WILBERT

Wildauer Bücher+E-Medien Recherche-Tool

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Cell & Developmental Biology  (41,698)
Collection
Publisher
Years
  • 1
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 68 (1998), S. 1-7 
    ISSN: 0730-2312
    Keywords: cell stress ; heat shock ; σ32 ; magnetic fields ; ribonuclease protection assay ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The mechanism of interaction between weak electromagnetic fields and cells is not understood. As a result, the health effect(s) induced by exposure to these fields remains unclear. In addition to questions relating to the site of initial magnetic field (MF) interactions, the nature of the cell's response to these perturbations is also unclear. We examined the hypothesis that the cells respond to MFs in a manner similar to other environmental stressors such as heat. Using the bacterium Escherichia coli, we examined the mRNA levels of σ32, a protein that interacts with RNA polymerase to help it recognize a variety of stress promoters in the cell. Our data show that the intracellular level of σ32 mRNA is enhanced following a 15-min exposure to a 60 Hz, 1.1 mT magnetic field. J. Cell. Biochem. 68:1-7, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 68 (1998), S. 8-21 
    ISSN: 0730-2312
    Keywords: gap junctions ; dye-coupling ; connexin43 ; parathyroid hormone ; prostaglandin E2 ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Connexin43 (Cx43) forms gap junctions that mediate intercellular communication between osteoblasts. We have examined the effects of prostaglandin E2 (PGE2) and parathyroid hormone (PTH) on gap junctional communication in the rat osteogenic sarcoma cells UMR 106-01. Incubation with either PGE2 or PTH rapidly (within 30 min) increased transfer of negatively charged dyes between UMR 106-01 cells. This stimulatory effect lasted for at least 4 h. Both PGE2 and PTH increased steady-state levels of Cx43 mRNA, but only after 2-4 h of incubation. Transfection with a Cx43 gene construct linked to luciferase showed that this effect of PTH was the result of transcriptional upregulation of Cx43 promoter. Stimulation of dye coupling and Cx43 gene transcription were reproduced by forskolin and 8Br-cAMP. Exposure to PGE2 for 30 min increased Cx43 abundance at appositional membranes in UMR 106-01, whereas total Cx43 protein levels increased only after 4-6 h of incubation with either PGE2 or PTH. Inhibition of protein synthesis by cycloheximide did not affect this early stimulation of dye coupling, but it significantly inhibited the sustained effect of PTH and forskolin on cell coupling. In summary, both PTH and PGE2, presumably through cAMP production, enhance gap junctional communication in osteoblastic cell cultures via two mechanisms: initial rapid redistribution of Cx43 to the cell membrane, and later stimulation of Cx43 gene expression. Modulation of intercellular communication represents a novel mechanism by which osteotropic factors regulate the activity of bone forming cells. J. Cell. Biochem. 68:8-21, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 68 (1998), S. 22-30 
    ISSN: 0730-2312
    Keywords: cathepsin-B ; tissue transglutaminase ; mesangial cell apoptosis ; mRNA expression ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Mesangial matrix is a dynamic structure which modulates mesangial cell function. Since accumulation of matrix precedes the development of focal glomerulosclerosis, we studied the effect of different matrices on mesangial cell (MC) apoptosis. Suspended mesangial cells became apoptotic in a time dependent manner. Collagen type III did not modulate MC apoptosis when compared to cells grown on plastic. MCs grown on Matrigel, collagen type I and IV showed an increased number of apoptotic cells when compared to MCs grown on plastic. DNA end-labeling further confirmed these observations. MCs grown on Matrigel showed enhanced (P < 0.05) mRNA expression for tissue transglutaminase (TTG) and cathepsin-B. Mesangial cells grown on Matrigel also showed enhanced expression of superoxide dismutase (SOD). We conclude that mesangial cells require attachment to the matrix for their survival and alteration of the quality of matrix modulates mesangial cell apoptosis. J. Cell. Biochem. 68:22-30, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 68 (1998), S. 50-61 
    ISSN: 0730-2312
    Keywords: Sp1 ; p62 ; interaction assay ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The transcription factor Sp1 plays an important role in the expression of many cellular genes. In studies of proteins that associate with Sp1, a 62-kDa glycoprotein was found in immunoprecipitates of Sp1. This protein was detected in these immunoprecipitates by the monoclonal antibody, RL2, which was originally raised against nuclear pore proteins but was subsequently found to recognize an epitope that contains O-linked N-acetylglucosamine (O-GlcNAc). The association of this protein with Sp1 could be blocked by SDS denaturation of the protein complex. Western blot analysis of the Sp1 immunoprecipitate using antibodies to p62 nucleoporin indicated that this nuclear pore protein associates with Sp1. Furthermore, immunoprecipitation of p62 nucleoporin resulted in the coprecipitation of Sp1. Recombinant p62, expressed as a GST-fusion protein using a vaccinia virus system, also interacted with both recombinant and native Sp1. This interaction between p62 and Sp1 required the C-terminus of p62 and the C-terminus was able to bind Sp1, albeit less efficiently than native p62. A mammalian two-hybrid interaction assay was devised in which p62 was fused to the Gal4 DNA-binding domain. This system also indicated that p62, through its C-terminus, interacts with Sp1 in the living cell. We propose that this interaction of a nuclear pore protein with Sp1 may reflect the nuclear organization required to bring transcribable DNA in contact with the transcription factors. J. Cell. Biochem. 68:50-61, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 68 (1998), S. 298-308 
    ISSN: 0730-2312
    Keywords: PEPCK ; adipocytes ; transcription ; fatty acids ; fibrates ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Phosphoenolpyruvate carboxykinase (PEPCK) exerts a glyceroneogenic function in adipocytes in which transcription of its gene is increased by unsaturated fatty acids and fibrates. We used cultured rat adipose tissue fragments and 3T3-F442A adipocytes to show that the antidiabetic thiazolidinedione BRL 49653, a ligand and an activator of the γ isoform of peroxisome proliferator activated receptors (PPARγ), is a potent inducer of PEPCK mRNA. In 3T3-F442A adipocytes, the effect of BRL 49653 is rapid and concentration dependent, with a maximum reached at 1 μM and a half-maximum at 10-100 nM. PEPCK mRNA is similarly induced by the natural ligand of PPARγ, the 15-deoxy-Δ12-14 prostaglandin J2. These observations strongly suggest that PPARγ is a primary regulator of PEPCK gene expression in adipocytes. Dexamethasone at 10 nM repress induction of PEPCK mRNA by 1 μM BRL 49653, 0.32 mM oleate, or 1 mM clofibrate, in a cycloheximide-independent manner. The antiglucocorticoid RU 38486 prevents dexamethasone action, demonstrating involvement of the glucocorticoid receptor. Stable transfectants of 3T3-F442A adipocytes bearing -2100 to +69 base pairs of the PEPCK gene promoter fused to the chloramphenicol acetyltransferase (CAT) gene respond to 1 μM BRL 49653 or 1 mM clofibrate by a large increase in CAT activity, which is prevented by the simultaneous addition of 10 nM dexamethasone. Hence, in adipocytes, glucocorticoids act directly through the 5′-flanking region of the PEPCK gene to repress, in a dominant fashion, the stimulation of PEPCK gene transcription by thiazolidinediones and fibrates. J. Cell. Biochem. 68:298-308, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 68 (1998), S. 328-338 
    ISSN: 0730-2312
    Keywords: cell proliferation ; tumor progression ; EGF receptor ; ErbB ; HER1 ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is an activating ligand for the EGF receptor (HER1/ErbB1) and the high-affinity receptor for diphtheria toxin (DT) in its transmembrane form (proHB-EGF). HB-EGF was immunolocalized within human benign and malignant prostatic tissues, using monospecific antibodies directed against the mature protein and against the cytoplasmic domain of proHB-EGF. Prostate carcinoma cells, normal glandular epithelial cells, undifferentiated fibroblasts, and inflammatory cells were not decorated by the anti-HB-EGF antibodies; however, interstitial and vascular smooth muscle cells were highly reactive, indicating that the smooth muscle compartments are the major sites of synthesis and localization of HB-EGF within the prostate. In marked contrast to prostatic epithelium, proHB-EGF was immunolocalized to seminal vesicle epithelium, indicating differential regulation of HB-EGF synthesis within various epithelia of the reproductive tract. HB-EGF was not overexpressed in this series of cancer tissues, in comparison to the benign tissues. In experiments with LNCaP human prostate carcinoma cells, HB-EGF was similar in potency to epidermal growth factor (EGF) in stimulating cell growth. Exogenous HB-EGF and EGF each activated HER1 and HER3 receptor tyrosine kinases and induced tyrosine phosphorylation of cellular proteins to a similar extent. LNCaP cells expressed detectable but low levels of HB-EGF mRNA; however, proHB-EGF was detected at the cell surface indirectly by demonstration of specific sensitivity to DT. HB-EGF is the first HER1 ligand to be identified predominantly as a smooth muscle cell product in the human prostate. Further, the observation that HB-EGF is similar to EGF in mitogenic potency for human prostate carcinoma cells suggests that it may be one of the hypothesized stromal mediators of prostate cancer growth. J. Cell. Biochem. 68:328-338, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 68 (1998), S. 309-327 
    ISSN: 0730-2312
    Keywords: in vitro replication ; ors8 ; Oct-1 transcription factor ; POU domain ; mammalian autonomously replicating DNA sequence ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: A 186-base pair fragment of ors8, a mammalian autonomously replicating DNA sequence isolated by extrusion of nascent monkey DNA in early S phase, has previously been identified as the minimal sequence required for replication function in vitro and in vivo. This 186-base pair fragment contains, among other sequence characteristics, an imperfect consensus binding site for the ubiquitous transcription factor Oct-1. We have investigated the role of Oct-1 protein in the in vitro replication of this mammalian origin. Depletion of the endogenous Oct-1 protein, by inclusion of an oligonucleotide comprising the Oct-1 binding site, inhibited the in vitro replication of p186 to approximately 15-20% of the control, whereas a mutated Oct-1 and a nonspecific oligonucleotide had no effect. Furthermore, immunodepletion of the Oct-1 protein from the HeLa cell extracts by addition of an anti-POU antibody to the in vitro replication reactioninhibited p186 replication to 25% of control levels. This inhibition of replication could be partially reversed to 50-65% of control levels, a two- to threefold increase, upon the addition of exogenous Oct-1 POU domain protein.Site-directed mutagenesis of the octamer binding site in p186 resulted in a mutant clone, p186-MutOct, which abolished Oct-1 binding but was still able to replicate as efficiently as the wild-type p186. The results suggest that Oct-1 protein is an enhancing component in the in vitro replication of p186 but that its effect on replication is not caused through direct binding to the octamer motif. J. Cell. Biochem. 68:309-327, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 68 (1998), S. 339-354 
    ISSN: 0730-2312
    Keywords: glutathione ; reactive oxygen intermediates ; HIV ; signal transduction ; cytokines ; redox state ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Both clinical and experimental evidence indicates that AIDS-related Kaposi's sarcoma (AIDS-KS) has a multifactorial pathogenesis with factors such as HIV viral load, latent virus induction, and opportunistic infections contributing to disease progression. However, a consistent feature that unites these apparently diverse putative etiologic agents is sustained serum elevations of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α). While virtually every cell responds to TNF-α with gene activation, the extent of TNF-α-mediated cellular signaling is regulated by a delicate balance between signal activation and signal arresting events. Reactive oxygen intermediates (ROI), which are generated as a consequence of TNF-α membrane interaction, are part of this TNF-α-initiated cellular activation cascade. Previous studies in our laboratory have shown that AIDS-KS cells possess impaired oxygen intermediate scavenging capacities, thereby establishing conditions permissive for the intracellular retention of ROI. In this study, we used cellular capacity to upregulate the cytoprotective enzyme superoxide dismutase (SOD) to address the extent of cellular response to TNF-α. Concurrent with the SOD analyses, nucleotide profiles were obtained to assess cellular bioenergetic responses during TNF-α challenge. Proliferative growth levels of mitochondrial (Mn)SOD activities showed an activity spectrum ranging from lowest activity in AIDS-KS cells, to intermediate levels in matched, nonlesional cells from the AIDS-KS donors, to highest activities in HIV- normal fibroblasts. In contrast, following TNF-α challenge, the AIDS-KS and KS donor nonlesional cells showed a 11.89- and 5.86-fold respective increase in MnSOD activity, while the normal fibroblasts demonstrated a 1.35-fold decrease. Subsequent thiol redox modulation studies showed that only the normal fibroblast cultures showed a potentiation of TNF-α-mediated MnSOD upregulation following GSH depletion. In addition, provision of the GSH precursor, N-acetylcysteine during TNF-α challenge only diminished MnSOD activity and mitochondrial compartmentalization in the AIDS-KS cells, a finding that likely reflects the lower levels of reduced thiols in this cellular population. Our data, which show that a perturbation in their cellular thiol redox status accentuates AIDS-KS cellular responsiveness to TNF-α, suggest a biochemical rationale for the recognized TNF-α AIDS-KS clinical correlation. J. Cell. Biochem. 68:339-354, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 68 (1998), S. 355-365 
    ISSN: 0730-2312
    Keywords: mechanical loading ; gene expression ; osteopontin ; myeloperoxidase ; rats ; differential display ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The skeleton has the ability to alter its mass, geometry, and strength in response to mechanical stress. In order to elucidate the molecular mechanisms underlying this phenomenon, differential display reverse transcriptase-polymerase chain reaction (DDRT-PCR) was used to analyze gene expression in endocortical bone of mature female rats. Female Sprague-Dawley rats, approximately 8 months old, received either a sham or bending load using a four-point loading apparatus on the right tibia. RNA was collected at 1 h and 24 h after load was applied, reverse-transcribed into cDNA, and used in DDRT-PCR. Parallel display of samples from sham and loaded bones on a sequencing gel showed several regulated bands. Further analysis of seven of these bands allowed us to isolate two genes that are regulated in response to a loading stimulus. Nucleotide analysis showed that one of the differentially expressed bands shares 99% sequence identity with rat osteopontin (OPN), a noncollagenous bone matrix protein. Northern blot analysis confirms that OPN mRNA expression is increased by nearly 4-fold, at 6 h and 24 h after loading. The second band shares 90% homology with mouse myeloperoxidase (MPO), a bactericidal enzyme found primarily in neutrophils and monocytes. Semiquantitative PCR confirms that MPO expression is decreased 4- to 10-fold, at 1 h and 24 h after loading. Tissue distribution analysis confirmed MPO expression in bone but not in other tissues examined. In vitro analysis showed that MPO expression was not detectable in total RNA from UMR 106 osteoblastic cells or in confluent primary cultures of osteoblasts derived from either rat primary spongiosa or diaphyseal marrow. Database analysis suggests that MPO is expressed by osteocytes. These findings reinforce the association of OPN expression to bone turnover and describes for the first time, decreased expression of MPO during load-induced bone formation. These results suggest a role for both OPN and MPO expression in bone cell function. J. Cell. Biochem. 68:355-365, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 68 (1998), S. 366-377 
    ISSN: 0730-2312
    Keywords: PC-1 ; insulin action ; insulin resistance ; insulin receptor ; tyrosine kinase ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: An elevated content of membrane glycoprotein PC-1 has been observed in cells and tissues of insulin resistant patients. In addition, in vitro overexpression of PC-1 in cultured cells induces insulin resistance associated with diminished insulin receptor tyrosine kinase activity. We now find that PC-1 overexpression also influences insulin receptor signaling at a step downstream of insulin receptor tyrosine kinase, independent of insulin receptor tyrosine kinase. In the present studies, we employed Chinese hamster ovary cells that overexpress the human insulin receptor (CHO IR cells; ∼106 receptors per cell), and transfected them with human PC-1 c-DNA (CHO IR PC-1). In CHO IR PC-1 cells, insulin receptor tyrosine kinase activity was unchanged, following insulin treatment of cells. However, several biological effects of insulin, including glucose and amino acid uptake, were decreased. In CHO IR PC-1 cells, insulin stimulation of mitogen-activated protein (MAP) kinase activity was normal, suggesting that PC-1 overexpression did not affect insulin receptor activation of Ras, which is upstream of MAP kinase. Also, insulin-stimulated phosphatidylinositol (PI)-3-kinase activity was normal, suggesting that PC-1 overexpression did not interfere with the activation of this enzyme by insulin receptor substrate-1. In these cells, however, insulin stimulation of p70 ribosomal S6 kinase activity was diminished. These studies suggest, therefore, that, in addition to blocking insulin receptor tyrosine kinase activation, PC-1 can also block insulin receptor signaling at a post-receptor site. J. Cell. Biochem. 68:366-377, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 11
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 68 (1998), S. 378-388 
    ISSN: 0730-2312
    Keywords: apoptosis ; growth suppression ; retinoic acid receptors ; ovarian cancer ; AHPN ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: We have used conformationally restricted retinoids to investigate the role of individual RAR subtypes and RXR in mediating the growth response of ovarian tumor cells to retinoids. Our results show that treatment of all-trans-RA-sensitive CAOV-3 cells with retinoids that bind and activate a single RAR or RXR led to a partial inhibition of growth. Treatment of all-trans-RA- resistant SKOV-3 cells did not alter growth. Maximum inhibition of growth, comparable to that observed following treatment with natural retinoids such as all-trans-RA and 9-cis-RA, was obtained only following treatment with a combination of an RAR-selective compound and an RXR-selective one. These results suggest that activation of both RAR and RXR classes is required in order to obtain maximum inhibition of ovarian tumor cell growth by retinoids. In addition, one compound, AHPN, was found to inhibit both RA-sensitive CAOV-3 and RA-resistant SKOV-3 cells. Further study of the effects of this retinoid showed that AHPN acts through an apoptotic pathway. Taken together, our results suggest that retinoids may serve as effective anti-proliferative agents in the treatment of ovarian cancer. J. Cell. Biochem. 68:378-388, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 12
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 68 (1998), S. 389-401 
    ISSN: 0730-2312
    Keywords: cytoskeleton ; cell motility ; intracellular dynamics ; stress fibers ; heavy chain ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Fluorescently labeled smooth muscle myosin II is often used to study myosin II dynamics in non-muscle cells. In order to provide more specific tools for tracking non-muscle myosin II in living cytoplasm, fluorescent analogues of non-muscle myosin IIA and IIB were prepared and characterized. In addition, smooth and non-muscle myosin II were labeled with both cy5 and rhodamine so that comparative, dynamic studies may be performed. Non-muscle myosin IIA was purified from bovine platelets, non-muscle myosin IIB from bovine brain, and smooth muscle myosin II from turkey gizzards. After being fluorescently labeled with tetramethylrhodamine-5-iodoacetamide or with a succinimidyl ester of cy5, they retained the following properties: (1) reversible assembly into thick filaments, (2) actin-activatable MgATPase, (3) phosphorylation by myosin light chain kinase, (4) increased MgATPase upon light-chain phosphorylation, (5) interconversion between 6S and 10S conformations, and (6) distribution into endogenous myosin II-containing structures when microinjected into cultured cells. These fluorescent analogues can be used to visualize isoform-specific dynamics of myosin II in living cells. J. Cell. Biochem. 68:389-401, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 13
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 68 (1998), S. 403-410 
    ISSN: 0730-2312
    Keywords: extracellular matrix ; gene therapy ; collagen ; matrix metalloproteinase ; tissue inhibitor of metalloproteinase ; transforming growth factor ; decorin ; cardiomyopathy ; hypertrophy ; ischemia ; fibrosis; functional genomics ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: In chronic congestive heart failure, an illness affecting more than 4 million Americans, there is impairment of myocardial extracellular matrix (ECM) remodeling. Failing human ventricular myocardium contains activated matrix metalloproteinases (MMPs), which are involved in adverse ECM remodeling. Our studies support the concept that impaired ECM remodeling and MMP activation are, in part, responsible for the cardiac structural deformation and heart failure.There is no known program that has declared its aim the investigation of the role of ECM gene therapy in heart failure. The development of transgenic technology, and emerging techniques for in vivo gene transfer, suggest a strategy for improving cardiac function by overexpressing or downregulation of the ECM components such as MMPs, tissue inhibitor of metalloproteinases (TIMPs), transforming growth factor-β1 (TGF-β), decorin, and collagen in cardiomyopathy and heart failure. J. Cell. Biochem. 68:403-410, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 68 (1998), S. 411-426 
    ISSN: 0730-2312
    Keywords: bone marrow stroma ; human ; differentiation ; TGF-β ; BMP-2 ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Osteoprogenitor cells in the human bone marrow stroma can be induced to differentiate into osteoblasts under stimulation with hormonal and local factors. We previously showed that human bone marrow stromal (HBMS) cells respond to dexamethasone and vitamin D by expressing several osteoblastic markers. In this study, we investigated the effects and interactions of local factors (BMP-2 and TGF-β2) on HBMS cell proliferation and differentiation in short-term and long-term cultures. We found that rhTGF-β2 increased DNA content and stimulated type I collagen synthesis, but inhibited ALP activity and mRNA levels, osteocalcin production, and mineralization of the matrix formed by HBMS cells. In contrast, rhBMP-2 increased ALP activity and mRNA levels, osteocalcin levels and calcium deposition in the extracellular matrix without affecting type I collagen synthesis and mRNA levels, showing that rhBMP-2 and rhTGF-β2 regulate differentially HBMS cells. Co-treatment with rhBMP-2 and rhTGF-β2 led to intermediate effects on HBMS cell proliferation and differentiation markers. rhTGF-β2 attenuated the stimulatory effect of rhBMP-2 on osteocalcin levels, and ALP activity and mRNA levels, whereas rhBMP-2 reduced the rhTGF-β2-enhanced DNA synthesis and type I collagen synthesis. We also investigated the effects of sequential treatments with rhBMP-2 and rhTGF-β2 on HBMS cell differentiation in long-term culture. A transient (9 days) treatment with rhBMP-2 abolished the rhTGF-β2 response of HBMS cells on ALP activity. In contrast, a transient (10 days) treatment with rhTGF-β2 did not influence the subsequent rhBMP-2 action on HBMS cell differentiation. The data show that TGF-β2 acts by increasing HBMS cell proliferation and type I collagen synthesis whereas BMP-2 acts by promoting HBMS cell differentiation. These observations suggest that TGF-β2 and BMP-2 may act in a sequential manner at different stages to promote human bone marrow stromal cell differentiation towards the osteoblast phenotype. J. Cell. Biochem. 68:411-426, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 15
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 68 (1998), S. 427-435 
    ISSN: 0730-2312
    Keywords: α2-macroglobulin ; albumin ; placenta ; zinc ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: We have investigated the binding and internalization of α2-macroglobulin and serum albumin by human placental syncytiotrophoblast cells in vitro. The time course (obtained at 4°C) of α2-macroglobulin binding indicated that an equilibrium was reached after 4 h. The binding of 125I-labelled α2-macroglobulin to syncytiotrophoblast cells was competitively reduced in the presence of excess unlabelled α2-macroglobulin. When the concentration-dependence of binding was examined over a wide concentration range, non-linear regression analysis yielded a Kd of 6.4 nM. In the case of albumin, binding was weak and ligand dissociated from the cell surface during aqueous washing making it impractical to analyze the binding reaction. In other experiments, syncytiotrophoblast cells were incubated with 125I-labelled α2-macroglobulin at 37°C. Under these conditions, trypsin-resistant cell-associated radioactivity increased with time consistent with ligand internalization. 125I-Labelled-ligand was internalized with a t1/2 of about 5 min. After a lag period some radioactivity was released back into the incubation medium. When measured at times up to 210 min, this was found to consist of mostly TCA-precipitable material that had been lost from the cell surface. However, when the incubation was extended to 24 h, almost 15% of the initial cell-associated radioactivity was released to the extracellular medium as TCA-soluble material, consistent with a slow rate of ligand degradation. The specific binding of 65Zn-labelled α2M was similar to that of the 125I-labelled ligand and trypsin-resistance measurements provided evidence of α2M-mediated 65Zn uptake. These results support a role for syncytiotrophoblast in the metabolism of α2-macroglobulin during pregnancy and are also consistent with a role for α2-macroglobulin in the maternal-fetal transport of zinc. J. Cell. Biochem. 68:427-435, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 16
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 68 (1998), S. 446-456 
    ISSN: 0730-2312
    Keywords: IGF-I ; IGF-II ; cAMP ; PKA ; PKC ; prostaglandin ; osteoblasts ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Bone cells synthesize and respond to IGF-I and IGF-II which contribute to bone remodeling and linear growth. In osteoblasts, prostaglandin (PG)E2 stimulates IGF-I but not IGF-II synthesis through a cAMP-dependent protein kinase A (PKA)-related event. However, protein kinase C (PKC) activation by PGE2 enhances replication and protein synthesis by less differentiated periosteal cells more so than in osteoblast-enriched cultures from fetal rat bone. Using various PGs and other PKA and PKC pathway activators, the importance of these aspects of PGE2 activity has now been examined on IGF receptors in these bone cell culture models. PGE2 and other agents that activate PKA enhanced 125I-IGF-II binding to type 2 IGF receptors on both cell populations. In contrast, agents that activate PKC enhanced 125I-IGF-I binding to type 1 receptors on less differentiated bone cells, and of these, only phorbol myristate acetate (PMA), which activates PKC in a receptor-independent way, was effective in osteoblast-enriched cultures. No stimulator increased total type 1 receptor protein in either cell population. Consequently, ligand binding to type 1 and type 2 IGF receptors is differentially modulated by specific intracellular pathways in bone cells. Importantly, changes in apparent type 1 receptor number occur rapidly and may do so at least in part through post-translational effects. These results may help to predict new ways to manipulate autocrine or paracrine actions by IGFs in skeletal tissue. J. Cell. Biochem. 68:446-456, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 17
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 68 (1998), S. 436-445 
    ISSN: 0730-2312
    Keywords: mouse ; PDI family proteins ; retinoic acid ; dibutyryl cAMP ; differentiation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: We investigated the expression of protein disulfide isomerase family proteins (PDI, ERp61, and ERp72) in mouse F9 teratocarcinoma cells during differentiation induced by treatment with retinoic acid and dibutyryl cAMP. Each member of this family was expressed at a constitutive level in undifferentiated F9 cells. During differentiation of F9 cells to parietal or visceral endodermal cells the protein level of all these enzymes increased, although the extent of this increase in both protein and mRNA levels varied among the enzymes. Certain proteins were found to be co-immunoprecipitated with PDI, ERp61, and ERp72 in the presence of a chemical crosslinker. Type IV collagen was significantly coprecipitated with PDI whereas laminin was equally coprecipitated with the three proteins. Furthermore, 210 kDa protein characteristically coprecipitated with ERp72. Thus, the induction of PDI family proteins during the differentiation of F9 cells and their association with different proteins may implicate specific functions of each member of this family despite the common redox activity capable of catalyzing the disulfide bond formation. J. Cell. Biochem. 68:436-445, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 68 (1998), S. 457-471 
    ISSN: 0730-2312
    Keywords: coated vesicles ; acetylcholine receptors ; AP180 ; myotube ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Monoclonal antibodies were generated to vesicular membranes of clathrin coated vesicles enriched for acetylcholinesterase (AChE). One of these, C172, recognizes vesicles which accumulate in muscle cells around nuclei associated with acetylcholine receptor AChR clusters. Immunoblots of muscle extracts and brain purified clathrin coated vesicles show that C172 recognizes a 100 kd band in muscle, but a 180 kd band in brain. Western blots of purified AP180 protein stained with the two antibodies AP180.1 and C172 displayed the same staining pattern. Tryptic digests probed with peptide antibodies (PS26 and PS27) generated to known sequences of AP180 were used to map the epitope for C172 within the brain AP180 sequence. On immunoblots of digested AP180, all AP180 antibodies and C172 recognized a 100 kd tryptic fragment, however only C172 recognized a smaller 60 kd. Our results suggest that the C172 epitope is located within amino acids 305-598 of the AP180 sequence. Confocal fluorescence microscopy of myoblasts and myotubes stained with the C172 antibody gives a punctate immunofluorescence pattern. Myoblasts stained with C172 revealed a polarized distribution of vesicles distinct from that observed when cells are stained with γ adaptin antibody which is known to localize to trans Golgi network. Myotubes stained with C172 antibody reveal a linear array of vesicular staining. Quantitative analysis of C172 reactive vesicles revealed a significant increase in number of vesicles present around the nuclei associated with the acetylcholine receptor clusters. These vesicles did not colocalize with the Golgi cisternae. These results indicate that a protein with homology to the neuron-specific coated vesicle protein AP180, is present in muscle cells associated with vesicles showing significant concentration around postsynaptic nuclei present in close proximity to AChR clusters. J. Cell. Biochem. 68:457-471, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 19
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 69 (1998), S. 271-281 
    ISSN: 0730-2312
    Keywords: butyrate ; isobutyramide ; prostate cancer ; LNCaP ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Progression to androgen independence remains the main obstacle to improving survival and quality of life in patients with advanced prostate cancer. Induction of differentiation may serve as a rational basis for prevention of progression to androgen independence by modulating gene expression activated by castration or upregulated during androgen-independent progression. The objectives of this study were to characterize the in vitro effects of sodium butyrate on human prostate cancer cell growth, PSA gene expression, and differentiation in the LNCaP tumor model and to determine whether tumor progression in vivo is delayed by isobutyramide, an orally bioavailable butyrate analogue with a longer half-life. The effects of isobutyramide on LNCaP tumor growth and serum PSA levels in both intact and castrate male mice were compared to controls. At concentrations > 1 mM, butyrate induced dose-dependent changes towards a more differentiated phenotype, G1 cell cycle arrest, and an 80% decrease in LNCaP cell growth rates. PSA gene expression was increased threefold by butyrate, indicative of differentiation-enhanced gene expression. The half-life of isobutyramide in athymic mice was determined by gas chromatography to be 4 h. During a 4 week period in intact-placebo mice, tumor volume and serum PSA increased 4.1- and 6.6-fold, respectively, compared to twofold and 2.7-fold increases in tumor volume and serum PSA in intact-treated mice. During a 7 week period in castrate-placebo mice, tumor volume and serum PSA levels increased 2.4-fold and fourfold, respectively, compared to a 50% reduction in tumor volume and a twofold increase in serum PSA above nadir levels in castrate mice treated with adjuvant isobutyramide. Isobutyramide treatment induced pronouced morphological changes in LNCaP tumor cells, with loss of defined nucleoli and dispersion of chromatin distribution. LNCaP tumor PSA mRNA levels actually increased threefold, indicative of differentiation-enhanced gene expression. This study demonstrates that butyrate causes LNCaP cell cycle arrest and increased PSA gene expression, both indicative of differentiation. The combination of castration and adjuvant isobutyramide was synergistic in delaying tumor progression. Decreased tumor cell proliferation and increased PSA gene expression induced by isobutyramide results in disconcordant changes in serum PSA and tumor volume and reduces the utility of serum PSA as a marker of response to therapy. J. Cell. Biochem. 69:271-281, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 20
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 69 (1998), S. 282-290 
    ISSN: 0730-2312
    Keywords: estrogen modulation ; osteoblastic cells ; plasma membrane receptors ; nuclear receptors ; gap junction communication ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Two osteoblastic cell populations, calvarial and marrow stromal cells, were exposed to estrogen derivatives in vitro. The hormonal effect was monitored by following intracellular Ca+2 levels [Ca+2]i and gap-junction communication. We measured fast changes in intracellular Ca+2 levels in response, of these cells, to the steroid hormones. The changes were dose dependent revealing maximal activity at 100 pM by 17-β-Estradiol and 1 nM by estradiol-CMO. Additionally, the effect of estrogen, on functional coupling of the cells, was measured using fluorescence dye migration and counting the number of neighboring cells coupled by gap junctions. An uncoupling effect was demonstrated in response of these cells to estrogen treatment. The quick stereospecific effect was achieved in the presence of 17-β-estradiol but not in the presence of 17-α-estradiol. These results suggest the involvement of plasma membrane receptors in addition to the already known nuclear receptors in transducing the hormone effects in the osteoblastic cells. J. Cell. Biochem. 69:282-290, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 21
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 68 (1998), S. 500-510 
    ISSN: 0730-2312
    Keywords: transcription factor ; nuclear matrix ; YY1 ; amino acids ; functional regulation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The multifunctional transcription factor YY1 is associated with the nuclear matrix. In osteoblasts, the interaction of several nuclear matrix-associated transcription factors with the bone specific osteocalcin gene contributes to tissue-specific and steroid hormone-mediated transcription. A canonical nuclear matrix targeting signal (NMTS) is present in all members of the AML/CBFβ transcription factor family, but not in other transcription factors. Therefore, we defined sequences that direct YY1 (414 amino acids) to the nuclear matrix. A series of epitope tagged deletion constructs were expressed in HeLa S3 and in human Saos-2 osteosarcoma cells. Subcellular distribution was determined in whole cells and nuclear matrices in situ by immunofluorescence. We demonstrated that amino acids 257-341 in the C-terminal domain of YY1 are necessary for nuclear matrix association. We also observed that sequences within the N-terminal domain of YY1 permit weak nuclear matrix binding. Our data further suggest that the Gal4 epitope tag contains sequences that affect subcellular localization, but not targeting to the nuclear matrix. The targeted association of YY1 with the nuclear matrix provides an additional level of functional regulation for this transcription factor that can exhibit positive and negative control. J. Cell. Biochem. 68:500-510, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 68 (1998), S. 511-524 
    ISSN: 0730-2312
    Keywords: actin ; permeability ; reoxygenation ; signal transduction ; cytoskeletal rearrangement ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Hypoxia/reoxygenation injury to cultured endothelial cells results in cytoskeletal rearrangement and second messenger activation related to increased monolayer junctional permeability. Cytoskeletal rearrangement by reactive oxygen species may be related to specific activation of the phospholipase D (PLD) pathway. Human umbilical vein endothelial cell monolayers are exposed to H2O2 (100 μM) or metabolites of the PLD pathway for 1-60 min. Changes in cAMP levels, Ca2+ levels, PIP2 production, filamin distribution, and intercellular gap formation are then quantitated. H2O2-induced filamin translocation from the membrane to the cytosol occurs after 1-min H2O2 treatment, while intercellular gap formation significantly increases after 15 min. H2O2 and phosphatidic acid exposure rapidly decrease intracellular cAMP levels, while increasing PIP2 levels in a Ca2+-independent manner. H2O2-induced cAMP decreases are prevented by inhibiting phospholipase D. H2O2-induced cytoskeletal changes are prevented by inhibiting phospholipase D, phosphatidylinositol-4-phosphate kinase, phosphoinositide turnover, or by adding a synthetic peptide that binds PIP2. These data indicate that metabolites produced downstream of H2O2-induced PLD activation may mediate filamin redistribution and F-actin rearrangement. J. Cell. Biochem. 68:511-524, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 23
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 69 (1998), S. 316-325 
    ISSN: 0730-2312
    Keywords: osteoprogenitors ; mineralization ; marrow stroma ; Src ; tyrosine kinase dexamethasone ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Src protein is essential for the regulation of bone turnover primarily via bone resorption because it is required in osteoclast differentiation and function. We followed temporal changes of Src protein abundance in marrow stromal cells induced to mineralize by dexamethasone (DEX), growth in cold temperature, or both. Given the tyrosine kinase function of Src and its numerous substrates, profiles of phosphotyrosine-containing proteins were followed as well. On day 11 of stimulation, specific alkaline phosphatase (ALP) activity at 30°C decreased under DEX relative to 37°C cultures, in accord with increased cell counts. Mineralization per well under DEX increased by 25% at 37°C, whereas at 30°C it increased by more than threefold regardless of the DEX stimulation. At 30°C, on a per cell basis mineralization increased 2.5 and 3 times with and without DEX, respectively. Cultures at 37°C showed a general drop per cell of many phosphotyrosine-containing proteins on day 3 relative to days 1 and 2 in both DEX-stimulated and nonstimulated cultures; several proteins did recover (recuperate) thereafter. On days 1 and 2, the phosphotyrosine signal was higher in several proteins under DEX stimulation; this trend became inverted after day 3. The changes in abundance per cell of Src protein (pp60src) followed a similar trend, and in addition a truncated Src molecule, p54/52src, was detected as a putative cleavage product presumably representing its carboxy terminus. The pp60src was most abundant, relative to its truncated product, in day 7 nonstimulated cultures, whereas under DEX stimulation the truncated species pp54/52src showed the highest relative abundance on days 7. At 30°C, DEX stimulation accentuated the increase in Src protein on day 3, showed no change on day 7, and returned to increase Src protein on day 10. Potassium ionophorvalinomycin, considered to select against mineralizing osteoprogenitors at 30°C, showed on day 10 in the absence of DEX a relative increase in truncated Src protein compared to both DEX-stimulated and nonstimulated cultures in the absence of valinomycin. On day 7 of DEX stimulation, the presence of valinomycin resulted in low p54/52src. Among phosphotyrosine-containing proteins, a 32-34 kDa band, as yet unidentified, showed the most concordant changes with mineralization induction. P32-34 decreased by DEX on days 2 and 8 and increased by low temperature alone or combined with DEX on day 3. On day 7, p32-34 did not change under DEX, but valinomycin selected cells with less phoshpotyrosine-containing p32-34. Taken together, high Src abundance at the start of osteogenic induction followed by a decrease 1 week later is probably related to energy metabolism-dependent induction of mineralization. This is in temporal accord with the increase in Src truncation and fluctuation in mitochondrial membrane potential (which affects mineralization). The reported binding of amino-terminal Src oligopeptide to p32 ADP/ATP carrier in the mitochondrial inner membrane raises the question of its possible involvement in mitochondria-regulated mineralization. J. Cell. Biochem. 69:316-325, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 69 (1998), S. 336-352 
    ISSN: 0730-2312
    Keywords: architectural transcription factor ; nuclear matrix ; osteoblast ; parathyroid hormone ; type I collagen ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: In connective tissue, cell structure contributes to type I collagen expression. Differences in osteoblast microarchitecture may account for the two distinct cis elements regulating basal expression, in vivo and in vitro, of the rat type I collagen α1(I) polypeptide chain (COL1A1). The COL1A1 promoter conformation may be the penultimate culmination of osteoblast structure. Architectural transcription factors bind to the minor groove of AT-rich DNA and bend it, altering interactions between other trans-acting proteins. Similarly, nuclear matrix (NM) proteins bind to the minor groove of AT-rich matrix-attachment regions, regulating transcription by altering DNA structure. We propose that osteoblast NM architectural transcription factors link cell structure to promoter geometry and COL1A1 transcription. Our objective was to identify potential osteoblast NM architectural transcription factors near the in vitro and in vivo regulatory regions of the rat COL1A1 promoter. Nuclear protein-promoter interactions were analyzed by gel shift analysis and related techniques. NM extracts were derived from rat osteosarcoma cells and from rat bone. The NM protein, NMP4, and a soluble nuclear protein, NP, both bound to two homologous poly(dT) elements within the COL1A1 in vitro regulatory region and proximal to the in vivo regulatory element. These proteins bound within the minor groove and bent the DNA. Parathyroid hormone increased NP/NMP4 binding to both poly(dT) elements and decreased COL1A1 mRNA in the osteosarcoma cells. NP/NMP4-COL1A1 promoter interactions may represent a molecular pathway by which osteoblast structure is coupled to COL1A1 expression. J. Cell. Biochem. 69:336-352. © 1998 Wiley-Liss, Inc.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 69 (1998), S. 30-43 
    ISSN: 0730-2312
    Keywords: hyperthermia ; calreticulin ; chaperone complexes ; prompt glycosylation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Acute heat stress leads to the glycosylation of a “prompt” stress glycoprotein, P-SG67/64, identified as calreticulin. In the present study, we used immunoprecipitation to investigate the interactions of P-SG/calreticulin with other proteins during cellular recovery from heat stress. In heat-stressed CHO and M21 cells, both glycosylated and unglycosylated P-SGs interact with HSP90, GRP94, GRP78, and the other prompt stress glycoprotein, P-SG50, in an ATP-independent manner. Specificity of HSP-P-SG interactions was determined by chemical cross-linking with the homo-bifunctional agent DSP (3,3′-dithiobis[succinimidyl propionate]). Characterization of the cross-linked complexes involving calreticulin and heat shock proteins (HSPs) showed an average mass of 400-600 kDa by gel filtration chromatography. Overall, the consistent association of glycosylated and unglycosylated calreticulin with P-SG50 and unglycosylated HSPs suggests that P-SG/calreticulin is an active member of the cast of glycone/aglycone chaperones that cooperate to achieve cellular recovery from acute heat stress. J. Cell. Biochem. 69:30-43, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 69 (1998), S. 44-54 
    ISSN: 0730-2312
    Keywords: genistein ; breast cancer ; p21WAF1/CIP1 ; G2/M arrest ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Genistein has been proposed to be responsible for lowering the rate of breast cancer in Asian women but the mechanism for this chemopreventive effect in vivo is unknown. In this study, we present in vitro evidence that genistein inhibits cell proliferation similarly in ER-positive and ER-negative human breast carcinoma cell lines. This inhibition is associated with specific G2/M arrest and induction of p21WAF1/CIP1 expression. Genistein results in a five- to six-fold increase in p21WAF1/CIP1 mRNA levels and a three- to four-fold increase in protein levels, only a 1.5-fold increase in p21WAF1/CIP1 transcription but a three- to six-fold increase in p21WAF1/CIP1 mRNA stability. The increase in p21WAF1/CIP1 is followed by increased apoptosis. The similar effects of genistein on a number of breast carcinoma cell lines with different ER and p53 status suggest that the actions of genistein reported here are mediated through ER and p53 independent mechanisms. The chemopreventive effects of genistein in vivo could be mediated along an identical or similar anti-proliferative pathway. J. Cell. Biochem. 69:44-54, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 27
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 69 (1998), S. 55-62 
    ISSN: 0730-2312
    Keywords: TGF-α ; antisense oligonucleotides ; head and neck cancer ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Interruption of an autocrine growth pathway involving TGF-α and EGFR may inhibit tumor growth and improve survival in head and neck cancer patients. We previously demonstrated that biopsy specimens and established cell lines from patients with squamous cell carcinoma of the head and neck (SCCHN) overexpress TGF-α and its receptor, epidermal growth factor receptor (EGFR) at both the mRNA and protein levels. Protein localization studies showed that TGF-α and EGFR are produced by the same epithelial cells in tissues from head and neck cancer patients further supporting a role for this ligand-receptor pair in an autocrine growth pathway. To confirm that TGF-α contributes to autocrine growth, we examined the effect of down regulation of TGF-α protein on SCCHN cell proliferation. Treatment of 6 SCCHN cell lines with antisense oligodeoxynucleotides targeting the translation start site of human TGF-α mRNA decreased TGF-α protein production by up to 93% and reduced cell proliferation by a mean of 76.2% compared to a 9.7% reduction with sense oligonucleotide (range P<0R > = 0.036-0.0001). TGF-α antisense oligonucleotide exposure also decreased TGF-α protein levels in normal oropharyngeal mucosal epithelial cells, however their growth rate was not affected. These findings indicate that TGF-α is participating in an autocrine signaling pathway in transformed, but not in normal mucosal epithelial cells, that promotes proliferation. J. Cell. Biochem. 69:55-62, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 28
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 69 (1998), S. 81-86 
    ISSN: 0730-2312
    Keywords: cell communication ; osteoblasts ; stromal cells ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: We characterized the formation and regulation of the gap junction in calvarial osteoblasts and in a series of subtypes from marrow stromal cells. The stromal cells included osteogenic, chondro-osteogenic, and endothelial cells. The cell coupling was measured by using fluorescence dye injected into single cells, and its migration to neighboring cells was measured. The functional coupling of cells was highly expressed by the osteoblastic cells. This process is mediated through fast changes in intracellular Ca+2 levels. Calcium ionophore (A 23187) demonstrated an uncoupling effect on the cells. In addition, the exposure of the cells to the parathyroid hormone increased the formation of the gap junction complex; the highest level was demonstrated in the osteoblastic cells. J. Cell. Biochem. 69:81-86, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 29
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 69 (1998), S. 72-80 
    ISSN: 0730-2312
    Keywords: human oocytes ; immunogold labeling ; splicing factors ; coilin ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The distribution of two splicing components (snRNP and SC-35) and coilin were studied by immunogold/electron microscopy in human oocytes from antral follicles at different levels of transcriptional activity (i.e., active, intermediate, and inactive). The results showed a decrease of snRNPs and SC-35 in the karyoplasm as the oocytes progress from a transcriptionally active to the inactive state. The main areas of accumulation of both these splicing components in all stages of oocytes appeared to be the interchromatin granule clusters (IGCs). Within the IGCs, the two splicing components seemed to be spatially segregated, with the snRNPs predominantly bound to the fibrillar region, whereas the SC-35 factors are being enriched in the granular zone. The p80 coilin was found only in the nucleolus-like body (NLB), which is present in all three stages of oocytes; no coiled bodies were evident. These data are consistent with the notion that splicing occurs in the karyoplasm and that the splicing components are mobilized from a storage site (IGCs) to the site of action. J. Cell. Biochem. 69:72-80, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 30
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 69 (1998), S. 63-71 
    ISSN: 0730-2312
    Keywords: angiotensin II ; G proteins ; Src tyrosine kinases ; c-Fos ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Angiotensin II stimulates a biphasic activation of Raf-1, MEK, and ERK in WB liver epithelial cells. The first peak of activity is rapid and transient and is followed by a sustained phase. Angiotensin II also causes a rapid activation of p21ras in these cells. Moreover, two Src family kinases (Fyn and Yes) were activated by angiotensin II in a time- and concentration-dependent manner. Microinjection of antibodies against Fyn and Yes blocked angiotensin II-induced DNA synthesis and c-Fos expression in WB cells, indicating an obligatory involvement of these tyrosine kinases in the activation of the ERK cascade by angiotensin II. Finally, substantial reduction of the angiotensin II-stimulated activation of Fyn, Raf-1, ERK, and expression of c-Fos by pertussis toxin pretreatment argues that G proteins of the Gi family as well as the Gq family are involved in angiotensin II-mediated mitogenic pathways in WB cells. J. Cell. Biochem. 69:63-71, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 31
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 69 (1998), S. 87-93 
    ISSN: 0730-2312
    Keywords: MAP kinase pathways ; JNK ; human osteoblasts ; interleukin-1β ; UMR-106 cells ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: We recently demonstrated the activation of extracellular signal- regulated protein kinase 1 and 2 (ERK1 and ERK2) by IGF-1, FGF-2, and PDGF-BB in normal human osteoblastic (HOB) cells as well as in rat and mouse osteoblastic cells. In this report, we have examined whether c-Jun NH2-Terminal Kinase (JNK) pathway is activated by growth factors and interleukin-1β (IL-1β) in normal HOB and rat UMR-106 cells using immune-complex kinase assay and anti-active JNK antibody, which recognizes activated forms of both JNK1 and JNK2. Results have demonstrated the presence of JNK1 and JNK2 proteins in normal HOB and UMR-106 cells. Both JNK1 and JNK2 were activated by IL-1β. IL-1β preferentially activated JNK pathway in a dose- and time-dependent manner and had little effect on ERK pathway. On the other hand, FGF-2 did not activate JNK but most strongly activated ERK pathway. The activation of JNK was maximal at 20 min whereas maximal activation of ERK1 and ERK2 was observed within 10 min. Results have clearly demonstrated that IL-1β preferentially activates JNK pathway whereas FGF-2 activates ERK pathway in normal human and rat UMR-106 osteoblastic cells. J. Cell. Biochem. 69:87-93, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 32
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 69 (1998), S. 95-103 
    ISSN: 0730-2312
    Keywords: mechanical strain ; interleukin (IL)-α and β gene expression ; proliferation ; protein synthesis ; morphology ; keratinocyte biology ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Recent studies in our laboratory have demonstrated that mechanical strain alters many facets of keratinocyte biology including proliferation, protein synthesis, and morphology. IL-1 is known to play an important role in the autocrine regulation of these basic cellular properties under basal and stimulated conditions. However, it is not known whether IL-1 plays a role in strain-induced alteration of keratinocyte biology. Thus, the objective of this study was to test the hypothesis that cyclic strain stimulates IL-1 expression and that strain-induced changes in keratinocyte function is regulated by IL-1. To test this hypothesis, we examined the effect of cyclic strain (10% average deformation) on keratinocyte IL-1 gene expression and the effect of neutralizing antibodies of IL-1α and IL-1β on strain-induced changes in keratinocyte proliferation, morphology, and orientation. Northern blot analyses demonstrated that steady state levels of IL-1α and β mRNA were elevated by 4 h, peaked at 12 h of cyclic strain (IL-1α, 304 ± 14.2%; IL-1β, 212 ± 5.6% increase vs. static controls) and decreased gradually by 24 h. IL-1 antibodies (IL-1α, 0.01 μg/ml; IL-1β, 0.01 μg/ml) significantly blocked strain-induced keratinocyte proliferation as well as the basal rate of proliferation. In contrast, IL-1 antibodies (IL-1α, 0.01 μg/ml; IL-1β, 0.1 μg/ml) had no effect on strain-induced morphological changes such as elongation and alignment. We conclude that mechanical strain induces IL-1 mRNA expression in keratinocytes. The role of IL-1 in mediating strain-induced changes in keratinocyte biology remains to be determined but appears to be independent of morphological changes. J. Cell. Biochem. 69:95-103, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 33
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 69 (1998), S. 104-116 
    ISSN: 0730-2312
    Keywords: mRNA export ; cell cycle ; gene transfection ; cultured mammalian cells ; hnRNP L ; nuclear transport ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The pre-mRNA processing enhancer (PPE) element is an RNA sequence element derived from the intronless HSV-TK gene. Insertion of the element into the highly intron-dependent human β-globin gene leads to efficient expression in the absence of splicing. We have analyzed the effect of the PPE element on the expression of mouse thymidylate synthase (TS) minigenes. We have previously shown that the expression of intronless TS minigenes is moderately (up to 20-fold) stimulated by the inclusion of introns. Furthermore, S phase-specific expression of TS minigenes in growth-stimulated cells depends on the presence of a spliceable intron as well as the TS promoter. The goal of our study was to determine if the PPE element would overcome the dependence on introns for efficient expression and for S phase-specific expression of transfected TS minigenes. We found that insertion of the PPE element into an intronless TS minigene partially overcame intron dependence. However, the increase in expression was much less than that observed for the intronless β-globin gene. We also found that intronless TS or HSV-TK genes that contained the PPE element and that were driven by the TS promoter were expressed at a constant level in serum-stimulated cells. However, when an intron was included in these genes, they were expressed in an S phase-specific manner. Thus the PPE element was not able to overcome the dependence on introns for S phase-specific expression of TS minigenes. J. Cell. Biochem. 69:104-116, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 34
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 69 (1998), S. 117-126 
    ISSN: 0730-2312
    Keywords: haemochromatosis gene ; histone gene cluster ; YACs ; cosmid contig ; sequences ; species comparison ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The HFE (HLA-H) gene is a strong candidate gene for hereditary haemochromatosis and was localized on the short arm of chromosome 6 to 6p21.3-p22. In addition, the sequence of the homologous mouse and rat cDNA and a partial sequence from the mouse gene have been reported recently. In this report, we describe the location of the human and the mouse HFE (HLA-H) gene within the histone gene clusters on the human chromosome 6 and the mouse chromosome 13. Both the human and the murine gene were located on syntenic regions within the histone gene clusters in the vicinity of the histone H1t gene. The genomic sequence of the human HFE (HLA-H) gene and the 3′ portion of the homologous mouse gene were determined. Comparison of the genomic sequences from man and mouse and the cDNA sequence from rat shows significant similarities, also beyond the transcribed region of the mouse gene. J. Cell. Biochem. 69:117-126, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 35
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 69 (1998), S. 127-142 
    ISSN: 0730-2312
    Keywords: chromosome architecture ; disassembly ; reassembly ; proteases ; in vitro model ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Topoisomerase II has been suggested to play a major role in chromosome organization based on its DNA decatenating activity and its ability to mediate direct binding interactions between DNA and nuclear matrix. However, this latter point remains controversial. Here we address the question of whether the chromatin binding activity of Topoisomerase II is sufficient to modify chromosome form using whole mammalian chromosomes in vitro. Intact chromosomes were microsurgically removed from living cells and disassembled by treatment with protease or heparin. When these disassembled chromosomes were incubated with recombinant human Topoisomerase II, the enzyme became incorporated into chromatin and reassembly resulted, leading to almost complete restoration of pre-existing chromosome shape and position within minutes. Chromosome reconstituition by Topoisomerase II was dose-dependent, saturable, and appeared to be controlled stoichiometrically, rather than enzymatically. Similar reassembly was observed in the absence of ATP and when a catalytically inactive thermosensitive Topoisomerase II mutant was used at the restrictive temperature. Chromosome recondensation also could be induced after the strand-passing activity of Topoisomerase II was blocked by treatment with an inhibitor of its catalytic activity, amsacrine. When a non-hydrolyzable β,γ-imido analog of ATP (AMP-PNP) was used to physiologically fix bound Topoisomerase II enzyme in a closed form around DNA, subsequent chromosome disassembly was prevented in the presence of high salt. These data suggest that Topoisomerase II may control higher order chromatin architecture through direct binding interactions, independently of its well-known catalytic activity. J. Cell. Biochem. 69:127-142, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 36
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 69 (1998), S. 143-153 
    ISSN: 0730-2312
    Keywords: HB-EGF ; cleavage-secretion ; PKC ; ErbB1 ; EGF receptor ; matrix metalloproteinase ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The phorbol ester, tetradecanoyl-phorbol 13-acetate (TPA), stimulates rapid proteolytic processing of the transmembrane, pro- form of heparin-binding epidermal growth factor-like growth factor (HB-EGF) at cell surfaces, suggesting the involvement of protein kinase C (PKC) isoforms in the HB-EGF secretion mechanism. To test this possibility, we expressed a chimeric protein, consisting of proHB-EGF fused to placental alkaline phosphatase (AP) near the amino terminus of processed HB-EGF, in NbMC-2 prostate epithelial cells. The proHB-EGF-AP chimera localized to plasma membranes and functioned as a diphtheria toxin receptor. Secreted HB-EGF-AP bound to heparin and exhibited potent growth factor activity. The presence of the AP moiety allowed highly quantitative measurements of cleavage-secretion responses of proHB-EGF to extracellular stimuli. As expected, rapid secretion of HB-EGF-AP was induced in a time- and dose-dependent manner by TPA. However, this was also observed with the Ca2+ionophore, ionomycin, suggesting the involvement of extracellular Ca2+ ions in the secretion mechanism. Ionomycin-induced secretion was inhibited by extracellular calcium chelation but not by the PKC inhibitors, GF109203X, staurosporine, or chelerythrine. The TPA-mediated secretion effect was inhibited by staurosporine, GF109203X, and by pretreatment with TPA, but not by calcium chelation. A small secretion response was induced by thapsigargin, which releases Ca2+ from intracellular stores, but this was completely eliminated by extracellular calcium chelation. Ionomycin- and TPA-induced HB-EGF-AP secretion was not dependent on the presence of the proHB-EGF cytoplasmic domain and was specifically inhibited by the metalloproteinase inhibitors 1,10-phenanthroline and tissue inhibitor of metalloproteinase-1 (TIMP-1). These data demonstrate that extracellular Ca2+ influx activates a membrane-associated metalloproteinase to process proHB-EGF by a pathway that does not require PKC. J. Cell. Biochem. 69:143-153, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 37
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 69 (1998), S. 483-489 
    ISSN: 0730-2312
    Keywords: Cordyceps sinensis ; adrenal cells ; steroidogenesis ; signal pathway ; PKC ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Cordyceps sinensiscontains a factor that stimulates corticosteroid production in the animal model. However, it is not known whether this drug acts directly on the adrenal glands or indirectly via the hypothalamus-pituitary axis. In the present study, we used primary rat adrenal cell cultures to investigate the pharmacological function of a water-soluble extract of Cordyceps sinensis(CS) and thesignaling pathway involved. Radioimmunoassay of corticosterone indicated that the amount of corticosterone produced by adrenal cells is increased in a positively dose-dependent manner by CS, reaching a maximun at 25 μg/ml. This stimulating effect was seen 1 h after CS treatment and was maintained for up to 24 h. Concomitantly, the lipid droplets in these cells became small and fewer in number. Immunostaining with a monoclonal antibody, A2, a specific marker for the lipid droplet capsule, demonstrated that detachment of the capsule from the lipid droplet occurs in response to CS application and that the period required for decapsulation is inversely related to the concentration of CS applied. The mechanism of CS-induced steroidogenesis is apparently different from that for ACTH, since intracellular cAMP levels were not increased in CS-treated cells. However, combined application with calphostin C, a PKC inhibitor, completely blocked the effect of CS on steroidogenesis, suggesting that activation of PKC may be responsible for the CS-induced steroidogenesis. J. Cell. Biochem. 69:483-489, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 38
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 69 (1998), S. 490-505 
    ISSN: 0730-2312
    Keywords: nucleolus ; nuclear import ; ribosomal protein L5 ; ribonucleoprotein particles ; ribosome assembly ; TFIIIA ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: In Xenopus laevis oocytes, 5S RNA is stored in the cytoplasm until vitellogenesis, at which time it is imported into the nucleus and targeted to nucleoli for ribosome assembly. This article shows that throughout oogenesis there is a pool of nuclear 5S RNA which is not nucleolar-associated. This distribution reflects that of oocyte-type 5S RNA, which is the major 5S RNA species in oocytes; only small amounts of somatic-type, which differs by six nucleotides, are synthesized. Indeed, 32P-labeled oocyte-type 5S RNA showed a degree of nucleolar localization similar to endogenous 5S RNA (33%) after microinjection. In contrast, 32P-labeled somatic-type 5S RNA showed significantly enhanced localization, whereby 70% of nuclear RNA was associated with nucleoli. A chimeric RNA molecule containing only one somatic-specific nucleotide substitution also showed enhanced localization, in addition to other somatic-specific phenotypes, including enhanced nuclear import and ribosome incorporation. The distribution of 35S-labeled ribosomal protein L5 was similar to that of oocyte-type 5S RNA, even when preassembled with somatic-type 5S RNA. The distribution of a series of 5S RNA mutants was also analyzed. These mutants showed various degrees of localization, suggesting that the efficiency of nucleolar targeting can be influenced by many discrete regions of the 5S RNA molecule. J. Cell. Biochem. 69:490-505, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 39
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 69 (1998), S. 506-521 
    ISSN: 0730-2312
    Keywords: heart ; development ; CaMPK ; cAPK ; CDK ; cGPK ; Kkialre ; PKC ; Wee1 ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: During early postnatal development, cardiomyocytes, which comprise about 80% of ventricular mass and volume, become phenotypically developed to facilitate their contractile functions and terminally differentiated to grow only in size but not in cell number. These changes are due to the expression of contractile proteins as well as the regulation of intracellular signal transduction proteins. In this study, the expression patterns of several protein kinases involved in various cardiac functions and cell-cycle control were analyzed by Western blotting of ventricular extracts from 1-, 10-, 20-, 50-, and 365-day-old rats. The expression level of cAMP-dependent protein kinase was slightly decreased (20%) over the first year, whereas no change was detected in cGMP-dependent protein kinase I. Calmodulin-dependent protein kinase II, which is involved in Ca2+ uptake into the sarcoplasmic reticulum, was increased as much as ten-fold. To the contrary, the expressions of protein kinase C-α and ι declined 77% with age. Cyclin-dependent protein kinases (CDKs) such as CDK1, CDK2, CDK4, and CDK5, which are required for cell-cycle progression, abruptly declined to almost undetectable levels after 10-20 days of age. In contrast, other CDK-related kinases, such as CDK8 or Kkialre, did not change significantly or increased up to 50% with age, respectively. Protein kinases implicated in CDK regulation such as CDK7 and Wee1 were either slightly increased in expression or did not change significantly. All of the proteins that were detected in ventricular extracts were also identified in isolated cardiac myocytes in equivalent amounts and analyzed for their relative expression in ten other adult rat tissues. J. Cell. Biochem. 69:506-521, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 40
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 70 (1998), S. 1-7 
    ISSN: 0730-2312
    Keywords: apoptosis ; p53 ; pRb2/p130 ; E2F ; transcriptional control ; leukemia ; protein phosphatases ; colon cancer ; retinoblastoma ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: A significant portion of published literature is dedicated to describing the cloning and the characterization of proteins involved in the progression of the cell cycle, which govern cell growth both in cancer and normal ontogenesis. With this abundance of information, the cascading pathways of molecular events that occur in the cell cycle are proving to be exceedingly complicated. The purpose of this conference was to attract the leading clinical and basic science investigators in the growth control field with a final goal to determine how this current wealth of knowledge can be used to impact upon patient care and management by the design of novel adjuvant therapeutics specifically targeted at tumor cells and the identification of molecular diagnostic and/or prognostic markers in an efficient and cost effective manner. J. Cell. Biochem. 70:1-7, 1998. © 1998 Wiley-Liss, Inc.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 41
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 70 (1998), S. 8-21 
    ISSN: 0730-2312
    Keywords: activin A ; bone marrow stromal cells ; gene regulation ; promoter activity ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Activin A, a member of the TGF-β superfamily, plays roles in differentiation and development, including hematopoiesis. Our previous studies indicated that the expression of activin A by human bone marrow cells and monocytes is highly regulated by inflammatory cytokines and glucocorticoids. The present study was undertaken to investigate the regulation of activin A gene expression in the human bone marrow stromal cell lines L87/4 and HS-5, as well as in primary stromal cells. Northern blots demonstrated that, like primary stromal cells, the cell lines expressed four activin A RNA transcripts (6.4, 4.0, 2.8, and 1.6 kb), although distribution of the RNA among the four sizes varied. The locations of the 5′ ends of the RNAs were investigated by Northern blots and RNase protection assays. The results identified a transcription start site at 212 nucleotides upstream of the translation start codon. In addition, luciferase expression assays of a series of deletion constructs were used to identify regulatory sequences upstream of the activin A gene. A 58 bp upstream sequence exhibits promoter activity. However, severalfold higher expression requires a positive element consisting of an additional 71 bp of the upstream region. Promoter activity was also identified between 2.5 and 3.6 kb upstream of the start codon. These findings suggest that expression of activin A at the transcriptional level follows complex patterns of regulation. J. Cell. Biochem. 70:8-21, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 42
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 69 (1998), S. 201-210 
    ISSN: 0730-2312
    Keywords: sodium butyrate ; alkaline phosphatase ; A5 cells ; A5-DAP cells ; A5-BAG cells ; β-galactosidase ; retroviral vectors ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: We have studied the effects of sodium butyrate (NaBu) on the expression of genes transduced by retroviral vectors and stably expressed in two salivary gland-derived cell lines, A5-DAP and A5-BAG, established earlier. These cell lines were obtained by infecting A5 cells with the retroviral vectors DAP and BAG, respectively, and by selecting neomycin-resistant transduced cells. A5-DAP cells express human placental alkaline phosphatase (PLAP) and A5-BAG cells bacterial β-galactosidase, both under the control of the viral long terminal repeat (LTR) enhancer-promoter. NaBu in the concentration of 2-8 mM inhibited the growth of A5-DAP cells, and induced the expression of heat-stable PLAP. These effects of NaBu were dose-dependent. Induction of PLAP in clones of A5-DAP cells that express different basal levels of the enzyme was not correlated with the relative inducibilty by NaBu. Exposure to 4 mM NaBu for 48 h increased the PLAP mRNA level by 31%. A5-DAP cells released, in a time-dependent manner, PLAP into the culture medium. Cells treated with NaBu released more PLAP than untreated cells in proportion to their elevated level of the enzyme. The parent A5 cells also express a low level of tissue non-specific type alkaline phosphatase, which was also induced by NaBu. NaBu inhibited the growth of A5-BAG cells also, and increased the β-galactosidase level. These data indicate the genes transduced by retroviral vectors can be induced by NaBu, which most likely interacts with the viral LTR. J. Cell. Biochem. 69:201-210, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 43
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 69 (1998), S. 211-220 
    ISSN: 0730-2312
    Keywords: nuclear matrix ; protein kinase CK2 ; disulfide bonds ; sodium tetrathionate ; iodoacetamide ; sulfhydryl crosslinking ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Nuclear matrix (NM) appears to be an intranuclear locale for significant and dynamic association of the ubiquitous multifunctional messenger-independent serine/threonine protein kinase CK2 that has been implicated in growth control [Tawfic et al. (1996): J Cell Biochem 61:165-171]. We have examined the nature of the association of CK2 with the NM. Nuclei prepared in the presence of a sulfhydryl-blocking reagent such as iodoacetamide demonstrate a reduction in the amount of CK2 associated with the NM to less than 5% of the control. On the other hand, when nuclei are treated with the sulfhydryl crosslinking reagent sodium tetrathionate, NM-associated CK2 increases severalfold. Treatment of nuclei with sodium tetrathionate followed by 2-mercaptoethanol blocks this increase. Nuclei isolated from rat liver and prostate behaved similarly, suggesting an identical mode of association of CK2 with the NM regardless of the organ. These results indicate a role of sulfhydryl interactions such that NM anchoring of CK2 occurs via its β subunit, which contains several vicinal cysteine residues. Further, various sulfhydryl-blocking reagents inhibited CK2 activity in a concentration-dependent manner, and the inhibitory effect was reversed by agents such as dithiothreitol, implying that cysteine residues in the CK2 play a role in its catalytic activity. J. Cell. Biochem. 69:211-220, 1998. Published 1998 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 44
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 69 (1998), S. 221-231 
    ISSN: 0730-2312
    Keywords: sodium fluoride ; stress response ; stress proteins ; heat shock proteins ; rat brain tumor 9L cells ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: We herein demonstrate that sodium fluoride (NaF) acts as a stress response inducer on HeLa and 9L rat brain tumor cells. NaF is only slightly cytotoxic, and inhibitory to Ser/Thr-phosphatases but not to Tyr-phosphatases in both cell lines. After treatment with 5 mM NaF for 2 h, the phosphorylation levels of vimentin and an alkali-resistant 65-kDa phosphoprotein were enhanced, a common phenomenon detected in cells under a variety of stress conditions. Under an identical treatment protocol, in which the cells were treated with 5 mM NaF for 2 h and then allowed to recover under normal growing conditions for up to 12 h, NaF differentially induced the cytoplasmic/nuclear heat-shock protein70s (including both the inducible and the constitutively expressed members of this protein family) in HeLa cells and the endoplasmic reticulum residing heat-shock protein70 (the glucose-regulated protein with an apparent molecular weight of 78 kDa) in 9L cells. Electrophoretic mobility shift assays (EMSA) using probes containing well-characterized regulatory elements revealed the activation of the heat-shock factor in HeLa but not in 9L cells; this is in good agreement with the stress protein induction pattern. Additional differential induction of binding activities toward EMSA probes individually containing NF-κB, AP-2, and CRE-like elements were detected in NaF-treated cells. The possible involvement of these binding sites as well as the corresponding factors in the stress response are discussed. J. Cell. Biochem. 69:221-231, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 45
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 69 (1998), S. 233-243 
    ISSN: 0730-2312
    Keywords: histamine ; polyamines ; cytochrome P450 ; cell growth ; cell proliferation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Histamine and polyamines have been implicated in the mediation of cell proliferation. Our previous work linked the growth-modulatory effects of histamine with its binding to intracellular sites in microsomes and nuclei of various tissues. In this study, we identify cytochrome P450 enzymes as a major component of microsomal intracellular sites in hepatocytes and demonstrate that polyamines compete with high affinity for histamine binding to them. Spectral measurement of histamine binding to P450 in liver microsomes resolved high and intermediate affinity binding sites (Ks1 = 2.4 ± 1.6 μM; Ks2 = 90 ± 17 μM) that corresponded to microsomal binding sites (Kd1 = 1.0 ± 0.9 μM; Kd2 = 57 ± 13 μM) resolved by 3H-histamine binding; additional low affinity (Kd3 ∼ 3 mM), and probably physiologically irrelevant, sites were resolved only by 3H-histamine radioligand studies. As determined spectrally, treatment of microsomes with NADPH/carbon monoxide decreased histamine binding to P450 by about 90% and, as determined by 3H-histamine binding, abolished the high affinity sites and reduced by 85% the number of intermediate sites. Spermine competed potently for 3H-histamine binding: in microsomes, Ki = 9.8 ± 5.8 μM; in nuclei, Ki = 13.7 ± 3.1 μM; in chromatin, Ki = 46 ± 33 nM. Polyamines inhibited the P450/histamine absorbance complex with the rank order of potency: spermine > spermidine ≫ putrescine. In contrast, histamine did not compete for 3H- spermidine binding in nuclei or microsomes, suggesting that polyamines modulate histamine binding allosterically. We propose that certain P450 isozymes that modulate gene function by controlling the level of oxygenated lipids, represent at least one common intracellular target of growth-regulatory endogenous bioamines and, as shown previously, of exogenous growth-modulatory drugs including antiestrogens, antiandrogens, and certain antidepressants and antihistamines. J. Cell. Biochem. 69:233-243, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 46
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 70 (1998), S. 200-212 
    ISSN: 0730-2312
    Keywords: gene expression ; AML/CBF transcription factors ; nuclear matrix ; cancer ; nuclear domains ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Functional interrelationships between components of nuclear architecture and control of gene expression are becoming increasingly evident. In this article we focus on the concept that association of genes and cognate transcription factors with the nuclear matrix may support the formation and/or activities of nuclear domains that facilitate transcriptional regulation. Several lines of evidence are consistent with the concept that association of transcription factors with the nuclear matrix may be obligatory for fidelity of gene expression and maximal transcriptional activity. The identification of specific regions of transcription factors that are responsible for intranuclear trafficking to nuclear matrix-associated sites that support transcription, reinforces the linkage of nuclear structure to regulation of genes. CBFA2/AML-1 and CBFA1/AML-3 provide paradigms for directing gene regulatory factors to RNA polymerase II containing foci within the nucleus. The implications of modifications in the intranuclear trafficking of transcription factors for developmental and tissue-specific control, as well as for aberrations in gene expression that are associated with cancer and neurological disorders, are addressed. J. Cell. Biochem. 70:200-212, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 47
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 70 (1998), S. 193-199 
    ISSN: 0730-2312
    Keywords: parathyroid hormone-related peptide ; nucleus ; nucleolus ; intracrine actions ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: It is becoming increasingly apparent that parathyroid hormone-related peptide (PTHrP) modulates cellular function in a dual mode of action: first, by binding and activating its cognate cell surface G-protein-coupled receptor and, second, by direct intracellular effects following translocation to the nucleus and/or nucleolus of the target cell. Little is presently known about the mechanisms and events that determine the timing and degree of PTHrP nuclear translocation or the role it may serve in normal or dysregulated cellular function. Clarifying the nuclear actions of PTHrP would add significantly to our present understanding of this protein as a signaling molecule during embryonic development and as an oncoprotein whose expression in many tumors correlates with increased tumor aggressiveness and propensity for metastasis. J. Cell. Biochem. 70:193-199, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 48
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 70 (1998), S. 213-221 
    ISSN: 0730-2312
    Keywords: transcription ; nucleus ; cell architecture ; nuclear matrix ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: After many years of reductionistic approaches to characterize molecular mechanisms involved in transcription, the number of factors recognized to take part in this process has increased remarkably and continues to grow. When considering posttranslational modifications in conjunction with the large number of factors involved in modulating the activity of transcription complex components, the overall intricacy becomes staggering. After two decades of intensive molecular investigations, there has been a concerted effort to integrate these findings with cellular approaches to understand transcription on a more global level. This sort of reasoning actually revisits studies of approximately 20 years ago that considered the functional consequences of steroid receptor association with nuclear structure. With an abundance of new molecular probes and increasingly powerful instruments to detect them in fixed and, more recently, live cells, the issue of functional subnuclear organization is receiving increased attention. In this report, we focus on advances in characterizing the functional significance of transcription factor association with the nucleoskeleton. In particular, we consider recent biochemical and “molecular morphology” data that point to the importance of dynamic spatial and solubility partitioning of gene regulators with nuclear architecture. J. Cell. Biochem. 70:213-221, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 49
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 70 (1998), S. 222-230 
    ISSN: 0730-2312
    Keywords: functional organization of the nucleus ; nucleolus ; speckled compartment ; targeting sequence ; DNA replication ; RNA splicing ; nuclear matrix ; cell cycle ; DNA methyltransferase ; DNA ligase I ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Though there are no separating membranes within the nucleus, different factors are often concentrated at sites where their respective function is required, a phenomenum referred to as functional organization of the nucleus. How is then this organization achieved and how are the different metabolic processes integrated in the nucleus? One emerging principle was revealed by the identification of protein domains that, though not involved in catalysis, regulate enzyme activity at a higher order level by targeting enzymes to the right place at the right time. These targeting sequences constitute an assembly code for nuclear ‘protein factories,’ which ensure the extremely high efficiency and accuracy needed in a complex and competitive environment as the living mammalian cell. J. Cell. Biochem. 70:222- 230, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 50
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 70 (1998), S. 84-93 
    ISSN: 0730-2312
    Keywords: PTHrP ; PTH/PTHrP receptor ; estrogen ; ovariectomy ; kidney ; rat ; in vivo ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The aim of the present study was to test the hypothesis that the decreased renal tubular reabsorption of calcium observed in estrogen deficiency is associated with a local regulation of either PTHrP or PTH/PTHrP receptor genes in the kidney. Rats were randomly sham-operated (S) or ovariectomized receiving either vehicule (OVX) or 4 μg E2/kg/day (OVX+E4) or 40 μg E2/kg/d (OVX+E40) during 14 days using alzet minipumps. Plasma PTH and calcium levels were lower in untreated OVX animals than in all other groups (P < 0.01). Plasma PTH was higher in OVX+E40 than in OVX+E4 (P < 0.05). PTHrP mRNA expression in the kidney was unaffected by ovariectomy but was increased in OVX+E40 (0.984 ± 0.452 for PTHrP/GAPDH mRNAs expression vs. 0.213 ± 0.078 in sham, P < 0.01). PTH/PTHrP receptor mRNA expression and the cAMP response of renal membranes to PTH were unaffected by ovariectomy and estrogen substitution. In conclusion, renal PTHrP and PTH/PTHrP receptor mRNAs are not modified by ovariectomy. However, 17β-estradiol increases renal expression of PTHrP mRNA without evident changes in its receptor expression and function. This may help to explain the pharmacological action of estrogen in the kidney, especially how it prevents the renal leak of calcium in postmenopausal women. J. Cell. Biochem. 70:84-93, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 51
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 70 (1998), S. 94-109 
    ISSN: 0730-2312
    Keywords: steroid hormone receptor ; 1,25-dihydroxyvitamin D3 ; nuclear retention ; DNA-binding ; transcriptional activation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The human vitamin D receptor (hVDR) possesses a unique array of five basic amino acids positioned between the two DNA-binding zinc fingers that is similar to well-characterized nuclear localization sequences in other proteins. When residues within this region are mutated to nonbasic amino acids, or when this domain is deleted, the receptor is still well expressed, but it no longer associates with the vitamin D-responsive element in DNA, in vitro, and hVDR-mediated transcriptional activation is abolished in transfected cells. Concomitantly, the mutated hVDRs exhibit a significant shift in hVDR cellular distribution favoring cytoplasmic over nuclear retention as assessed by subcellular fractionation and immunoblotting. Independent immunocytochemical studies employing a VDR-specific monoclonal antibody demonstrate that mutation or deletion of this basic domain dramatically attenuates hVDR nuclear localization in transfected COS-7 cells. Although wild-type hVDR is partitioned predominantly to the nucleus in the absence of the 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) hormone, treatment with ligand further enhances nuclear translocation, as it does to some degree in receptors with the basic region altered. The role of 1,25(OH)2D3may be to facilitate hVDR heterodimerization with retinoid X receptors, stimulating subsequent DNA binding and ultimately enhancing nuclear retention. Taken together, these data reveal that the region of hVDR between Arg-49 and Lys-55 contains a novel constitutive nuclear localization signal, RRSMKRK. J. Cell. Biochem. 70:94-109, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 52
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 70 (1998), S. 110-120 
    ISSN: 0730-2312
    Keywords: myosin heavy chains ; rat heart ; naturally occurring antisense mRNA ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Analysis of mRNA by Northern blot and reverse transcription-polymerase chain reaction demonstrated the expression of sense and considerable amounts of naturally occurring antisense mRNA for β-myosin heavy chain (MHC) and α-MHC in the neonatal rat heart: antisense MHC mRNA expression of α-MHC and β-MHC was approximately half of the corresponding sense MHC mRNA expression. Using a computational approach, we could identify a reverse Pol II promoter in the β-MHC gene. Both sense and antisense MHC mRNA demonstrated similar sizes of approximately 6,000 bp in the Northern blot. Alpha-MHC antisense mRNA consisted of approximately 3,700 bp of complementary exon sequences and β-MHC consisted of approximately 2,700 bp, suggesting a higher probability of α-MHC mRNA dimerization. Hence, sense mRNA transcripts and protein of α-MHC should exist at different relative levels in the neonatal state. In fact, the relative proportion of α-MHC was 52.0 ± 2.6% on the sense mRNA but only 36.3 ± 1.8% on the protein level. Because of its high abundance in the heart, we suggest that in the neonatal heart naturally occurring antisense mRNA may play a role in the regulation of MHC expression and, therefore, in the control of the energetical and contractile behaviour of the heart. J. Cell. Biochem. 70:110-120, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 70 (1998), S. 121-129 
    ISSN: 0730-2312
    Keywords: giant cell tumor of bone ; MCP-1 ; TGF-β ; CD68+ ; chemotaxis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Giant cell tumor of bone (GCT) is one of a few neoplasms in which the macrophage/osteoclast precursor cells and osteoclast-like giant cells infiltrate the tumor mass. Monocyte chemoattractant protein 1 (MCP-1) is a potent chemotactic factor specific for monocytes. In search of relevant cytokines that may enhance the recruitment of these reactive cells, we evaluated the localization and regulation of MCP-1 mRNA and protein in GCT by using Northern blot analysis, in situ hybridization and immunohistochemistry. We also determined whether conditioned medium obtained from GCT cultures can recruit human peripheral blood monocytes (CD68+) in an in vitro chemotactic assay. Using Northern blot analysis, we detected the specific gene transcript for MCP-1 in all GCT samples tested. In situ hybridization and immunohistochemistry revealed that both MCP-1 gene transcript and protein were consistently present in the cytoplasm of stromal-like tumor cells of GCT. Treatment of mononuclear cells from GCT at third passage with TGF-β1 for 24 h increased the level of MCP-1 mRNA in a dose-dependent manner, with the maximum effect at 1 ng/ml. Conditioned media from GCT cultures promoted the chemotactic migration of CD68+ peripheral monocytes, an activity which was abolished by the addition of MCP-1 antibody to the conditioned medium. Thus, the results of this study suggest that recruitment of CD68+ macrophage-like cells may be due to the production MCP-1 by stromal-like tumor cells. These CD68+ cells may originate from peripheral blood and could have the capability of further differentiating into osteoclasts in the tumor. J. Cell. Biochem. 70:121-129, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 54
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 70 (1998), S. 281-287 
    ISSN: 0730-2312
    Keywords: retinoblastoma protein ; TATA-binding protein ; repressor ; TSA ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The retinoblastoma (RB) tumour suppressor protein negatively regulates cell proliferation by modulating transcription of growth-regulatory genes. Recruitment of Rb to promoters, by association with E2F complex or by fusion with heterologous DNA-binding domains, demonstrated that Rb represses directly transcription. Recent studies also suggest that the RB protein is able to repress gene transcription mediated by the RNA polymerase I and III. Since the TATA-binding protein (TBP) is an important component for transcription mediated by all three RNA polymerases, we have analysed the functional interaction between Rb and TBP in vivo in the context of RNA pol II-driven transcription. We demonstrated that in mammalian cells Rb tethered to promoter represses TBP-mediated activation in vivo, and Rb-mediated repression is reversed in the presence of the inhibition of histone deacetylase activity by trichostatin A (TSA). J. Cell. Biochem. 70:281-287, 1998. © 1998 Wiley-Liss, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 55
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 70 (1998), S. 288-288