bluuebunny/crossref_metadata_2025_split huggingface dataset:
miR‐29 suppression of osteonectin in osteoblasts: Regulation during differentiation and by canonical Wnt signaling
Authors: Kapinas Kristina , Kessler Catherine B. , Delany Anne M. 
Published: June 2009

AbstractThe matricellular protein osteonectin, secreted protein acidic and rich in cysteine (SPARC, BM‐40), is the most abundant non‐collagenous matrix protein in bone. Matricellular proteins play a fundamental role in the skeleton as regulators of bone remodeling. In the skeleton, osteonectin is essential for the maintenance of bone mass and for balancing bone formation and resorption in response to parathyroid hormone (PTH). It promotes osteoblast differentiation and cell survival. Mechanisms regulating the expression of osteonectin in the skeleton and in other tissues remain poorly understood. We found that the proximal region of the mouse osteonectin 3′ untranslated region (UTR) contains a well‐conserved, dominant regulatory motif that interacts with microRNAs (miRs)‐29a and ‐29c. Transfection of osteoblastic cells with miR‐29a inhibitors increased osteonectin protein levels, whereas transfection of miR‐29a precursor RNA decreased osteonectin. miR‐29a and ‐29c were increased during osteoblastic differentiation in vitro. The up‐regulation of these miRNAs correlated with decreased osteonectin protein during the matrix maturation and mineralization phases of late differentiation. In contrast, osteonectin transcript levels remained relatively constant during this process, implying repression of translation. Treatment of osteoblasts with LiCl induced miR‐29a and ‐29c expression and decreased osteonectin synthesis. When cells were treated with Dickkopf‐1 (Dkk‐1), miR‐29a and ‐29c expression was repressed. These data suggest that canonical Wnt signaling, which is increased during osteoblastic differentiation, induces expression of miR‐29. Osteonectin and miR‐29 are co‐expressed in extra‐skeletal tissues, and the post‐transcriptional mechanisms regulating osteonectin in osteoblasts are likely to be active in other cell systems. J. Cell. Biochem. 108: 216–224, 2009. © 2009 Wiley‐Liss, Inc.
Eupatilin inhibits T‐cell activation by modulation of intracellular calcium flux and NF‐κB and NF‐AT activity
Authors: Kim Young‐Dae , Choi Suck‐Chei , Oh Tae‐Young , Chun Jang‐Soo , Jun Chang‐Duk 
Published: June 2009

AbstractEupatilin, one of the pharmacologically active ingredients of Artemisia princeps, exhibits a potent anti‐ulcer activity, but its effects on T‐cell immunity have not been investigated. Here, we show that eupatilin has a profound inhibitory effect on IL‐2 production in Jurkat T cells as well as in human peripheral blood leukocytes. Eupatilin neither influenced clustering of CD3 and LFA‐1 to the immunological synapse nor inhibited conjugate formation between T cells and B cells in the presence or absence of superantigen (SEE). Eupatilin also failed to inhibit T‐cell receptor (TCR) internalization, thereby, suggesting that eupatilin does not interfere with TCR‐mediated signals on the membrane proximal region. In unstimulated T cells, eupatilin significantly induced apoptotic cell death, as evidenced by an increased population of annexin V+/PI+ cells and cleavage of caspase‐3 and PARP. To our surprise, however, once cells were activated, eupatilin had little effect on apoptosis, and instead slightly protected cells from activation‐induced cell death, suggesting that apoptosis also is not a mechanism for eupatilin‐induced T‐cell suppression. On the contrary, eupatilin dramatically inhibited I‐κBα degradation and NF‐AT dephosphorylation and, consequently, inhibited NF‐κB and NF‐AT promoter activities in PMA/A23187‐stimulated T cells. Interestingly, intracellular calcium flux was significantly perturbed in cells pre‐treated with eupatilin, suggesting that calcium‐dependent cascades might be targets for eupatilin action. Collectively, our results provide evidence for dual regulatory functions of eupatilin: (1) a pro‐apoptotic effect on resting T cells and (2) an immunosuppressive effect on activated T cells, presumably through modulation of Ca2+ flux. J. Cell. Biochem. 108: 225–236, 2009. © 2009 Wiley‐Liss, Inc.
Zebrafish blood stem cells
Authors: Chen Aye T. , Zon Leonard I. 
Published: June 2009

AbstractWithin the past two decades, the zebrafish (Danio rerio) has become an excellent model to study the development of hematopoietic stem cells (HSCs). All vertebrates including zebrafish have primitive and definitive waves of hematopoiesis, but self‐renewing pluripotent HSCs are only produced by the definitive wave. The primitive wave occurs in two intraembryonic locations called the intermediate cell mass (ICM) and the anterior lateral mesoderm (ALM). Primitive erythropoiesis is in the ICM, whereas myelopoiesis initiates in the ALM. After circulation starts at 24 h post‐fertilization, hematopoiesis shifts to the posterior blood island (PBI) for a brief period. The definitive wave starts in the aorta‐gonad‐mesonephros (AGM). There are three different HSC migration and colonization events that begin 2 days post‐fertilization: AGM progenitor cells migrate to (1) the caudal hematopoietic tissue (CHT), which is an intermediate site of blood development; (2) the thymus, which is a site of lymphocyte maturation; and (3) the developing kidney marrow, which is the larval and adult location for production of all hematopoietic cell types, and is comparable to the bone marrow of mammals. Many of the transcription factors and signaling pathways that regulate the formation of HSCs in a zebrafish are conserved with mammals. Large‐scale forward and reverse genetic screens have identified zebrafish blood and HSC mutants that represent models for known human diseases. Along with the technological advancements in the field of zebrafish research, future HSC studies in zebrafish will help us illuminate the genetic network controlling the development and function of stem cells in all vertebrates. J. Cell. Biochem. 108: 35–42, 2009. © 2009 Wiley‐Liss, Inc.
DNA methylation and histone modification regulate silencing of OPG during tumor progression
Authors: Lu Tung‐Ying , Kao Cheng‐Fu , Lin Chin‐Tarng , Huang Dah‐Yeou , Chiu Chien‐Yu , Huang Yu‐Shin , Wu Han‐Chung 
Published: June 2009

AbstractThe identification of molecules that are down‐regulated in malignant phenotype is important for understanding tumor biology and their role in tumor suppression. We compared the expression profile of four normal nasal mucosal (NNM) epithelia and a series of nasopharyngeal cancinoma (NPC) cell lines using cDNA microarray and confirmed the actual expression of the selected genes, and found osteoprotegerin (OPG) to be ubiquitously deficient in NPC cells. We also found OPG to be down‐regulated in various cancer cell lines, including oral, cervical, ovarian, lung, breast, pancreas, colon, renal, prostate cancer, and hepatoma. Administration of recombinant OPG (rOPG) brought about a reduction in cancer cell growth through apoptotic mechanism. We generated eleven monoclonal antibodies (MAbs) against OPG to study OPG's expression and biological functions in cancer cells. OPG was detected in the tumor stromal regions, but not in the cancer cell per se in surgical specimens of liver cancer. Quantitative reverse transcription‐polymerase chain reaction (Q‐RT‐PCR) revealed that OPG was down‐regulated in NPC tissues compared with normal nasal polyp (NNP) tissues. In addition, we showed OPG silencing to be associated with promoter methylation as well as histone modifications. In OPG‐silenced cancer cell lines, the OPG gene promoter CpG dinucleotides were highly methylated. Compared to normal cells, silenced OPG gene in cancer cells were found to have reduced histone 3 lysine 4 tri‐methylation (H3K4me3) and increased histone 3 lysine 27 tri‐methylation (H3K27me3). Taken together, these results suggest that OPG silencing in carcinoma cancer cells occurs through epigenetic repression. J. Cell. Biochem. 108: 315–325, 2009. © 2009 Wiley‐Liss, Inc.
Threonine 393 of β‐catenin regulates interaction with Axin
Authors: Wu Hao , Symes Karen , Seldin David C. , Dominguez Isabel 
Published: June 2009

AbstractCK2 is a regulatory kinase implicated in embryonic development and in cancer. Among the CK2 substrates is β‐catenin, a protein with dual function in Wnt signaling and cell adhesion. Previously, we reported that CK2 activity is required for β‐catenin stability and we identified threonine (T) 393 as a major CK2 phosphorylation site in β‐catenin. However, it is not known whether phosphorylation at T393 increases β‐catenin stability and if so, what is the mechanism. In this study we investigate the molecular mechanism of β‐catenin stabilization through phosphorylation at T393. We found that pseudophosphorylation of β‐catenin at T393 resulted in a stable activated form of β‐catenin with decreased affinity for Axin in vitro. This phosphomimetic mutant also displayed decreased regulation by Axin in vivo in a bioassay in Xenopus laevis embryos. In contrast, the binding of T393 pseudophosphorylated β‐catenin to E‐cadherin was unaffected. Further analysis showed that pseudophosphorylation at T393 did not prevent β‐catenin phosphorylation by GSK3β. Interestingly, we found that in the presence of pseudophophorylated β‐catenin and another activated form of β‐catenin, the recruitment of GSK3β to Axin is enhanced. These findings indicate that phosphorylation of T393 by CK2 may affect the stability of β‐catenin through decreased binding to Axin. In addition, the increased recruitment of GSK3β to the destruction complex in the presence of activated β‐catenin mutants could be a feedback mechanism to suppress overactive Wnt signaling. J. Cell. Biochem. 108: 52–63, 2009. © 2009 Wiley‐Liss, Inc.
Hypoxia‐induced expression of bradykinin type‐2 receptors in endothelial cells triggers NO production, cell migration, and angiogenesis
Authors: Liesmaa Inka , Leskinen Hanna K. , Kokkonen Jorma O. , Ruskoaho Heikki , Kovanen Petri T. , Lindstedt Ken A. 
Published: June 2009

AbstractBradykinin receptors are differentially expressed in the coronary vascular endothelium of rat and human hearts during the pathogenesis of heart failure, but the mechanisms responsible for this regulation have remained vague. Here we show by quantitative real‐time PCR, Western blot analysis, and immunohistochemistry, that hypoxia triggers the expression of bradykinin type‐2 receptors (BK‐2Rs) in cultured human coronary artery endothelial cells (HCAECs), in isolated rat cardiac microvascular endothelial cells (RCMECs), and in rat hearts subjected to ligation of the left anterior descending coronary artery. Mild hypoxia (5% O2) induced a fourfold temporal increase in BK‐2R mRNA expression in HCAECs, which was also observed at the protein level, whereas severe hypoxia (1% O2) slightly inhibited the mRNA expression of BK‐2Rs. In addition, HOE‐140, a BK‐2R antagonist, inhibited mRNA and protein expression of BK‐2Rs. The BK‐2Rs induced by mild hypoxia were biologically active, that is, capable of inducing intracellular production of nitric oxide (NO) upon activation of HCAECs with bradykinin (BK), a response attenuated by HOE‐140. In rat hearts recovering from myocardial infarction, BK‐2Rs were upregulated in the endothelium of vessels forming at the border zone between fibrotic scar tissue and healthy myocardium. Furthermore, in an in vitro wound‐healing assay, RCMEC migration was increased under mild hypoxic culture conditions in the presence of BK and was attenuated with HOE‐140. Our present results show that mild hypoxia triggers a temporal expression of functional BK‐2Rs in human and rat endothelial cells and support a role for BK‐2Rs in hypoxia‐induced angiogenesis. J. Cell. Physiol. 221: 359–366, 2009. © 2009 Wiley‐Liss, Inc.
Optimization of C:N ratio and minimal initial carbon source for poly(3‐hydroxybutyrate) production by Bacillus megaterium
Authors: Faccin Débora Jung Luvizetto , Martins Ivana , Cardozo Nilo Sérgio Medeiros , Rech Rosane , Ayub Marco Antônio Záchia , Alves Tito Lívio Moitinho , Gambetta Rossano , Resende Secchi Argimiro 
Published: June 2009

AbstractBACKGROUND: The aim of this research was the optimization of poly(3‐hydroxybutyrate)—P(3HB)—production in submerged cultures of Bacillus megaterium in a mineral medium using sucrose as carbon source and nitrogen as the limiting substrate. Small‐scale experiments were carried out in shake flasks at 30 °C and 160 rpm in order to evaluate the best initial sucrose concentration and carbon:nitrogen ratio to maximize biomass accumulation and biopolymer production. An objective function in terms of residual sucrose and P(3HB) production was proposed in order to optimize the amount of carbon source used and the production of P(3HB).RESULTS: High production of P(3HB) was obtained, with approximately 70% (CDW) accumulation in cells without nitrogen limitation and strongly correlated with the pH of the culture. Scaling‐up the system to cultures in a bioreactor, with or without pH control, a reduction of P(3HB) accumulation (around 30% CDW) was observed when compared with shaker cultures, suggesting a possible role of oxygen limitation as a stress signaling for P(3HB) synthesis.CONCLUSIONS: Results of our experiments showed that Bacillus megaterium was able to produce P(3HB) at one of the highest production rates so far reported for this bacterium, making this microorganism very interesting for industrial applications. Comparisons of shaker and bench‐scale bioreactor experiments show both the importance of pH and aeration strategies. It is likely that complex aeration strategies linked to cell metabolism will be necessary for further developments using this bacterium. Copyright © 2009 Society of Chemical Industry
A systematic study of the function of the human β‐globin introns on the expression of the human coagulation factor IX in cultured Chinese hamster ovary cells
Authors: Haddad‐Mashadrizeh Aliakbar , Zomorodipour Alireza , Izadpanah Mehrnaz , Sam Mohammad Reza , Ataei Fariba , Sabouni Farzaneh , Hosseini Seyed Javad 
Published: June 2009

AbstractBackgroundIntronic sequences have the potential to improve gene expression in eukaryotes by a variety of mechanisms. In this context, human β‐globin (hBG) introns were inserted into the human factor IX (hFIX) cDNA in cytomegalovirus (CMV)‐regulated plasmids. The resulting construct was then used for further expression analysis in vitro.MethodsSeven hFIX‐expressing plasmids with different combinations of the two hBG introns and the Kozak element were constructed and used for a systematic expression analysis in cultured Chinese hamster ovary (CHO) cells. In parallel, the hBG intronic sequences were analysed for the presence of possible regulatory elements.ResultsAll the constructed plasmids resulted in transient expression of the hFIX. However, the coagulation activities varied according to the particular constructs used. Based on the hFIX antigenic assay, a wide range of variation was observed during persistent expression. The second hBG intron appears to be more effective than the first one. The expression level was further increased upon the inclusion of the Kozak element. Sequence analysis has detected several transcription factor binding (TFB) motifs in both of the introns, but with a higher frequency in the second one.ConclusionsPotentials of hBG introns as enhancer‐like elements for the expression of the hFIX in cultured CHO cells and a higher activity with respect to the second hBG intron compared to the first one were demonstrated. The larger number of TFBs in the second hBG intron reflects its stronger effect. The results obtained suggest possible synergistic functions of the hBG introns and Kozak on the expression level of hFIX in vitro. Copyright © 2009 John Wiley & Sons, Ltd.
Thermal desorption counter‐flow introduction atmospheric pressure chemical ionization for direct mass spectrometry of ecstasy tablets
Authors: Inoue Hiroyuki , Hashimoto Hiroaki , Watanabe Susumu , Iwata Yuko T. , Kanamori Tatsuyuki , Miyaguchi Hajime , Tsujikawa Kenji , Kuwayama Kenji , Tachi Noriyuki , Uetake Naohito 
Published: June 2009

AbstractA novel approach to the analysis of ecstasy tablets by direct mass spectrometry coupled with thermal desorption (TD) and counter‐flow introduction atmospheric pressure chemical ionization (CFI‐APCI) is described. Analytes were thermally desorbed with a metal block heater and introduced to a CFI‐APCI source with ambient air by a diaphragm pump. Water in the air was sufficient to act as the reactive reagent responsible for the generation of ions in the positive corona discharge. TD‐CFI‐APCI required neither a nebulizing gas nor solvent flow and the accompanying laborious optimizations. Ions generated were sent in the direction opposite to the air flow by an electric field and introduced into an ion trap mass spectrometer. The major ions corresponding to the protonated molecules ([M + H]+) were observed with several fragment ions in full scan mass spectrometry (MS) mode. Collision‐induced dissociation of protonated molecules gave characteristic product‐ion mass spectra and provided identification of the analytes within 5 s. The method required neither sample pretreatment nor a chromatographic separation step. The effectiveness of the combination of TD and CFI‐APCI was demonstrated by application to the direct mass spectrometric analysis of ecstasy tablets and legal pharmaceutical products. Copyright © 2009 John Wiley & Sons, Ltd.
Elucidation of phototransformation reactions of the X‐ray contrast medium iopromide under simulated solar radiation using UPLC‐ESI‐QqTOF‐MS
Authors: Pérez Sandra , Eichhorn Peter , Ceballos Vanesa , Barceló Damià 
Published: June 2009

AbstractThe highly polar, nonionic X‐ray contrast agent iopromide (C18H24N3O8I3; 791 Da) is resistant to microbial degradation during the activated sludge process in wastewater treatment plants and hence is released into the aquatic environment. Against this background, the present study was conducted to evaluate the phototransformation, potentially constituting the most relevant removal mechanism in rivers and streams. The photolysis of the iodinated aromatic compound was investigated in a Suntest solar simulator using aqueous solutions. Following a 120‐min irradiation period, an almost complete primary degradation of iopromide gave rise to a series of photoproducts that were chromatographed on a reversed‐phase UPLC and subsequently characterized by a combination of accurate mass measurements on a ESI‐QqToF‐MS instrument and H/D‐exchange experiments. This analytical approach facilitated confident identification of eight prominent products with the following elemental compositions and molecular weights: C18H25N3O9I2 (681 Da); C18H25N3O8I2 (665 Da); C17H23N3O8I2 (651 Da); C18H24N3O9I (553 Da); C17H24N3O8I (525 Da); C15H20N3O6I (465 Da); C14H18N3O6I (451 Da); and C18H25N3O9 (427 Da). Their formation was the result of four principal photoreactions: (1) gradual, and eventually complete, deiodination of the aromatic ring; (2) substitution of the halogen by a hydroxyl group; (3) N‐dealkylation of the amide in the hydroxylated side chain; and (4) oxidation of a methylene group in the hydroxylated side chain to the corresponding ketone. In conclusion, the findings of the artificial sunlight irradiation experiments indicated that in real environmental settings iopromide might suffer partial or even complete deiodination. Copyright © 2009 John Wiley & Sons, Ltd.
Down‐regulation of Bcl‐2 enhances autophagy activation and cell death induced by mitochondrial dysfunction in rat striatum
Authors: Zhang Xing‐Ding , Wang Ye , Wu Jun‐Chao , Lin Fang , Han Rong , Han Feng , Fukunaga Kohji , Qin Zheng‐Hong 
Published: June 2009

AbstractIn vivo administration of the mitochondrial inhibitor 3‐nitropropionic acid (3‐NP) produces striatal pathology mimicking Huntington's disease (HD). However, the mechanisms of cell death induced by metabolic impairment are not fully understood. Previous studies showed that 3‐NP triggered p53‐depedent autophagy activation and cell death. The present study investigated the contribution of the Bcl‐2 signaling pathway to autophagy activation and cell death induced by 3‐NP. Rat striatum was intoxicated with 3‐NP by stereotaxic injection. 3‐NP up‐regulated the expression of the autophagic protein beclin 1 but down‐regulated the expression of the antiapoptotic protein Bcl‐2. Pretreatment with the autophagy inhibitor 3‐methyladenine (3‐MA) significantly inhibited the 3‐NP‐induced alterations in beclin 1 and Bcl‐2 protein levels. Similarly, the 3‐NP‐induced decline in Bcl‐2 was also prevented by the lysosomal inhibitor E64, indicating degradation of Bcl‐2 by lysosomes. In agreement with the time course of 3‐NP‐induced cell death, an increase in the release of cytochrome c from mitochondria was observed. 3‐MA also attenuated the 3‐NP‐induced release of cytochrome c. On the other hand, 3‐NP‐induced elevations in proapoptotic protein Bax and autophagic protein beclin 1 and LC3‐II were significantly enhanced by the Bcl‐2‐specific inhibitor HA14‐1. Furthermore, HA14‐1 increased the release of cytochrome c and 3‐NP‐induced striatal damage. These results suggest that induction of autophagy leads to degradation of Bcl‐2. Meanwhile, down‐regulation of Bcl‐2 amplifies autophagy activation and apoptotic signaling. Bcl‐2 thus plays important roles in mitochondria dysfunction‐induced apoptotic death of stritatal neurons by modulating both autophagic and apoptotic processes. © 2009 Wiley‐Liss, Inc.
Spinal anterior horn has the capacity to self‐regenerate in amyotrophic lateral sclerosis model mice
Authors: Miyazaki Kazunori , Nagai Makiko , Morimoto Nobutoshi , Kurata Tomoko , Takehisa Yasushi , Ikeda Yoshio , Abe Koji 
Published: June 2009

AbstractThe exact host environment necessary for neural regeneration in amyotrophic lateral sclerosis (ALS) has not yet been fully elucidated. We first focused on the extracellular matrix proteins in ALS model mice during development of the disease and then attempted to examine whether regeneration occurs in the ALS spinal cord under regenerative conditions. A progressive increase in γ1 laminin (a promoter of regeneration) and a progressive decrease in semaphorin3A (Sema3A; an inhibitor of regeneration) were observed, mainly in the neuropil of the spinal anterior horn from 15 to 18 weeks, when astrocytes began to express both γ1 laminin and Sema3A. On the other hand, a progressive increase in growth‐associated protein 43 (GAP43; synaptic regeneration site) and a progressive decrease in synaptotagmin1 (actual synaptic bouton) were observed in the same areas of the spinal anterior horn from 15 to 18 weeks. Thus, the present data suggest that, although the spinal anterior horn in ALS models loses motor neurons, it initially possesses the capacity to self‐regenerate but displays a progressive loss of ability to regenerate new effective synapses. © 2009 Wiley‐Liss, Inc.