bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gfi‐1 attaches to the nuclear matrix, associates with ETO (MTG8) and histone deacetylase proteins, and represses transcription using a TSA‐sensitive mechanism
Authors: McGhee Laura , Bryan Josh , Elliott Liza , Grimes H. Leighton , Kazanjian Avedis , Davis J. Nathan , Meyers Shari 
Published: July 2003

AbstractGfi‐1 and Gfi‐1B can repress transcription and play important roles in hematopoietic cell survival and differentiation. Although these proteins are known to bind DNA through a C‐terminal zinc‐finger domain and may require an N‐terminal SNAG domain (SNAIL/Gfi‐1) to repress transcription, the mechanism by which Gfi‐1 and Gfi‐1B act is unknown. A first step towards understanding the mechanism by which these proteins repress transcription is to identify interacting proteins that could contribute to transcriptional repression. ETO (also termed MTG8), was first identified through its involvement in the (8;21) translocation associated with acute myelogenous leukemia. It attaches to the nuclear matrix and associates with histone deacetylases and the co‐repressors N‐CoR, SMRT, and mSin3A, and may act as a co‐repressor for site‐specific transcriptions factors. In this report we demonstrate that Gfi‐1 interacts with ETO and related proteins both in vitro and in vivo and with histone deacetylase proteins in vivo. We observed that a portion of Gfi‐1 and Gfi‐1B associated with the nuclear matrix, as is the case with ETO. Moreover, Gfi‐1 and ETO co‐localize to punctate subnuclear structures. When co‐expressed in mammalian cells, Gfi‐1 associates with histone deacetylse‐1 (HDAC‐1), HDAC‐2, and HDAC‐3. These data identify ETO as a partner for Gfi‐1 and Gfi‐1B, and suggest that Gfi‐1 proteins repress transcription through recruitment of histone deacetylase‐containing complexes. J. Cell. Biochem. 89: 1005–1018, 2003. © 2003 Wiley‐Liss, Inc.
Differential apoptosis‐inducing effect of quercetin and its glycosides in human promyeloleukemic HL‐60 cells by alternative activation of the caspase 3 cascade
Authors: Shen Shing‐Chuan , Chen Yen‐Chou , Hsu Feng‐Lin , Lee Woan‐Rouh 
Published: July 2003

AbstractFlavonoids were demonstrated to possess several biological effects including antitumor, antioxidant, and anti‐inflammatory activities in our previous studies. However, the effect of glycosylation on their biological functions is still undefined. In the present study, the apoptosis‐inducing activities of three structure‐related flavonoids including aglycone quercetin (QUE), and glycone rutin (RUT; QUE‐3‐O‐rutinoside), and glycone quercitrin (QUI; QUE‐3‐O‐rhamnoside) were studied. Both RUT and QUI are QUE glycosides, and possess rutinose and rhamnose at the C3 position of QUE, respectively. Results of the MTT assay showed that QUE, but not RUT and QUI, exhibits significant cytotoxic effect on HL‐60 cells, accompanied by the dose‐ and time‐dependent appearance of characteristics of apoptosis including an increase in DNA ladder intensity, morphological changes, apoptotic bodies, and an increase in hypodiploid cells by flow cytometry analysis. QUE, but not RUT or QUI, caused rapid and transient induction of caspase 3/CPP32 activity, but not caspase 1 activity, according to cleavage of caspase 3 substrates poly(ADP‐ribose) polymerase (PARP) and D4‐GDI proteins, and the appearance of cleaved caspase 3 fragments being detected in QUE‐ but not RUT‐ or QUI‐treated HL‐60 cells. A decrease in the anti‐apoptotic protein, Mcl‐1, was detected in QUE‐treated HL‐60 cells, whereas other Bcl‐2 family proteins including Bax, Bcl‐2, Bcl‐XL, and Bag remained unchanged. The caspase 3 inhibitor, Ac‐DEVD‐FMK, but not the caspase 1 inhibitor, Ac‐YVAD‐FMK, attenuated QUE‐induced cell death. Results of DCHF‐DA assay indicate that no significant increase in intracellular peroxide level was found in QUE‐treated cells, and QUE inhibited the H2O2‐induced intracellular peroxide level. Free radical scavengers N‐acetyl‐cysteine (NAC) and catalase showed no prevention of QUE‐induced apoptosis. In addition, QUE did not induce apoptosis in an mature monocytic cell line THP‐1, as characterized by a lack of DNA ladders, caspase 3 activation, PARP cleavage, and an Mcl‐1 decrease, compared with those in HL‐60 cells. Our experiments provide evidence to indicate that the addition of rutinose or rhamnose attenuates the apoptosis‐inducing activity of QUE, and that the caspase 3 cascade but not free radical production is involved. J. Cell. Biochem. 89: 1044–1055, 2003. © 2003 Wiley‐Liss, Inc.
Adenosine inhibits activation‐induced T cell expression of CD2 and CD28 co‐stimulatory molecules: Role of interleukin‐2 and cyclic AMP signaling pathways
Authors: Butler Jared J. , Mader Jamie S. , Watson Carrie L. , Zhang Hong , Blay Jonathan , Hoskin David W. 
Published: July 2003

AbstractAdenosine is an immunosuppressive molecule that is associated with the microenvironment of solid tumors. Mouse T cells activated with anti‐CD3 antibody in the presence of adenosine with or without coformycin (to prevent adenosine breakdown by adenosine deaminase) exhibited decreased tyrosine phosphorylation of some intracellular proteins and were inhibited in their ability to proliferate and synthesize interleukin (IL)‐2. In addition, adenosine interfered with activation‐induced expression of the co‐stimulatory molecules CD2 and CD28. Activation‐induced CD2 and CD28 expression was also diminished when T cells were activated in the presence of anti‐IL‐2 and anti‐CD25 antibodies to neutralize IL‐2 bioactivity. Collectively, these data suggest that CD2 and CD28 up‐regulation following T cell activation is IL‐2‐dependent; and that adenosine inhibits activation‐induced T cell expression of CD2 and CD28 by interfering with IL‐2‐dependent signaling. The inhibitory effect of adenosine on activation‐induced CD2 and CD28 expression could not be attributed to cyclic AMP (cAMP) accumulation resulting from the stimulation of adenylyl cyclase‐coupled adenosine receptors, even though cAMP at concentrations much higher than those generated following adenosine stimulation was inhibitory for both CD2 and CD28 expression. We conclude that adenosine interferes with IL‐2‐dependent T cell expression of co‐stimulatory molecules via a mechanism that does not involve the accumulation of intracellular cAMP. J. Cell. Biochem. 89: 975–991, 2003. © 2003 Wiley‐Liss, Inc.
N‐terminal methionine removal and methionine metabolism in Saccharomyces cerevisiae
Authors: Dummitt Benjamin , Micka William S. , Chang Yie‐Hwa 
Published: July 2003

AbstractMethionine aminopeptidase (MetAP) catalyzes removal of the initiator methionine from nascent polypeptides. In eukaryotes, there are two forms of MetAP, type 1 and type 2, whose combined activities are essential, but whose relative intracellular roles are unclear. Methionine metabolism is an important aspect of cellular physiology, involved in oxidative stress, methylation, and cell cycle. Due to the potential of MetAP activity to provide a methionine salvage pathway, we evaluated the relationship between methionine metabolism and MetAP activity in Saccharomyces cerevisiae. We provide the first demonstration that yeast MetAP1 plays a significant role in methionine metabolism, namely, preventing premature activation of MET genes through MetAP function in methionine salvage. Interestingly, in cells lacking MetAP1, excess methionine dramatically inhibits cell growth. Growth inhibition is independent of the ability of methionine to repress MET genes and does not result from inhibition of synthesis of another metabolite, rather it results from product inhibition of MetAP2. Inhibition by methionine is selective for MetAP2 over MetAP1. These results provide an explanation for the previously observed dominance of MetAP1 in terms of N‐terminal processing and cell growth in yeast. Additionally, differential regulation of the two isoforms may be indicative of different intracellular roles for the two enzymes. J. Cell. Biochem. 89: 964–974, 2003. © 2003 Wiley‐Liss, Inc.
A reassessment of insulin‐like growth factor binding protein gene expression in the human retinal pigment epithelium
Authors: Yang Huaitao , Chaum Edward 
Published: July 2003

AbstractThe role of insulin‐like growth factors (IGF) in regulating cell differentiation and proliferation is in part modulated by the IGF binding protein (IGFBP) family of genes. Previous studies of the human retinal pigment epithelium (RPE) have detected expression of IGFBP‐2, ‐3, and ‐6. However, recent experiments in our lab have suggested a broader pattern of IGFBP gene family expression in the RPE cell than has previously been recognized. We have examined the gene expression profile of IGFBP‐1 to ‐6 and the related protein, IGFBP‐rP1, in RPE cell lines derived from ten donors eyes using RT‐PCR, ELISA, and Western methods. Transcripts of IGFBP‐1 to ‐6 and ‐rP1 were consistently detected in human RPE cells. IGFBP‐3, ‐5, ‐6, and ‐rP‐1, appear to be constitutively expressed in the RPE, whereas IGFBP‐1, ‐2, and ‐4, were expressed at variable levels in the cell lines examined. IGFBP secretion by the RPE in vitro was confirmed by ELISA (IGFBP‐1, ‐2, ‐3, ‐4, and ‐6) and Western blot analysis (IGFBP‐5 and ‐rP1). There was, in general, a strong correlation between gene‐specific transcription levels and protein secretion by the RPE. Our studies demonstrate that the major IGFBP family genes are ubiquitously expressed in explanted human RPE cells in vitro. This broad expression profile and the recent evidence that IGFBPs have IGF‐independent biological activity suggest that the IGFBP family genes may constitute a previously unrecognized and complex regulatory system in the human retina and RPE. J. Cell. Biochem. 89: 933–943, 2003. © 2003 Wiley‐Liss, Inc.
The establishment and characterization of an immortal cell line with a stable chondrocytic phenotype
Authors: King Karen B. , Kimura James H. 
Published: July 2003

AbstractA cell line was developed from the transplantable Swarm rat chondrosarcoma (RCS) and has been maintained in continuous monolayer tissue culture for a number of years. This long term‐cultured (LTC) cell line exhibits the morphological and biochemical characteristics of chondrocytes and resembles the RCS tumor by electron and light microscopy. The cell line differs from the original tumor cells in that about 90% of the sulfated macromolecules are retained in the LTC extracellular matrix as compared to 30% by primary cultures of cells from the RCS tumor. An interesting and useful feature of this cell line is that it contains clonal populations of cells which differ in the quality and quantity of matrix produced. Two such clones serve to illustrate the diversity of cell types within the LTC cell line. One termed Rex accumulates an intensely staining matrix around it, while the other, Ng, accumulates a matrix, that remains virtually unstained. The chondrocytic nature and ease of cloning make these cells ideal for biochemical analysis of the chondrocyte and its extracellular matrix. J. Cell. Biochem. 89: 992–1004, 2003. © 2003 Wiley‐Liss, Inc.
Cytoprotection by pro‐vitamin C against ischemic injuries in perfused rat heart together with differential activation of MAP kinase family
Authors: Eguchi Masahiro , Fujiwara Mayumi , Mizukami Yoichi , Miwa Nobuhiko 
Published: July 2003

AbstractThe cardiac muscle cells are known to be killed by ischemia‐reperfusion (I/R) treatment that produce reactive oxygen species (ROS). We analyzed the function of the autooxidation‐resistant pro‐vitamin C, 2‐O‐alpha‐D‐glucosylated derivative (Asc2G) of ascorbic acid (Asc), in protecting against I/R injury of the heart in rat. The serum release of the intracellular enzyme CPK due to I/R injury decreased upon injection with Asc2G. Out of the mitogen‐activated protein (MAP) kinase family members, MAP kinase and JNK underwent the down‐regulation in contrast to up‐regulation of p38 compared with the I/R‐treated control in the absence of Asc2G. These data suggest important roles for differential activation of the MAP kinase family in cytoprotection against I/R injury by Asc2G. J. Cell. Biochem. 89: 863–867, 2003. © 2003 Wiley‐Liss, Inc.
The targets of vitamin D depend on the differentiation and activation status of CD4 positive T cells
Authors: Mahon Brett D. , Wittke Anja , Weaver Veronika , Cantorna Margherita T. 
Published: July 2003

AbstractVitamin D is a potent immune system regulator. The active form of vitamin D (1,25(OH)2D3) suppresses the development of animal models of human autoimmune diseases. 1,25(OH)2D3 decreased the proliferation of all T helper (h) cells and decreased the production of IFN‐γ, IL‐2, and IL‐5. In Th2 cells 1,25(OH)2D3 increased the production of IL‐4. Quiescent CD4+ T cells express vitamin D receptors but only at a low level, which increased five‐fold following activation. 1,25(OH)2D3 treatment of Th0 cells, but not Th1 or Th2 cells, induced the expression of the transcription factor GATA‐3. Microarray technology identified over 102 targets of 1,25(OH)2D3 in CD4+ T cells. Of the 102 genes, 57 genes were down‐regulated and 45 were up‐regulated by 1,25(OH)2D3 treatment of the CD4+ T cells. Two of the identified genes are regulators of NFkB. Other genes of interest included the IL‐2Rβ gene and IgE binding factor. Th2 and Th0 cells produced more IgE binding factor after treatment with 1,25(OH)2D3 while Th1 cell IgE binding factor expression was unaffected by 1,25(OH)2D3 addition. It is unclear why some of the genes identified are expressed in CD4+ T cells and furthermore why 1,25(OH)2D3 regulates the expression of these genes. Clearly CD4+ T cells can be direct targets of vitamin D. The targets of vitamin D in CD4+ T cells depend on the state of activation and differentiation status of the cells. J. Cell. Biochem. 89: 922–932, 2003. © 2003 Wiley‐Liss, Inc.
Comparison of stress induced by manual restraint and immobilisation in the estuarine crocodile, crocodylus porosus
Authors: Franklin Craig E. , Davis Bernie M. , Peucker S.K.J. , Stephenson H. , Mayer R. , Whittier J. , Lever J. , Grigg G.C. 
Published: July 2003

AbstractThis study compared the stress induced in captive estuarine crocodiles, Crocodylus porosus, by two different handling methods: manual restraint (noosing with ropes) and immobilization by electro‐stunning. To stun, a short charge (approx. 6 s) at 110 V was delivered to the back of the necks of C. porosus using a custom‐built device, which immobilized the animals for 5–10 min. Immobilized and restrained animals were measured and sexed, and the condition of the skin assessed. Blood samples were taken from some animals immediately after restraint or immobilization. Other animals were returned to their pens to recover for periods of 30 min, 1, 4, 12, 24 or 48 hours after which they were stunned and blood samples taken. Individual animals (mean body length 1.96 m, N=99) were bled only once. Haematocrit and haemoglobin concentrations were measured and plasma samples were analysed for corticosterone, glucose and lactate levels. Following restraint, there were significant increases in haematocrit, haemoglobin, glucose, lactate and corticosterone concentrations in C. porosus. For restrained animals, recovery to baseline levels occurred after approximately 8 hours. The stress response of stunned animals was significantly reduced compared to manually captured and restrained crocodiles. Both groups showed a significant increase in haematocrit, haemoglobin concentration and lactate levels, however the magnitude of change was significantly reduced, and recovery was faster in stunned animals. No increase in either glucose or corticosterone levels occurred with immobilisation. The results imply that immobilization by electro‐stunning is much less stressful. J. Exp. Zool. 298A:86–92, 2003. © 2003 Wiley‐Liss, Inc.
Influence of cortisol on osmoregulation and energy metabolism in gilthead seabream Sparus aurata
Authors: Laiz‐carrión Raúl , Martín Del Río María P. , Miguez Jesús M. , Mancera Juan M. , Soengas José L. 
Published: July 2003

AbstractGilthead seabream Sparus aurata were injected intraperitoneally with slow‐release implants of coconut oil alone or containing cortisol (50 and 100 µg.g−1 body weight), and sampled after two, five, and seven days to assess the simultaneous effects of cortisol on both osmoregulation and energy metabolism. Plasma cortisol levels increased in treated fish to 50–70 ng.ml−1. An enhanced hypoosmoregulatory capacity of cortisol‐implanted fish is suggested by the increase observed in gill Na+, K+‐ATPase activity, and the decrease observed in plasma ion concentration (Na+ and Cl−) and osmolality. Cortisol also elicited metabolic changes in liver (increased gluconeogenic potential suggested by elevated FBPase activity, and decreased potential of glycolysis and pentose‐phosphate shunt, suggested by the decreased activities of both PK and G6PDH) supporting changes in levels of plasma metabolites suitable for use in other tissues. Thus in this study, we demonstrate for the first time in fish that cortisol treatments elicit changes in the use of exogenous glucose in gills (decreased HK activity) and an increased glycolytic and glycogenic potential in brain (increased GPase, PK and PFK activities). J. Exp. Zool. 298A:105–118, 2003. © 2003 Wiley‐Liss, Inc.
Upgraded expression of 5S rRNA preludes the production of fibroin by spider glands
Authors: Vázquez Edwin , Arroyo Gerado , Cajigas Iván J. , Candelas Graciela C. 
Published: July 2003

AbstractWe have developed the large ampullate glands of the orb‐web spider Nephila clavipes as a model system in which to study the production of a tissue‐specific secretory protein. Through simple manipulations, the glands' fibroin production can be practically abolished and subsequently elicited into high levels of synthesis through a mechanical stimulus applied to the organism. The tissue specific responses evoked by the stimulus can be monitored through time‐course studies. The latter have revealed an orchestrated series of tissue and time specific macromolecular syntheses, which optimize the glandular tissues with components of the protein synthesis machinery. This work shows the upgraded accumulation of 5S rRNA in the glands as response to the stimulus within the earliest of the prelude events. Further enquiries on this accumulation must be conducted at the level of differential gene expressions, a chore we have initiated. A DNA fragment containing a single copy 5S rRNA gene has been isolated, cloned, sequenced, and transcribed in a cell‐free system. We enclose a discussion on the similarity between the genomic organization of this gene to that of a 5S rRNA gene of Bombyx mori. Our studies have revealed a considerable number of similarities in the silk production strategies of Nephila clavipes and the silkworm Bombyx mori, some of them rather unusual. J. Exp. Zool. 298A:128–133, 2003. © 2003 Wiley‐Liss, Inc.
Induction of pseudopregnancy in the American Black Bear (Ursus americanus)
Authors: Clamon Schulz Laura , Nelson Ralph A. , Pyter Leah M. , Bahr Janice M. 
Published: July 2003

AbstractThe aim of this study was to determine whether American Black Bears (Ursus americanus) can experience a pseudopregnancy of the same duration as pregnancy. To do this, we treated three nonmated, captive female bears with human chorionic gonadotropin (hCG) during one breeding season, and saline during another. Progesterone concentrations were measured in monthly blood samples to determine whether pseudopregnancy had occurred. Elevated progesterone concentrations were observed in two out of three bears treated with hCG. We conclude that 1) Elevated progesterone concentrations can be induced in black bears by injection of 35 U/kg hCG during the mating season. 2) Bears can experience a pseudopregnancy, identical in length to pregnancy, in which progesterone profiles are indistinguishable from those of pregnancy. J. Exp. Zool. 162–166, 2003. © 2003 Wiley‐Liss, Inc.
Effect of temperature on gene expression of the Gh/Igf system during embryonic development in rainbow trout (Oncorhynchus mykiss)
Authors: Gabillard Jean‐Charles , Rescan Pierre‐Yves , Fauconneau Benoit , Weil Claudine , Le Bail Pierre‐Yves 
Published: July 2003

AbstractIn fish, the GH/IGF system installs very early during development suggesting that this system could promote embryonic growth and development. In contrast to mammals, the embryonic growth rate of poikilotherms depends considerably on the incubation temperature. Therefore, the aim of this study was to determine if variations of embryo growth in response to temperature could be associated with modifications in the gene expression of the GH/IGF system.In this study, using whole mount in situ hybridisation, we demonstrated that embryo incubation temperature (4, 8, and 12°C) did not change the timing of GH–1 and GH–2 mRNA expression in somatotroph cells (stage 24). Similarly, at hatching (stage 30), we did not observe an obvious difference in GH protein and GH–1 and GH–2 transcript amounts in relation to the incubation temperature. Furthermore, from stage 22 to 25, the highest temperature led to a specific up‐regulation of IGF–2 (2–fold between 4 and 12°C), and both IGF‐RIa and IGFRIb mRNA (1.5–fold between 4 and 12°C), while no difference was observed for IGF–1 mRNA. Conversely, at hatching, the highest temperature specifically down‐regulated IGF–2 (3fold between 4 and 12°C) and both IGF receptor mRNAs (2 fold between 4 and 12°C) present in the head, while no difference was observed in the trunk.Our results demonstrated that different incubation temperatures during trout embryonic development did not change the stage of somatotroph cell appearance. Before hatching, IGF–2 and both IGF receptors, but not IGF–1 mRNA, were specifically up‐regulated by high temperatures and could be related to the enhancement of embryonic growth rate. J. Exp. Zool. 298A:134–142, 2003. © 2003 Wiley‐Liss, Inc.
On constructible graphs, locally Helly graphs, and convexity
Authors: Polat Norbert 
Published: July 2003

AbstractA (finite or infinite) graph G is constructible if there exists a well‐ordering ≤ of its vertices such that for every vertex x which is not the smallest element, there is a vertex y < x which is adjacent to x and to every neighbor z of x with z < x. Particular constructible graphs are Helly graphs and connected bridged graphs. In this paper we study a new class of constructible graphs, the class of locally Helly graphs. A graph G is locally Helly if, for every pair (x,y) of vertices of G whose distance is d ≥ 2, there exists a vertex whose distance to x is d − 1 and which is adjacent to y and to all neighbors of y whose distance to x is at most d. Helly graphs are locally Helly, and the converse holds for finite graphs. Among different properties we prove that a locally Helly graph is strongly dismantable, hence cop‐win, if and only if it contains no isometric rays. We show that a locally Helly graph G is finitely Helly, that is, every finite family of pairwise non‐disjoint balls of G has a non‐empty intersection. We give a sufficient condition by forbidden subgraphs so that the three concepts of Helly graphs, of locally Helly graphs and of finitely Helly graphs are equivalent. Finally, generalizing different results, in particular those of Bandelt and Chepoi 1 about Helly graphs and bridged graphs, we prove that the Helly number h(G) of the geodesic convexity in a constructible graph G is equal to its clique number ω(G), provided that ω(G) is finite. © 2003 Wiley Periodicals, Inc. J Graph Theory 43: 280–298, 2003
Planar graphs producing no strongly almost trivial embedding
Authors: Huh Youngsik , Oh Seungsang 
Published: July 2003

AbstractWe present here infinitely many planar graphs which have no strongly almost trivial embeddings. Then we conclude that “strongly almost trivial” is more strict concept than “almost trivial.”. © 2003 Wiley Periodicals, Inc. J Graph Theory 43: 319–326, 2003