bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of long‐term administration of N‐3 polyunsaturated fatty acids (PUFA) and selective estrogen receptor modulator (SERM) derivatives in ovariectomized (OVX) mice
Authors: Zeitlin L. , Segev E. , Fried A. , Wientroub S. 
Published: September 2003

AbstractWe studied the beneficial effects of dietary consumption of n‐3 polyunsaturated fatty acids (PUFA) and two selective estrogen receptor modulator (SERM) derivatives (SERM‐I and SERM‐II) and their combined effect on serum lipids, skin dermis and adipose layers, bone marrow adipogenesis, and cytokine secretion in mice. Two different ovariectomized (OVX) models were studied: treatment began immediately post‐OVX in one and 3 months post‐OVX in the other. Our results showed that n‐3 PUFA and both SERMs decreased triglyceride levels in the serum, and that SERMs also decreased serum cholesterol levels while n‐3 PUFA had no similar effect. SERMs had no effect on IL‐6, IL‐1 beta, or IL‐10 levels, but they decreased ex vivo tumor necrosis factor (TNF‐α). N‐3 PUFA decreased secretion of non‐induced IL‐6 and TNF‐α from cultured BMC and IL‐1 beta levels in vivo (i.e., in bone marrow plasma), but its main effect was a significant elevation in the secretion of IL‐10, a known anti‐inflammatory cytokine. OVX‐induced B‐lymphopoiesis was not affected by LY‐139481 (SERM‐I) while LY‐353381 (SERM‐II) exhibited an estrogen‐antagonistic effect in sham and OVX mice and elevated the amount of B‐cells in bone marrow. Fish oil consumption prevented the elevation in B‐lymphopoiesis caused by OVX, but had no curative effect on established augmented B‐lymphopoiesis. This activity could be mediated via the elevation of IL‐10 which was shown to suppress B‐lymphopoiesis. Both SERMs and n‐3 PUFA inhibited the increase in adipose tissue thickness caused by OVX in mice. Our results showed that n‐3 PUFA, could prevent some of the deleterious outcomes of estrogen deficiency that were not affected by SERMs. We observed no significant beneficial effects of the combined administration of SERM‐I, SERM‐II, and PUFA on the studied parameters.The exact mechanism by which polyunsaturated fatty acids exert their activities is still not clear, but peroxisome proliferator‐activated receptors (PPARs) might be involved in processes which are modulated by n‐3 PUFA. J. Cell. Biochem. 90: 347–360, 2003. © 2003 Wiley‐Liss, Inc.
Inorganic phosphate as a signaling molecule in osteoblast differentiation
Authors: Beck George R. 
Published: September 2003

AbstractThe spatial and temporal coordination of the many events required for osteogenic cells to create a mineralized matrix are only partially understood. The complexity of this process, and the nature of the final product, demand that these cells have mechanisms to carefully monitor events in the extracellular environment and have the ability to respond through cellular and molecular changes. The generation of inorganic phosphate during the process of differentiation may be one such signal. In addition to the requirement of inorganic phosphate as a component of hydroxyapatite mineral, Ca10(PO4)6(OH)2, a number of studies have also suggested it is required in the events preceding mineralization. However, contrasting results, physiological relevance, and the lack of a clear mechanism(s) have created some debate as to the significance of elevated phosphate in the differentiation process. More recently, a number of studies have begun to shed light on possible cellular and molecular consequences of elevated intracellular inorganic phosphate. These results suggest a model in which the generation of inorganic phosphate during osteoblast differentiation may in and of itself represent a signal capable of facilitating the temporal coordination of expression and regulation of multiple factors necessary for mineralization. The regulation of protein function and gene expression by elevated inorganic phosphate during osteoblast differentiation may represent a mechanism by which mineralizing cells monitor and respond to the changing extracellular environment. J. Cell. Biochem. 90: 234–243, 2003. Published 2003 Wiley‐Liss, Inc.
In vivo administration of 1,25‐dihydroxyvitamin D3 suppresses the expression of RANKL mRNA in bone of thyroparathyroidectomized rats constantly infused with PTH
Authors: Ueno Yutaka , Shinki Toshimasa , Nagai Yumiko , Murayama Hisashi , Fujii Katsuyuki , Suda Tatsuo 
Published: September 2003

AbstractIt is known that pharmacological or toxic doses of vitamin D induce bone resorption both in vivo and in vitro, whereas physiological doses of the vitamin have a protective effect on bone in vivo. To investigate the discrepancies of the dose‐dependent effect of vitamin D on bone resorption, we examined the in vivo effect of 1,25‐dihydroxyvitamin D3 [1,25(OH)2D3] on the expression of the receptor activator of nuclear factor‐κB (NF‐κB) ligand (RANKL) and osteoprotegerin (OPG) mRNAs in bone of thyroparathyroidectomized (TPTX) rats infused with or without parathyroid hormone (PTH). Continuous infusion of 50 ng/h of PTH greatly increased the expression of RANKL mRNA in bone of TPTX rats. Expression of OPG mRNA was not altered by PTH infusion. When graded doses of 1,25(OH)2D3 was daily administered orally for 14 days to normocalcemic TPTX rats constantly infused with PTH, 0.01 and 0.1 μg/kg of 1,25(OH)2D3 inhibited the PTH‐induced RANKL mRNA expression, but 0.5 μg/kg of the vitamin did not inhibit it. Regulator of G protein signaling‐2 (RGS‐2) gene expression was suppressed by 1,25(OH)2D3 dose‐dependently, but PTH/PTHrP receptor mRNA expression was not altered. Bone morphometric analyses revealed that 1,25(OH)2D3 suppressed PTH‐induced osteoclast number in vivo. These results suggest that pharmacological or toxic doses of 1,25(OH)2D3 stimulate bone resorption by inducing RANKL, but a certain range of physiological doses of the vitamin inhibit PTH‐induced bone resorption, the latter mechanism appeared to be mediated, at least in part, by the suppression of the PTH/PTHrP receptor‐mediated signaling. J. Cell. Biochem. 90: 267–277, 2003. © 2003 Wiley‐Liss, Inc.
A proteomic study of the arabidopsis nuclear matrix
Authors: Calikowski Tomasz T. , Meulia Tea , Meier Iris 
Published: September 2003

AbstractThe eukaryotic nucleus has been proposed to be organized by two interdependent nucleoprotein structures, the DNA‐based chromatin and the RNA‐dependent nuclear matrix. The functional composition and molecular organization of the second component have not yet been resolved. Here, we describe the isolation of the nuclear matrix from the model plant Arabidopsis, its initial characterization by confocal and electron microscopy, and the identification of 36 proteins by mass spectrometry. Electron microscopy of resinless samples confirmed a structure very similar to that described for the animal nuclear matrix. Two‐dimensional gel electrophoresis resolved approximately 300 protein spots. Proteins were identified in batches by ESI tandem mass spectrometry after resolution by 1D SDS–PAGE. Among the identified proteins were a number of demonstrated or predicted Arabidopsis homologs of nucleolar proteins such as IMP4, Nop56, Nop58, fibrillarins, nucleolin, as well as ribosomal components and a putative histone deacetylase. Others included homologs of eEF‐1, HSP/HSC70, and DnaJ, which have also been identified in the nucleolus or nuclear matrix of human cells, as well as a number of novel proteins with unknown function. This study is the first proteomic approach towards the characterization of a higher plant nuclear matrix. It demonstrates the striking similarities both in structure and protein composition of the operationally defined nuclear matrix across kingdoms whose unicellular ancestors have separated more than one billion years ago. J. Cell. Biochem. 90: 361–378, 2003. © 2003 Wiley‐Liss, Inc.
NMDA glutamate receptors are expressed by osteoclast precursors and involved in the regulation of osteoclastogenesis
Authors: Merle Blandine , Itzstein Cecile , Delmas Pierre D. , Chenu Chantal 
Published: September 2003

AbstractWe previously identified functional N‐methyl‐d‐aspartate (NMDA) glutamate receptors in mature osteoclasts and demonstrated that they are involved in bone resorption in vitro. In the present work, we studied the expression of NMDA receptors (NMDAR) by osteoclast precursors and their role in osteoclastogenesis using two in vitro models, the murine myelomonocytic RAW 264.7 cell line and mouse bone marrow cells, both of which differentiate into osteoclasts in the presence of macrophage colony‐stimulating factor (M‐CSF) and Rank ligand (RankL). Using RT‐PCR analysis with specific probes, we showed that RAW 264.7 cells and mouse bone marrow cells express mRNA of NMDAR subunits NMDA receptor 1 (NR1) and NMDA receptor 2 (NR2) A, B, and D. These subunits are expressed all along the differentiation sequence from undifferentiated precursors to mature resorbing osteoclasts. Semi‐quantitative PCR analysis showed no regulation of the expression of these subunits during the differentiation process. Two specific non competitive antagonists of NMDAR, MK801 and DEP, dose‐dependently inhibited osteoclast formation in both models, indicating that osteoclastogenesis requires the activation of NMDAR expressed by osteoclast precursors. MK801 had no effect when added only during the first 2 days of culture, suggesting that NMDAR are rather involved in the late stages of osteoclast formation. Finally, we demonstrated using Western‐blotting and immunofluorescence that activation of NMDAR in RAW 264.7 cells by specific agonists induces nuclear translocation of NF‐kappa B, a factor required for osteoclast formation. Altogether, our results indicate that osteoclast precursors express NMDAR that are involved in the osteoclast differentiation process through activation of the NF‐kappa B pathway. J. Cell. Biochem. 90: 424–436, 2003. © 2003 Wiley‐Liss, Inc.
Effects of iron deficiency on the secretion of interleukin‐10 by mitogen‐activated and non‐activated murine spleen cells
Authors: Kuvibidila Solo , Yu L. , Ode D. , Velez M. , Gardner R. , Warrier R.P. 
Published: September 2003

AbstractInterleukin (IL)‐10 plays crucial regulatory roles in immune responses by inhibiting the secretion of several cytokines (IL‐2, IL‐12, interferon‐gamma (IFN‐γ)) and lymphocyte proliferation. Iron deficiency, a public health problem for children, alters these immune responses. To determine whether these changes are related to altered IL‐10 secretion, we measured IL‐10 in 24 and 48 h supernatant of spleen cell cultures from iron deficient (ID), control (C), pairfed (PF), and ID mice fed the control diet (iron repletion) for 3 (R3) and 14 (R14) days (d, n = 12/group). Mean levels of hemoglobin, hematocrit, and liver iron stores varied as follows: C ≈ PF ≈ R14 > R3 > ID (P < 0.01). Mean baseline IL‐10 levels of ID mice tended to be higher than those of other groups (P > 0.05, ANOVA). Mean IL‐10 levels secreted by concanavalin A (Con A) and antibody raised against cluster of differentiation molecule 3 (anti‐CD3)‐treated cells (±background) were lower in ID than in C (48 h) and iron replete mice (P < 0.05). Underfeeding also reduced IL‐10 secretion by anti‐CD3‐treated cells (48 h, P < 0.05). Lymphocyte proliferative responses to anti‐CD3 ± anti‐CD28 antibodies were lower in ID than in C and PF mice, and they were corrected by iron repletion (P < 0.05). IL‐10 levels negatively correlated with indicators of iron status (r ≤ −0.285) and lymphocyte proliferation (r ≤ −0.379 [r ≤ −0.743 for ID mice]), but positively correlated with IFN‐γ levels (r ≤ 0.47; P < 0.05). Data suggest that iron deficiency has a generalized deleterious effect on cells that secrete both cytokines. Reduced IL‐10 secretion by activated cells does not overcome the inhibition of lymphocyte proliferation due to other factors of T cell activation that are regulated by iron. J. Cell. Biochem. 90: 278–286, 2003. © 2003 Wiley‐Liss, Inc.
Suppression of AP‐1 constitutive activity interferes with polyomavirus MT antigen transformation ability
Authors: Winnischofer Sheila Maria Brochado , de Oliveira Maria Leonor Sarno , Sogayar Mari Cleide 
Published: September 2003

AbstractPolyomavirus (Py) encodes a potent oncogene, the middle T antigen (MT), that induces cell transformation by binding to and activating several cytoplasmic proteins which take part in transduction of growth factors‐induced mitogenic signal to the nucleus. We have previously reported that the AP‐1 transcriptional complex is a target for MT during cell transformation although, its activation was not sufficient for establishment of the transformed phenotype. Here we show that expression of a dominant‐negative cJun mutant in MT transformed cell lines inhibits its transformation ability, indicating that constitutive AP‐1 activity is necessary for cell transformation mediated by MT. Evidences also suggest that proliferation of MT transformed cells in low serum concentrations and their ability to form colonies in agarose are controlled by distinct mechanisms. J. Cell. Biochem. 90: 253–266, 2003. © 2003 Wiley‐Liss, Inc.
Human cardiomyocytes express high level of Na+/glucose cotransporter 1 (SGLT1)
Authors: Zhou Lubing , Cryan Ellen V. , D'Andrea Michael R. , Belkowski Stanley , Conway Bruce R. , Demarest Keith T. 
Published: September 2003

AbstractWe have quantitatively measured gene expression for the sodium‐dependent glucose cotransporters 1 and 2 (SGLT1 and SGLT2) in 23 human tissues using the method of real time PCR. As predicted, our results revealed that the expression of SGLT1 was very high in the small intestine (1.2E + 6 molecules/μg total RNA) relative to that in the kidney (3E + 4 molecules/μg total RNA). Surprisingly, we observed that the expression of SGLT1 in human heart was unexpectedly high (3.4E + 5 molecules/μg total RNA), approximately 10‐fold higher than that observed in kidney tissue. DNA sequencing confirmed that the PCR amplified fragment was indeed the human SGLT1 gene. Moreover, in situ hybridization studies using a digoxigenin (DIG)‐labeled antisense cRNA probe corresponding to human SGLT1 cDNA confirm that human cardiomyocytes express SGLT1 mRNA. In contrast, the expression of SGLT2 in human tissues appears to be ubiquitous, with levels ranging from 6.7E + 4 molecules/μg total RNA (in skeletal muscle) to 3.2E + 6 molecules/μg total RNA (in kidney), levels 10–100‐fold higher than the expression of SGLT1 in the same tissues. Our finding that human cardiomyocytes express high levels of SGLT1 RNA suggests that SGLT1 may have a functional role in cardiac glucose transport. Since several SGLT inhibitors are currently in development as potential anti‐diabetic agents, it may be important to assess the functional consequences of inhibition of SGLT1 in the heart. J. Cell. Biochem. 90: 339–346, 2003. © 2003 Wiley‐Liss, Inc.
Estrogen receptor isoform‐specific regulation of endogenous gene expression in human osteoblastic cell lines expressing either ERα or ERβ
Authors: Monroe David G. , Getz Barbara J. , Johnsen Steven A. , Riggs B. Lawrence , Khosla Sundeep , Spelsberg Thomas C. 
Published: September 2003

AbstractEstrogen (17β‐estradiol, E2) plays pivotal roles in the function and maintenance of the skeleton, including the bone‐forming osteoblasts (OBs). The functions of E2 are largely mediated through two distinct estrogen receptor isoforms, ERα and ERβ, both of which are expressed in OBs. The level of each isoform dominates at early or late stages of OB differentiation. To date, only a limited comparison between the transcriptional targets of ERα and ERβ on endogenous gene expression has been reported. We have developed new stable cell lines, which contain doxycycline (Dox)‐inducible ERα and ERβ, in the U2OS human osteosarcoma to determine the global transcriptional profile of ERα‐ and ERβ‐regulation of endogenous gene expression. The U2OS‐ERα and U2OS‐ERβ cell lines were treated with Dox and either vehicle control or E2 for 24 h. Gene expression analysis was performed using a microarray containing ∼6,800 full‐length genes. We detected 63 genes that were regulated solely by ERα and 59 genes that were only regulated solely by ERβ. Of the ERα‐regulated genes, 81% were upregulated and 19% were inhibited. Similarly 76% of the ERβ‐regulated genes were upregulated whereas 24% were inhibited by E2. Surprisingly, only 17 genes were induced by both ERα and ERβ. Real‐time PCR was employed to confirm the expression of a selected number of genes. The regulation of a number of known E2‐responsive genes in human OBs, as well as many interesting novel genes, is shown. The distinct patterns of E2‐dependent gene regulation in the U2OS cells by ERα and ERβ shown here suggest that during OB differentiation, when either isoform dominates, a unique pattern of gene responses will occur, partially due to the differentiation state and the ER isoform present. J. Cell. Biochem. 90: 315–326, 2003. © 2003 Wiley‐Liss, Inc.
Hemin‐dependent induction and internalization of CD38 in K562 cells
Authors: Yalcintepe Leman , Ercelen Sebnem , Adin‐Cinar Suzan , Badur Selim , Tiryaki Demir , Bermek Engin 
Published: September 2003

AbstractThe cell surface antigen, CD38, is a bifunctional ecto‐enzyme, which is predominantly expressed on hematopoietic cells during differentiation. In the present study, it is shown that hemin treatment of K562 cells gives rise to induction of enzymatic activities inherent to CD38. GDP‐ribosyl cyclase activity, an indicator of CD38, increased initially in response to hemin in a time‐dependent manner, reached a maximum level on the 5th day and, thereafter, declined sharply to the initial level. The increase in NAD+ glycohydrolase and ADP‐ribose uptake activities followed a similar time course. However, the decline in the latter activities after the 5th day of induction appeared to be rather slow in contrast to GDP‐ribosyl cyclase activity. The time course of these changes was well correlated with the FACScan findings obtained by use of anti‐CD38 monoclonal antibody. SDS–PAGE and Western blot analyses by use of the monoclonal antibody OKT10 revealed a transient hemin‐dependent appearence of a 43 kDa membrane protein with maximum signal intensity on the first 4 days of incubation. There was subsequently a gradual decrease on the 5th day, concomitant with a reciprocal increase in activity of the internalized protein fraction. The results together indicated that hemin‐induced expression of CD38 was followed by its down‐regulation. J. Cell. Biochem. 90: 379–386, 2003. © 2003 Wiley‐Liss, Inc.
Curcumin inhibits UV irradiation‐induced oxidative stress and apoptotic biochemical changes in human epidermoid carcinoma A431 cells
Authors: Chan Wen‐Hsiung , Wu Chih‐Ching , Yu Jau‐Song 
Published: September 2003

AbstractUltraviolet (UV) light is a strong apoptotic trigger that induces caspase‐dependent biochemical changes in cells. Previously we showed that UV irradiation can activate caspase‐3, and the subsequent cleavage and activation of p21Cdc42/Rac‐activated kinase 2 (PAK2) in human epidermoid carcinoma A431 cells. In this study we demonstrate that curcumin (Cur), the yellow pigment of Curcuma longa with known anti‐oxidant and anti‐inflammatory properties, can prevent UV irradiation‐induced apoptotic changes, including c‐Jun N‐terminal kinase (JNK) activation, loss of mitochondrial membrane potential (MMP), mitochondrial release of cytochrome C, caspase‐3 activation, and cleavage/activation of PAK2 in A431 cells. Flow cytometric analysis using the cell permeable dye 2′,7′‐dichlorofluorescin diacetate (DCF‐DA) as an indicator of reactive oxygen species (ROS) generation revealed that the increase in intracellular oxidative stress caused by UV irradiation could be abolished by Cur. In addition, we found that SP600125, a JNK‐specific inhibitor, reduced UV irradiation‐induced JNK activation as well as caspase‐3 activation, indicating that JNK activity is required for UV irradiation‐induced caspase activation. Collectively, our results demonstrate that Cur significantly attenuates UV irradiation‐induced ROS formation, and suggest that ROS triggers JNK activation, which in turn causes MMP change, cytochrome C release, caspase activation, and subsequent apoptotic biochemical changes. J. Cell. Biochem. 90: 327–338, 2003. © 2003 Wiley‐Liss, Inc.
Direct, rapid effects of 25‐hydroxyvitamin D3 on isolated intestinal cells
Authors: Phadnis Ruta , Nemere Ilka 
Published: September 2003

AbstractScattered reports in the literature have suggested that the metabolite 25‐hydroxyvitamin D3 [25(OH)D3] has biological activity. In the present work, perfusion of isolated duodenal loops of normal chickens with 100 nM 25(OH)D3 resulted in enhanced transport of 45Ca within 2 min relative to the vehicle controls. We then tested the effect of a range of 25(OH)D3 concentrations on 45Ca handling by isolated intestinal cells in time course studies. Following a basal uptake period, cell suspensions from 7‐week old chicks were treated either with 25, 100, or 300 nM 25(OH)D3, or the vehicle ethanol (0.01%, final concentration). Both 25 and 100 nM 25(OH)D3 resulted in a significant (P < 0.05) reduction in 45Ca levels, relative to controls, between 1–10 min after treatment, while 300 nM 25(OH)D3 resulted in a significant increase in 45Ca levels, relative to controls, after 10 min of incubation. The effect of 100 nM 25(OH)D3 (a physiological level) on cell calcium was abolished by the presence of 6.5 nM 24,25‐dihydroxyvitamin D3. In cell preparations from 14‐ or 28‐week old birds 100nM 25(OH)D3 had no effect, relative to vehicle controls. Incubation of cells with 2 μM BAY K8644, a calcium channel activator, stimulated 45Ca uptake within 3 min relative to vehicle controls (P < 0.05), while addition of either 20 μM forskolin or 100 nM phorbol ester (stimulators of the PKA and PKC pathways, respectively) resulted in enhanced radionuclide levels after 10 min of incubation (P < 0.05, relative to corresponding controls). Finally, cells were treated with 100 nM 25(OH)D3 or vehicle and samples taken at various times for analyses of protein kinase C and A activities. No effect of 25(OH)D3 on protein kinase C activity was observed, while protein kinase A activity was stimulated to nearly 200% of controls at 1 min after 25(OH)D3 addition (P < 0.05, relative to corresponding controls) and began declining at 3 min, returning to control levels 5 min after additions. We conclude that 25(OH)D3 has a direct effect on calcium handling in enterocytes of young animals that may in part be mediated by the protein kinase A signal transduction pathway. J. Cell. Biochem. 90: 287–293, 2003. © 2003 Wiley‐Liss, Inc.