bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inductive effect of recombinant human interleukin‐1 α and β on differentiation of macrophage‐like tumor cell line P388D1
Authors: Hanazawa Shigemasa , Hanaizumi Chika , Amano Shigeru , Hirose Kimiharu , Ohmori Yoshihiro , Kumegawa Masayoshi , Yamaura Kohichi , Kitano Shigeo 
Published: February 2005

AbstractWe used the mouse monocyte/macrophage‐like tumor cell line P388D1 to test whether or not interleukin‐1 (IL‐1) stimulates differentiation of monocyte/macrophage progenitors. Incubation of these cells with recombinant human interleukin‐1 (rhIL‐1) α and β resulted in their increased adherence, stimulation of nonspecific esterase activity, and increased Fc rosette formation. rhIL‐1s inhibited cell growth and stimulated Fc rosette formation in a dose‐dependent fashion. The cell growth inhibition due to rhIL‐1s depended on the concentration of serum in culture medium. Synergism between rhIL‐1 and calcium ionophore A23187 was found for the cell growth inhibition and Fc rosette formation. The presence of ethylene glycol bis‐ (β‐aminoethyl ether) N,N,N,N‐tetraacetic acid(EGTA) in the medium abolished the stimulatory effect of rhIL‐1 on Fc rosette formation of the cell line. These results demonstrate that rhIL‐1s are a potent inducer of the differentiation of the macrophage‐like tumor cell line P388D1.
Transforming growth factor β responsiveness is modulated by the extracellular collagen matrix during hepatic ito cell culture
Authors: Davis Bernard H. 
Published: February 2005

AbstractHepatic sinusoidal Ito cells have the capacity to produce interstitial collagen types I and Ill as well as other matrix proteins and may be involved in hepatic fibrogenesis. Transforming growth factor β (TGF β) responsiveness was evaluated during in vitro cell culture, since increasing evidence suggests that this ubiquitous polypeptide can stimulate the production of collagenous proteins in a variety of cell types. TGF β induced marked inhibition of Ito cell proliferation for cells grown on either a type I or a type IV collagen matrix. In marked contrast, the collagen synthetic response was considerably different for cells grown on a type I versus a type IV collagen matrix. When cells were grown on a type I collagen matrix, TGF β caused a significant increase in the accumulation of collagen type I and III. When Ito cells were grown on a type IV collagen matrix, there was no stimulation of collagen production. TGF β respsonsiveness was also evaluated in the setting of altered vitamin A concentrations. Freshly isolated Ito cells are engorged with vitamin A, the usual physiologic storage site for hepatic vitamin A. During in vitro culture and during in vivo fibrogenesis, Ito cells lose their vitamin A stores coincident with a transformation to a collagen‐producing myofibroblast‐like cell. When cultured Ito cells were grown on a type I collagen matrix and re‐exposed to an increased concentration of vitamin A, the production of interstitial collagen was reduced. However, when the vitamin A‐enriched Ito cells were exposed to TGF β, the production of interstitial collagen was increased, similar to cells that had not received vitamin A.
Lysosomal enzymes in extracellular digestion in the unicellular eukaryote Tetrahymena
Authors: Tiedtke Arno , Rasmussen Leif 
Published: February 2005

AbstractThe ciliate Tetrahymena thermophila was starved for orthophosphate in a synthetic medium at pH 7.5. These cells did not utilize phosphorylcholine, final concentration 1 mM, as a phosphate source for cell growth and multiplication. If the phosphorylcholine solution, however, was incubated for 24 h at pH 5.5 with extracellular, “spent” medium from a culture in early stationary phase of growth, then it promoted culture growth readily at pH 7.5. It was shown that the spent medium in the same concentration did not stimulate growth in itself. It is concluded that extracellular digestion of phosphorylcholine enabled the cells to grow and multiply in a nutrient medium having organic phosphate compounds as the only phosphate source. It is argued that the phosphatases in the spent medium are of lysosomal origin.
Cytoarchitecture of kirsten sarcoma virus‐transformed rat kidney fibroblasts: Butyrate‐induced reorganization within the actin microfilament network
Authors: Ryan Michael P. , Higgins Paul J. 
Published: February 2005

AbstractMurine sarcoma virus‐transformed rat fibroblasts (KNRK cells) undergo marked cytoarchitectural reorganization during in vitro exposure to sodium‐n‐butyrate (NaB) resulting in restoration of (1) a more typical fibroblastoid morphology, (2) proper cell‐to‐cell orientation, and (3) substratum adherence. Augmented cell spreading, involving > 90% of the population was a function of culture density and time of exposure to NaB (2 mM final concentration). Induced cell spreading reflected a 2.5‐ to 3.0‐fold increase in both total cellular actin content and deposition of actin into the detergent‐resistent cytoskeleton. Cytoskeletal actin deposition in response to NaB was accompanied by the formation of occasionally dense, parallel alignments of F‐actin‐containing microfilaments and by a dramatic increase in the size and incidence of actin‐enriched membrane ruffles. Long‐term NaB‐treated cells exhibited parallel orientations of microfilaments similar to those found in untransformed fibroblasts. Increased cytoskeletal actin occurred within 24 hr of NaB exposure, correlating with the initial reorganization of actin‐containing microfilaments detected microscopically, and reflected concomitant 3‐fold increases in cellular alpha‐actinin and fibronectin content. In contrast, the amount of vimentin, tropomyosin, and tubulin in NaB‐treated cells was significantly decreased. NaB‐induced morphologic restructuring of sarcoma virus‐transformed fibroblast, thus, impacts on all three basic cytoskeletal systems. Selective increases, however, were evident in particular cytoskeletal proteins (actin, alpha‐actinin, fibronectin) implicated in microfilament networking and cell spreading.
Murine cerebral microvascular endothelium incorporate and metabolize 12‐hydroxyeicosatetraenoic acid
Authors: Moore Steven A. , Prokuski Laura J. , Figard Paul H. , Spector Arthur A. , Hart Michael N. 
Published: February 2005

AbstractCultured murine cerebromicrovascular endothelial cells were employed to study the metabolism of 12‐hydroxyeicosatetraenoic acid (12‐HETE) in an in vitro model of the blood‐brain barrier. These endothelial cells convert 12‐HETE to at least four, more polar compounds. Analysis of the least polar and predominant metabolite by gas chromatography combined with chemical ionization and electron impact mass spectrometry of reduced and nonreduced derivatives indicate that the compound is 8‐hydroxyhexadecatrienoic acid (8‐HHDTrE). The uptake of 12‐HETE into cell phospholipids peaks at 2 hr, and is not saturable up to the highest concentration tested, 5 μM. Seventy‐five to 92% of this 12‐HETE is incorporated into phosphatidylcholine, while the remainder is divided between the inositol and ethanolamine phospholipids. Incorporation into neutral lipids is slower, with radioactivity gradually accumulating in triglycerides over 24 hr. Saponification of cell lipids demonstrated that not only 12‐HETE, but also its major metabolite, 8‐HHDTrE, is incorporated into the cell lipids. Prostacyclin and prostaglandin E2 production by the cerebral endothelial cells is inhibited by up to 56% with 1 μM and 90% with 5 μM 12‐HETE. These data demonstrate that 12‐HETE is actively metabolized by cerebral endothelium and suggest at least two mechanisms through which 12‐HETE may alter cerebromi‐crovascular function: (1) incorporation into cerebral endothelial membranes and (2) inhibition of cerebral endothelial prostaglandin production. Conversion of 12‐HETE to more polar compounds, particularly 8‐HHDTrE, may be interpreted as either the inactivation of 12‐HETE or the production of additional, biological mediators.
Regulation of the heat‐shock response by interferon in mouse L cells
Authors: Dubois M. F. , Mezger V. , Morange M. , Ferrieux C. , Lebon P. , Bensaude O. 
Published: February 2005

AbstractInterferon (IFN) is not able to induce heat‐shock protein (HSP) synthesis. However IFN pretreatment of mouse L cells has been shown to enhance the decrease of overall protein synthesis which follows a heat shock, and to stimulate the accumulation of HSPs. We show here that the synthesis of a protein (the hepatitis B virus surface antigen) under the control of a Drosophila HSP 70 promoter is also stimulated in IFN‐pretreated cells. The regulation by IFN takes place at two levels: first, the rate of HSP gene transcription is increased in nuclei isolated from IFN‐treated cells; second, the synthesis of HSPs is prolonged after pretreatment with IFN. Experiments performed in the presence of actinomycin D show that this effect is due to a stablization by IFN of mRNAs coding for HSPs.
Calcium is essential in the fusion of mouse alveolar macrophages induced by 1α, 25‐dihydroxyvitamin D3
Authors: Jin Cheng He , Segawa Akishisa , Miyaura Chisato , Tanaka Hirofumi , Abe Ersuko , Suda Tatsuo 
Published: February 2005

AbstractWe have reported that the active form of vitamin D3, 1α, 25‐dihydroxyvitamin D3 [1α, 25(OH)2D3], directly induces activation and fusion of mouse alveolar macrophages (Abe et al., 1983, 1984). The activated state appeared to be a prerequisite to the fusion of macrophages. Macrophages began to fuse 36 hr after adding 1α, 25(OH)2D3; the fusion rate attained a maximum of 70–80% at 72 hr. During the course of further investigating the mechanisms of fusion induced by the vitamin, we found that the calcium ion is closely involved in the fusion process of macrophages induced by 1α, 25(OH)2D3. When alveolar macrophages were cultured with 1α, 25(OH)2D3 in medium with graded concentrations (0.13–1.85 mM) of calcium, the fusion rate went down in parallel with the decrease of medium calcium. Neither calcium ionophore A23187 nor 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) induced fusion of freshly isolated macrophages, but the two compounds greatly promoted fusion of the macrophages pretreated for 18 hr with 1α, 25(OH)2D3. The vitamin effect for the first 18 hr was similar, irrespective of the medium calcium concentration. In contrast, millimolar amounts of calcium were essential in the subsequent period of incubation(18–72 hr) for inducing fusion. The activation of macrophages measured by the induction of cytotoxicity and the enhancement of glucose consumption by 1α,25(OH)2D3 occurred similarly, irrespective of the medium calcium concentration. These results clearly indicate that the fusion process of alveolar macrophages induced by 1α, 25(OH)2D3 can be divided into two phases: (1) the calcium‐independent priming phase (0–18 hr) and (2) the calcium‐dependent progression phase (18–72 hr). 1α,25(OH)2D3 is necessary only in the priming phase; A23187 and TPA can be substituted for 1α,25(OH)2D3 in the progression phase.
Comparison of the biological actions of TGF beta‐1 and TGF beta‐2: Differential activity in endothelial cells
Authors: Jennings John C. , Mohan Subburaman , Linkhart Thomas A. , Widstrom Richard , Baylink David J. 
Published: February 2005

AbstractBeta transforming growth factor (TGF beta) has multiple in vitro biological effects including stimulation or inhibition of proliferation of specific cell types. A second major form of TGF beta, TGF beta‐2, has recently been isolated from porcine platelets, from bovine bone matrix, and from several other sources. The two forms of TGF beta are biologically equipotent with the exception that TGF beta‐2 was much less active than TGF beta‐1 for inhibition of proliferation of a rat pleuripotent hematopoietic stem cell line. During the purification of beta TGF from bone, we obtained two fraction pools that differed in their ability to inhibit 3H‐thymidine incorporation into aortic endothelial cells (AEC). We therefore compared highly purified TGF beta‐1 and TGF beta‐2 isolated from porcine platelets for inhibition of DNA synthesis in mink lung epithelial cells (MvlLu), and in AEC, and for stimulation of 3H‐thymidine incorporation in calvarial bone cells (CBC) in 3 experiments. TGF beta‐1 and TGF beta‐2 inhibited cell proliferation in MvlLu with no significant differences in the ED50 (31± 8pg/ml vs 23± 7). TGF beta‐2 was much less potent than TGF beta‐1 in inhibiting DNA synthesis in AEC (6310 ± 985 pg/ml vs 101 ± 34). The reduced specific activity of TGF beta‐2 was also observed in adrenal capillary endothelial cells. Both beta‐1 and beta‐2 stimulated proliferation of CBC (ED50 26 ± 2 pg/ml vs 10 ± 4). We also examined the specificity of the MvlLu and AEC inhibition assays. Epidermal growth factor (EGF), platelet derived growth factor (PDGF), acidic and basic fibroblast growth factor (FGF), skeletal growth factor (SGF)/insulin‐like growth factor‐II (IGF‐II), and insulin‐like growth factor‐I (IGF‐I) did not inhibit DNA synthesis in either assay system. However, when the growth factors were added to maximal inhibiting concentrations of TGF beta‐1, both acidic and basic FGF significantly reduced TGF beta‐1 inhibition in AEC. We conclude that (1) inhibition of DNA synthesis in endothelial cells is relatively specific for TGF beta‐1, (2) inhibition of DNA synthesis in MvlLu is a sensitive and specific assay for generic TGF beta activity but does not distinguish beta‐1 from beta‐2, (3) the relative inhibition of DNA synthesis in MvlLu and AEC may provide a means to quantitatively estimate TGF beta‐1 and TGF beta‐2, and (4) both TGF beta‐1 ad TGF beta‐2 are potent mitogens for chicken embryonic calvarial bone cells.
Role of polyamines in the stimulation of synthesis and secretion of plasminogen activator from bovine aortic endothelial cells
Authors: Kuo Be‐Sheng , Korner Gil , Dryjski Maciej , Bjornsson Thorir D. 
Published: February 2005

AbstractThe effects of the polyamines putrescine (PUT), spermidine (SPD), and spermine (SPM) on the secretion of plasminogen activator (PA) and plasminogen activator inhibitor (PAI) were evaluated using cultured bovine aortic endothelial cells. All three polyamines enhanced PA secretion in a time‐ and dose‐dependent manner, with a potency rank order of SPM > SPD > PUT. The PA stimulation required both RNA and protein synthesis, as evidenced by inhibition of polyamine‐induced PA secretion by actinomycin D and cycloheximide. The inhibitors of polyamine biosynthesis methylglyoxal bis‐(guanylhydrazone) (MGBG) and dl‐(difluoromethyl) ornithine (DFMO) alone did not affect basal or polyamine‐induced PA secretion, with the exception that MGBG reduced the effect of PUT. Polyamine‐treated cells enhanced secretions of both tissue‐type and urokinase‐type PA. The results of the present study suggest that polyamines may play a role in the regulation of PA synthesis and secretion and that this function can be modified under pathophysiological conditions affecting cellular and tissue levels of polyamines.
Cyclic AMP increasing agents rapidly stimulate vimentin phosphorylation in quiescent cultures of Swiss 3T3 cells
Authors: Escribano Josefa , Rozengurt Enrique 
Published: February 2005

AbstractThe results presented here demonstrate that an elevation in the cellular levels of cyclic AMP (cAMP) increases the phosphorylation of an Mr = 58,000 cellular protein in quiescent cultures of Swiss 3T3 cells. The enhancement of 32Pi incorporation into the Mr = 58,000 cellular protein was detected as early as 1 min and reached a maximum after 20 min of treatment. The role of cAMP in the phosphorylation of Mr = 58,000 protein is substantiated by the following lines of evidence: (a) a variety of agents that cause cAMP accumulation in 3T3 cells, including cholera toxin, 5′‐N‐ethylcarboxamideadenosine (NECA), PGE1, and 3‐isobutyl‐1‐methyl‐xanthine (IBMX) increased the phosphorylation of the same Mr 58,000 cellular protein as demonstrated by peptide mapping; (b) inhibitors of cyclic nucleotide phosphodiesterase potentiated the ability of low concentrations of the adenylate cyclase activators NECA, PGE1, and forskolin to increase Mr 58,000 phosphorylation; and (c) permeable derivatives of cAMP such as 8BrcAMP were also effective and specific in promoting Mr 58,000 phosphorylation. Detergent extraction, immunoblotting, and immunoprecipitation identified the Mr = 58,000 phosphoprotein as vimentin, the main protein subunit of the intermediate filaments of mesenchymal cells including Swiss 3T3 cells. Studies with intact 3T3 cells revealed that an increase in the intracellular level of cAMP induced a marked redistribution and collapse of the intermediate filaments. These results raise the possibility that an intact intermediate filament network may restrict the reinitiation of DNA synthesis.
Specific binding of basic fibroblast growth factor to basement membrane‐like structures and to purified heparan sulfate proteoglycan of the EHS tumor
Authors: Vigny M. , Ollier‐Hartmann M. P. , Lavigne M. , Fayein N. , Jeanny J. C. , Laurent M. , Courtois Y. 
Published: February 2005

AbstractThe binding of iodinated basic fibroblast growth factor (bFGF) to low‐density heparan sulfate proteoglycan purified from the Engelbreth Holm Swarm (EHS) sarcoma was investigated using different techniques. The tumor clearly contained bFGF, the level being comparable to that found in other tissues such as human or bovine brain. 125I bFGF strongly bound to the basement membrane‐like matrix of EHS frozen sections as revealed by autoradiography. Iodinated bFGF bound to purified heparan sulfate proteoglycan but not to laminin or collagen type IV, three components isolated from the same tumor. In contrast, acidic fibroblast growth factor (aFGF) displayed negligible binding to heparan sulfate proteoglycan. Binding of bFGF to frozen sections and to purified proteoglycan could be strongly inhibited by heparin and was displaced by an excess of unlabeled factor and completely suppressed after heparitinase and heparinase treatments. Binding was a function of the salt concentration and was abolished at 0.6 M NaCl. Scatchard analysis indicated the affinity site had a Kd of about 30 nM, a value 10–15 higher than that recently reported by Moscatelli (J. Cell. Physiol., 131:123–130, 1987) in the case of the low‐affinity binding sites present on the surface of baby hamster kidney (BHK) cells.
Tumor‐promoting phorbol esters stimulate the proliferation of interleukin‐3 dependent cells
Authors: Hogans Beth B. , Spivak Jerry L. 
Published: February 2005

AbstractTo determine whether activation of protein kinase C is involved in the proliferation of interleukin‐3 (IL‐3) ‐dependent cells, we examined the effect of tumor‐promoting phorbol esters on the in vitro proliferation of the IL‐3‐dependent cell lines FD and DA‐1. The viability of FD and DA‐1 cells cultured for 24 hours in 100 nM phorbol myristate acetate (PMA) and 10% FCS was similar to that of cells cultured in 25% WEHI‐3 conditioned medium as a source of IL‐3, and 10% FCS. FD cells failed to proliferate in concentrations of FCS of up to 50%, while DA‐1 cell proliferation was not markedly influenced by FCS. By contrast, PMA promoted the proliferation of FD and DA‐1 cells in the absence of FCS and enhanced their proliferation in the presence of 10% FCS, 60‐ and 20‐fold, respectively. Stimulation of proliferation was achieved with as little as 10 nM PMA and was maximal at 100 nM PMA. Low concentrations (0.05‐0.1%) of WEHI‐3 CM promoted the proliferative response of FD and DA‐1 cells to PMA, but at concentrations of WEHI‐3 CM greater than 0.8%, no further increment in proliferation was obtained with PMA. As little as 1/2 hour of exposure to phorbol esters was sufficient to cause translocation of protein kinase C from the cytosol to the membranes of DA‐1 cells, and 1 hour of exposure to phorbol esters was sufficient to stimulate DNA synthesis. A protein kinase C inhibitor, H‐7, at a concentration of 10 μM inhibited phorbol ester‐induced stimulation of DA‐1 cell proliferation. When DA‐1 cells were exposed to the calcium ionophore A23187 in addition to both a phorbol ester and IL‐3, their proliferation was enhanced over that stimulated by only the phorbol ester and IL‐3. The data indicate that stimulation of proliferation of IL‐3‐dependent cells involves the activation of protein kinase C.
Direct evidence of intercellular sharing of glutathione via metabolic cooperation
Authors: Kavanagh Terrance J. , Martin George M. , Livesey John C. , Rabinovitch Peter S. 
Published: February 2005

AbstractIntracellular glutathione (GSH) content and cell density are known to be two important determinants of cell sensitivity to free radicals and radiation. We have investigated intercellular sharing of GSH via metabolic cooperation (MC) by measuring the GSH content of Chinese hamster V79 cells under conditions that varied MC among cells. GSH was measured by flow cytometry with monochlorobimane, which becomes fluorescent after conjugation to GSH by GSH‐S‐transferase. High‐performance liquid chromatography was used to confirm the accuracy of GSH measurements by flow cytometry. Several lines of evidence indicate sharing of GSH or its precursor γ‐glutamylcysteine via MC. These include a cell density‐dependent heterogeneity in GSH content, reconstitution of GSH in GSH‐depleted cells by coculture with nondepleted cells (except when the depleted cells were MC deficient), and decreased equilibration of GSH among GSH‐depleted cells and nondepleted cells when an inhibitor of MC (phorbol myristate acetate) was present. The equilibration of GSH among GSH‐depleted cells and nondepleted cells in coculture was not inhibitable by acivicin, suggesting that this form of intercellular sharing of GSH does not rely on γ‐glutamyltransferase‐mediated extracellular transport of GSH.