bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flow‐dependent regulation of angiopoietin‐2
Authors: Goettsch Winfried , Gryczka Corina , Korff Thomas , Ernst Evelyn , Goettsch Claudia , Seebach Jochen , Schnittler Hans‐Joachim , Augustin Hellmut G. , Morawietz Henning 
Published: October 2007

AbstractEndothelial cells are constantly exposed to high or low shear stress in arteries and veins by the flowing blood. Angiopoietin‐2 (Ang‐2) is acting as a critical regulator of vessel maturation and endothelial cell quiescence. In this study, flow‐dependent regulation of Ang‐2 was analyzed in vitro and in vivo. Ang‐2 mRNA, protein expression and release was upregulated by 24 h of low (1 dyne/cm2), but downregulated by high flow (30 dyne/cm2) in human endothelial cells. Increased endothelial NO synthase expression and NO formation was not affecting regulation of Ang‐2 by low or high flow. Low and high flow increased VEGF‐A expression. Inhibition of VEGFR‐2 prevented upregulation of Ang‐2 by low flow, but not downregulation of Ang‐2 by high flow. Furthermore, upregulation of Ang‐2 by VEGF was reduced by application of high flow. Forkhead box O (FOXO) transcription factor FOXO1 has been shown to regulate Ang‐2 expression in endothelial cells. FOXO1 binding activity was reduced by high flow. Nuclear localization of transcription factor FOXO1 was not changed by low flow, but reduced by high flow. In vivo, Ang‐2 was higher expressed in veins compared to arteries. Arterial ligation augmented Ang‐2 expression in distal arterial low flow areas. Our results support a VEGF‐dependent induction of Ang‐2 in low flow areas, and FOXO1‐dependent downregulation of Ang‐2 in high flow areas. These data suggest a new mechanism of flow‐dependent regulation of vessel stability and differentiation. J. Cell. Physiol. 214: 491–503, 2008. © 2007 Wiley‐Liss, Inc.
Functional characterization and cloning of amino acid transporter B0,+ (ATB0,+) in primary cultured rat pneumocytes
Authors: Uchiyama Tomomi , Fujita Takuya , Gukasyan Hovhannes J. , Kim Kwang‐Jin , Borok Zea , Crandall Edward D. , Lee Vincent H.L. 
Published: October 2007

AbstractCationic amino acid transport in primary cultured rat pneumocytes exhibiting characteristics of alveolar epithelial type I‐like cells are described. Asymmetry and activator ion dependency of 3H‐L‐arginine uptake were characterized from the apical or basolateral fluid of pneumocytes grown on permeable support. Substrate specificity of transport was evaluated as a function of 3H‐L‐arginine uptake inhibition in the presence of other amino acids. Transepithelial transport studies estimated 3H‐L‐arginine flux in the apical‐to‐basolateral and basolateral‐to‐apical directions. Full length cDNA of rat amino acid transporter B0,+ (rATB0,+) was cloned and its relative expression level studied. Results indicate that uptake of 3H‐L‐arginine from apical fluid is dependent on Na+ and Cl−. Zwitterionic and cationic amino acids (excluding L‐proline and anionic amino acids) inhibited uptake of 3H‐L‐arginine from apical, but not basolateral incubation fluid. Apical‐to‐basolateral transepithelial flux of 3H‐L‐arginine was 20× higher than basolateral‐to‐apical transport. Kinetic studies of 3H‐L‐arginine uptake from apical fluid revealed maximal velocity (Vmax) and Michaelis–Menten constants (Kt) of 33.32 ± 2.12 pmol/mg protein/15 min and 0.50 ± 0.11 mM, respectively, in a cooperative process having a coupling ratio of 1.18 ± 0.16 with Na+ and 1.11 ± 0.13 with Cl−. Expression of rATB0,+ mRNA was identified by RT‐PCR and Northern analysis. Corresponding cloned 3.2 kb rATB0,+ cDNA sequence exhibits pronounced homology in deduced amino acid sequence to mouse (95% identity and 97% similarity) and human (89% identity and 95% similarity) ATB0,+ homologues. We conclude that rat pneumocytes express ATB0,+, which may partly contribute towards recovering cationic and neutral amino acids from alveolar luminal fluid. J. Cell. Physiol. 214: 645–654, 2008. © 2007 Wiley‐Liss, Inc.
xRic‐8 is a GEF for Gsα and participates in maintaining meiotic arrest in Xenopus laevis oocytes
Authors: Romo Ximena , Pastén Pamela , Martínez Silvana , Soto Ximena , Lara Pablo , de Arellano Antonieta Ramírez , Torrejón Marcela , Montecino Martín , Hinrichs María Victoria , Olate Juan 
Published: October 2007

AbstractImmature stage VI Xenopus oocytes are arrested at the G2/M border of meiosis I until exposed to progesterone, which induces meiotic resumption through a non‐genomic mechanism. One of the earliest events produced by this hormone is inhibition of the plasma membrane enzyme adenylyl cyclase (AC), with the concomitant drop in intracellular cAMP levels and reinitiation of the cell cycle. Recently Gsα and Gβγ have been shown to play an important role as positive regulators of Xenopus oocyte AC, maintaining the oocyte in the arrested state. However, a question that still remains unanswered, is how the activated state of Gsα and Gβγ is achieved in the immature oocyte, since no receptor or ligand have been found to be required. Here we provide evidence that xRic‐8 can act in vitro and in vivo as a GEF for Gsα. Overexpression of xRic‐8, through mRNA injection, greatly inhibits progesterone induced oocyte maturation and endogenous xRic‐8 mRNA depletion, through siRNA microinjection, induces spontaneous oocyte maturation. These results suggest that xRic‐8 is participating in the immature oocyte by keeping Gsα‐Gβγ‐AC signaling complex in an activated state and therefore maintaining G2 arrest. J. Cell. Physiol. 214: 673–680, 2008. © 2007 Wiley‐Liss, Inc.
Epidermal growth factor upregulates motility of Mat‐LyLu rat prostate cancer cells partially via voltage‐gated Na+ channel activity
Authors: Ding Yanning , Brackenbury William J. , Onganer Pinar U. , Montano Ximena , Porter Louise M. , Bates Lucy F. , Djamgoz Mustafa B.A. 
Published: October 2007

AbstractThe main aim of this investigation was to determine whether a functional relationship existed between epidermal growth factor (EGF) and voltage‐gated sodium channel (VGSC) upregulation, both associated with strongly metastatic prostate cancer cells. Incubation with EGF for 24 h more than doubled VGSC current density. Similar treatment with EGF significantly and dose‐dependently enhanced the cells' migration through Transwell filters. Both the patch clamp recordings and the migration assay suggested that endogenous EGF played a similar role. Importantly, co‐application of EGF and tetrodotoxin, a highly selective VGSC blocker, abolished 65% of the potentiating effect of EGF. It is suggested that a significant portion of the EGF‐induced enhancement of migration occurred via VGSC activity. J. Cell. Physiol. 215: 77–81, 2008. © 2007 Wiley‐Liss, Inc.
Protein kinase A and mitogen‐activated protein kinase pathways mediate cAMP induction of α‐Epithelial Na+ channels (α‐ENaC)
Authors: Mustafa Shamimunisa B. , Castro Robert , Falck Alison J. , Petershack Jean A. , Henson Barbara M. , Mendoza Yvonne M. , Choudary Ahsan , Seidner Steven R. 
Published: October 2007

AbstractA major mechanism for Na+ transport across epithelia occurs through epithelial Na+ channels (ENaC). ENaC is a multimeric channel consisting of three subunits (α, β, and γ). The α‐subunit is critical for ENaC function. In specific culture conditions, the rat submandibular gland epithelial cell line (SMG‐C6) demonstrates minimal Na+ transport properties and exposure to dibutyryl cAMP (DbcAMP) for up to 48 h caused an elevation of α‐ENaC mRNA and protein expression and amiloride‐sensitive short‐circuit current (ISC). Here we examined the early signaling pathways evoked by DbcAMP which contribute to the eventual increase in Na+ transport is present. Treatment with either of the protein kinase A (PKA) inhibitors KT5720 or H‐89 followed by exposure to 1 mM DbcAMP for 24 h markedly attenuated DbcAMP‐induced α‐ENaC protein formation and ISC. Exposure of SMG‐C6 cells to 1 mM DbcAMP induced a rapid, transient phosphorylation of the cAMP response element binding protein (CREB). This response was attenuated in the presence of either KT5720 or H‐89. Dominant‐negative CREB decreased DbcAMP‐induced α‐ENaC expression. Suppression of the extracellular signal‐regulated protein kinase (ERK 1,2) with PD98059 or the p38 mitogen‐activated protein kinase (MAPK) pathway with SB203580 reduced DbcAMP‐induced α‐ENaC protein levels in SMG‐C6 cells. DbcAMP‐induced phosphorylation of CREB was markedly attenuated by PD98059 or SB203580. DbcAMP‐induced activation of the either the p38 or the ERK 1,2 MAPK pathways was abolished by either of the PKA inhibitors, H‐89 or KT5720. Cross talk between these signaling pathways induced by DbcAMP via the activation of CREB appears to contribute to increased levels of α‐ENaC observed after 24 h of treatment in SMG‐C6 epithelial cells. J. Cell. Physiol. 215: 101–110, 2008. © 2007 Wiley‐Liss, Inc.
Centrosome duplication proceeds during mimosine‐induced G1 cell cycle arrest
Authors: Durcan Thomas M. , Halpin Elizabeth S. , Casaletti Luciana , Vaughan Kevin T. , Pierson Maggie R. , Woods Shane , Hinchcliffe Edward H. 
Published: October 2007

AbstractCentrosome duplication must remain coordinated with cell cycle progression to ensure the formation of a strictly bipolar mitotic spindle, but the mechanisms that regulate this coordination are poorly understood. Previous work has shown that prolonged S‐phase is permissive for centrosome duplication, but prolonging either G2 or M‐phase cannot support duplication. To examine whether G1 is permissive for centrosome duplication, we release serum‐starved G0 cells into mimosine, which delays the cell cycle in G1. We find that in mimosine, centrosome duplication does occur, albeit slowly compared with cells that progress into S‐phase; centrosome duplication in mimosine‐treated cells also proceeds in the absence of a rise in Cdk2 kinase activity normally associated with the G1/S transition. CHO cells arrested with mimosine can also assemble more than four centrioles (termed “centrosome amplification”), but the extent of centrosome amplification during prolonged G1 is decreased compared to cells that enter S‐phase and activate the Cdk2‐cyclin complex. Together, our results suggest a model, which predicts that entry into S‐phase and the rise in Cdk2 activity associated with this transition are not absolutely required to initiate centrosome duplication, but rather, serve to entrain the centrosome reproduction cycle with cell cycle progression. J. Cell. Physiol. 215: 182–191, 2008. © 2007 Wiley‐Liss, Inc.
Systemically transplanted bone marrow stromal cells contributing to bone tissue regeneration
Authors: Li S. , Tu Q. , Zhang J. , Stein G. , Lian J. , Yang P.S. , Chen J. 
Published: October 2007

AbstractBone marrow stromal cells (BMSCs) are a rich source of osteogenic progenitor cells. A fundamental question is whether systemically transplanted BMSCs participate in bone regeneration. Luciferase and GFP double‐labeled BMSCs were transplanted into irradiated mice. Five weeks after transplantation, artificial bone wounds were created in the mandibles and calvaria of the recipients. Animals were sacrificed at weeks 2, 4, and 6 after surgery and the expressions of luciferase and GFP were determined using Xenogen IVIS Imaging System, immunohistochemical staining and RT‐PCR. The results demonstrated that transplanted BMSCs can be detected in wound sites as early as 2 weeks and lasted the whole experimental period. Luciferase expression peaked at 2 weeks after surgery and decreased thereafter, exhibiting a similar expression pattern as that of BSP, while GFP expression was relatively stable during the experimental period. In conclusion, BMSCs can migrate to bone wound sites and participate in bone regeneration in orocraniofacial region. J. Cell. Physiol. 215: 204–209, 2008. © 2007 Wiley‐Liss, Inc.
Regulation of collagen gene expression in the Tsk2 mouse
Authors: Barisic‐Dujmovic Tatjana , Boban Ivana , Clark Stephen H. 
Published: October 2007

AbstractThe tight skin 2 (Tsk2) mutation is an ENU induced dominant mutation localized on mouse chromosome 1. While the molecular defect is unknown, Tsk2/+ mice display cutaneous thickening associated with excessive matrix production and are used as a model of scleroderma. The purpose of this study was to examine the cellular mechanisms associated with the excessive synthesis of matrix macromolecules using a collagen promoter GFP reporter transgene (pOBCol3.6GFP) as a marker of Col1a1 expression. This analysis of pOBCol3.6GFP expression in Tsk2/+ skin showed an increase in transgene activity compared to wild‐type (+/+) samples. In addition, an increased area of “high” GFP fluorescence in Tsk2/+ dermis in both 1‐ and 4‐month‐old mice was observed that was also associated with an increased number of dermal fibroblasts per unit area of dermis. These data collectively suggest an important mechanism of Tsk2/+ skin fibrosis; an increased number of collagen expressing cells as well as elevated collagen expression on a per cell basis. During this study it was noted that Tsk2/+ mice appeared consistently smaller than wild‐type (+/+) siblings and measurements of body length revealed a decrease (5–10%) in 1‐ and 2‐month‐old Tsk2/+ mice as well as a decrease in body weight in both age groups as compared to wild‐type (+/+) control mice. Femur length was also decreased (2–9%) in Tsk2/+ mice. Finally, in contrast to Tsk/+ mice that display an emphysema‐like lung pathology, histological sections of lungs from Tsk2/+ mice were normal and indistinguishable from wild‐type (+/+) controls. J. Cell. Physiol. 215: 464–471, 2008. © 2007 Wiley‐Liss, Inc.
Microscopic observation and laser‐controlled microoptothermal drive mechanism
Authors: Zhang Dongxian , Zhang Haijun , Liu Chao , Jiang Jianzhong 
Published: October 2007

AbstractThe mechanism of novel optothermal microactuators (OTA) was analyzed with a microscope system, a charge‐coupled device‐combined light microscope, and a computer system. One OTA, two optothermal microswitches (OTS) with different length and shape were machined by an excimer laser micromatching system using single layer material. They all had two thin expansion arms with different widths. The mechanism of the OTA/OTS is that the different optothermal expansion controlled by asymmetric topology and shape of the arms causes a magnified lateral deflection or vibration. A red laser diode (650 nm) with maximum power output of 30 mW was employed as the external power source to drive the OTA/OTS. Experiments were carried out with the microscope system, and serial images and videos were acquired. The results indicate that the structure of the OTA/OTS is simple and easy to be manufactured. They can practically generate an obvious lateral deflection or vibration. When the location of the laser spot on the OTA changed, the direction of its deflection is also changed. When the value of laser power that irradiated on the OTS increased, the lateral deflection of the OTS enlarged, the maximum could be larger than 30 μm. This kind of novel microactuator has the advantages of remote wireless controlling, large displacement, simple structure, easy to be machined, and therefore will be quite useful for the practical applications in the fields of micro/nanotechnology. Microsc. Res. Tech., 2008. © 2007 Wiley‐Liss, Inc.
Enhanced contraceptive response by co‐immunization of DNA and protein vaccines encoding the mouse zona pellucida 3 with minimal oophoritis in mouse ovary
Authors: Li Jinyao , Jin Huali , Zhang Ailian , Li Yijie , Wang Bin , Zhang Fuchun 
Published: October 2007

AbstractZona pellucida 3 (ZP3) acts as the primary sperm receptor, induces autoantibody that can prevent oocyte fertilization and has been proposed as a vaccine candidate for contraception in humans. Due to the elicited autoreactive T cell inflammation that causes ovarian destruction, ZP3‐based vaccine with removed T epitopes from the ZP3 is considered as a preferred approach. We present here a new strategy to eliminate the T cell inflammation while retaining a high level of antibody by co‐immunization of mZP3 DNA and protein vaccines, which resulted in a higher reduction rate of fertility in this group. Histological analysis showed that there were normal follicular developments of infertile mice in the co‐immunized group; while other vaccine groups of the most infertile mice lacked mature follicles. There was a significant correlation between normal follicular development and the inhibition of T cell response in co‐immunized mice. At the same time, co‐immunization reduced the production of inflammatory cytokine, IFN‐γ, and increased the productions of IL‐10 and FoxP3 in CD4 T cells, suggesting the anti‐inflammation may be via a T regulatory function. The results indicate that co‐immunization of mZP3 DNA‐ and protein‐based vaccines can reduce fertility without interfering with the normal follicular development and present a novel strategy to develop a contraceptive vaccine in humans. Copyright © 2007 John Wiley & Sons, Ltd.
Proteomic analysis of the cortisol‐mediated stress response in THP‐1 monocytes using DIGE technology
Authors: Billing Anja M. , Fack Fred , Renaut Jenny , Olinger Christophe M. , Schote Andrea B. , Turner Jonathan D. , Muller Claude P. 
Published: October 2007

AbstractThe glucocorticoid (GC) cortisol, the main mediator of the hypothalamic‐pituitary‐adrenal axis has many implications in metabolism, stress response and the immune system. Its function is mediated via binding to the glucocorticoid receptor (GR), a member of the superfamily of ligand‐activated nuclear hormone receptors. The activity of the ligated GR results from its binding as a transcription factor to glucocorticoid response elements (GREs). Two‐dimensional gel electrophoresis with DIGE (fluorescence difference gel electrophoresis) technology was applied to study the effects of cortisol on the human THP‐1 monocytic cell line. A total of 28 cortisol‐modulated proteins were identified belonging to five functional groups: cytoskeleton (8), chaperones (9), immune response (4), metabolism (3) and transcription/translation (4). Their corresponding genes were screened for putative GREs in their + 10 kb/− 0.2 kb promoter regions including all alternative promoters available within the Database for Transcription Start Sites (DBTSS). FKBP51, known to be induced by cortisol, was identified as the strongest differentially expressed protein, and contains the highest number of strict GREs. Genomic analysis of five alternativeFKBP5promoter regions suggests GC inducibility of all transcripts. Additionally, proteomics (2D DIGE and 2D immunoblotting) revealed the existence of several FKBP51 isoforms, which were not previously described. To our knowledge this is the first proteomic study that addresses the effects of cortisol on immune cells. FKBP51 isoforms found on the gel map were linked to alternative promoter usage on the genetic level, successfully correlating both the specific proteomic and genomic findings. Copyright © 2007 John Wiley & Sons, Ltd.
Application of two‐dimensional electrophoresis and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry for proteomic analysis of the sexually transmitted parasite Trichomonas vaginalis
Authors: De Jesus Jose Batista , Cuervo Patricia , Junqueira Magno , Britto Constança , Silva‐Filho Fernando Costa , Sabóia‐Vahia Leonardo , González Luis Javier , Barbosa Domont Gilberto 
Published: October 2007

AbstractTrichomonas vaginalis is a sexually transmitted protozoan parasite that infects the human urogenital tract causing trichomoniasis, a worldwide disease. In this work, a fresh clinical isolate of T. vaginalis was used for study of the protein expression in this species. Two‐dimensional gel electrophoresis (2‐DE) and MALDI‐TOF/TOF mass spectrometry (MS) were employed to create a reference map of soluble proteins in the pH range 4–7. A set of 116 proteins belonging to functional classes expressed in high and low abundance was identified by peptide mass fingerprinting and tandem MS. These identifications corresponded to 67 different proteins, suggesting that post‐translational modifications are common phenomena in T. vaginalis. Identified proteins were classified into 16 groups according to biological processes. Among detected proteins we identified the major enzymes involved in both cytosolic and hydrogenosomal metabolic pathways, as well as putative protein targets for new drug design. In addition, this analysis allows validation of previous gene predictions confirming the expression of 15 hypothetical proteins. Finally, the findings here reported represent the first reference proteome map of T. vaginalis and the first steps towards the description of a comprehensive proteome map of this parasite. Copyright © 2007 John Wiley & Sons, Ltd.
LC‐MSMS identification of Arabidopsis thaliana heat‐stable seed proteins: Enriching for LEA‐type proteins by acid treatment
Authors: Oliveira E. , Amara I. , Bellido D. , Odena M. A. , Domínguez E. , Pagès M. , Goday A. 
Published: October 2007

AbstractProtein identification in systems containing very highly abundant proteins is not always efficient and usually requires previous enrichment or fractionation steps in order to uncover minor proteins. In plant seeds, identification of late embryogenesis abundant (LEA) proteins is often masked by the presence of the large family of storage proteins. LEA‐proteins are predicted to play a role in plant stress tolerance. They are highly hydrophilic proteins, generally heat‐stable, and correlate with dehydration in seeds or vegetative tissues. In the present work, we analyze the protein composition of heat‐stable Arabidopsis thaliana seed extracts after treatment with trichloroacetic acid (TCA). The composition of the proteins that precipitate and those that remain in solution in 3% TCA was analyzed by two different approaches: 1D SDS‐PAGE coupled to LC‐ESI‐MSMS analysis and a gel‐free protocol associated with LC‐MALDI‐MSMS.Our results indicate that treating total heat‐soluble extracts with 3% TCA is an effective procedure to remove storage proteins by selective precipitation and this fractionation step provides a soluble fraction highly enriched in Lea‐type proteins. The analysis and determination of protein identities in this acid‐soluble fraction by MS technology is a suitable system for large‐scale identification of Lea‐proteins present in seeds. Copyright © 2007 John Wiley & Sons, Ltd.
Systematic determination of ion score cutoffs based on calculated false positive rates: application for identifying ubiquitinated proteins by tandem mass spectrometry
Authors: Vasilescu Julian , Smith Jeffrey C. , Zweitzig Daniel R. , Denis Nicholas J. , Haines Dale S. , Figeys Daniel 
Published: October 2007

AbstractWe report a simple approach for determining ion score cutoffs that permit the confident identification of ubiquitinated proteins by tandem mass spectrometry (MS/MS). Initial experiments involving the analysis of gel bands containing multi‐Ubiquitin chains with quadrupole time‐of‐flight and quadrupole ion trap mass spectrometers revealed that standard ion score cutoffs used for database searching were not sufficiently stringent. We also found that false positive and false negative rates (FPR and FNR) varied significantly depending on the cutoff scores used and that appropriate cutoffs could only be determined following a systematic evaluation of false positive rates. When standard cutoff scores were used for the analysis of complex mixtures of ubiquitinated proteins, unacceptably high FPR were observed. Finally, we found that FPR for ubiquitinated proteins are affected by the size of the protein database that is searched. These observations may be applicable for the study of other post‐translational modifications. Copyright © 2007 John Wiley & Sons, Ltd.