /sup 3/H/sub 2/O production from tritiated D-glucose. The present data do not indicate a role of other amino acids or D-glucose in L-leucine-stimulated insulin release.

Effects of glucocorticoid hormones on radiation induced and 12-O-tetradecanoylphorbol-13-acetate enhanced radiation transformation in vitro

International Nuclear Information System (INIS)

Kennedy, A.R.; Umans, R.S.

1988-01-01

We have studied the interactions of glucocorticoid hormones with radiation in the induction of transformation in vitro in C3AH10T1/2 cells. We have observed that cortisone has its primary enhancing effect on radiation transformation when present after the radiation exposure during the ''expression period'', or the time after carcinogen exposure during which promoting agents have been shown to enhance radiation transformation in vitro, and that two different glucocorticoid hormones, dexamethasone and cortisone, have a suppressive effect on the 12-O-tetradecanoylphorbol-13-acetate (TPA) enhancement of radiation transformation in vitro

Reaction of some selected soybean varieties ( Glycine max (L) Merril)

African Journals Online (AJOL)

In nematode endemic ecological zones, TGX-1985 – 8F is therefore recommended as it proved to contain some specialized genes that conferred a higher level of tolerance against root- knot nematode, Meloidogyne incognita. Key Words: Glycine max, root – knot nematode, Dominant loci, Mi – 1.2, leucine zipper and R ...

Leucine metabolism in regulation of insulin secretion from pancreatic beta cells

OpenAIRE

Yang, Jichun; Chi, Yujing; Burkhardt, Brant R.; Guan, Youfei; Wolf, Bryan A

2010-01-01

Leucine, a the branched-chain amino acids that must be supplied in daily diet, plays an important role in controlling protein synthesis and regulating cell metabolism in various cell types. In pancreatic β cells, leucine acutely stimulates insulin secretion by serving as both metabolic fuel and allosteric activator of glutamate dehydrogenase to enhance glutaminolysis. Leucine has also been shown to regulate gene transcription and protein synthesis in pancreatic islet β cells via both mTOR-dep...

Modulation of central glucocorticoid receptors in short- and long-term experimental hyperthyroidism.

Science.gov (United States)

Nikolopoulou, Elena; Mytilinaios, Dimitrios; Calogero, Aldo E; Kamilaris, Themis C; Troupis, Theodore; Chrousos, George P; Johnson, Elizabeth O

2015-08-01

Hyperthyroidism is associated with a significant increase in circulating glucocorticoid levels and hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis. The aim of this study was to examine whether the HPA axis hyperactivity observed in hyperthyroidism may be explained by a disturbed feedback inhibition of endogenous glucocorticoids through two specific intracellular receptors in the brain: the high affinity mineralocorticoid receptor (MR) and the lower affinity glucocorticoid receptor (GR). Cytosolic receptor binding and gene expression was assessed in rats with short (7 days) and long standing (60 days) eu- and hyperthyroidism. Glucocorticoid receptor number and binding affinity (Kd) in the hippocampus were measured using [(3)H2]-dexamethasone radioreceptor assay. In situ hybridization was employed to examine the effects of hyperthyroidism on the GR and MR mRNA levels in the hippocampus and the pituitary. Both short- and long-term hyperthyroid rats showed pronounced reduction in the concentration of cytosolic GR in the hippocampus, without changes in binding affinity or changes in GR expression. In contrast, GR mRNA in the pituitary increased after 7 days and decreased after 60 days of thyroxin treatment. MR mRNA was moderately affected. Hyperthyroidism is associated with significant decreases in hippocampal GR levels supporting the hypothesis that hyperactivity of the HPA axis observed in experimentally induced hyperthyroidism may be attributed, at least in part, to decreased negative feedback at the level of the hippocampus. These findings further support the notion that a central locus is principally responsible for the hyperactivity of the HPA axis observed in hyperthyroidism.

Psychosocial animal model of PTSD produces a long-lasting traumatic memory, an increase in general anxiety and PTSD-like glucocorticoid abnormalities.

Science.gov (United States)

Zoladz, Phillip R; Fleshner, Monika; Diamond, David M

2012-09-01

Post-traumatic stress disorder (PTSD) is characterized by a pathologically intense memory for a traumatic experience, persistent anxiety and physiological abnormalities, such as low baseline glucocorticoid levels and increased sensitivity to dexamethasone. We have addressed the hypothesis that rats subjected to chronic psychosocial stress would exhibit PTSD-like sequelae, including traumatic memory expression, increased anxiety and abnormal glucocorticoid responses. Adult male Sprague-Dawley rats were exposed to a cat on two occasions separated by 10 days, in conjunction with chronic social instability. Three weeks after the second cat exposure, the rats were tested for glucocorticoid abnormalities, general anxiety and their fear-conditioned memory of the two cat exposures. Stressed rats exhibited reduced basal glucocorticoid levels, increased glucocorticoid suppression following dexamethasone administration, heightened anxiety and a robust fear memory in response to cues that were paired with the two cat exposures. The commonalities in endocrine and behavioral measures between psychosocially stressed rats and traumatized people with PTSD provide the opportunity to explore mechanisms underlying psychological trauma-induced changes in neuroendocrine systems and cognition. Copyright © 2012 Elsevier Ltd. All rights reserved.

Comparison of the fates of ingested leucine and ingested 2-ketoisocaproate in rats

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Imura, K.; Walser, M. (Johns Hopkins Univ. School of Medicine, Baltimore, MD (USA))

1990-05-01

We previously reported that the ratio, R, of 14C to 3H in the leucine of whole body protein, measured 6 h after ingestion of (3H)leucine and (1-14C)2-ketoisocaproate is equal to ratio of the dose of leucine to the dose of 2-ketoisocaproate (KIC) (on a leucine-free diet) required to achieve the same rate of growth. To determine whether R is dependent on the interval between injection and sampling, R was measured at intervals in purified whole body protein after oral injection of these isotopes in groups of rats; it was constant from 1 h onward for 1 wk, averaging 0.64 +/- 0.01 (means +/- SEM). Thus, the extent of incorporation into the leucine of whole body protein of ingested KIC remains close to 64% of the incorporation of ingested leucine administered as such simultaneously, from 1 h onward for at least 1 wk.

FBXW7 regulates glucocorticoid response in T-cell acute lymphoblastic leukaemia by targeting the glucocorticoid receptor for degradation.

Science.gov (United States)

Malyukova, A; Brown, S; Papa, R; O'Brien, R; Giles, J; Trahair, T N; Dalla Pozza, L; Sutton, R; Liu, T; Haber, M; Norris, M D; Lock, R B; Sangfelt, O; Marshall, G M

2013-04-01

Loss of function mutation in FBXW7, an E3 ubiquitin ligase, is associated with good prognosis and early glucocorticoid treatment response in childhood T-cell acute lymphoblastic leukemia (T-ALL) by unknown mechanisms. Here, we show that FBXW7 targets the glucocorticoid receptor α (GRα) for ubiquitylation and proteasomal degradation in a manner dependent on glycogen synthase kinase 3 β-mediated phsophorylation. FBXW7 inactivation caused elevated GRα levels, and enhanced the transcriptional response to glucocorticoids. There was significant enhancement of GR transcriptional responses in FBXW7-deficient cell lines and primary T-ALL samples, in particular, for those pro-apoptotic regulatory proteins, BIM and PUMA. Reduced FBXW7 expression or function promoted glucocorticoid sensitivity, but not sensitivity to other chemotherapeutic agents used in T-ALL. Moreover, this was a general feature of different cancer cell types. Taken together, our work defines GRα as a novel FBXW7 substrate and demonstrates that favorable patient prognosis in T-ALL is associated with FBXW7 mutations due to enhanced GRα levels and steroid sensitivity. These findings suggest that inactivation of FBXW7, a putative tumor suppressor protein, may create a synthetic lethal state in the presence of specific anticancer therapies.

Functional interaction between the glucocorticoid receptor and GANP/MCM3AP

International Nuclear Information System (INIS)

Osman, Waffa; Laine, Sanna; Zilliacus, Johanna

2006-01-01

Glucocorticoids are widely used to treat inflammatory diseases but have a number of side effects that partly are connected to inhibition of cell proliferation. Glucocorticoids mediated their action by binding to the glucocorticoid receptor. In the present study, we have identified by two-hybrid screens the germinal center-associated protein (GANP) and MCM3-associated protein (MCM3AP), a splicing variant of GANP, as glucocorticoid receptor interacting proteins. GANP and MCM3AP can bind to the MCM3 protein involved in initiation of DNA replication. Glutathione-S-transferase-pull-down and co-immunoprecipitation assays showed that the C-terminal domain of GANP, encompassing MCM3AP, interacts with the ligand-binding domain of the glucocorticoid receptor. Characterization of the intracellular localization of GANP revealed that GANP is shuttling between the nucleus and the cytoplasm. Furthermore, we show that glucocorticoids are unable to inhibit DNA replication in HeLa cells overexpressing MCM3AP suggesting a role for both glucocorticoid receptor and GANP/MCM3AP in regulating cell proliferation

Quintupling Inhaled Glucocorticoids to Prevent Childhood Asthma Exacerbations.

Science.gov (United States)

Jackson, Daniel J; Bacharier, Leonard B; Mauger, David T; Boehmer, Susan; Beigelman, Avraham; Chmiel, James F; Fitzpatrick, Anne M; Gaffin, Jonathan M; Morgan, Wayne J; Peters, Stephen P; Phipatanakul, Wanda; Sheehan, William J; Cabana, Michael D; Holguin, Fernando; Martinez, Fernando D; Pongracic, Jacqueline A; Baxi, Sachin N; Benson, Mindy; Blake, Kathryn; Covar, Ronina; Gentile, Deborah A; Israel, Elliot; Krishnan, Jerry A; Kumar, Harsha V; Lang, Jason E; Lazarus, Stephen C; Lima, John J; Long, Dayna; Ly, Ngoc; Marbin, Jyothi; Moy, James N; Myers, Ross E; Olin, J Tod; Raissy, Hengameh H; Robison, Rachel G; Ross, Kristie; Sorkness, Christine A; Lemanske, Robert F

2018-03-08

Asthma exacerbations occur frequently despite the regular use of asthma-controller therapies, such as inhaled glucocorticoids. Clinicians commonly increase the doses of inhaled glucocorticoids at early signs of loss of asthma control. However, data on the safety and efficacy of this strategy in children are limited. We studied 254 children, 5 to 11 years of age, who had mild-to-moderate persistent asthma and had had at least one asthma exacerbation treated with systemic glucocorticoids in the previous year. Children were treated for 48 weeks with maintenance low-dose inhaled glucocorticoids (fluticasone propionate at a dose of 44 μg per inhalation, two inhalations twice daily) and were randomly assigned to either continue the same dose (low-dose group) or use a quintupled dose (high-dose group; fluticasone at a dose of 220 μg per inhalation, two inhalations twice daily) for 7 days at the early signs of loss of asthma control ("yellow zone"). Treatment was provided in a double-blind fashion. The primary outcome was the rate of severe asthma exacerbations treated with systemic glucocorticoids. The rate of severe asthma exacerbations treated with systemic glucocorticoids did not differ significantly between groups (0.48 exacerbations per year in the high-dose group and 0.37 exacerbations per year in the low-dose group; relative rate, 1.3; 95% confidence interval, 0.8 to 2.1; P=0.30). The time to the first exacerbation, the rate of treatment failure, symptom scores, and albuterol use during yellow-zone episodes did not differ significantly between groups. The total glucocorticoid exposure was 16% higher in the high-dose group than in the low-dose group. The difference in linear growth between the high-dose group and the low-dose group was -0.23 cm per year (P=0.06). In children with mild-to-moderate persistent asthma treated with daily inhaled glucocorticoids, quintupling the dose at the early signs of loss of asthma control did not reduce the rate of severe asthma

Glucocorticoid Receptor-Mediated Repression of Pro-Inflammatory Genes in Rheumatoid Arthritis

Science.gov (United States)

2015-10-01

Braun TP, Zhu X, Szumowski M, Scott GD, Grossberg AJ, et al. 2011. Central nervous system inflam - mation induces muscle atrophy via activation of the...glucocorticoid receptor and nutritional sensor mTOR in skeletal muscle . Cell Metab. 13:170–82 133. Lutzner N, Kalbacher H, Krones-Herzig A, Rosl F. 2012...suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704

Glucocorticoid stimulates expression of corticotropin-releasing hormone gene in human placenta

International Nuclear Information System (INIS)

Robinson, B.G.; Emanuel, R.L.; Frim, D.M.; Majzoub, J.A.

1988-01-01

Primary cultures of purified human cytotrophoblasts have been used to examine the expression of the corticotropin-releasing hormone (CRH) gene in placenta. The authors report here that glucocorticoids stimulate placental CRH synthesis and secretion in primary cultures of human placenta. This stimulation is in contrast to the glucocorticoid suppression of CRH expression in hypothalamus. The positive regulation of CRH by glucocorticoids suggests that the rise in CRH preceding parturition could result from the previously described rise in fetal glucocorticoids. Furthermore, this increase in placental CRH could stimulate, via adrenocorticotropic hormone, a further rise in fetal glucocorticoids, completing a positive feedback loop that would be terminated by delivery

Circulating cortisol-associated signature of glucocorticoid-related gene expression in subcutaneous fat of obese subjects.

Science.gov (United States)

Pavlatou, Maria G; Vickers, Kasey C; Varma, Sudhir; Malek, Rana; Sampson, Maureen; Remaley, Alan T; Gold, Philip W; Skarulis, Monica C; Kino, Tomoshige

2013-05-01

Serum cortisol concentrations fluctuate in a circadian fashion, and glucocorticoids exert strong effects on adipose tissue and induce obesity through the glucocorticoid receptor. To examine the impact of physiologic levels of circulating cortisol on subcutaneous adipose tissue, 25 overweight and obese subjects were employed, and their serum levels of morning (AM) and evening (PM) cortisol, AM/PM cortisol ratios, and 24-h urinary-free cortisol (UFC) were compared with their clinical parameters, serum cytokine levels, and mRNA expression of 93 receptor action-regulating and 93 glucocorticoid-responsive genes in abdominal subcutaneous fat. AM cortisol levels did not correlate with mRNA expression of the all genes examined, whereas PM cortisol levels, AM/PM cortisol ratios, and 24-h UFC were associated with distinct sets of these genes. Body mass index did not significantly correlate with the four cortisol parameters employed. These results suggest that physiologic levels of AM serum cortisol do not solely represent biological effects of circulating cortisol on the expression of glucocorticoid-related genes in subcutaneous adipose tissue, whereas PM levels, amplitude, and net amounts of the diurnally fluctuating serum cortisol have distinct effects. Through the genes identified in this study, glucocorticoids appear to influence intermediary metabolism, energy balance, inflammation, and local circadian rythmicity in subcutaneous fat. Our results may also explain in part the development of metabolic abnormality and obesity in subjects under stress or patients with melancholic/atypical depression who demonstrate elevated levels of PM serum cortisol. Copyright © 2013 The Obesity Society.

Addison disease in patients treated with glucocorticoid therapy.

LENUS (Irish Health Repository)

Cronin, C C

2012-02-03

Acute adrenal crisis in patients with unrecognized chronic adrenocortical failure is difficult to diagnose and potentially fatal. We describe 2 patients with acute adrenal crisis whose diagnoses were hindered because of concomitant glucocorticoid treatment. Acute adrenal insufficiency is primarily a state of mineralocorticoid deficiency. Prednisolone and prednisone, the most frequently prescribed anti-inflammatory corticosteroid agents, have minimal mineralocorticoid activity. Several conditions that may be treated with pharmacological glucocorticoids are associated with an increased risk of Addison disease. An acute adrenal crisis, against which concurrent glucocorticoid therapy does not confer adequate protection, may develop in such patients.

Leucine supplementation attenuates macrophage foam-cell formation: Studies in humans, mice, and cultured macrophages.

Science.gov (United States)

Grajeda-Iglesias, Claudia; Rom, Oren; Hamoud, Shadi; Volkova, Nina; Hayek, Tony; Abu-Saleh, Niroz; Aviram, Michael

2018-02-05

Whereas atherogenicity of dietary lipids has been largely studied, relatively little is known about the possible contribution of dietary amino acids to macrophage foam-cell formation, a hallmark of early atherogenesis. Recently, we showed that leucine has antiatherogenic properties in the macrophage model system. In this study, an in-depth investigation of the role of leucine in macrophage lipid metabolism was conducted by supplementing humans, mice, or cultured macrophages with leucine. Macrophage incubation with serum obtained from healthy adults supplemented with leucine (5 g/d, 3 weeks) significantly decreased cellular cholesterol mass by inhibiting the rate of cholesterol biosynthesis and increasing cholesterol efflux from macrophages. Similarly, leucine supplementation to C57BL/6 mice (8 weeks) resulted in decreased cholesterol content in their harvested peritoneal macrophages (MPM) in relation with reduced cholesterol biosynthesis rate. Studies in J774A.1 murine macrophages revealed that leucine dose-dependently decreased cellular cholesterol and triglyceride mass. Macrophages treated with leucine (0.2 mM) showed attenuated uptake of very low-density lipoproteins and triglyceride biosynthesis rate, with a concurrent down-regulation of diacylglycerol acyltransferase-1, a key enzyme catalyzing triglyceride biosynthesis in macrophages. Similar effects were observed when macrophages were treated with α-ketoisocaproate, a key leucine metabolite. Finally, both in vivo and in vitro leucine supplementation significantly improved macrophage mitochondrial respiration and ATP production. The above studies, conducted in human, mice, and cultured macrophages, highlight a protective role for leucine attenuating macrophage foam-cell formation by mechanisms related to the metabolism of cholesterol, triglycerides, and energy production. © 2018 BioFactors, 2018. © 2018 International Union of Biochemistry and Molecular Biology.

Evaluation of the leucine incorporation technique for detection of pollution-induced community tolerance to copper in a long-term agricultural field trial with urban waste fertilizers

DEFF Research Database (Denmark)

Lekfeldt, Jonas Duus Stevens; Magid, Jakob; Holm, Peter Engelund

2014-01-01

increased bacterial community tolerance to Cu was observed for soils amended with organic waste fertilizers and was positively correlated with total soil Cu. However, metal speciation and whole-cell bacterial biosensor analysis demonstrated that the observed PICT responses could be explained entirely by Cu......Copper (Cu) is known to accumulate in agricultural soils receiving urban waste products as fertilizers. We here report the use of the leucine incorporation technique to determine pollution-induced community tolerance (Leu-PICT) to Cu in a long-term agricultural field trial. A significantly...

Determination of Optimum Condition of Leucine Content in Beef Protein Hydrolysate using Response Surface Methodology

International Nuclear Information System (INIS)

Siti Roha Ab Mutalib; Zainal Samicho; Noriham Abdullah

2016-01-01

The aim of this study is to determine the optimum condition of leucine content in beef hydrolysate. Beef hydrolysate was prepared by enzymatic hydrolysis using bromelain enzyme produced from pineapple peel. Parameter conditions such as concentration of bromelain, hydrolysis temperature and hydrolysis time were assessed to obtain the optimum leucine content of beef hydrolysate according to experimental design which was recommended by response surface methodology (RSM). Leucine content in beef hydrolysate was determined using AccQ. Tag amino acid analysis method using high performance liquid chromatography (HPLC). The condition of optimum leucine content was at bromelain concentration of 1.38 %, hydrolysis temperature of 42.5 degree Celcius and hydrolysis time of 31.59 hours with the predicted leucine content of 26.57 %. The optimum condition was verified with the leucine value obtained was 26.25 %. Since there was no significant difference (p>0.05) between the predicted and verified leucine values, thus it indicates that the predicted optimum condition by RSM can be accepted to predict the optimum leucine content in beef hydrolysate. (author)

The Pro-inflammatory Effects of Glucocorticoids in the Brain

Science.gov (United States)

Duque, Erica de Almeida; Munhoz, Carolina Demarchi

2016-01-01

Glucocorticoids are a class of steroid hormones derived from cholesterol. Their actions are mediated by the glucocorticoid and mineralocorticoid receptors, members of the superfamily of nuclear receptors, which, once bound to their ligands, act as transcription factors that can directly modulate gene expression. Through protein–protein interactions with other transcription factors, they can also regulate the activity of many genes in a composite or tethering way. Rapid non-genomic signaling was also demonstrated since glucocorticoids can act through membrane receptors and activate signal transduction pathways, such as protein kinases cascades, to modulate other transcriptions factors and activate or repress various target genes. By all these different mechanisms, glucocorticoids regulate numerous important functions in a large variety of cells, not only in the peripheral organs but also in the central nervous system during development and adulthood. In general, glucocorticoids are considered anti-inflammatory and protective agents due to their ability to inhibit gene expression of pro-inflammatory mediators and other possible damaging molecules. Nonetheless, recent studies have uncovered situations in which these hormones can act as pro-inflammatory agents depending on the dose, chronicity of exposure, and the structure/organ analyzed. In this review, we will provide an overview of the conditions under which these phenomena occur, a discussion that will serve as a basis for exploring the mechanistic foundation of glucocorticoids pro-inflammatory gene regulation in the brain. PMID:27445981

Chronic stress triggers social aversion via glucocorticoid receptor in dopaminoceptive neurons.

Science.gov (United States)

Barik, Jacques; Marti, Fabio; Morel, Carole; Fernandez, Sebastian P; Lanteri, Christophe; Godeheu, Gérard; Tassin, Jean-Pol; Mombereau, Cédric; Faure, Philippe; Tronche, François

2013-01-18

Repeated traumatic events induce long-lasting behavioral changes that are key to organism adaptation and that affect cognitive, emotional, and social behaviors. Rodents subjected to repeated instances of aggression develop enduring social aversion and increased anxiety. Such repeated aggressions trigger a stress response, resulting in glucocorticoid release and activation of the ascending dopamine (DA) system. We bred mice with selective inactivation of the gene encoding the glucocorticoid receptor (GR) along the DA pathway, and exposed them to repeated aggressions. GR in dopaminoceptive but not DA-releasing neurons specifically promoted social aversion as well as dopaminergic neurochemical and electrophysiological neuroadaptations. Anxiety and fear memories remained unaffected. Acute inhibition of the activity of DA-releasing neurons fully restored social interaction in socially defeated wild-type mice. Our data suggest a GR-dependent neuronal dichotomy for the regulation of emotional and social behaviors, and clearly implicate GR as a link between stress resiliency and dopaminergic tone.

Leucine and HMB differentially modulate proteasome system in skeletal muscle under different sarcopenic conditions.

Science.gov (United States)

Baptista, Igor L; Silva, Willian J; Artioli, Guilherme G; Guilherme, Joao Paulo L F; Leal, Marcelo L; Aoki, Marcelo S; Miyabara, Elen H; Moriscot, Anselmo S

2013-01-01

In the present study we have compared the effects of leucine supplementation and its metabolite β-hydroxy-β-methyl butyrate (HMB) on the ubiquitin-proteasome system and the PI3K/Akt pathway during two distinct atrophic conditions, hindlimb immobilization and dexamethasone treatment. Leucine supplementation was able to minimize the reduction in rat soleus mass driven by immobilization. On the other hand, leucine supplementation was unable to provide protection against soleus mass loss in dexamethasone treated rats. Interestingly, HMB supplementation was unable to provide protection against mass loss in all treatments. While solely fiber type I cross sectional area (CSA) was protected in immobilized soleus of leucine-supplemented rats, none of the fiber types were protected by leucine supplementation in rats under dexamethasone treatment. In addition and in line with muscle mass results, HMB treatment did not attenuate CSA decrease in all fiber types against either immobilization or dexamethasone treatment. While leucine supplementation was able to minimize increased expression of both Mafbx/Atrogin and MuRF1 in immobilized rats, leucine was only able to minimize Mafbx/Atrogin in dexamethasone treated rats. In contrast, HMB was unable to restrain the increase in those atrogenes in immobilized rats, but in dexamethasone treated rats, HMB minimized increased expression of Mafbx/Atrogin. The amount of ubiquitinated proteins, as expected, was increased in immobilized and dexamethasone treated rats and only leucine was able to block this increase in immobilized rats but not in dexamethasone treated rats. Leucine supplementation maintained soleus tetanic peak force in immobilized rats at normal level. On the other hand, HMB treatment failed to maintain tetanic peak force regardless of treatment. The present data suggested that the anti-atrophic effects of leucine are not mediated by its metabolite HMB.

Leucine and HMB differentially modulate proteasome system in skeletal muscle under different sarcopenic conditions.

Directory of Open Access Journals (Sweden)

Igor L Baptista

Full Text Available In the present study we have compared the effects of leucine supplementation and its metabolite β-hydroxy-β-methyl butyrate (HMB on the ubiquitin-proteasome system and the PI3K/Akt pathway during two distinct atrophic conditions, hindlimb immobilization and dexamethasone treatment. Leucine supplementation was able to minimize the reduction in rat soleus mass driven by immobilization. On the other hand, leucine supplementation was unable to provide protection against soleus mass loss in dexamethasone treated rats. Interestingly, HMB supplementation was unable to provide protection against mass loss in all treatments. While solely fiber type I cross sectional area (CSA was protected in immobilized soleus of leucine-supplemented rats, none of the fiber types were protected by leucine supplementation in rats under dexamethasone treatment. In addition and in line with muscle mass results, HMB treatment did not attenuate CSA decrease in all fiber types against either immobilization or dexamethasone treatment. While leucine supplementation was able to minimize increased expression of both Mafbx/Atrogin and MuRF1 in immobilized rats, leucine was only able to minimize Mafbx/Atrogin in dexamethasone treated rats. In contrast, HMB was unable to restrain the increase in those atrogenes in immobilized rats, but in dexamethasone treated rats, HMB minimized increased expression of Mafbx/Atrogin. The amount of ubiquitinated proteins, as expected, was increased in immobilized and dexamethasone treated rats and only leucine was able to block this increase in immobilized rats but not in dexamethasone treated rats. Leucine supplementation maintained soleus tetanic peak force in immobilized rats at normal level. On the other hand, HMB treatment failed to maintain tetanic peak force regardless of treatment. The present data suggested that the anti-atrophic effects of leucine are not mediated by its metabolite HMB.

Incorporation of [h]leucine and [h]valine into protein of freshwater bacteria: field applications.

Science.gov (United States)

Jørgensen, N O

1992-11-01

Incorporation of leucine and valine into proteins of freshwater bacteria as a measure of bacterial production was tested in two eutrophic Danish lakes and was related to bacterial production measured by thymidine incorporation. In a depth profile (0 to 8 m) in Frederiksborg Castle Lake, incorporation of 100 nM leucine and valine gave similar rates of protein production. In terms of carbon, this production was about 50% lower than incorporation of 10 nM thymidine. In another depth profile in the same lake, incorporations of 10 nM valine and 100 nM leucine were identical, but differed from incorporations of 10 nM leucine and 100 nM valine. Bacterial carbon production calculated from incorporations of 10 nM thymidine and 10 nM leucine was similar, whereas 10 nM valine and 100 nM leucine and valine indicated an up to 2.4-fold-higher rate of carbon production. In a diel study in Lake Bagsvaerd, incorporation of 100 nM leucine and valine indicated a similar protein production, but the calculated carbon production was about 1.9-fold higher than the production based on uptake of 10 nM thymidine. Different diel changes in incorporation of the two amino acids and in incorporation of thymidine were observed. In both lakes, concentrations of naturally occurring leucine and valine were activity of a H isotope added at a concentration of 100 nM usually was diluted a maximum of 5%. Net assimilation of natural free amino acids in the lakes sustained 8 to 69% of the net bacterial carbon requirement, estimated from incorporation of leucine, valine, or thymidine. The present results indicate that incorporation of leucine and valine permits realistic measurements of bacterial production in freshwater environments.

Immunoglobulin production induced in vitro by glucocorticoid hormones: T cell-dependent stimulation of immunoglobulin production without B cell proliferation in cultures of human peripheral blood lymphocytes

International Nuclear Information System (INIS)

Grayson, J.; Dooley, N.J.; Koski, I.R.; Blaese, R.M.

1981-01-01

The direct effects of steroid hormones on the production of immunoglobulins and DNA synthesis by human T and B lymphocytes was evaluated in cultures of peripheral blood mononuclear cells. As detected by a reverse hemolytic plaque assay, the addition of 0.1 mM to 10 nM hydrocortisone to lymphocytes in culture in the absence of other stimulants or mitogens, resulted in the dramatic induction of immunoglobulin production with responses comparable to those seen in similar cultures stimulated with pokeweed mitogen. Steroid-stimulated immunoglobulin production was first seen after 48 h and peaked at 8-10 d of culture. The production of IgG, IgA, and IgM was induced following incubation with steroid. Glucocorticoids, but not estrogens or androgens, were capable of mediating this effect, and only compounds with affinity for the glucocorticoid receptor were active. The induction of immunoglobulin production was dependent on both T cells and monocytes; cultures depleted of either cell type did not produce immunoglobulin when stimulated with glucocorticoid hormones. Proliferation of B cells or T cells could not be detected by [/sup 3/H]thymidine incorporation or total cell recovery from steroid-stimulated cultures, even though such cultures demonstrated marked increases in immunoglobulin production. The mechanism responsible for this functional maturation of B cells to become high rate immunoglobulin producing cells is as yet undefined, although it appears to involve more than merely steroid mediated inactivation of suppressor T cells

Live cell imaging unveils multiple domain requirements for in vivo dimerization of the glucocorticoid receptor.

Directory of Open Access Journals (Sweden)

Diego M Presman

2014-03-01

Full Text Available Glucocorticoids are essential for life, but are also implicated in disease pathogenesis and may produce unwanted effects when given in high doses. Glucocorticoid receptor (GR transcriptional activity and clinical outcome have been linked to its oligomerization state. Although a point mutation within the GR DNA-binding domain (GRdim mutant has been reported as crucial for receptor dimerization and DNA binding, this assumption has recently been challenged. Here we have analyzed the GR oligomerization state in vivo using the number and brightness assay. Our results suggest a complete, reversible, and DNA-independent ligand-induced model for GR dimerization. We demonstrate that the GRdim forms dimers in vivo whereas adding another mutation in the ligand-binding domain (I634A severely compromises homodimer formation. Contrary to dogma, no correlation between the GR monomeric/dimeric state and transcriptional activity was observed. Finally, the state of dimerization affected DNA binding only to a subset of GR binding sites. These results have major implications on future searches for therapeutic glucocorticoids with reduced side effects.

Functional and structural analysis of the DNA sequence conferring glucocorticoid inducibility to the mouse mammary tumor virus gene

International Nuclear Information System (INIS)

Skroch, P.

1987-05-01

In the first part of my thesis I show that the DNA element conferring glucocorticoid inducibility to the Mouse Mammary Tumor Virus (HRE) has enhancer properties. It activates a heterologous promoter - that of the β-globin gene, independently of distance, position and orientation. These properties however have to be regarded in relation to the remaining regulatory elements of the activated gene as the recombinants between HRE and the TK gene have demonstrated. In the second part of my thesis I investigated the biological significance of certain sequence motifs of the HRE, which are remarkable by their interaction with transacting factors or sequence homologies with other regulatory DNA elements. I could confirm the generally postulated modular structure of enhancers for the HRE and bring the relevance of the single subdomains for the function of the element into relationship. (orig.) [de

Remembering under stress: different roles of autonomic arousal and glucocorticoids in memory retrieval.

Science.gov (United States)

Schönfeld, Pia; Ackermann, Karina; Schwabe, Lars

2014-01-01

It is commonly assumed that stress impairs memory retrieval. Glucocorticoids, released with a delay of several minutes in response to stressful experiences, are thought to play a key role in the stress-induced retrieval impairment. Accordingly, most studies on the impact of stress on retrieval tested memory a considerable time after stressor exposure, when glucocorticoid levels were elevated. Here, we asked how stress affects memory when retrieval takes place under stress, that is, when stress is part of the retrieval situation and glucocorticoids are not yet increased at the time of testing. To contrast stress effects on ongoing and delayed memory retrieval, 72 participants learned first neutral and emotional material. Twenty-four hours later, half of the learned material was tested either in a stressful, oral examination-like testing situation or in a standard, non-stressful free recall test. Memory for the other half of the learned material was assessed 25 min after the first, stressful or non-stressful retention test. Significant increases in blood pressure and salivary cortisol confirmed the stress induction by the first, examination-like testing situation. Retrieval performance under stress was positively correlated with the blood pressure response to the stressor but unaffected by cortisol. Conversely, retrieval performance 25 min post stress was negatively correlated with the cortisol response to the stressor, particularly for emotional items. These results suggest that the same stressor may have opposite effects on ongoing and delayed memory retrieval, depending on the presence of autonomic arousal and glucocorticoids. Copyright © 2013 Elsevier Ltd. All rights reserved.

Glucocorticoids and fetal programming part 1: Outcomes.

Science.gov (United States)

Moisiadis, Vasilis G; Matthews, Stephen G

2014-07-01

Fetal development is a critical period for shaping the lifelong health of an individual. However, the fetus is susceptible to internal and external stimuli that can lead to adverse long-term health consequences. Glucocorticoids are an important developmental switch, driving changes in gene regulation that are necessary for normal growth and maturation. The fetal hypothalamic-pituitary-adrenal (HPA) axis is particularly susceptible to long-term programming by glucocorticoids; these effects can persist throughout the life of an organism. Dysfunction of the HPA axis as a result of fetal programming has been associated with impaired brain growth, altered behaviour and increased susceptibility to chronic disease (such as metabolic and cardiovascular disease). Moreover, the effects of glucocorticoid-mediated programming are evident in subsequent generations, and transmission of these changes can occur through both maternal and paternal lineages.

Concentration-Dependent Patterns of Leucine Incorporation by Coastal Picoplankton

Science.gov (United States)

Alonso, Cecilia; Pernthaler, Jakob

2006-01-01

Coastal pelagic environments are believed to feature concentration gradients of dissolved organic carbon at a microscale, and they are characterized by pronounced seasonal differences in substrate availability for the heterotrophic picoplankton. Microbial taxa that coexist in such habitats might thus differ in their ability to incorporate substrates at various concentrations. We investigated the incorporation patterns of leucine in four microbial lineages from the coastal North Sea at concentrations between 0.1 and 100 nM before and during a spring phytoplankton bloom. Community bulk incorporation rates and the fraction of leucine-incorporating cells in the different populations were analyzed. Significantly fewer bacterial cells incorporated the amino acid before (13 to 35%) than during (23 to 47%) the bloom at all but the highest concentration. The incorporation rate per active cell in the prebloom situation was constant above 0.1 nM added leucine, whereas it increased steeply with substrate concentration during the bloom. At both time points, a high proportion of members of the Roseobacter clade incorporated leucine at all concentrations (55 to 80% and 86 to 94%, respectively). In contrast, the fractions of leucine-incorporating cells increased substantially with substrate availability in bacteria from the SAR86 clade (8 to 31%) and from DE cluster 2 of the Flavobacteria-Sphingobacteria (14 to 33%). The incorporation patterns of marine Euryarchaeota were between these extremes (30 to 56% and 48 to 70%, respectively). Our results suggest that the contribution of microbial taxa to the turnover of particular substrates may be concentration dependent. This may help us to understand the specific niches of coexisting populations that appear to compete for the same resources. PMID:16517664

The Populus Class III HD ZIP, popREVOLUTA, influences cambium initiation and patterning of woody stems

Science.gov (United States)

Marcel Robischon; Juan Du; Eriko Miura; Andrew Groover

2011-01-01

The secondary growth of a woody stem requires the formation of a vascular cambium at an appropriate position and proper patterning of the vascular tissues derived from the cambium. Class III homeodomain-leucine zipper (HD ZIP) transcription factors have been implicated in polarity determination and patterning in lateral organs and primary vascular tissues and in the...

Defect-mediated relaxation in the random tiling phase of a binary mixture: Birth, death and mobility of an atomic zipper

Energy Technology Data Exchange (ETDEWEB)

Tondl, Elisabeth; Ramsay, Malcolm; Harrowell, Peter; Widmer-Cooper, Asaph [School of Chemistry, University of Sydney, Sydney, NSW 2006 (Australia)

2014-03-14

This paper describes the mechanism of defect-mediated relaxation in a dodecagonal square-triangle random tiling phase exhibited by a simulated binary mixture of soft discs in 2D. We examine the internal transitions within the elementary mobile defect (christened the “zipper”) that allow it to move, as well as the mechanisms by which the zipper is created and annihilated. The structural relaxation of the random tiling phase is quantified and we show that this relaxation is well described by a model based on the distribution of waiting times for each atom to be visited by the diffusing zipper. This system, representing one of the few instances where a well defined mobile defect is capable of structural relaxation, can provide a valuable test case for general theories of relaxation in complex and disordered materials.

Defect-mediated relaxation in the random tiling phase of a binary mixture: Birth, death and mobility of an atomic zipper

International Nuclear Information System (INIS)

Tondl, Elisabeth; Ramsay, Malcolm; Harrowell, Peter; Widmer-Cooper, Asaph

2014-01-01

This paper describes the mechanism of defect-mediated relaxation in a dodecagonal square-triangle random tiling phase exhibited by a simulated binary mixture of soft discs in 2D. We examine the internal transitions within the elementary mobile defect (christened the “zipper”) that allow it to move, as well as the mechanisms by which the zipper is created and annihilated. The structural relaxation of the random tiling phase is quantified and we show that this relaxation is well described by a model based on the distribution of waiting times for each atom to be visited by the diffusing zipper. This system, representing one of the few instances where a well defined mobile defect is capable of structural relaxation, can provide a valuable test case for general theories of relaxation in complex and disordered materials

Differential response of risedronate on tibial and mandibular bone quality in glucocorticoid-treated growing rats

International Nuclear Information System (INIS)

Fujita, Yuko

2008-01-01

Glucocorticoids induce bone loss and retard bone growth in children. In this study we investigated the effect of treatment with risedronate on glucocorticoid -prednisolone-induced decreases in bone density, quality, strength and growth of the tibia and mandible in growing rats. Trabecular and cortical bone structure was measured by peripheral quantitative computed tomography (pQCT) and three-dimensional (3D) micro-computed tomography (micro-CT). Indicators of bone strength were calculated from cortical bone density and the modulus of sections obtained from pQCT analysis. Tibial and mandibular bone sizes were also measured. Prednisolone decreased the bone growth of both tibia and mandible. It also caused deterioration of trabecular and cortical bone structure and strength in the mandible, and in cortical bone in the tibia, but had no effect on trabecular bone in the tibia. Risedronate inhibited the prednisolone-induced decreases in tibial width and mandibular length and height but did not improve the retardation of longitudinal bone growth. Risedronate prevented prednisolone-induced deterioration of trabecular and cortical bone architecture. In the mandible, this protective effect of risedronate was accompanied by an increase in cortical bone density and in bone strength. These findings show that risedronate inhibits prednisolone-induced loss of bone density, structure, decrease in bone strength, and retardation of bone growth in the mandible in young growing rats. (author)

Glucocorticoid Antagonism Reduces Insulin Resistance and Associated Lipid Abnormalities in High-Fructose-Fed Mice.

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Priyadarshini, Emayavaramban; Anuradha, Carani Venkatraman

2017-02-01

High intake of dietary fructose causes perturbation in lipid metabolism and provokes lipid-induced insulin resistance. A rise in glucocorticoids (GCs) has recently been suggested to be involved in fructose-induced insulin resistance. The objective of the study was to investigate the effect of GC blockade on lipid abnormalities in insulin-resistant mice. Insulin resistance was induced in mice by administering a high-fructose diet (HFrD) for 60 days. Mifepristone (RU486), a GC antagonist, was administered to HFrD-fed mice for the last 18 days, and the intracellular and extracellular GC levels, the glucocorticoid receptor (GR) activation and the expression of GC-regulated genes involved in lipid metabolism were examined. HFrD elevated the intracellular GC content in both liver and adipose tissue and enhanced the GR nuclear translocation. The plasma GC level remained unchanged. The levels of free fatty acids and triglycerides in plasma were elevated, accompanied by increased plasma insulin and glucose levels and decreased hepatic glycogen content. Treatment with RU486 reduced plasma lipid levels, tissue GC levels and the expression of GC-targeted genes involved in lipid accumulation, and it improved insulin sensitivity. This study demonstrated that HFrD-induced lipid accumulation and insulin resistance are mediated by enhanced GC in liver and adipose tissue and that GC antagonism might reduce fructose-induced lipid abnormalities and insulin resistance. Copyright © 2016 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

Results of a prospective randomised study comparing a non-invasive surgical zipper versus intracutaneous sutures for wound closure

NARCIS (Netherlands)

Roolker, W.; Kraaneveld, E.; Been, H. D.; Marti, R. K.

2002-01-01

A prospective randomised study was undertaken to investigate the advantages and disadvantages of a non-invasive surgical zipper (Medizip) vs intracutaneous sutures skin closure in orthopaedic surgery. The study group consisted of 120 consecutive patients, 45 men and 75 women with a mean age of 47

Effects of acute restraint-induced stress on glucocorticoid receptors and brain-derived neurotrophic factor after mild traumatic brain injury.

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Griesbach, G S; Vincelli, J; Tio, D L; Hovda, D A

2012-05-17

We have previously reported that experimental mild traumatic brain injury results in increased sensitivity to stressful events during the first post-injury weeks, as determined by analyzing the hypothalamic-pituitary-adrenal (HPA) axis regulation following restraint-induced stress. This is the same time period when rehabilitative exercise has proven to be ineffective after a mild fluid-percussion injury (FPI). Here we evaluated effects of stress on neuroplasticity. Adult male rats underwent either an FPI or sham injury. Additional rats were only exposed to anesthesia. Rats were exposed to 30 min of restraint stress, followed by tail vein blood collection at post-injury days (PID) 1, 7, and 14. The response to dexamethasone (DEX) was also evaluated. Hippocampal tissue was collected 120 min after stress onset. Brain-derived neurotrophic factor (BDNF) along with glucocorticoid (GR) and mineralocorticoid (MR) receptors was determined by Western blot analysis. Results indicated injury-dependent changes in glucocorticoid and mineralocorticoid receptors that were influenced by the presence of dexamethasone. Control and FPI rats responded differentially to DEX in that GR increases after receiving the lower dose of DEX were longer lasting in the FPI group. A suppression of MR was found at PID 1 in vehicle-treated FPI and Sham groups. Decreases in the precursor form of BDNF were observed in different FPI groups at PIDs 7 and 14. These findings suggest that the increased sensitivity to stressful events during the first post-injury weeks, after a mild FPI, has an impact on hippocampal neuroplasticity. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

OSTEOPENIA in cancellous bone of sheep induced by Glucocorticoid alone

DEFF Research Database (Denmark)

Ding, Ming; Cheng, L.; Bollen, Peter

2008-01-01

Introduction: There is a great need for suitable large animal models that closely resemble osteoporosis in humans, and that they have adequate bone size for bone prosthesis and biomaterial research. Previous investigations have shown that osteoporotic sheep model requires glucocorticoid (GC......) microarchitectural properties and mechanical properties of sheep cancellous bone after a 7 months steroid treatment; and thus to validate a large animal model for orthopaedic implant/biomaterial research. Materials and Methods: Eighteen female sheep were randomly allocated into 3 groups: group 1 (GC-1) received GC......, osteocalcin was significantly reduced after 7 months but a rebound phenomenon was observed 3 months after cessation of GC. In conclusion, this study has validated an osteopenia sheep model. Bone quality was significantly reduced following a 7 months GC-treatment and recovered after further 3 month observation...

Transcriptional effects of glucocorticoid receptors in the dentate gyrus increase anxiety-related behaviors.

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Nadège Sarrazin

Full Text Available The Glucocorticoid Receptor (GR is a transcription factor ubiquitously expressed in the brain. Activation of brain GRs by high levels of glucocorticoid (GC hormones modifies a large variety of physiological and pathological-related behaviors. Unfortunately the specific cellular targets of GR-mediated behavioral effects of GC are still largely unknown. To address this issue, we generated a mutated form of the GR called DeltaGR. DeltaGR is a constitutively transcriptionally active form of the GR that is localized in the nuclei and activates transcription without binding to glucocorticoids. Using the tetracycline-regulated system (Tet-OFF, we developed an inducible transgenic approach that allows the expression of the DeltaGR in specific brain areas. We focused our study on a mouse line that expressed DeltaGR almost selectively in the glutamatergic neurons of the dentate gyrus (DG of the hippocampus. This restricted expression of the DeltaGR increased anxiety-related behaviors without affecting other behaviors that could indirectly influence performance in anxiety-related tests. This behavioral phenotype was also associated with an up-regulation of the MAPK signaling pathway and Egr-1 protein in the DG. These findings identify glutamatergic neurons in the DG as one of the cellular substrate of stress-related pathologies.

Stress inducible overexpression of AtHDG11 leads to improved drought and salt stress tolerance in peanut (Arachis hypogaea L.)

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Banavath, Jayanna N.; Chakradhar, Thammineni; Pandit, Varakumar; Konduru, Sravani; Guduru, Krishna K.; Akila, Chandra S.; Podha, Sudhakar; Puli, Chandra O. R.

2018-03-01

Peanut is an important oilseed and food legume cultivated as a rain-fed crop in semi-arid tropics. Drought and high salinity are the major abiotic stresses limiting the peanut productivity in this region. Development of drought and salt tolerant peanut varieties with improved yield potential using biotechnological approach is highly desirable to improve the peanut productivity in marginal geographies. As abiotic stress tolerance and yield represent complex traits, engineering of regulatory genes to produce abiotic stress-resilient transgenic crops appears to be a viable approach. In the present study, we developed transgenic peanut plants expressing an Arabidopsis homeodomain-leucine zipper transcription factor (AtHDG11) under stress inducible rd29Apromoter. A stress-inducible expression of AtHDG11 in three independent homozygous transgenic peanut lines resulted in improved drought and salt tolerance through up-regulation of known stress responsive genes(LEA, HSP70, Cu/Zn SOD, APX, P5CS, NCED1, RRS5, ERF1, NAC4, MIPS, Aquaporin, TIP, ELIP ) in the stress gene network , antioxidative enzymes, free proline along with improved water use efficiency traits such as longer root system, reduced stomatal density, higher chlorophyll content, increased specific leaf area, improved photosynthetic rates and increased intrinsic instantaneous WUE. Transgenic peanut plants displayed high yield compared to non-transgenic plants under both drought and salt stress conditions. Holistically, our study demonstrates the potentiality of stress-induced expression of AtHDG11 to improve the drought, salt tolerance in peanut.

Effect of burn and first-pass splanchnic leucine extraction on protein kinetics in rats

International Nuclear Information System (INIS)

Karlstad, M.D.; DeMichele, S.J.; Istfan, N.; Blackburn, G.L.; Bistrian, B.R.

1988-01-01

The effects of burn and first-pass splanchnic leucine extraction (FPE) on protein kinetics and energy expenditure were assessed by measuring O 2 consumption, CO 2 production, nitrogen balance, leucine kinetics, and tissue fractional protein synthetic rates (FSR-%/day) in enterally fed rats. Anesthetized male rats (200 g) were scalded on their dorsum with boiling water (25-30% body surface area) and enterally fed isovolemic diets that provided 60 kcal/day and 2.4 g of amino acids/day for 3 days. Controls were not burned. An intravenous or intragastric infusion of L-[1- 14 C]leucine was used to assess protein kinetics on day 3. FPE was taken as the ratio of intragastric to intravenous plasma leucine specific activity. There was a 69% reduction in cumulative nitrogen balance (P less than 0.001) and a 17-19% increase in leucine oxidation (P less than 0.05) and total energy expenditure (P less than 0.01) in burned rats. A 15% decrease in plasma leucine clearance (P less than 0.05) was accompanied by a 20% increase in plasma [leucine] (P less than 0.01) in burned rats. Burn decreased rectus muscle FSR from 5.0 +/- 0.4 to 3.5 +/- 0.5 (P less than 0.05) and increased liver FSR from 19.0 +/- 0.5 to 39.2 +/- 3.4 (P less than 0.01). First pass extraction of dietary leucine by the splanchnic bed was 8% in controls and 26% in burned rats. Leucine kinetics corrected for FPE showed increased protein degradation with burn that was not evident without FPE correction. This hypermetabolic burn model can be useful in the design of enteral diets that optimize rates of protein synthesis and degradation

Stress, glucocorticoids and memory: implications for treating fear-related disorders.

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de Quervain, Dominique; Schwabe, Lars; Roozendaal, Benno

2017-01-01

Glucocorticoid stress hormones are crucially involved in modulating mnemonic processing of emotionally arousing experiences. They enhance the consolidation of new memories, including those that extinguish older memories, but impair the retrieval of information stored in long-term memory. As strong aversive memories lie at the core of several fear-related disorders, including post-traumatic stress disorder and phobias, the memory-modulating properties of glucocorticoids have recently become of considerable translational interest. Clinical trials have provided the first evidence that glucocorticoid-based pharmacotherapies aimed at attenuating aversive memories might be helpful in the treatment of fear-related disorders. Here, we review important advances in the understanding of how glucocorticoids mediate stress effects on memory processes, and discuss the translational potential of these new conceptual insights.

Oxidative stress in the developing brain: effects of postnatal glucocorticoid therapy and antioxidants in the rat.

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Emily J Camm

Full Text Available In premature infants, glucocorticoids ameliorate chronic lung disease, but have adverse effects on long-term neurological function. Glucocorticoid excess promotes free radical overproduction. We hypothesised that the adverse effects of postnatal glucocorticoid therapy on the developing brain are secondary to oxidative stress and that antioxidant treatment would diminish unwanted effects. Male rat pups received a clinically-relevant tapering course of dexamethasone (DEX; 0.5, 0.3, and 0.1 mg x kg(-1 x day(-1, with or without antioxidant vitamins C and E (DEXCE; 200 mg x kg(-1 x day(-1 and 100 mg x kg(-1 x day(-1, respectively, on postnatal days 1-6 (P1-6. Controls received saline or saline with vitamins. At weaning, relative to controls, DEX decreased total brain volume (704.4±34.7 mm(3 vs. 564.0±20.0 mm(3, the soma volume of neurons in the CA1 (1172.6±30.4 µm(3 vs. 1002.4±11.8 µm(3 and in the dentate gyrus (525.9±27.2 µm(3 vs. 421.5±24.6 µm(3 of the hippocampus, and induced oxidative stress in the cortex (protein expression: heat shock protein 70 [Hsp70]: +68%; 4-hydroxynonenal [4-HNE]: +118% and nitrotyrosine [NT]: +20%. Dexamethasone in combination with vitamins resulted in improvements in total brain volume (637.5±43.1 mm(3, and soma volume of neurons in the CA1 (1157.5±42.4 µm(3 and the dentate gyrus (536.1±27.2 µm(3. Hsp70 protein expression was unaltered in the cortex (+9%, however, 4-HNE (+95% and NT (+24% protein expression remained upregulated. Treatment of neonates with vitamins alone induced oxidative stress in the cortex (Hsp70: +67%; 4-HNE: +73%; NT: +22% and in the hippocampus (NT: +35%. Combined glucocorticoid and antioxidant therapy in premature infants may be safer for the developing brain than glucocorticoids alone in the treatment of chronic lung disease. However, antioxidant therapy in healthy offspring is not recommended.

Fructose, Glucocorticoids and Adipose Tissue: Implications for the Metabolic Syndrome.

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Legeza, Balázs; Marcolongo, Paola; Gamberucci, Alessandra; Varga, Viola; Bánhegyi, Gábor; Benedetti, Angiolo; Odermatt, Alex

2017-04-26

The modern Western society lifestyle is characterized by a hyperenergetic, high sugar containing food intake. Sugar intake increased dramatically during the last few decades, due to the excessive consumption of high-sugar drinks and high-fructose corn syrup. Current evidence suggests that high fructose intake when combined with overeating and adiposity promotes adverse metabolic health effects including dyslipidemia, insulin resistance, type II diabetes, and inflammation. Similarly, elevated glucocorticoid levels, especially the enhanced generation of active glucocorticoids in the adipose tissue due to increased 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) activity, have been associated with metabolic diseases. Moreover, recent evidence suggests that fructose stimulates the 11β-HSD1-mediated glucocorticoid activation by enhancing the availability of its cofactor NADPH. In adipocytes, fructose was found to stimulate 11β-HSD1 expression and activity, thereby promoting the adipogenic effects of glucocorticoids. This article aims to highlight the interconnections between overwhelmed fructose metabolism, intracellular glucocorticoid activation in adipose tissue, and their metabolic effects on the progression of the metabolic syndrome.

A case report: Familial glucocorticoid deficiency associated with familial focal segmental glomerulosclerosis

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Ram Nanik

2012-12-01

Full Text Available Abstract Background Familial glucocorticoid deficiency (FGD is a rare autosomal recessive disorder characterized by isolated glucocorticoid deficiency in the presence of normal plasma renin and aldosterone level. Focal segmental glomerulosclerosis (FSGS is a form of glomerular disease associated with proteinuria and nephritic syndrome. This is the first case of familial glucocorticoid deficiency associated with familial focal segmental glomerulosclerosis. Case presentation An eight month old boy presented with increased genital pigmentation. Initial investigation revealed that he was glucocorticoid deficient and was started on hydrocortisone and fludrocortisone with a diagnosis of primary adrenal insufficiency. Later fludrocortisone was withdrawn and he was diagnosed to have isolated glucocorticoid deficiency. He later developed focal segmental glomerulosclerosis for which he underwent renal transplantation at the age of five years. Now at the age of twelve years, this boy is doing well on hydrocortisone treatment. His two siblings and a first degree cousin also had isolated glucocorticoid deficiency. One of the above two siblings died due to renal failure secondary to focal segmental glomerulosclerosis. Conclusion Patients with familial glucocorticoid deficiency should be carefully followed for development of features of nephrotic syndrome.

Chronic restraint stress causes anxiety- and depression-like behaviors, downregulates glucocorticoid receptor expression, and attenuates glutamate release induced by brain-derived neurotrophic factor in the prefrontal cortex.

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Chiba, Shuichi; Numakawa, Tadahiro; Ninomiya, Midori; Richards, Misty C; Wakabayashi, Chisato; Kunugi, Hiroshi

2012-10-01

Stress and the resulting increase in glucocorticoid levels have been implicated in the pathophysiology of depressive disorders. We investigated the effects of chronic restraint stress (CRS: 6 hours × 28 days) on anxiety- and depression-like behaviors in rats and on the possible changes in glucocorticoid receptor (GR) expression as well as brain-derived neurotrophic factor (BDNF)-dependent neural function in the prefrontal cortex (PFC). We observed significant reductions in body weight gain, food intake and sucrose preference from 1 week after the onset of CRS. In the 5th week of CRS, we conducted open-field (OFT), elevated plus-maze (EPM) and forced swim tests (FST). We observed a decrease in the number of entries into open arms during the EPM (anxiety-like behavior) and increased immobility during the FST (depression-like behavior). When the PFC was removed after CRS and subject to western blot analysis, the GR expression reduced compared with control, while the levels of BDNF and its receptors remained unchanged. Basal glutamate concentrations in PFC acute slice which were measured by high performance liquid chromatography were not influenced by CRS. However, BDNF-induced glutamate release was attenuated after CRS. These results suggest that reduced GR expression and altered BDNF function may be involved in chronic stress-induced anxiety--and depression-like behaviors. Copyright © 2012 Elsevier Inc. All rights reserved.

Investigation of L-leucine in reducing the moisture-induced deterioration of spray-dried salbutamol sulfate power for inhalation.

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Li, Liang; Leung, Sharon Shui Yee; Gengenbach, Thomas; Yu, Jiaqi; Gao, Ge Fiona; Tang, Patricia; Zhou, Qi Tony; Chan, Hak-Kim

2017-09-15

The aim of this study was to investigate the ability of L-leucine (LL) in preventing moisture-induced deterioration in the in vitro aerosolization performance of spray-dried (SD) salbutamol sulfate (SS). Increasing mass fraction of LL (5-80%) were co-spray dried with SS, and the physicochemical properties of the powders were characterized by laser diffraction, X-ray powder diffraction (XRD) and dynamic vapour sorption (DVS). Furthermore, the surface morphology and chemistry of fine particles was analyzed by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The in vitro aerosolization performance of powders stored at different relative humidity (RH) was evaluated by a next generation impactor (NGI). The SD SS powders were moderately hygroscopic and amorphous, of which the uptake of moisture upon storage caused a drop in the aerosolization performance. The results showed that 40% (w/w) LL was sufficient to eliminate the effect of moisture on the aerosolization performance at 60% RH. The formulation containing 40% (w/w) LL also maximized the aerosolization performance of SD SS powders (stored in desiccator) with the emitted fraction being 90.0±1.8%, and the fine particle fraction based on the recovered dose (FPF recovered ) and emitted dose (FPF emitted ) being 78.0±3.7% and 86.6±2.9%, respectively. The underlying mechanisms were that the crystalline LL increased the degree of particle surface corrugation, and reduced particle fusion and cohesiveness to facilitate dispersion. However, there is still a great challenge to prevent the moisture-induced deterioration in the aerosolization performance at 75% RH due to the recrystallization of SD SS. In conclusion, LL is a potential excipient for reducing moisture-induced deterioration in the aerosolization performance of SD amorphous powders, but still has drawbacks in preventing the recrystallization-induced deterioration. Copyright © 2017 Elsevier B.V. All rights reserved.

Application of Key Events Dose Response Framework to defining the upper intake level of leucine in young men.

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Pencharz, Paul B; Russell, Robert M

2012-12-01

Leucine is sold in large doses in health food stores and is ingested by weight-training athletes. The safety of ingestion of large doses of leucine is unknown. Before designing chronic high-dose leucine supplementation experiments, we decided to determine the effect of graded doses of leucine in healthy participants. The Key Events Dose Response Framework is an organizational and analytical framework that dissects the various biologic steps (key events) that occur between exposure to a substance and an eventual adverse effect. Each biologic event is looked at for its unique dose-response characteristics. For nutrients, there are a number of biologic homeostatic mechanisms that work to keep circulating/tissue levels in a safe, nontoxic range. If a response mechanism at a particular key event is especially vulnerable and easily overwhelmed, this is known as a determining event, because this event drives the overall slope or shape of the dose-response relationship. In this paper, the Key Events Dose Framework has been applied to the problem of leucine toxicity and leucine's tolerable upper level. After analyzing the experimental data vis a vis key events for leucine leading to toxicity, it became evident that the rate of leucine oxidation was the determining event. A dose-response study has been conducted to graded intakes of leucine in healthy human adult male volunteers. All participants were started at the mean requirement level of leucine [50 mg/(kg · d)] and the highest leucine intake was 1250 mg/( kg · d), which is 25 times the mean requirement. No gut intolerance was seen. Blood glucose fell progressively but remained within normal values without any changes in plasma insulin. Maximal leucine oxidation levels occurred at an intake of 550 mg leucine/( kg · d), after which plasma leucine progressively increased and plasma ammonia also increased in response to leucine intakes >500 mg/( kg · d). Thus, the "key determining event" appears to be when the

Measurement of L-[1-14C]leucine kinetics in splanchnic and leg tissues in humans. Effect of amino acid infusion

International Nuclear Information System (INIS)

Gelfand, R.A.; Glickman, M.G.; Castellino, P.; Louard, R.J.; DeFronzo, R.A.

1988-01-01

Although whole-body leucine flux is widely measured to study body protein turnover in humans, the contribution of specific tissues to the total-body measurement remains unknown. By combining the organ-balance technique with the systemic infusion of L-[1-14C]leucine, we quantitated leucine production and disposal by splanchnic and leg tissues and by the whole body, simultaneously, in six normal men before and during amino acid infusion. At steady state, disposal of arterial leucine by splanchnic and leg tissues was calculated from the percent extraction (E) of L-[1-14C]leucine counts: uptake = E x [Leu]a x flow. Tissue release of cold leucine (from protein turnover) into vein was calculated as the difference between leucine uptake and the net tissue leucine balance. In the postabsorptive state, despite substantial (P less than .01) extraction of L-[1-14C]leucine by splanchnic (23 +/- 1%) and leg (18 +/- 2%) tissues, net leucine balance across both tissue beds was small, indicating active simultaneous disposal and production of leucine at nearly equivalent rates. Splanchnic tissues accounted for approximately 50% of the measured total-body leucine flux. During amino acid infusion, the net leucine balance across splanchnic and leg tissues became positive, reflecting not only an increase in leucine uptake but also a marked suppression (by approximately 50%, P less than .02) of cold leucine release. This reduction in splanchnic and leg leucine release was indicated by a sharp decline in whole-body endogenous leucine flux

Multimerization of the p12 domain is necessary for Mason–Pfizer monkey virus Gag assembly in vitro

Czech Academy of Sciences Publication Activity Database

Knejzlík, Z.; Smékalová, Z.; Ruml, Tomáš; Sakalian, M.

2007-01-01

Roč. 365, č. 2 (2007), s. 260-270 ISSN 0042-6822 R&D Projects: GA MŠk(CZ) 1M0520; GA ČR GESCO/06/E001 Grant - others:NIH(US) AI43230 Institutional research plan: CEZ:AV0Z40550506 Keywords : M-PMV * p12 protein * oligomerization * leucine zipper Subject RIV: CE - Biochemistry Impact factor: 3.765, year: 2007

Glucocorticoid-induced tumor necrosis factor receptor expression in patients with cervical human papillomavirus infection

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Cacilda Tezelli Junqueira Padovani

2013-06-01

Full Text Available Introduction The progression of human papillomavirus (HPV infection in the anogenital tract has been associated with the involvement of cells with regulatory properties. Evidence has shown that glucocorticoid-induced tumor necrosis factor receptor (GITR is an important surface molecule for the characterization of these cells and proposes that GITR ligand may constitute a rational treatment for many cancer types. We aimed to detect the presence of GITR and CD25 in cervical stroma cells with and without pathological changes or HPV infection to better understand the immune response in the infected tissue microenvironment. Methods We subjected 49 paraffin-embedded cervical tissue samples to HPV DNA detection and histopathological analysis, and subsequently immunohistochemistry to detect GITR and CD25 in lymphocytes. Results We observed that 76.9% of all samples with high GITR expression were HPV-positive regardless of histopathological findings. High GITR expression (77.8% was predominant in samples with ≥1,000 RLU/PCB. Of the HPV-positive samples negative for intraepithelial lesion and malignancy, 62.5% had high GITR expression. High GITR expression was observed in both carcinoma and high-grade squamous intraepithelial lesion (HSIL samples (p = 0.16. CD25 was present in great quantities in all samples. Conclusions The predominance of high GITR expression in samples with high viral load that were classified as HSIL and carcinoma suggests that GITR+ cells can exhibit regulatory properties and may contribute to the progression of HPV-induced cervical neoplasia, emphasizing the importance of GITR as a potential target for immune therapy of cervical cancer and as a disease evolution biomarker.

Leptin and glucocorticoid signaling pathways in the hypothalamus of female and male fructose-fed rats

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Vojnović-Milutinović Danijela

2014-01-01

Full Text Available Alterations in leptin and glucocorticoid signaling pathways in the hypothalamus of male and female rats subjected to a fructose-enriched diet were studied. The level of expression of the key components of the leptin signaling pathway (neuropeptide Y /NPY/ and suppressor of cytokine signaling 3 /SOCS3/, and the glucocorticoid signaling pathway (glucocorticoid receptor /GR/, 11β-hydroxysteroid dehydrogenase type 1 /11βHSD1/ and hexose-6-phosphate dehydrogenase /H6PDH/ did not differ between fructose-fed rats and control animals of both genders. However, in females, a fructose-enriched diet provoked increases in the adiposity index, plasma leptin and triglyceride concentrations, and displayed a tendency to decrease the leptin receptor (ObRb protein and mRNA levels. In male rats, the fructose diet caused elevations in plasma non-esterified fatty acids and triglycerides, as well as in both plasma and hypothalamic leptin concentrations. Our results suggest that a fructose-enriched diet can induce hyperleptinemia in both female and male rats, but with a more pronounced effect on hypothalamic leptin sensitivity in females, probably contributing to the observed development of visceral adiposity. [Projekat Ministarstva nauke Republike Srbije, br. III41009

Nutritional leucine supplementation attenuates cardiac failure in tumour-bearing cachectic animals.

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Toneto, Aline Tatiane; Ferreira Ramos, Luiz Alberto; Salomão, Emilianne Miguel; Tomasin, Rebeka; Aereas, Miguel Arcanjo; Gomes-Marcondes, Maria Cristina Cintra

2016-12-01

The condition known as cachexia presents in most patients with malignant tumours, leading to a poor quality of life and premature death. Although the cancer-cachexia state primarily affects skeletal muscle, possible damage in the cardiac muscle remains to be better characterized and elucidated. Leucine, which is a branched chain amino acid, is very useful for preserving lean body mass. Thus, this amino acid has been studied as a coadjuvant therapy in cachectic cancer patients, but whether this treatment attenuates the effects of cachexia and improves cardiac function remains poorly understood. Therefore, using an experimental cancer-cachexia model, we evaluated whether leucine supplementation ameliorates cachexia in the heart. Male Wistar rats were fed either a leucine-rich or a normoprotein diet and implanted or not with subcutaneous Walker-256 carcinoma. During the cachectic stage (approximately 21 days after tumour implantation), when the tumour mass was greater than 10% of body weight, the rats were subjected to an electrocardiogram analysis to evaluate the heart rate, QT-c, and T wave amplitude. The myocardial tissues were assayed for proteolytic enzymes (chymotrypsin, alkaline phosphatase, cathepsin, and calpain), cardiomyopathy biomarkers (myeloperoxidase, tissue inhibitor of metalloproteinases, and total plasminogen activator inhibitor 1), and caspase-8, -9, -3, and -7 activity. Both groups of tumour-bearing rats, especially the untreated group, had electrocardiography alterations that were suggestive of ischemia, dilated cardiomyopathy, and sudden death risk. Additionally, the rats in the untreated tumour-bearing group but not their leucine-supplemented littermates exhibited remarkable increases in chymotrypsin activity and all three heart failure biomarkers analysed, including an increase in caspase-3 and -7 activity. Our data suggest that a leucine-rich diet could modulate heart damage, cardiomyocyte proteolysis, and apoptosis driven by cancer

Allosteric analysis of glucocorticoid receptor-DNA interface induced by cyclic Py-Im polyamide: a molecular dynamics simulation study.

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Yaru Wang

Full Text Available BACKGROUND: It has been extensively developed in recent years that cell-permeable small molecules, such as polyamide, can be programmed to disrupt transcription factor-DNA interfaces and can silence aberrant gene expression. For example, cyclic pyrrole-imidazole polyamide that competes with glucocorticoid receptor (GR for binding to glucocorticoid response elements could be expected to affect the DNA dependent binding by interfering with the protein-DNA interface. However, how such small molecules affect the transcription factor-DNA interfaces and gene regulatory pathways through DNA structure distortion is not fully understood so far. METHODOLOGY/PRINCIPAL FINDINGS: In the present work, we have constructed some models, especially the ternary model of polyamides+DNA+GR DNA-binding domain (GRDBD dimer, and carried out molecular dynamics simulations and free energy calculations for them to address how polyamide molecules disrupt the GRDBD and DNA interface when polyamide and protein bind at the same sites on opposite grooves of DNA. CONCLUSIONS/SIGNIFICANCE: We found that the cyclic polyamide binding in minor groove of DNA can induce a large structural perturbation of DNA, i.e. a >4 Å widening of the DNA minor groove and a compression of the major groove by more than 4 Å as compared with the DNA molecule in the GRDBD dimer+DNA complex. Further investigations for the ternary system of polyamides+DNA+GRDBD dimer and the binary system of allosteric DNA+GRDBD dimer revealed that the compression of DNA major groove surface causes GRDBD to move away from the DNA major groove with the initial average distance of ∼4 Å to the final average distance of ∼10 Å during 40 ns simulation course. Therefore, this study straightforward explores how small molecule targeting specific sites in the DNA minor groove disrupts the transcription factor-DNA interface in DNA major groove, and consequently modulates gene expression.

Maternal PTSD associates with greater glucocorticoid sensitivity in offspring of Holocaust survivors.

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Lehrner, Amy; Bierer, Linda M; Passarelli, Vincent; Pratchett, Laura C; Flory, Janine D; Bader, Heather N; Harris, Iris R; Bedi, Aarti; Daskalakis, Nikolaos P; Makotkine, Iouri; Yehuda, Rachel

2014-02-01

Intergenerational effects of trauma have been observed clinically in a wide range of populations, and parental PTSD has been associated with an increased risk for psychopathology in offspring. In studies of Holocaust survivor offspring, parental PTSD, and particularly maternal PTSD, has been associated with increased risk for PTSD, low basal urinary cortisol excretion and enhanced cortisol suppression in response to dexamethasone. Such findings implicate maternally derived glucocorticoid programming in the intergenerational transmission of trauma-related consequences, potentially resulting from in utero influences or early life experiences. This study investigated the relative influence of Holocaust exposure and PTSD in mothers and fathers on glucocorticoid sensitivity in offspring. Eighty Holocaust offspring and 15 offspring of non-exposed Jewish parents completed evaluations and provided blood and urine samples. Glucocorticoid sensitivity was evaluated using the lysozyme suppression test (LST), an in vitro measure of glucocorticoid receptor sensitivity in a peripheral tissue, the dexamethasone suppression test (DST), and 24-h urinary cortisol excretion. Maternal PTSD was associated with greater glucocorticoid sensitivity in offspring across all three measures of glucocorticoid function. An interaction of maternal and paternal PTSD on the DST and 24-h urinary cortisol showed an effect of decreased glucocorticoid sensitivity in offspring with paternal, but not maternal, PTSD. Although indirect, these findings are consistent with the hypothesis that epigenetic programming may be involved in the intergenerational transmission of trauma-related effects on glucocorticoid regulation. Published by Elsevier Ltd.

Radiobiological half-lives for carbon-14 and hydrogen-3 leucine in man

International Nuclear Information System (INIS)

Classic, K.L.; Schwenk, W.F.; Haymond, M.W.

1986-01-01

In vivo estimates of protein metabolism in many are often made by oral or intravenous administration of leucine or its ∼-ketoacid, ∼-ketoisocaproate, labeled with 14 C or 3 H. Previous estimates of radiation dose from such tracers have been based on the measurement of 14 CO 2 in breath. Using measurements of the decay of 3 H or 14 C leucine from plasma proteins, longer biological half-lives for these compounds were obtained. The estimated total-body radiation absorbed dose is 0.97 mrad/uCi for [1- 14 C]KIC (or [1- 14 C]leucine) and 0.11 mrad/ + Ci for ]4,5- 3 H]leucine (or [ 3 H]KIC). Assuming administered doses of 100 μCi each, the total-body radiation absorbed dose is still well within the limits set by the FDA for Radioactive Drug Research Committees. 12 references, 3 figures, 3 tables

Infusion and sampling site effects on two-pool model estimates of leucine metabolism

International Nuclear Information System (INIS)

Helland, S.J.; Grisdale-Helland, B.; Nissen, S.

1988-01-01

To assess the effect of site of isotope infusion on estimates of leucine metabolism infusions of alpha-[4,5-3H]ketoisocaproate (KIC) and [U- 14 C]leucine were made into the left or right ventricles of sheep and pigs. Blood was sampled from the opposite ventricle. In both species, left ventricular infusions resulted in significantly lower specific radioactivities (SA) of [ 14 C]leucine and [ 3 H]KIC. [ 14 C]KIC SA was found to be insensitive to infusion and sampling sites. [ 14 C]KIC was in addition found to be equal to the SA of [ 14 C]leucine only during the left heart infusions. Therefore, [ 14 C]KIC SA was used as the only estimate for [ 14 C]SA in the equations for the two-pool model. This model eliminated the influence of site of infusion and blood sampling on the estimates for leucine entry and reduced the impact on the estimates for proteolysis and oxidation. This two-pool model could not compensate for the underestimation of transamination reactions occurring during the traditional venous isotope infusion and arterial blood sampling

Glucocorticoid receptors in anorexia nervosa and Cushing's disease.

Science.gov (United States)

Invitti, C; Redaelli, G; Baldi, G; Cavagnini, F

1999-06-01

Patients with anorexia nervosa do not display cushingoid features in spite of elevated cortisol plasma levels. Whether a cortisol resistance or a reduced availability of the metabolic substrates necessary to develop the effect of glucocorticoids is responsible for this has not been established. Twenty-two patients with severe restrictive anorexia nervosa, 10 patients with active Cushing's disease, and 24 healthy volunteers without psychiatric disorders or mood alterations were investigated. Glucocorticoid receptor characteristics were examined on mononuclear leukocytes by measuring [3H]dexamethasone binding and the effect of dexamethasone on [3H]thymidine incorporation, which represents an index of DNA synthesis. The number of glucocorticoid receptors on mononuclear leukocytes (MNL) was comparable in patients with anorexia nervosa, patients with active Cushing's disease, and normal subjects (binding capacity 3.3 +/- 0.23 vs. 3.7 +/- 0.30 and 3.5 +/- 0.20 fmol/10(6) cells). Conversely, glucocorticoid receptor affinity was significantly decreased in anorexia nervosa as well as in Cushing's patients compared to control subjects (dissociation constant 4.0 +/- 0.31 and 4.1 +/- 0.34 vs. 2.9 +/- 0.29 nmol/L, p Cushing's patients compared to control subjects (p Cushing's disease. In patients with anorexia nervosa, the incorporation of [3H]thymidine into the MNL was inversely correlated with urinary free cortisol levels. These data indicate that the lack of cushingoid features in patients with anorexia nervosa is not ascribable to a reduced sensitivity to glucocorticoids but is more likely due to the paucity of metabolic substrates.

Neuropsychiatric findings in Cushing syndrome and exogenous glucocorticoid administration.

Science.gov (United States)

Starkman, Monica N

2013-09-01

This article reviews the neuropsychiatric presentations elicited by spontaneous hypercortisolism and exogenous supraphysiologic glucocorticoids. Patients with Cushing disease and syndrome develop a depressive syndrome: irritable and depressed mood, decreased libido, disrupted sleep and cognitive decrements. Exogenous short-term glucocorticoid administration may elicit a hypomanic syndrome with mood, sleep and cognitive disruptions. Treatment options are discussed. Brain imaging and neuropsychological studies indicate elevated cortisol and other glucocorticoids are especially deleterious to hippocampus and frontal lobe. The research findings also shed light on neuropsychiatric abnormalities in conditions that have substantial subgroups exhibiting elevated and dysregulated cortisol: aging, major depressive disorder and Alzheimer's disease. Copyright © 2013 Elsevier Inc. All rights reserved.

Methodological investigation on the use of 14C-leucine and 15N-leucine for studying the absorption of amino acids in the experimental rat

International Nuclear Information System (INIS)

Bergner, H.; Bergner, U.; Adam, K.

1980-01-01

After nine days of adaptation to a whole-egg diet, albino rats were given 14 C-U-L-leucine and 15 N-L-leucine in addition by the oral route. Each rat received the labelled leucine via a pellet made from the whole-egg diet after food deprivation for 15 h. Thereafter, the experimental animals consumed the unlabelled experimental diet ad libitum. Four times, 30 min, and 1, 2, 4 and 8 h after ingestion of the labelled food, four experimental rats were sacrificed. The contents of the digestive tract and tissue samples were examined for 14 C and 15 N. The halftime of disappearance of the 14 C activity and of the 15 N excess from the TCA-soluble fraction of the gastric contents lay between 1.9 and 2.2 h. Up to the fourth hour of experiment, the 15 N level of the TCA-soluble fraction of the gastric contents was high. The free leucine is obviously absorbed in the stomach and is used for the synthesis of enzyme protein and mucoproteides. In the TCA-soluble fraction of the total contents of the small intestine, the following values (expressed as percentages of the total amounts ingested at the times of measurement) were found: 14 C = 2.0; 6.5; 9.6; 7.4 and 1.5; 15 N excess = 0.8; 1.2; 1.6; 1.6 and 1.2 Were these values regarded as non-absorbed leucine, the 14 C values obtained during the one-to-four hour period of experiment would unequivocally be too high. Presumably, they are simulated by other 14 C-metabolites which originate from the leucine catabolism and reach the intestinal lumen through the intestinal wall. Amino acids labelled with 15 N should be preferred in studies on the absorption of amino acids because, in case of catabolization, the 15 N-amino group is excreted mainly in the form of urea. 14 C-amino acids can be recommended for such studies only if the specific 14 C activity of the amino acid used is also measured. (author)

Quadrupling Inhaled Glucocorticoid Dose to Abort Asthma Exacerbations.

Science.gov (United States)

McKeever, Tricia; Mortimer, Kevin; Wilson, Andrew; Walker, Samantha; Brightling, Christopher; Skeggs, Andrew; Pavord, Ian; Price, David; Duley, Lelia; Thomas, Mike; Bradshaw, Lucy; Higgins, Bernard; Haydock, Rebecca; Mitchell, Eleanor; Devereux, Graham; Harrison, Timothy

2018-03-08

Asthma exacerbations are frightening for patients and are occasionally fatal. We tested the concept that a plan for patients to manage their asthma (self-management plan), which included a temporary quadrupling of the dose of inhaled glucocorticoids when asthma control started to deteriorate, would reduce the incidence of severe asthma exacerbations among adults and adolescents with asthma. We conducted a pragmatic, unblinded, randomized trial involving adults and adolescents with asthma who were receiving inhaled glucocorticoids, with or without add-on therapy, and who had had at least one exacerbation in the previous 12 months. We compared a self-management plan that included an increase in the dose of inhaled glucocorticoids by a factor of 4 (quadrupling group) with the same plan without such an increase (non-quadrupling group), over a period of 12 months. The primary outcome was the time to a first severe asthma exacerbation, defined as treatment with systemic glucocorticoids or an unscheduled health care consultation for asthma. A total of 1922 participants underwent randomization, of whom 1871 were included in the primary analysis. The number of participants who had a severe asthma exacerbation in the year after randomization was 420 (45%) in the quadrupling group as compared with 484 (52%) in the non-quadrupling group, with an adjusted hazard ratio for the time to a first severe exacerbation of 0.81 (95% confidence interval, 0.71 to 0.92; P=0.002). The rate of adverse effects, which were related primarily to local effects of inhaled glucocorticoids, was higher in the quadrupling group than in the non-quadrupling group. In this trial involving adults and adolescents with asthma, a personalized self-management plan that included a temporary quadrupling of the dose of inhaled glucocorticoids when asthma control started to deteriorate resulted in fewer severe asthma exacerbations than a plan in which the dose was not increased. (Funded by the Health Technology

Raman spectroscopy detects deterioration in biomechanical properties of bone in a glucocorticoid-treated mouse model of rheumatoid arthritis

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Maher, Jason R.; Takahata, Masahiko; Awad, Hani A.; Berger, Andrew J.

2011-08-01

Although glucocorticoids are frequently prescribed for the symptomatic management of inflammatory disorders such as rheumatoid arthritis, extended glucocorticoid exposure is the leading cause of physician-induced osteoporosis and leaves patients at a high risk of fracture. To study the biochemical effects of glucocorticoid exposure and how they might affect biomechanical properties of the bone, Raman spectra were acquired from ex vivo tibiae of glucocorticoid- and placebo-treated wild-type mice and a transgenic mouse model of rheumatoid arthritis. Statistically significant spectral differences were observed due to both treatment regimen and mouse genotype. These differences are attributed to changes in the overall bone mineral composition, as well as the degree of phosphate mineralization in tibial cortical bone. In addition, partial least squares regression was used to generate a Raman-based prediction of each tibia's biomechanical strength as quantified by a torsion test. The Raman-based predictions were as accurate as those produced by microcomputed tomography derived parameters, and more accurate than the clinically-used parameter of bone mineral density. These results suggest that Raman spectroscopy could be a valuable tool for monitoring bone biochemistry in studies of bone diseases such as osteoporosis, including tests of drugs being developed to combat these diseases.

Adverse consequences of glucocorticoid medication: psychological, cognitive, and behavioral effects

NARCIS (Netherlands)

Judd, L.L.; Schettler, P.J.; Brown, E.S.; Wolkowitz, O.M.; Sternberg, E.M.; Bender, B.G.; Bulloch, K.; Cidlowski, J.A.; Kloet, E.R. de; Fardet, L.; Joels, M.; Leung, D.Y.; McEwen, B.S.; Roozendaal, B.; Rossum, E.F. van; Ahn, J.; Brown, D.W.; Plitt, A.; Singh, G.

2014-01-01

Glucocorticoids are the most commonly prescribed anti-inflammatory/immunosuppressant medications worldwide. This article highlights the risk of clinically significant and sometimes severe psychological, cognitive, and behavioral disturbances that may be associated with glucocorticoid use, as well as

Adverse Consequences of Glucocorticoid Medication : Psychological, Cognitive, and Behavioral Effects

NARCIS (Netherlands)

Judd, Lewis L.; Schettler, Pamela J.; Brown, E. Sherwood; Wolkowitz, Owen M.; Sternberg, Esther M.; Bender, Bruce G.; Bulloch, Karen; Cidlowski, John A.; de Kloet, E. Ronald; Fardet, Laurence; Joëls, Marian; Leung, Donald Y. M.; McEwen, Bruce S.; Roozendaal, Benno; Van Rossum, Elisabeth F. C.; Ahn, Junyoung; Brown, David W.; Plitt, Aaron; Singh, Gagandeep

2014-01-01

Glucocorticoids are the most commonly prescribed anti-inflammatory/immunosuppressant medications worldwide. This article highlights the risk of clinically significant and sometimes severe psychological, cognitive, and behavioral disturbances that may be associated with glucocorticoid use, as well as

Reviewing the Effects of l-Leucine Supplementation in the Regulation of Food Intake, Energy Balance, and Glucose Homeostasis

Directory of Open Access Journals (Sweden)

João A.B. Pedroso

2015-05-01

Full Text Available Leucine is a well-known activator of the mammalian target of rapamycin (mTOR. Because mTOR signaling regulates several aspects of metabolism, the potential of leucine as a dietary supplement for treating obesity and diabetes mellitus has been investigated. The objective of the present review was to summarize and discuss the available evidence regarding the mechanisms and the effects of leucine supplementation on the regulation of food intake, energy balance, and glucose homeostasis. Based on the available evidence, we conclude that although central leucine injection decreases food intake, this effect is not well reproduced when leucine is provided as a dietary supplement. Consequently, no robust evidence indicates that oral leucine supplementation significantly affects food intake, although several studies have shown that leucine supplementation may help to decrease body adiposity in specific conditions. However, more studies are necessary to assess the effects of leucine supplementation in already-obese subjects. Finally, although several studies have found that leucine supplementation improves glucose homeostasis, the underlying mechanisms involved in these potential beneficial effects remain unknown and may be partially dependent on weight loss.

Glucocorticoids and the regulation of memory in health and disease

NARCIS (Netherlands)

de Quervain, Dominique J. -F; Aerni, Amanda; Schelling, Gustav; Roozendaal, Benno

Over the last decades considerable evidence has accumulated indicating that glucocorticoids - stress hormones released from the adrenal cortex - are crucially involved in the regulation of memory. Specifically, glucocorticoids have been shown to enhance memory consolidation of emotionally arousing

Eosinophil Resistance to Glucocorticoid-Induced Apoptosis is Mediated by the Transcription Factor NFIL3

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Pazdrak, Konrad; Moon, Young; Straub, Christof; Stafford, Susan; Kurosky, Alexander

2016-01-01

The mainstay of asthma therapy, glucocorticoids (GCs) exert their therapeutic effects through the inhibition of inflammatory signaling and induction of eosinophil apoptosis. However, laboratory and clinical observations of GC-resistant asthma suggest that GCs' effects on eosinophil viability may depend on the state of eosinophil activation. In the present study we demonstrate that eosinophils stimulated with IL-5 show impaired prop-aptoptotic response to GCs. We sought to determine the contribution of GC-mediated transactivating (TA) and transrepressing (TR) pathways in modulation of activated eosinophils' response to GC by comparing their response to the selective GC receptor (GR) agonist Compound A (CpdA) devoid of TA activity to that upon treatment with Dexamethasone (Dex). IL-5-activated eosinophils showed contrasting responses to CpdA and Dex, as IL-5-treated eosinophils showed no increase in apoptosis compared to cells treated with Dex alone, while CpdA elicited an apoptotic response regardless of IL-5 stimulation. Proteomic analysis revealed that both Nuclear Factor IL-3 (NFIL3) and Map Kinase Phosphatase 1 (MKP1) were inducible by IL-5 and enhanced by Dex; however, CpdA had no effect on NFIL3 and MKP1 expression. We found that inhibiting NFIL3 with specific siRNA or by blocking the IL-5-inducible Pim-1 kinase abrogated the protective effect of IL-5 on Dex-induced apoptosis, indicating crosstalk between IL-5 anti-apoptotic pathways and GR-mediated TA signaling occurring via the NFIL3 molecule. Collectively, these results indicate that 1) GCs' TA pathway may support eosinophil viability in IL-5-stimulated cells through synergistic upregulation of NFIL3; and 2) functional inhibition of IL-5 signaling (anti-Pim1) or the use of selective GR agonists that don't upregulate NFIL3 may be effective strategies for the restoring pro-apoptotic effect of GCs on IL-5-activated eosinophils. PMID:26880402

Investigation on the absorption of 14C-leucine and 15N-leucine in rats after feeding a fish meal diet in comparison with a gelatine diet

International Nuclear Information System (INIS)

Bergner, U.; Adam, K.; Bergner, H.

1981-01-01

Albino rats received after nine days of adaptation to a fish meal diet in comparison with a gelatine diet 14 C-U-L-leucine and 15 N-L-leucine via a pellet made from the specific diet after food deprivation for 15 h. Thereafter, the animals consumed the non-labelled experimental diet ad libitum. 30 min, and 1, 2, 4 and 8 h, resp., after intake of the labelled food, four rats at a time were sacrificed. The contents of the digestive tract and tissue samples were examined for 14 C and 15 N and their percentages in the TCA-soluble fraction determined. If these values are regarded as non-absorbed leucine, the 14 C values obtained up to the four hour period of the experiment would be too high. Presumably, they are in the case of both diets simulated by other 14 C metabolites which originate from the leucine catabolism and reach the intestinal lumen. Amino acids labelled with 15 N should be preferred in studies on the absorption of amino acids because, in case of catabolization, the 15 N aminogroup is excreted mainly as urea via urine. (author)

Comparative Physiological and Proteomic Analysis Reveals the Leaf Response to Cadmium-Induced Stress in Poplar (Populus yunnanensis.

Directory of Open Access Journals (Sweden)

Yunqiang Yang

Full Text Available Excess amounts of heavy metals are important environmental pollutants with significant ecological and nutritional effects. Cdmium (Cd is of particular concern because of its widespread occurrence and high toxicity. We conducted physiological and proteomic analyses to improve our understanding of the responses of Populus yunnanensis to Cd stress. The plantlets experienced two apparent stages in their response to Cd stress. During the first stage, transiently induced defense-response molecules, photosynthesis- and energy-associated proteins, antioxidant enzymes and heat shock proteins (HSPs accumulated to enhance protein stability and establish a new cellular homeostasis. This activity explains why plant photosynthetic capability during this period barely changed. During the second stage, a decline of ribulose-1, 5-bisphosphate carboxylase (RuBisCO and HSP levels led to imbalance of the plant photosynthetic system. Additionally, the expression of Mitogen-activated protein kinase 3 (MPK3, Mitogen-activated protein kinase 6 (MPK6 and a homeobox-leucine zipper protein was higher in the second stage. Higher expression of caffeoyl-CoA O-methyltransferase (CCoAOMT may regulate plant cell wall synthesis for greater Cd storage. These genes may be candidates for further research and use in genetic manipulation of poplar tolerance to Cd stress.

Differential effects of leucine and leucine-enriched whey protein on skeletal muscle protein synthesis in aged mice

NARCIS (Netherlands)

Dijk, Francina J.; Dijk, van Miriam; Walrand, Stéphane; Loon, van Luc J.C.; Norren, van Klaske; Luiking, Yvette C.

2018-01-01

Background & aims: It has been suggested that anabolic resistance, or a blunted protein synthetic response to anabolic stimuli, contributes to the failure of muscle mass maintenance in older adults. The amino acid leucine is one of the most prominent food-related anabolic stimuli. However, data

Glucocorticoid-induced diabetes in patients with metastatic spinal cord compression

DEFF Research Database (Denmark)

Schultz, Helga; Engelholm, Svend Aage; Harder, Eva

2018-01-01

in a prospective, observational cohort study. The primary endpoint was development of DM defined by two or more plasma glucose values ≥11.1 mmol/L. Plasma glucose was monitored on a daily basis for 12 days during radiotherapy. RESULTS: Fifty-six of the patients (43%; 95% CI 35-52%) were diagnosed with DM based...... spinal cord compression (MSCC) in patients referred to radiotherapy. Furthermore, to describe the time course of development of DM. SUBJECTS AND METHODS: 140 patients were recruited (131 were included in the analysis) with MSCC receiving high-dose glucocorticoid ≥100 mg prednisolone per day were included...... on plasma glucose measurements during the study period. Sixteen patients, 12% (95% CI 6-18%), were treated with insulin. At multivariate analysis, only high baseline HbA1c predicted the development of insulin-treated DM. An HbA1c-value value of 96...

Cannabinoid receptors activation and glucocorticoid receptors deactivation in the amygdala prevent the stress-induced enhancement of a negative learning experience.

Science.gov (United States)

Ramot, Assaf; Akirav, Irit

2012-05-01

The enhancement of emotional memory is clearly important as emotional stimuli are generally more significant than neutral stimuli for surviving and reproduction purposes. Yet, the enhancement of a negative emotional memory following exposure to stress may result in dysfunctional or intrusive memory that underlies several psychiatric disorders. Here we examined the effects of stress exposure on a negative emotional learning experience as measured by a decrease in the magnitude of the expected quantity of reinforcements in an alley maze. In contrast to other fear-related negative experiences, reward reduction is more associated with frustration and is assessed by measuring the latency to run the length of the alley to consume the reduced quantity of reward. We also examined whether the cannabinoid receptors agonist WIN55,212-2 (5 μg/side) and the glucocorticoid receptors (GRs) antagonist RU-486 (10 ng/side) administered into the rat basolateral amygdala (BLA) could prevent the stress-induced enhancement. We found that intra-BLA RU-486 or WIN55,212 before stress exposure prevented the stress-induced enhancement of memory consolidation for reduction in reward magnitude. These findings suggest that cannabinoid receptors and GRs in the BLA are important modulators of stress-induced enhancement of emotional memory. Copyright © 2012 Elsevier Inc. All rights reserved.

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

Leucine-based receptor sorting motifs are dependent on the spacing relative to the plasma membrane

DEFF Research Database (Denmark)

Geisler, C; Dietrich, J; Nielsen, B L

1998-01-01

Many integral membrane proteins contain leucine-based motifs within their cytoplasmic domains that mediate internalization and intracellular sorting. Two types of leucine-based motifs have been identified. One type is dependent on phosphorylation, whereas the other type, which includes an acidic...... amino acid, is constitutively active. In this study, we have investigated how the spacing relative to the plasma membrane affects the function of both types of leucine-based motifs. For phosphorylation-dependent leucine-based motifs, a minimal spacing of 7 residues between the plasma membrane...... and the phospho-acceptor was required for phosphorylation and thereby activation of the motifs. For constitutively active leucine-based motifs, a minimal spacing of 6 residues between the plasma membrane and the acidic residue was required for optimal activity of the motifs. In addition, we found that the acidic...

Puff and bite: the relationship between the glucocorticoid stress response and anti-predator performance in checkered puffer (Sphoeroides testudineus).

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Cull, Felicia; O'Connor, Constance M; Suski, Cory D; Shultz, Aaron D; Danylchuk, Andy J; Cooke, Steven J

2015-04-01

Individual variation in the endocrine stress response has been linked to survival and performance in a variety of species. Here, we evaluate the relationship between the endocrine stress response and anti-predator behaviors in wild checkered puffers (Sphoeroides testudineus) captured at Eleuthera Island, Bahamas. The checkered puffer has a unique and easily measurable predator avoidance strategy, which is to inflate or 'puff' to deter potential predators. In this study, we measured baseline and stress-induced circulating glucocorticoid levels, as well as bite force, a performance measure that is relevant to both feeding and predator defence, and 'puff' performance. We found that puff performance and bite force were consistent within individuals, but generally decreased following a standardized stressor. Larger puffers were able to generate a higher bite force, and larger puffers were able to maintain a more robust puff performance following a standardized stressor relative to smaller puffers. In terms of the relationship between the glucocorticoid stress response and performance metrics, we found no relationship between post-stress glucocorticoid levels and either puff performance or bite force. However, we did find that baseline glucocorticoid levels predicted the ability of a puffer to maintain a robust puff response following a repeated stressor, and this relationship was more pronounced in larger individuals. Our work provides a novel example of how baseline glucocorticoids can predict a fitness-related anti-predator behavior. Copyright © 2015 Elsevier Inc. All rights reserved.

From receptor balance to rational glucocorticoid therapy.

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de Kloet, E Ron

2014-08-01

Corticosteroids secreted as end product of the hypothalamic-pituitary-adrenal axis act like a double-edged sword in the brain. The hormones coordinate appraisal processes and decision making during the initial phase of a stressful experience and promote subsequently cognitive performance underlying the management of stress adaptation. This action exerted by the steroids on the initiation and termination of the stress response is mediated by 2 related receptor systems: mineralocorticoid receptors (MRs) and glucocorticoid receptors (GRs). The receptor types are unevenly distributed but colocalized in abundance in neurons of the limbic brain to enable these complementary hormone actions. This contribution starts from a historical perspective with the observation that phasic occupancy of GR during ultradian rhythmicity is needed to maintain responsiveness to corticosteroids. Then, during stress, initially MR activation enhances excitability of limbic networks that are engaged in appraisal and emotion regulation. Next, the rising hormone concentration occupies GR, resulting in reallocation of energy to limbic-cortical circuits with a role in behavioral adaptation and memory storage. Upon MR:GR imbalance, dysregulation of the hypothalamic-pituitary-adrenal axis occurs, which can enhance an individual's vulnerability. Imbalance is characteristic for chronic stress experience and depression but also occurs during exposure to synthetic glucocorticoids. Hence, glucocorticoid psychopathology may develop in susceptible individuals because of suppression of ultradian/circadian rhythmicity and depletion of endogenous corticosterone from brain MR. This knowledge generated from testing the balance hypothesis can be translated to a rational glucocorticoid therapy.

Glucocorticoid receptor antagonism reverts docetaxel resistance in human prostate cancer

NARCIS (Netherlands)

Kroon, Jan; Puhr, Martin; Buijs, Jeroen T.; Van Der Horst, Geertje; Lemhemmer, Daniël; Marijt, Koen A.; Hwang, Ming S.; Masood, Motasim; Grimm, Stefan; Storm, Gert; Metselaar, Josbert M.|info:eu-repo/dai/nl/244207690; Meijer, Onno C.; Culig, Zoran; Van Der Pluijm, Gabri

2016-01-01

Resistance to docetaxel is a major clinical problem in advanced prostate cancer (PCA). Although glucocorticoids (GCs) are frequently used in combination with docetaxel, it is unclear to what extent GCs and their receptor, the glucocorticoid receptor (GR), contribute to the chemotherapy resistance.

Glucocorticoid receptor antagonism reverts docetaxel resistance in human prostate cancer

NARCIS (Netherlands)

Kroon, Jan; Kroon, Jan; Puhr, M.; Buijs, J.T.; van der Horst, G.; Hemmer, D.M.; Marijt, K.A.; Hwang, M.S.; Masood, M.; Grimm, S.; Storm, Gerrit; Metselaar, Josbert Maarten; Meijer, O.C.; Culig, Z.; van der Pluijm, M.

2016-01-01

Resistance to docetaxel is a major clinical problem in advanced prostate cancer (PCa). Although glucocorticoids (GCs) are frequently used in combination with docetaxel, it is unclear to what extent GCs and their receptor, the glucocorticoid receptor (GR), contribute to the chemotherapy resistance.

The perennial ryegrass GenomeZipper: targeted use of genome resources for comparative grass genomics.

Science.gov (United States)

Pfeifer, Matthias; Martis, Mihaela; Asp, Torben; Mayer, Klaus F X; Lübberstedt, Thomas; Byrne, Stephen; Frei, Ursula; Studer, Bruno

2013-02-01

Whole-genome sequences established for model and major crop species constitute a key resource for advanced genomic research. For outbreeding forage and turf grass species like ryegrasses (Lolium spp.), such resources have yet to be developed. Here, we present a model of the perennial ryegrass (Lolium perenne) genome on the basis of conserved synteny to barley (Hordeum vulgare) and the model grass genome Brachypodium (Brachypodium distachyon) as well as rice (Oryza sativa) and sorghum (Sorghum bicolor). A transcriptome-based genetic linkage map of perennial ryegrass served as a scaffold to establish the chromosomal arrangement of syntenic genes from model grass species. This scaffold revealed a high degree of synteny and macrocollinearity and was then utilized to anchor a collection of perennial ryegrass genes in silico to their predicted genome positions. This resulted in the unambiguous assignment of 3,315 out of 8,876 previously unmapped genes to the respective chromosomes. In total, the GenomeZipper incorporates 4,035 conserved grass gene loci, which were used for the first genome-wide sequence divergence analysis between perennial ryegrass, barley, Brachypodium, rice, and sorghum. The perennial ryegrass GenomeZipper is an ordered, information-rich genome scaffold, facilitating map-based cloning and genome assembly in perennial ryegrass and closely related Poaceae species. It also represents a milestone in describing synteny between perennial ryegrass and fully sequenced model grass genomes, thereby increasing our understanding of genome organization and evolution in the most important temperate forage and turf grass species.

Glucocorticoid treatment, immobility, and constipation are associated with nutritional risk.

Science.gov (United States)

Gutzwiller, Jean-Pierre; Aschwanden, Josef; Iff, Samuel; Leuenberger, Michèle; Perrig, Martin; Stanga, Zeno

2011-12-01

The hypothesis of this clinical study was to determine whether glucocorticoid use and immobility were associated with in-hospital nutritional risk. One hundred and one patients consecutively admitted to the medical wards were enrolled. Current medical conditions, symptoms, medical history, eating and drinking habits, diagnosis, laboratory findings, medications, and anthropometrics were recorded. The Nutrition Risk Score 2002 (NRS-2002) was used as a screening instrument to identify nutritional risk. The results confirmed that glucocorticoid use and immobility are independently associated with nutritional risk determined by the NRS-2002. Constipation could be determined as an additional cofactor independently associated with nutritional risk. Glucocorticoid treatment, immobility, and constipation are associated with nutritional risk in a mixed hospitalized population. The presence of long-time glucocorticoid use, immobility, or constipation should alert the clinician to check for nutritional status, which is an important factor in mortality and morbidity.

Glucocorticoid induced osteopenia in cancellous bone of sheep: validation of large animal model for spine fusion and biomaterial research

DEFF Research Database (Denmark)

Ding, Ming; Cheng, Liming; Bollen, Peter

2010-01-01

STUDY DESIGN: Glucocorticoid with low calcium and phosphorus intake induces osteopenia in cancellous bone of sheep. OBJECTIVE: To validate a large animal model for spine fusion and biomaterial research. SUMMARY OF BACKGROUND DATA: A variety of ovariectomized animals has been used to study...... osteoporosis. Most experimental spine fusions were based on normal animals, and there is a great need for suitable large animal models with adequate bone size that closely resemble osteoporosis in humans. METHODS: Eighteen female skeletal mature sheep were randomly allocated into 3 groups, 6 each. Group 1 (GC......-1) received prednisolone (GC) treatment (0.60 mg/kg/day, 5 times weekly) for 7 months. Group 2 (GC-2) received the same treatment as GC-1 for 7 months followed by 3 months without treatment. Group 3 was left untreated and served as the controls. All sheep received restricted diet with low calcium...

Anti-Apoptotic Protein Bcl-xL Expression in the Midbrain Raphe Region Is Sensitive to Stress and Glucocorticoids.

Science.gov (United States)

Shishkina, Galina T; Kalinina, Tatyana S; Bulygina, Veta V; Lanshakov, Dmitry A; Babluk, Ekaterina V; Dygalo, Nikolay N

2015-01-01

Anti-apoptotic proteins are suggested to be important for the normal health of neurons and synapses as well as for resilience to stress. In order to determine whether stressful events may influence the expression of anti-apoptotic protein Bcl-xL in the midbrain and specifically in the midbrain serotonergic (5-HT) neurons involved in neurobehavioral responses to adverse stimuli, adult male rats were subjected to short-term or chronic forced swim stress. A short-term stress rapidly increased the midbrain bcl-xl mRNA levels and significantly elevated Bcl-xL immunoreactivity in the midbrain 5-HT cells. Stress-induced increase in glucocorticoid secretion was implicated in the observed effect. The levels of bcl-xl mRNA were decreased after stress when glucocorticoid elevation was inhibited by metyrapone (MET, 150 mg/kg), and this decrease was attenuated by glucocorticoid replacement with dexamethasone (DEX; 0.2 mg/kg). Both short-term stress and acute DEX administration, in parallel with Bcl-xL, caused a significant increase in tph2 mRNA levels and slightly enhanced tryptophan hydroxylase immunoreactivity in the midbrain. The increasing effect on the bcl-xl expression was specific to the short-term stress. Forced swim repeated daily for 2 weeks led to a decrease in bcl-xl mRNA in the midbrain without any effects on the Bcl-xL protein expression in the 5-HT neurons. In chronically stressed animals, an increase in tph2 gene expression was not associated with any changes in tryptophan hydroxylase protein levels. Our findings are the first to demonstrate that both short-term stress and acute glucocorticoid exposures induce Bcl-xL protein expression in the midbrain 5-HT neurons concomitantly with the activation of the 5-HT synthesis pathway in these neurons.

Anti-Apoptotic Protein Bcl-xL Expression in the Midbrain Raphe Region Is Sensitive to Stress and Glucocorticoids.

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Galina T Shishkina

Full Text Available Anti-apoptotic proteins are suggested to be important for the normal health of neurons and synapses as well as for resilience to stress. In order to determine whether stressful events may influence the expression of anti-apoptotic protein Bcl-xL in the midbrain and specifically in the midbrain serotonergic (5-HT neurons involved in neurobehavioral responses to adverse stimuli, adult male rats were subjected to short-term or chronic forced swim stress. A short-term stress rapidly increased the midbrain bcl-xl mRNA levels and significantly elevated Bcl-xL immunoreactivity in the midbrain 5-HT cells. Stress-induced increase in glucocorticoid secretion was implicated in the observed effect. The levels of bcl-xl mRNA were decreased after stress when glucocorticoid elevation was inhibited by metyrapone (MET, 150 mg/kg, and this decrease was attenuated by glucocorticoid replacement with dexamethasone (DEX; 0.2 mg/kg. Both short-term stress and acute DEX administration, in parallel with Bcl-xL, caused a significant increase in tph2 mRNA levels and slightly enhanced tryptophan hydroxylase immunoreactivity in the midbrain. The increasing effect on the bcl-xl expression was specific to the short-term stress. Forced swim repeated daily for 2 weeks led to a decrease in bcl-xl mRNA in the midbrain without any effects on the Bcl-xL protein expression in the 5-HT neurons. In chronically stressed animals, an increase in tph2 gene expression was not associated with any changes in tryptophan hydroxylase protein levels. Our findings are the first to demonstrate that both short-term stress and acute glucocorticoid exposures induce Bcl-xL protein expression in the midbrain 5-HT neurons concomitantly with the activation of the 5-HT synthesis pathway in these neurons.

Hypothalamic-Pituitary-Adrenal Axis Modulation of Glucocorticoids in the Cardiovascular System.

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Burford, Natalie G; Webster, Natalia A; Cruz-Topete, Diana

2017-10-16

The collective of endocrine organs acting in homeostatic regulation-known as the hypothalamic-pituitary-adrenal (HPA) axis-comprises an integration of the central nervous system as well as peripheral tissues. These organs respond to imminent or perceived threats that elicit a stress response, primarily culminating in the release of glucocorticoids into the systemic circulation by the adrenal glands. Although the secretion of glucocorticoids serves to protect and maintain homeostasis in the typical operation at baseline levels, inadequate regulation can lead to physiologic and psychologic pathologies. The cardiovascular system is especially susceptible to prolonged dysregulation of the HPA axis and glucocorticoid production. There is debate about whether cardiovascular health risks arise from the direct detrimental effects of stress axis activation or whether pathologies develop secondary to the accompanying metabolic strain of excess glucocorticoids. In this review, we will explore the emerging research that indicates stress does have direct effects on the cardiovascular system via the HPA axis activation, with emphasis on the latest research on the impact of glucocorticoids signaling in the vasculature and the heart.

Hypothalamic-Pituitary-Adrenal Axis Modulation of Glucocorticoids in the Cardiovascular System

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Natalie G. Burford

2017-10-01

Full Text Available The collective of endocrine organs acting in homeostatic regulation—known as the hypothalamic-pituitary-adrenal (HPA axis—comprises an integration of the central nervous system as well as peripheral tissues. These organs respond to imminent or perceived threats that elicit a stress response, primarily culminating in the release of glucocorticoids into the systemic circulation by the adrenal glands. Although the secretion of glucocorticoids serves to protect and maintain homeostasis in the typical operation at baseline levels, inadequate regulation can lead to physiologic and psychologic pathologies. The cardiovascular system is especially susceptible to prolonged dysregulation of the HPA axis and glucocorticoid production. There is debate about whether cardiovascular health risks arise from the direct detrimental effects of stress axis activation or whether pathologies develop secondary to the accompanying metabolic strain of excess glucocorticoids. In this review, we will explore the emerging research that indicates stress does have direct effects on the cardiovascular system via the HPA axis activation, with emphasis on the latest research on the impact of glucocorticoids signaling in the vasculature and the heart.

70Z/3 Cbl induces PLC gamma 1 activation in T lymphocytes via an alternate Lat- and Slp-76-independent signaling mechanism.

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Graham, Laurie J; Verí, Maria-Concetta; DeBell, Karen E; Noviello, Cristiana; Rawat, Rashmi; Jen, Sandy; Bonvini, Ezio; Rellahan, Barbara

2003-04-24

The oncoprotein 70Z/3 Cbl signals in an autonomous fashion or through blockade of endogenous c-Cbl, a negative regulator of signaling. The mechanism of 70Z/3 Cbl-induced signaling was investigated by comparing the molecular requirements for 70Z/3 Cbl- and TCR-induced phospholipase C gamma 1 (PLC gamma 1) activation. 70Z/3 Cbl-induced PLC gamma 1 tyrosine phosphorylation required, in addition to the PLC gamma 1 N-terminal SH2 domain, the C-terminal SH2 and SH3 domains that were dispensable for TCR-induced phosphorylation. Deletion of the leucine zipper of 70Z/3 Cbl did not eliminate 70Z/3 Cbl-induced PLC gamma 1 phosphorylation, suggesting that blockage of c-Cbl via dimerization with 70Z/3 Cbl cannot fully explain 70Z/3 Cbl activating characteristics. The complete elimination of PLC gamma 1 phosphorylation required deleting the SH3 domain-binding region of 70Z/3 Cbl, consistent with 70Z/3 Cbl binding the PLC gamma 1 SH3 domain. 70Z/3 Cbl-induced PLC gamma 1 phosphorylation required Zap-70, as for the TCR, and the tyrosine kinase binding domain of 70Z/3 Cbl, which binds Zap-70, but did not require PLC gamma 1 binding to Lat, a crucial interaction in TCR-induced PLC gamma 1 phosphorylation. Furthermore, 70Z/3 Cbl-induced activation of NFAT, a PLC gamma 1/Ca(2+)-dependent transcriptional event, required Zap-70, but was independent of Slp-76, an adapter required for TCR-induced NFAT activation. These results suggest that 70Z/3 Cbl and PLC gamma 1 form a TCR-, Lat- and Slp-76-independent complex that leads to PLC gamma 1 phosphorylation and activation.

Total brain, cortical and white matter volumes in children previously treated with glucocorticoids

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Holm, Sara K; Madsen, Kathrine S; Vestergaard, Martin

2018-01-01

BACKGROUND: Perinatal exposure to glucocorticoids and elevated endogenous glucocorticoid-levels during childhood can have detrimental effects on the developing brain. Here, we examined the impact of glucocorticoid-treatment during childhood on brain volumes. METHODS: Thirty children and adolescents...... with rheumatic or nephrotic disease previously treated with glucocorticoids and 30 controls matched on age, sex, and parent education underwent magnetic resonance imaging (MRI) of the brain. Total cortical grey and white matter, brain, and intracranial volume, and total cortical thickness and surface area were...... were mainly driven by the children with rheumatic disease. Total cortical thickness and cortical surface area did not significantly differ between groups. We found no significant associations between glucocorticoid-treatment variables and volumetric measures. CONCLUSION: Observed smaller total brain...

Proteomics unveil corticoid-induced S100A11 shuttling in keratinocyte differentiation

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Dezitter, Xavier; Hammoudi, Fatma; Belverge, Nicolas; Deloulme, Jean-Christophe; Drobecq, Herve; Masselot, Bernadette; Formstecher, Pierre; Mendy, Denise; Idziorek, Thierry

2007-01-01

Unlike classical protein extraction techniques, proteomic mapping using a selective subcellular extraction kit revealed S100A11 as a new member of the S100 protein family modulated by glucocorticoids in keratinocytes. Glucocorticoids (GC)-induced S100A11 redistribution in the 'organelles and membranes' compartment. Microscopic examination indicated that glucocorticoids specifically routed cytoplasmic S100A11 toward perinuclear compartment. Calcium, a key component of skin terminal differentiation, directed S100A11 to the plasma membrane as previously reported. When calcium was added to glucocorticoids, minor change was observed at the proteomic level while confocal microscopy revealed a rapid and dramatic translocation of S100A11 toward plasma membrane. This effect was accompanied by strong nuclear condensation, loss of mitochondrial potential and DNA content, and increased high molecular weight S100A11 immunoreactivity, suggesting corticoids accelerate calcium-induced terminal differentiation. Finally, our results suggest GC-induced S100A11 relocalization could be a key step in both keratinocyte homeostasis and glucocorticoids side effects in human epidermis

Memory consolidation in human sleep depends on inhibition of glucocorticoid release.

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Plihal, W; Born, J

1999-09-09

Early sleep dominated by slow-wave sleep has been found to be particularly relevant for declarative memory formation via hippocampo-neocortical networks. Concurrently, early nocturnal sleep is characterized by an inhibition of glucocorticoid release from the adrenals. Here, we show in healthy humans that this inhibition serves to support declarative memory consolidation during sleep. Elevating plasma glucocorticoid concentration during early sleep by administration of cortisol impaired consolidation of paired associate words, but not of non-declarative memory of visuomotor skills. Since glucocorticoid concentration was enhanced only during retention sleep, but not during acquisition or retrieval, a specific effect on the consolidation process is indicated. Blocking mineralocorticoid receptors by canrenoate did not affect memory, suggesting inactivation of glucocorticoid receptors to be the essential prerequisite for memory consolidation during early sleep.

Glucocorticoid regulation of a novel HPV-E6-p53-miR-145 pathway modulates invasion and therapy resistance of cervical cancer cells.

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Shi, Ming; Du, Libin; Liu, Dan; Qian, Lu; Hu, Meiru; Yu, Ming; Yang, Zhengyan; Zhao, Mingzhen; Chen, Changguo; Guo, Liang; Wang, Lina; Song, Lun; Ma, Yuanfang; Guo, Ning

2012-10-01

Glucocorticoids are stress-responsive neuroendocrine mediators and play an important role in malignant progression, especially in solid tumours. We demonstrate a novel mechanism by which glucocorticoids modulate p53-dependent miR-145 expression in HPV-positive cervical cancer cells through induction of E6 proteins. We found that expression of miR-145 was reduced in cervical cancer tissues. Cortisol induced HPV-E6 expression and suppressed p53 and miR-145 in cervical cancer cells. MiR-145 expression in cervical cancer cells was wild-type p53-dependent, and cortisol-induced down-regulation of miR-145 expression prevented chemotherapy-induced apoptosis, whereas over-expression of miR-145 enhanced sensitivity to mitomycin and reversed the chemoresistance induced by glucocorticoids. We also show that miR-145 augments the effects of p53 by suppressing the inhibitors of p53 in cervical cancer cells, suggesting that miR-145 plays a role in p53 tumour suppression. Finally, we demonstrate that miR-145 inhibits both the motility and invasion of cervical cancer cells. Our findings identify a novel pathway through which the neuroendocrine macroenvironment affects cervical tumour growth, invasion and therapy resistance and show that miR-145 may serve as a target for cervical cancer therapy. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Glucocorticoid induced osteopenia in cancellous bone of sheep: validation of large animal model for spine fusion and biomaterial research.

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Ding, Ming; Cheng, Liming; Bollen, Peter; Schwarz, Peter; Overgaard, Søren

2010-02-15

Glucocorticoid with low calcium and phosphorus intake induces osteopenia in cancellous bone of sheep. To validate a large animal model for spine fusion and biomaterial research. A variety of ovariectomized animals has been used to study osteoporosis. Most experimental spine fusions were based on normal animals, and there is a great need for suitable large animal models with adequate bone size that closely resemble osteoporosis in humans. Eighteen female skeletal mature sheep were randomly allocated into 3 groups, 6 each. Group 1 (GC-1) received prednisolone (GC) treatment (0.60 mg/kg/day, 5 times weekly) for 7 months. Group 2 (GC-2) received the same treatment as GC-1 for 7 months followed by 3 months without treatment. Group 3 was left untreated and served as the controls. All sheep received restricted diet with low calcium and phosphorus during experiment. After killing the animals, cancellous bone specimens from the vertebra, femurs, and tibias were micro-CT scanned and tested mechanically. Serum biomarkers were determined. In lumbar vertebra, the GC treatment resulted in significant decrease of cancellous bone volume fraction and trabecular thickness, and bone strength. However, the microarchitecture and bone strength of GC-2 recovered to a similar level of the controls. A similar trend of microarchitectural changes was also observed in the distal femur and proximal tibia of both GC treated sheep. The bone formation marker serum-osteocalcin was largely reduced in GC-1 compared to the controls, but recovered with a rebound increase at month 10 in GC-2. The current investigation demonstrates that the changes in microarchitecture and mechanical properties were comparable with those observed in humans after long-term GC treatment. A prolonged GC treatment is needed for a long-term observation to keep osteopenic bone. This model resembles long-term glucocorticoid treated osteoporotic model, and is useful in preclinical studies.

Glucocorticoid receptors in monocytes in type 1 diabetes mellitus

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Damm, P; Binder, C

1989-01-01

Glucocorticoid receptor binding characteristics were investigated in 8 males with poorly controlled Type 1 diabetes mellitus and 14 healthy males. The cell type studied was monocytes, and a method for correction for heterogeneity in glucocorticoid binding in a mononuclear leucocyte population...... or with HbA1c. In conclusion, no major abnormalities in glucocorticoid receptor binding characteristics could be demonstrated in Type 1 diabetes mellitus....... was introduced. The number of receptors and the dissociation constant KD were, respectively, 13,699 and 2.93 X 10(-8) mol/l for the control group and 15,788 and 2.75 X 10(-8) mol/l for diabetics (p greater than 0.05). In diabetics, KD correlated negatively with blood glucose (r = 0.762, p less than 0...

The actions of exogenous leucine on mTOR signalling and amino acid transporters in human myotubes

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Cameron-Smith David

2011-06-01

Full Text Available Abstract Background The branched-chain amino acid (BCAA leucine has been identified to be a key regulator of skeletal muscle anabolism. Activation of anabolic signalling occurs via the mammalian target of rapamycin (mTOR through an undefined mechanism. System A and L solute carriers transport essential amino acids across plasma membranes; however it remains unknown whether an exogenous supply of leucine regulates their gene expression. The aim of the present study was to investigate the effects of acute and chronic leucine stimulation of anabolic signalling and specific amino acid transporters, using cultured primary human skeletal muscle cells. Results Human myotubes were treated with leucine, insulin or co-treated with leucine and insulin for 30 min, 3 h or 24 h. Activation of mTOR signalling kinases were examined, together with putative nutrient sensor human vacuolar protein sorting 34 (hVps34 and gene expression of selected amino acid transporters. Phosphorylation of mTOR and p70S6K was transiently increased following leucine exposure, independently to insulin. hVps34 protein expression was also significantly increased. However, genes encoding amino acid transporters were differentially regulated by insulin and not leucine. Conclusions mTOR signalling is transiently activated by leucine within human myotubes independently of insulin stimulation. While this occurred in the absence of changes in gene expression of amino acid transporters, protein expression of hVps34 increased.

A role for glucocorticoids in stress-impaired reproduction: beyond the hypothalamus and pituitary.

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Whirledge, Shannon; Cidlowski, John A

2013-12-01

In addition to the well-characterized role of the sex steroid receptors in regulating fertility and reproduction, reproductive events are also mediated by the hypothalamic-pituitary-adrenal axis in response to an individual's environment. Glucocorticoid secretion in response to stress contributes to the well-characterized suppression of the hypothalamic-pituitary-gonadal axis through central actions in the hypothalamus and pituitary. However, both animal and in vitro studies indicate that other components of the reproductive system are also regulated by glucocorticoids. Furthermore, in the absence of stress, it appears that homeostatic glucocorticoid signaling plays a significant role in reproduction and fertility in all tissues comprising the hypothalamic-pituitary-gonadal axis. Indeed, as central regulators of the immune response, glucocorticoids are uniquely poised to integrate an individual's infectious, inflammatory, stress, nutritional, and metabolic status through glucocorticoid receptor signaling in target tissues. Endocrine signaling between tissues regulating the immune and stress response and those determining reproductive status provides an evolutionary advantage, facilitating the trade-off between reproductive investment and offspring fitness. This review focuses on the actions of glucocorticoids in tissues important for fertility and reproduction, highlighting recent studies that show glucocorticoid signaling plays a significant role throughout the hypothalamic-pituitary-gonadal axis and characterizing these effects as permissive or inhibitory in terms of facilitating reproductive success.

Osteoporosis secundaria y Osteoporosis inducida por glucocorticoides (OIG

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Elías Forero Illera

2006-01-01

Full Text Available La osteoporosis es un problema de salud pública importante a nivel mundial, y su prevalencia está aumentando. La osteoporosis secundaria se puede producir por varias patologías y el uso de ciertos medicamentos. Los glucocorticoides son un grupo de fármacos usados extensamente en la práctica médica debido a su indiscutible utilidad. La osteoporosis inducida por glucocorticoides es un problema de salud pública. Aunque la patogénesis de la pérdida producida por los glucocorticoides en el hueso no se conoce totalmente, investigaciones recientes han proporcionado nuevas conocimientos en los mecanismos de estos fármacos a nivel celular y molecular. Diversas guías han sido propuestas por diversos grupos para el tratamiento de la OIG; desafortunadamente, las guías del tratamiento no se utilizan adecuadamente en los pacientes.

Glucocorticoid receptor polymorphism in obesity and glucose homeostasis.

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Majer-Łobodzińska, Agnieszka; Adamiec-Mroczek, Joanna

2017-01-01

Glucocorticoid receptor (GR) activity plays a significant role in the etiology of obesity and is essential for glucose homeostasis, the development of hyperinsulinaemia and subsequent increased fat deposition. Several polymorphisms in the GR gene have been described, and at least three of them seem to be associated with altered glucocorticoid sensitivity and changes in glucose homeostasis, and other metabolic parameters. The N363S polymorphism has been associated with increased sensitivity to glucocorticoides, increased insulin response to dexamethasone and increased plasma glucose level. BclI polymorphism is associated with increased abdominal obesity, hyperinsulinaemia and increased insulin resistance. Another polymorphism, ER22/23EK, in contrast to the others, is associated with relative resistance to glucocoricides actions and more beneficial metabolic profile-lower insulin resistance level, decreased lower cardiovascular risk and subseuent prolongation of life time. More research is still needed to understand the mechanisms behind these associations at the molecular level.

Dexamethasone-Induced Myeloid-Derived Suppressor Cells Prolong Allo Cardiac Graft Survival through iNOS- and Glucocorticoid Receptor-Dependent Mechanism

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Yang Zhao

2018-02-01

Full Text Available How to induce immune tolerance without long-term need for immunosuppressive drugs has always been a central problem in solid organ transplantation. Modulating immunoregulatory cells represents a potential target to resolve this problem. Myeloid-derived suppressor cells (MDSCs are novel key immunoregulatory cells in the context of tumor development or transplantation, and can be generated in vitro. However, none of current systems for in vitro differentiation of MDSCs have successfully achieved long-term immune tolerance. Herein, we combined dexamethasone (Dex, which is a classic immune regulatory drug in the clinic, with common MDSCs inducing cytokine granulocyte macrophage colony stimulating factor (GM-CSF to generate MDSCs in vitro. Addition of Dex into GM-CSF system specifically increased the number of CD11b+ Gr-1int/low MDSCs with an enhanced immunosuppressive function in vitro. Adoptive transfer of these MDSCs significantly prolonged heart allograft survival and also favored the expansion of regulatory T cells in vivo. Mechanistic studies showed that inducible nitric oxide sythase (iNOS signaling was required for MDSCs in the control of T-cell response and glucocorticoid receptor (GR signaling played a critical role in the recruitment of transferred MDSCs into allograft through upregulating CXCR2 expression on MDSCs. Blockade of GR signaling with its specific inhibitor or genetic deletion of iNOS reversed the protective effect of Dex-induced MDSCs on allograft rejection. Together, our results indicated that co-application of Dex and GM-CSF may be a new and important strategy for the induction of potent MDSCs to achieve immune tolerance in organ transplantation.

Effects of environmental conditions, human activity, reproduction, antler cycle and grouping on fecal glucocorticoids of free-ranging Pampas deer stags (Ozotoceros bezoarticus bezoarticus).

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Garcia Pereira, Ricardo José; Barbanti Duarte, José Maurício; Negrão, João Alberto

2006-01-01

In this study, a commercial enzyme immunoassay (EIA) was validated in detecting glucocorticoids in Pampas deer feces, in order to investigate the influence of several factors on the adrenocortical function. Fecal samples, behavioral data and information concerning male grouping and antlers status were collected at a monthly basis during a 1 year period from free-ranging stags living at Emas National Park, Brazil (18 degrees S/52 degrees W). The results revealed that concentrations of fecal glucocorticoids in winter were significantly higher than those corresponding to spring and summer. In addition, dry season data presented higher levels than during the wet season. Significant difference was found between fecal levels of breeding stags in summer and nonbreeding stags, whereas no difference was observed between breeding stags in winter and nonbreeding stags. On the other hand, males from areas with frequent human disturbance exhibited higher glucocorticoid concentrations and flight distances than individuals from areas of lower human activity. Males with antlers in velvet had elevated levels compared with animals in hard antler or antler casting. Also, we found that glucocorticoid levels were higher in groups with three or more males than in groups with only one male. The flight distances showed positive correlation with fecal glucocorticoid. These data indicate that fecal glucocorticoid provides a useful approach in the evaluation of physiological effects of environment, inter-individuals relationship and human-induced stressors on free-ranging Pampas deer stags.

Impaired intracortical transmission in G2019S leucine rich-repeat kinase Parkinson patients.

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Ponzo, Viviana; Di Lorenzo, Francesco; Brusa, Livia; Schirinzi, Tommaso; Battistini, Stefania; Ricci, Claudia; Sambucci, Manolo; Caltagirone, Carlo; Koch, Giacomo

2017-05-01

A mutation in leucine-rich repeat kinase 2 is the most common cause of hereditary Parkinson's disease (PD), yet the neural mechanisms and the circuitry potentially involved are poorly understood. We used different transcranial magnetic stimulation protocols to explore in the primary motor cortex the activity of intracortical circuits and cortical plasticity (long-term potentiation) in patients with the G2019S leucine-rich repeat kinase 2 gene mutation when compared with idiopathic PD patients and age-matched healthy subjects. Paired pulse transcranial magnetic stimulation was used to investigate short intracortical inhibition and facilitation and short afferent inhibition. Intermittent theta burst stimulation, a form of repetitive transcranial magnetic stimulation, was used to test long-term potentiation-like cortical plasticity. Leucine-rich repeat kinase 2 and idiopathic PD were tested both in ON and in OFF l-dopa therapy. When compared with idiopathic PD and healthy subjects, leucine-rich repeat kinase 2 PD patients showed a remarkable reduction of short intracortical inhibition in both ON and in OFF l-dopa therapy. This reduction was paralleled by an increase of intracortical facilitation in OFF l-dopa therapy. Leucine-rich repeat kinase 2 PD showed abnormal long-term potentiation-like cortical plasticity in ON l-dopa therapy. The motor cortex in leucine-rich repeat kinase 2 mutated PD patients is strongly disinhibited and hyperexcitable. These abnormalities could be a result of an impairment of inhibitory (gamma-Aminobutyric acid) transmission eventually related to altered neurotransmitter release. © 2017 International Parkinson and Movement Disorder Society. © 2017 International Parkinson and Movement Disorder Society.

Use of the [(14)C]leucine incorporation technique to measure bacterial production in river sediments and the epiphyton.

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Fischer, H; Pusch, M

1999-10-01

Bacterial production is a key parameter for the understanding of carbon cycling in aquatic ecosystems, yet it remains difficult to measure in many aquatic habitats. We therefore tested the applicability of the [(14)C]leucine incorporation technique for the measurement of bulk bacterial production in various habitats of a lowland river ecosystem. To evaluate the method, we determined (i) extraction efficiencies of bacterial protein from the sediments, (ii) substrate saturation of leucine in sediments, the biofilms on aquatic plants (epiphyton), and the pelagic zone, (iii) bacterial activities at different leucine concentrations, (iv) specificity of leucine uptake by bacteria, and (v) the effect of the incubation technique (perfused-core incubation versus slurry incubation) on leucine incorporation into protein. Bacterial protein was best extracted from sediments and precipitated by hot trichloroacetic acid treatment following ultrasonication. For epiphyton, an alkaline-extraction procedure was most efficient. Leucine incorporation saturation occurred at 1 microM in epiphyton and 100 nM in the pelagic zone. Saturation curves in sediments were difficult to model but showed the first level of leucine saturation at 50 microM. Increased uptake at higher leucine concentrations could be partly attributed to eukaryotes. Addition of micromolar concentrations of leucine did not enhance bacterial electron transport activity or DNA replication activity. Similar rates of leucine incorporation into protein calculated for whole sediment cores were observed after slurry and perfused-core incubations, but the rates exhibited strong vertical gradients after the core incubation. We conclude that the leucine incorporation method can measure bacterial production in a wide range of aquatic habitats, including fluvial sediments, if substrate saturation and isotope dilution are determined.

Use of the [14C]Leucine Incorporation Technique To Measure Bacterial Production in River Sediments and the Epiphyton

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Fischer, Helmut; Pusch, Martin

1999-01-01

Bacterial production is a key parameter for the understanding of carbon cycling in aquatic ecosystems, yet it remains difficult to measure in many aquatic habitats. We therefore tested the applicability of the [14C]leucine incorporation technique for the measurement of bulk bacterial production in various habitats of a lowland river ecosystem. To evaluate the method, we determined (i) extraction efficiencies of bacterial protein from the sediments, (ii) substrate saturation of leucine in sediments, the biofilms on aquatic plants (epiphyton), and the pelagic zone, (iii) bacterial activities at different leucine concentrations, (iv) specificity of leucine uptake by bacteria, and (v) the effect of the incubation technique (perfused-core incubation versus slurry incubation) on leucine incorporation into protein. Bacterial protein was best extracted from sediments and precipitated by hot trichloroacetic acid treatment following ultrasonication. For epiphyton, an alkaline-extraction procedure was most efficient. Leucine incorporation saturation occurred at 1 μM in epiphyton and 100 nM in the pelagic zone. Saturation curves in sediments were difficult to model but showed the first level of leucine saturation at 50 μM. Increased uptake at higher leucine concentrations could be partly attributed to eukaryotes. Addition of micromolar concentrations of leucine did not enhance bacterial electron transport activity or DNA replication activity. Similar rates of leucine incorporation into protein calculated for whole sediment cores were observed after slurry and perfused-core incubations, but the rates exhibited strong vertical gradients after the core incubation. We conclude that the leucine incorporation method can measure bacterial production in a wide range of aquatic habitats, including fluvial sediments, if substrate saturation and isotope dilution are determined. PMID:10508068

Glucocorticoids interact with the noradrenergic arousal system in the nucleus accumbens shell to enhance memory consolidation of both appetitive and aversive taste learning.

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Wichmann, Romy; Fornari, Raquel V; Roozendaal, Benno

2012-09-01

It is well established that glucocorticoid hormones strengthen the consolidation of long-term memory of emotionally arousing experiences but have little effect on memory of low-arousing experiences. Although both positive and negative emotionally arousing events tend to be well remembered, studies investigating the neural mechanism underlying glucocorticoid-induced memory enhancement focused primarily on negatively motivated training experiences. In the present study we show an involvement of glucocorticoids within the nucleus accumbens (NAc) in enhancing memory consolidation of both an appetitive and aversive form of taste learning. The specific glucocorticoid receptor (GR) agonist RU 28362 (1 or 3ng) administered bilaterally into the NAc shell, but not core, of male Sprague-Dawley rats immediately after an appetitive saccharin drinking experience dose-dependently enhanced 24-h retention of the safe taste, resulting in a facilitated attenuation of neophobia. Similarly, GR agonist infusions given into the NAc shell immediately after pairing of the saccharin taste with a malaise-inducing agent enhanced memory of this negative experience, resulting in an intensified conditioned aversion. Importantly, a suppression of noradrenergic activity within the NAc shell with the β-adrenoceptor antagonist propranolol blocked the facilitating effect of a concurrently administered GR agonist on memory consolidation in both the appetitive and aversive learning task. Thus, these findings indicate that GR activation interacts with the noradrenergic arousal system within the NAc to enhance memory consolidation of emotionally arousing training experiences regardless of valence. Copyright © 2012 Elsevier Inc. All rights reserved.

Fecal glucocorticoid response to environmental stressors in green iguanas (Iguana iguana).

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Kalliokoski, Otto; Timm, Jeanette A; Ibsen, Ida B; Hau, Jann; Frederiksen, Anne-Marie B; Bertelsen, Mads F

2012-05-15

Quantification of glucocorticoid metabolites in feces has been shown to be a powerful tool in evaluating well-being in vertebrates. Little is known however about the hypothalamic-pituitary-adrenal axis response to stressors, and consequent glucocorticoid excretion, in reptiles. In a longitudinal study, fecal corticosterone metabolite (FCM) levels in green iguanas (Iguana iguana) were quantified during periods of rest and exposure to hypothesized stressors. FCM quantification was combined with behavioral analysis to further contextualize the measured increases. It was shown that both daily 5-minute handling/restraint, as well as housing devoid of climbing opportunity, resulted in increased FCM excretion. Behavioral analysis suggested that the iguanas were chronically stressed by the lack of climbing opportunity, whereas handling may have induced only a transient stress response. The experimental design, using repeated periods of stressor-exposure, also revealed a facilitating effect, where the two stressors potentiated one another. Furthermore, the order of the two stressors was found to be important. The study provides insight into the functioning of the hormonal stress response in green iguanas, and to the refining of their housing and handling. Copyright © 2012 Elsevier Inc. All rights reserved.

Risk of cardiovascular events in people prescribed glucocorticoids with iatrogenic Cushing's syndrome: cohort study.

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Fardet, Laurence; Petersen, Irene; Nazareth, Irwin

2012-07-30

To investigate whether there is an increased risk of cardiovascular events in people who exhibit iatrogenic Cushing's syndrome during treatment with glucocorticoids. Cohort study. 424 UK general practices contributing to The Health Improvement Network database. People prescribed systemic glucocorticoids and with a diagnosis of iatrogenic Cushing's syndrome (n = 547) and two comparison groups: those prescribed glucocorticoids and with no diagnosis of iatrogenic Cushing's syndrome (n = 3231) and those not prescribed systemic glucocorticoids (n = 3282). Incidence of cardiovascular events within a year after diagnosis of iatrogenic Cushing's syndrome or after a randomly selected date, and association between iatrogenic Cushing's syndrome and risk of cardiovascular events. 417 cardiovascular events occurred in 341 patients. Taking into account only the first event by patient (coronary heart disease n = 177, heart failure n = 101, ischaemic stroke n = 63), the incidence rates of cardiovascular events per 100 person years at risk were 15.1 (95% confidence interval 11.8 to 18.4) in those prescribed glucocorticoids and with a diagnosis of iatrogenic Cushing's syndrome, 6.4 (5.5 to 7.3) in those prescribed glucocorticoids without a diagnosis of iatrogenic Cushing's syndrome, and 4.1 (3.4 to 4.8) in those not prescribed glucocorticoids. In multivariate analyses adjusted for sex, age, intensity of glucocorticoid use, underlying disease, smoking status, and use of aspirin, diabetes drugs, antihypertensive drugs, lipid lowering drugs, or oral anticoagulant drugs, the relation between iatrogenic Cushing's syndrome and cardiovascular events was strong (adjusted hazard ratios 2.27 (95% confidence interval 1.48 to 3.47) for coronary heart disease, 3.77 (2.41 to 5.90) for heart failure, and 2.23 (0.96 to 5.17) for ischaemic cerebrovascular events). The adjusted hazard ratio for any cardiovascular event was 4.16 (2.98 to 5.82) when the group prescribed glucocorticoids and with

Prednisolone-induced differential gene expression in mouse liver carrying wild type or a dimerization-defective glucocorticoid receptor

Directory of Open Access Journals (Sweden)

Dokter Wim

2010-06-01

Full Text Available Abstract Background Glucocorticoids (GCs control expression of a large number of genes via binding to the GC receptor (GR. Transcription may be regulated either by binding of the GR dimer to DNA regulatory elements or by protein-protein interactions of GR monomers with other transcription factors. Although the type of regulation for a number of individual target genes is known, the relative contribution of both mechanisms to the regulation of the entire transcriptional program remains elusive. To study the importance of GR dimerization in the regulation of gene expression, we performed gene expression profiling of livers of prednisolone-treated wild type (WT and mice that have lost the ability to form GR dimers (GRdim. Results The GR target genes identified in WT mice were predominantly related to glucose metabolism, the cell cycle, apoptosis and inflammation. In GRdim mice, the level of prednisolone-induced gene expression was significantly reduced compared to WT, but not completely absent. Interestingly, for a set of genes, involved in cell cycle and apoptosis processes and strongly related to Foxo3a and p53, induction by prednisolone was completely abolished in GRdim mice. In contrast, glucose metabolism-related genes were still modestly upregulated in GRdim mice upon prednisolone treatment. Finally, we identified several novel GC-inducible genes from which Fam107a, a putative histone acetyltransferase complex interacting protein, was most strongly dependent on GR dimerization. Conclusions This study on prednisolone-induced effects in livers of WT and GRdim mice identified a number of interesting candidate genes and pathways regulated by GR dimers and sheds new light onto the complex transcriptional regulation of liver function by GCs.

Inhibition of Curcumin on ZAKα Activity Resultant in Apoptosis and Anchorage-Independent Growth in Cancer Cells.

Science.gov (United States)

Lee, Jin-Sun; Wang, Tsu-Shing; Lin, Ming Cheng; Lin, Wei-Wen; Yang, Jaw-Ji

2017-10-31

Curcumin, a popular yellow pigment of the dietary spice turmeric, has been reported to inhibit cell growth and to induce apoptosis in a wide variety of cancer cells. Although numerous studies have investigated anticancer effects of curcumin, the precise molecular mechanism of action remains unidentified. Whereas curcumin mediates cell survival and apoptosis through mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) signaling cascades, its impact on the upstream regulation of MAPK is unclear. The leucine-zipper and sterile-α motif kinase alpha (ZAKα), a mitogen-activated protein kinase kinase kinase (MAP3K), activates the c-Jun N-terminal kinase (JNK) and NF-κB pathway. This paper investigated the prospective involvement of ZAKα in curcumin-induced effects on cancer cells. Our results suggest that the antitumor activity of curcumin is mediated via a mechanism involving inhibition of ZAKα activity.

Investigation on the absorption of /sup 14/C-leucine and /sup 15/N-leucine in rats after feeding a fish meal diet in comparison with a gelatine diet

Energy Technology Data Exchange (ETDEWEB)

Bergner, U; Adam, K; Bergner, H [Humboldt-Universitaet, Berlin (German Democratic Republic). Sektion Tierproduktion und Veterinaermedizin

1981-01-01

Albino rats received after nine days of adaptation to a fish meal diet in comparison with a gelatine diet /sup 14/C-U-L-leucine and /sup 15/N-L-leucine via a pellet made from the specific diet after food deprivation for 15 h. Thereafter, the animals consumed the non-labelled experimental diet ad libitum. 30 min, and 1, 2, 4 and 8 h, resp., after intake of the labelled food, four rats at a time were sacrificed. The contents of the digestive tract and tissue samples were examined for /sup 14/C and /sup 15/N and their percentages in the TCA-soluble fraction determined. If these values are regarded as non-absorbed leucine, the /sup 14/C values obtained up to the four hour period of the experiment would be too high. Presumably, they are in the case of both diets simulated by other /sup 14/C metabolites which originate from the leucine catabolism and reach the intestinal lumen. Amino acids labelled with /sup 15/N should be preferred in studies on the absorption of amino acids because, in case of catabolization, the /sup 15/N aminogroup is excreted mainly as urea via urine.

Role of field-induced nanostructures, zippering and size polydispersity on effective thermal transport in magnetic fluids without significant viscosity enhancement

Science.gov (United States)

Vinod, Sithara; Philip, John

2017-12-01

Magnetic nanofluids or ferrofluids exhibit extraordinary field dependant tunable thermal conductivity (k), which make them potential candidates for microelectronic cooling applications. However, the associated viscosity enhancement under an external stimulus is undesirable for practical applications. Further, the exact mechanism of heat transport and the role of field induced nanostructures on thermal transport is not clearly understood. In this paper, through systematic thermal, rheological and microscopic studies in 'model ferrofluids', we demonstrate for the first time, the conditions to achieve very high thermal conductivity to viscosity ratio. Highly stable ferrofluids with similar crystallite size, base fluid, capping agent and magnetic properties, but with slightly different size distributions, are synthesized and characterized by X-ray diffraction, small angle X-ray scattering, transmission electron microscopy, dynamic light scattering, vibrating sample magnetometer, Fourier transform infrared spectroscopy and thermo-gravimetry. The average hydrodynamic diameters of the particles were 11.7 and 10.1 nm and the polydispersity indices (σ), were 0.226 and 0.151, respectively. We observe that the system with smaller polydispersity (σ = 0.151) gives larger k enhancement (130% for 150 G) as compared to the one with σ = 0.226 (73% for 80 G). Further, our results show that dispersions without larger aggregates and with high density interfacial capping (with surfactant) can provide very high enhancement in thermal conductivity, with insignificant viscosity enhancement, due to minimal interfacial losses. We also provide experimental evidence for the effective heat conduction (parallel mode) through a large number of space filling linear aggregates with high aspect ratio. Microscopic studies reveal that the larger particles act as nucleating sites and facilitate lateral aggregation (zippering) of linear chains that considerably reduces the number density of space

Cell-specific expression of the glucocorticoid receptor within granular convoluted tubules of the rat submaxillary gland

International Nuclear Information System (INIS)

Antakly, T.; Zhang, C.X.; Sarrieau, A.; Raquidan, D.

1991-01-01

The submaxillary gland, a heterogeneous tissue composed essentially of two functionally distinct cell types (tubular epithelial and acinar), offers an interesting system in which to study the mechanisms of steroid-dependent growth and differentiation. One cell type, the granular convoluted tubular (GCT) cell, secretes a large number of physiologically important polypeptides, including epidermal and nerve growth factors. Two steroids, androgens and glucocorticoids, greatly influence the growth, differentiation, and secretory activity of GCT cells. Because glucocorticoids can partially mimic or potentiate androgen effects, it has been thought that glucocorticoids act via androgen receptors. Since the presence of glucocorticoid receptors is a prerequisite for glucocorticoid action, we have investigated the presence and cellular distribution of glucocorticoid receptors within the rat submaxillary gland. Binding experiments using [3H]dexamethasone revealed the presence of high affinity binding sites in rat submaxillary tissue homogenates. Most of these sites were specifically competed by dexamethasone, corticosterone, and a pure glucocorticoid agonist RU 28362. Neither testosterone nor dihydrotestosterone competed for glucocorticoid binding. The cellular distribution of glucocorticoid receptors within the submaxillary gland was investigated by immunocytochemistry, using two highly specific glucocorticoid receptor antibodies. The receptor was localized in the GCT cells, but not in the acinar cells of rat and mouse submaxillary tissue sections. In GCT cells, the glucocorticoid receptor colocalized with several secretory polypeptides, including epidermal growth factor, nerve growth factor, alpha 2u-globulin, and atrial natriuretic factor

Leucine incorporation into mixed skeletal muscle protein in humans

International Nuclear Information System (INIS)

Nair, K.S.; Halliday, D.; Griggs, R.C.

1988-01-01

Fractional mixed skeletal muscle protein synthesis (FMPS) was estimated in 10 postabsorptive healthy men by determining the increment in the abundance of [ 13 C]-leucine in quadriceps muscle protein during an intravenous infusion of L-[1- 13 C]leucine. Whole-body muscle protein synthesis (MPS) was calculated based on the estimation of muscle mass from creatinine excretion and compared with whole-body protein synthesis (WBPS) calculated from the nonoxidative portion of leucine flux. A significant correlation was found between MPS. The contribution of MPS to WBPS was 27 ± 1%, which is comparable to the reports in other species. Morphometric analyses of adjacent muscle samples in eight subjects demonstrated that the biopsy specimens consisted of 86.5 ± 2% muscular as opposed to other tissues. Because fiber type composition varies between biopsies, the authors examined the relationship between proportions of each fiber type and FMPS. Variation in the composition of biopsies and in fiber-type proportion did not affect the estimation of muscle protein synthesis rate. They conclude that stable isotope techniques using serial needle biopsies permit the direct measurement of FMPS in humans and that this estimation is correlated with an indirect estimation of WBPS

Assignment of the human gene for the glucocorticoid receptor to chromosome 5.

OpenAIRE

Gehring, U; Segnitz, B; Foellmer, B; Francke, U

1985-01-01

Human lymphoblastic leukemia cells of line CEM-C7 are glucocroticoid-sensitive and contain glucocorticoid receptors of wild-type characteristics. EL4 mouse lymphoma cells are resistant to lysis by glucocorticoids due to mutant receptors that exhibit abnormal DNA binding. Hybrids between the two cell lines were prepared and analyzed with respect to glucocorticoid responsiveness and to receptor types by DNA-cellulose chromatrography. Sensitive hybrid cell clones contained the CEM-C7-specific re...

Prevalent glucocorticoid and androgen activity in US water sources.

Science.gov (United States)

Stavreva, Diana A; George, Anuja A; Klausmeyer, Paul; Varticovski, Lyuba; Sack, Daniel; Voss, Ty C; Schiltz, R Louis; Blazer, Vicki S; Iwanowicz, Luke R; Hager, Gordon L

2012-01-01

Contamination of the environment with endocrine disrupting chemicals (EDCs) is a major health concern. The presence of estrogenic compounds in water and their deleterious effect are well documented. However, detection and monitoring of other classes of EDCs is limited. Here we utilize a high-throughput live cell assay based on sub-cellular relocalization of GFP-tagged glucocorticoid and androgen receptors (GFP-GR and GFP-AR), in combination with gene transcription analysis, to screen for glucocorticoid and androgen activity in water samples. We report previously unrecognized glucocorticoid activity in 27%, and androgen activity in 35% of tested water sources from 14 states in the US. Steroids of both classes impact body development, metabolism, and interfere with reproductive, endocrine, and immune systems. This prevalent contamination could negatively affect wildlife and human populations.

Adrenal gland hypofunction in active polymyalgia rheumatica. effect of glucocorticoid treatment on adrenal hormones and interleukin 6.

Science.gov (United States)

Cutolo, Maurizio; Straub, Rainer H; Foppiani, Luca; Prete, Camilla; Pulsatelli, Lia; Sulli, Alberto; Boiardi, Luigi; Macchioni, Pierluigi; Giusti, Massimo; Pizzorni, Carmen; Seriolo, Bruno; Salvarani, Carlo

2002-04-01

administration, a significant cortisol peak was detected in patients and controls, whereas no significant difference in cortisol area-under-the-curve (AUC) was found between the groups. In contrast, ACTH induced a significantly higher (p < 0.05) peak of 17-OHP and AUC in PMR patients than in controls. This study found reduced production of adrenal hormones (cortisol, DHEAS) at baseline in patients with active and untreated PMR. The defect seems mainly related to altered adrenal responsiveness to the ACTH stimulation (i.e., increased 17-OHP), at least in untreated patients. The 12 month glucocorticoid treatment of patients reduced the production of inflammatory mediators (i.e., IL-6) in a stable manner that persisted after glucocorticoids were tapered.

Increased dependence of leucine in posttraumatic sepsis: leucine/tyrosine clearance ratio as an indicator of hepatic impairment in septic multiple organ failure syndrome.

Science.gov (United States)

Pittiruti, M; Siegel, J H; Sganga, G; Coleman, B; Wiles, C E; Belzberg, H; Wedel, S; Placko, R

1985-09-01

The body clearance of 10 plasma amino acids (AA) was determined from the rate of compared muscle-released AA and AA administered by infusion of total parenteral nutrition (TPN) compared to their estimated extracellular (ECW) pool in patients with multiple trauma with (n = 10) or without (n = 16) sepsis at 8-hour intervals. In both nonseptic and septic trauma, increasing TPN increased the mean clearance rate of all infused AA. When the individual AA clearance rates were normalized by the total AA infusion rate, regression-covariance analysis revealed that patients with sepsis had relatively impaired clearances of alanine (p less than 0.01) and methionine, proline, phenylalanine, and tyrosine p less than 0.05 for all). In contrast, the clearances of branched-chain AA (BCAA) valine and isoleucine were maintained, and the clearance of leucine was higher (p less than 0.05) in trauma patients with sepsis than in those without. At any AA infusion rate, compared with surviving patients with sepsis (p less than 0.05), patients who developed fatal multiple organ failure syndrome (MOFS) showed increased clearances of all BCAA with further impaired clearance of tyrosine. The clearance ratio of leucine/tyrosine was increased in MOFS at any AA infusion rate (p less than 0.0001), was an indicator of severity, and, if persistent, was a manifestation of a fatal outcome. Because tyrosine metabolism occurs almost entirely in the liver while leucine can be utilized by viscera and muscle, these data suggest early and progressive septic impairment of the pattern of hepatic uptake and oxidation of AA with a greater body dependence on BCAA, especially leucine, as septic MOFS develops.

Fecal glucocorticoid response to environmental stressors in green iguanas (Iguana iguana)

DEFF Research Database (Denmark)

Kalliokoski, Otto; Timm, Jeanette; Ibsen, Ida

2012-01-01

Quantification of glucocorticoid metabolites in feces has been shown to be a powerful tool in evaluating well-being in vertebrates. Little is known however about the hypothalamic–pituitary–adrenal axis response to stressors, and consequent glucocorticoid excretion, in reptiles. In a longitudinal...

Glucocorticoids and Preterm Hypoxic-Ischemic Brain Injury: The Good and the Bad

Directory of Open Access Journals (Sweden)

Laura Bennet

2012-01-01

Full Text Available Fetuses at risk of premature delivery are now routinely exposed to maternal treatment with synthetic glucocorticoids. In randomized clinical trials, these substantially reduce acute neonatal systemic morbidity, and mortality, after premature birth and reduce intraventricular hemorrhage. However, the overall neurodevelopmental impact is surprisingly unclear; worryingly, postnatal glucocorticoids are consistently associated with impaired brain development. We review the clinical and experimental evidence on how glucocorticoids may affect the developing brain and highlight the need for systematic research.

Glucocorticoids in early rheumatoid arthritis

NARCIS (Netherlands)

Everdingen, Amalia A. van

2002-01-01

For 50 years, glucocorticoids (GC) are used for symptomatic treatment of rheumatoid arthritis (RA). In the last decade, results from clinical studies of treatment with GC as additional therapy to long-acting antirheumatic drugs in patients with early RA suggested also disease-modifying properties of