bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of tumor‐associated mutant E‐cadherin variants with defects in exons 8 or 9 on matrix metalloproteinase 3
Authors: Fuchs Margit , Hermannstädter Christine , Specht Katja , Knyazev Pjotr , Ullrich Axel , Rosivatz Erika , Busch Raymonde , Hutzler Peter , Höfler Heinz , Luber Birgit 
Published: August 2004

AbstractTumor progression is characterized by loss of cell adhesion and increase of invasion and metastasis. The cell adhesion molecule E‐cadherin is frequently down‐regulated or mutated in tumors. In addition to down‐regulation of cell adhesion, degradation of the extracellular matrix by matrix metalloproteinases is necessary for tumor cell spread. To investigate a possible link between E‐cadherin and matrix metalloproteinase 3 (MMP‐3), we examined expression of MMP‐3 in human MDA‐MB‐435S cells transfected with wild‐type (wt) or three different tumor‐associated mutant E‐cadherin variants with alterations in exons 8 or 9, originally identified in gastric carcinoma patients. In the presence of wt E‐cadherin, the MMP‐3 protein level was decreased in cellular lysates and in the supernatant where a secreted form of the protein is detectable. Down‐regulation of MMP‐3 was not found in MDA‐MB‐435S transfectants expressing mutant E‐cadherin variants which indicates that E‐cadherin mutations interfere with the MMP‐3 suppressing function of E‐cadherin. The mechanism of regulation of MMP‐3 by E‐cadherin is presently not clear. We have previously found that cell motility is enhanced by expression of the mutant E‐cadherin variants used in this study. Here, we found that application of the synthetic inhibitor of MMP‐3 NNGH and small interfering RNA (siRNA) directed against MMP‐3 reduce mutant E‐cadherin‐enhanced cell motility. Taken together, our results point to a functional link between MMP‐3 and E‐cadherin. MMP‐3 is differentially regulated by expression of wt or mutant E‐cadherin. On the other hand, MMP‐3 plays a role in the enhancement of cell motility by mutant E‐cadherin. Both observations may be highly relevant for tumor progression since they concern degradation of the extracellular matrix and tumor cell spread. © 2004 Wiley‐Liss, Inc.
Sugarcane bagasse hydrolysis with phosphoric and sulfuric acids and hydrolysate detoxification for xylitol production
Authors: Carvalho Walter , Batista Marcio A , Canilha Larissa , Santos Julio C , Converti Attilio , Silva Silvio S 
Published: August 2004

AbstractThe effectiveness of phosphoric acid to release xylose from sugarcane bagasse hemicellulose was assessed through a 23 full factorial design. The maximum xylose concentration in the hydrolysate (17.1 g dm−3) was attained when the bagasse was treated at 160 °C for 60 min, using 70 mg of phosphoric acid per gram of dry‐bagasse. Hydrolysis carried out with sulfuric acid, under optimum conditions previously determined, provided a hydrolysate with a similar xylose concentration (17.2 g dm−3). After vacuum concentration, these hydrolysates were detoxified and used for xylitol production with the yeast Candida guilliermondii. Two different detoxification strategies, which consisted of adjusting the pH of the hydrolysates to 5.5 with either calcium oxide or ammonium hydroxide, both followed by active charcoal adsorption, were tested. The best xylitol productions (18.1 and 19.2 g dm−3) were observed when calcium oxide was used to adjust the pH of both the phosphoric and the sulfuric acid hydrolysates, respectively. Copyright © 2004 Society of Chemical Industry
Contrasting modes of natural selection acting on pigmentation genes in the Drosophila dunni subgroup
Authors: Wilder J.A. , Dyreson E.G. , O'Neill R.J. , Spangler M.L. , Gupta R. , Wilder A.S. , Hollocher H. 
Published: August 2004

AbstractGenes that encode for divergent adaptive traits may have genealogies that contrast with those from loci that are not functionally involved in differentiation. Here, we examine DNA sequence variation among the species of the eastern Caribbean Drosophila dunni subgroup at two loci, yellow and dopa decaboxylase (Ddc), which both play integral roles in pigmentation patterning of adult Drosophila. Phylogenetic analyses of these loci produce gene genealogies with topologies that mirror those described for other nuclear genes: the six morphologically distinct species within the subgroup are divided into only three lineages, with one lineage containing four species that share extensive ancestral polymorphism. At the Ddc locus these major lineages are delineated only by silent site variation. We observe a significantly higher rate of synonymous site divergence than non‐synonymous divergence, consistent with strong purifying selection acting on the locus. In contrast, the yellow locus exhibits patterns of amino acid divergence and nucleotide diversity that are consistent with recent diversifying selection acting in two different lineages. This selection appears to be targeting amino acid variants in the signal sequence of the Yellow protein, a region which is tightly constrained among members of the larger D. cardini radiation. This result highlights not only the potential importance of yellow in the evolution of divergent pigmentation patterns among members of the D. dunni subgroup, but also hints that variation in signal peptide sequences may play a role in phenotypic diversification. J. Exp. Zool. (Mol. Dev. Evol.) 302B:1–14, 2004. © 2004 Wiley‐Liss, Inc.
Human amnion mesenchyme cells express phenotypes of neuroglial progenitor cells
Authors: Sakuragawa Norio , Kakinuma Kenichi , Kikuchi Aiko , Okano Hideyuki , Uchida Saiko , Kamo Isao , Kobayashi Mamoru , Yokoyama Yasunobu 
Published: August 2004

AbstractPrevious studies from our laboratory showed that human amnion epithelial cells (AECs) have multiple functions, such as synthesis and release of catecholamines, acetylcholine, neurotrophic factors, activin, and noggin. In this study, we investigated the identity of neural progenitor cells in human amnion mesenchyme cells (AMCs), which lie immediately adjacent to the AECs. Cryostat sections revealed that vimentin expression was detected in the AMCs and CK19 in AECs. Vimentin‐positive cells made up 97.5% of total cells tested in cultured AMCs. Interestingly, 3.6% of total AMCs expressed the phenotype CK19+/vimentin+, indicating coexpression of epithelial and mesenchyme cell markers. In culturing with bromodeoxyuridine (BrdU) for 24 hr, 66–82% of cells were found to be BrdU positive, suggesting that they have proliferating potency. By using RT‐PCR, AMCs express mRNA of nestin and Musashi1. With a neural cell differentiating protocol, cell bodies extended long bipolar or complex multipolar processes. Nestin (87.7% of total cells tested) and Musashi1 (93.1%) were expressed in undifferentiated cells, and their positively stained cells increased in number slightly after induction. Undifferentiated cells were stained by anti‐Tuj1 and NF‐M, and their positively stained cells increased significantly in number after induction, to 72.8% and 46.0%, respectively. Meanwhile, glial fibrillary acidic protein‐positive cells increased from 25.4% to 43.2% after induction. These studies demonstrate that AMCs have phenotypes of neuroglial progenitor cells and can be differentiated into neuroglial phenotypes by optimal differentiation protocol. Eventually, AMC‐derived stem cells may be a favorable cell vehicle in regenerative medicine. © 2004 Wiley‐Liss, Inc.An Erratum has been published for this article in J Neurosci Res 79: 725, 2005.
Hormonal control of somatic cell oocyte interactions during ovarian follicle development
Authors: Combelles Catherine M.H. , Carabatsos Mary Jo , Kumar T. Rajendra , Matzuk Martin M. , Albertini David F. 
Published: August 2004

AbstractIn the mammalian ovarian follicle, paracrine signaling between the oocyte and somatic granulosa cells is bidirectional but the structural basis and physiological regulations of communication between gametic and somatic compartments remain unknown. The present experiments were designed to test the hypothesis that follicle stimulating hormone (FSH) regulates the ability of granulosa cells to make connections with the oocyte. We show that in prepubertal unprimed mice and mice carrying a targeted deletion of the FSHβ subunit gene, granulosa cells exhibit orientation towards the oocyte manifest by the elaboration of transzonal projections (TZPs) and “apical” centrosome positioning at sites of granulosa‐zona contact. In vivo FSH treatment results in a retraction of TZPs. Coincident with TZP retraction induced by FSH are changes in oocyte transcriptional activity and meiotic competence, which suggests one means by which the oocyte‐granulosa cell dialogue may be modulated during development of ovarian follicles. Mol. Reprod. Dev. 69: 347–355, 2004. © 2004 Wiley‐Liss, Inc.
Birth of calves expressing the enhanced green fluorescent protein after transfer of fresh or vitrified/thawed blastocysts produced by somatic cell nuclear transfer
Authors: Gong Guochun , Dai Yunping , Fan Baoliang , Zhu Huabing , Zhu Shien , Wang Haiping , Wang Lili , Tang Bo , Li Rong , Wan Rong , Liu Ying , Huang Yinhua , Zhang Lei , Sun Xiuzhu , Li Ning 
Published: August 2004

AbstractThe present study examined effects of genetic manipulation and serum starvation on in vitro developmental potential of bovine somatic cell nuclear transfer (SCNT) embryos and vitrification on in vivo developmental competence of transgenic SCNT blastocysts. Fetal oviduct epithelial cells (FOECs) were isolated from the oviduct of a Day 147 bovine fetus and transfected with a plasmid (pCE‐EGFP‐IRES‐NEO) containing the enhanced green fluorescent protein (EGFP) and neomycin‐resistant (Neor) genes. There were no significant differences (P > 0.05) in cleavage rates or development rates to the blastocyst stage for SCNT embryos derived from FOECs (72.5 and 47.8%, respectively) or transfected FOECs (TFOECs, 73.8 and 47.7%, respectively); nor from serum‐fed (73.6 and 47.2%, respectively) or serum‐starved (72.7 and 48.3%, respectively) cells. Seventeen of Day 7 GFP‐embryos (eight fresh blastocysts and nine vitrified/thawed blastocysts ) were transferred to recipients with one embryo per recipient. Two (25%) recipients were confirmed pregnant at Day 60 in fresh blastocysts group, and three recipients (33%) were confirmed pregnant at Day 60 in vitrified/thawed blastocysts group. Two healthy calves (25%) were obtained from fresh blastocysts and one (11%) from vitrified/thawed blastocysts. Microsatellite analysis confirmed that the three clones were genetically identical to the donor cells. Moreover, PCR and Southern blot demonstrated integration of transgene in genomic DNA of all three cloned calves. Expression of GFP in skin biopsies isolated from transgenic cloned calves and fibroblasts derived from the skin biopsies revealed the activity of EGFP gene, and G418 resistance in vitro of these fibroblasts confirmed the activity of Neor gene. Our results show that genetic manipulation and serum starvation of donor cells (FOECs) do not affect in vitro developmental competence of bovine SCNT embryos, and vitrified transgenic SCNT blastocysts can develop to term successfully. Mol. Reprod. Dev. 69: 278–288, 2004. © 2004 Wiley‐Liss, Inc.
Macaque sperm release ESP13.2 and PSP94 during capacitation: The absence of ESP13.2 is linked to sperm‐zona recognition and binding
Authors: Tollner Theodore L. , Yudin Ashley I. , Treece Cathy A. , Overstreet James W. , Cherr Gary N. 
Published: August 2004

AbstractESP13.2 coats the entire surface of macaque sperm and remains until sperm become capacitated (Yudin et al., 2003: Biol Reprod 69: 1118–1128). Capacitation of macaque sperm is synchronized by treatment with dibutyrl cAMP (dbcAMP) and caffeine. ESP13.2 and PSP94 constituted ∼95% of the proteins released from the sperm surface following treatment with caffeine + dbcAMP. Caffeine and dbcAMP alone induce different patterns of ESP13.2 release. As determined by ELISAs of supernatants and immuno‐fluorescent labeling of sperm heads, caffeine alone and caffeine + dbcAMP induced comparable release of ESP13.2, while dbcAMP‐treated sperm did not differ from controls. Sperm treated with caffeine + dbcAMP showed a reduction of ESP13.2 from the entire surface, while caffeine treatment alone induced removal of ESP13.2 from the sperm head and midpiece. As confirmed with immunofluorescence, ESP13.2 could be added back to the surfaces of sperm that had been previously exposed to caffeine. Treatment with caffeine significantly increased the number of sperm that bound tightly to the zona pellucida as compared with controls (42 ± 9 and 13 ± 3 sperm/zona, respectively; P ≤ 0.01). This increase in binding was inhibited by “adding back” ESP13.2 to the sperm surface (12.8 ± 3; P ≤ 0.01). Alexa‐conjugated anti‐ESP13.2 Ig labeling of live sperm showed that only sperm lacking ESP13.2 over the head were capable of tight binding to the zona. Our results suggest that ESP13.2 masks zona pellucida ligands on the sperm surface and its release, as part of capacitation, is required for sperm–zona interaction. Mol. Reprod. Dev. 69: 325–337, 2004. © 2004 Wiley‐Liss, Inc.
Regulation of cleavage by protein kinase C in Chaetopterus
Authors: Yang Dazhi , Hinton Shantá D. , Eckberg William R. 
Published: August 2004

AbstractWe report that protein kinase C (PKC) plays a regulatory role in early cleavage in Chaetopterus eggs. Using Western blotting, we assayed the expression patterns of conventional PKCs (cPKC), novel PKCs (nPKC), and atypical PKCs (aPKC). During early development after fertilization, PKC protein levels varied independently by isoform. PKC protein expression during differentiation, without cleavage and after parthenogenetic activation, was very similar to that during normal development indicating that PKC gene expression does not require cellularization. Since PKC has been shown to regulate meiosis in this organism, we also assayed the membrane association of these isoforms as an indicator of their activation during meiosis and early cleavage. PKC‐γ transiently associated with membranes and therefore became activated before meiotic division and cleavage, whereas PKC‐α and ‐β transiently dissociated from membranes and therefore became inactivated at these times. Inhibition of these PKC isoforms by bisindolylmaleimide I had no effect on cleavage or early development to the trochophore larva, indicating that PKC‐γ activation is not essential for cleavage or early development. However, their persistent activation by thymeleatoxin blocked cleavage. The results indicate that the dissociation of PKC‐α and/or ‐β from the membrane fraction, and therefore their inactivation, is essential for normal cleavage. Elevated PKC activity is essential for nuclear envelope breakdown and spindle formation at meiosis I. By contrast, down‐regulation of this activity is essential for cleavage after fertilization. Mol. Reprod. Dev. 69: 308–315, 2004. © 2004 Wiley‐Liss, Inc.
Molecular modification of Penaeus monodon sperm in female thelycum and its consequent responses
Authors: Vanichviriyakit Rapeepun , Kruevaisayawan Hathairat , Weerachatyanukul Wattana , Tawipreeda Pattira , Withyachumnarnkul Boonsirm , Pratoomchat Boonyarath , Chavadej Jittipan , Sobhon Prasert 
Published: August 2004

AbstractUsing Penaeus monodon as the model, we demonstrated the molecular changes and the mechanism of thelycal‐dependent sperm modification resulting in an enhanced acrosome reaction (AR) response. Attention was paid to the modification of the sperm plasma membrane which was mediated through an adsorption or removal of sperm peripheral and integral membrane proteins as indicated by the different profiles of these proteins in spermatophore (S) and thelycal (T) sperm. In vitro adsorption of Alexa‐488 conjugated T proteins onto the entire S‐sperm surface confirmed protein transfer in a time–dependent manner. Specific anchoring of 83 and 140 kDa proteins to sperm peripheral proteins as well as 53/55 and 60 kDa proteins to sperm lipids was demonstrated. Apart from membrane modification, a substantial increase in protein tyrosine phosphorylation was shown to be closely associated with T‐dependent sperm modification event. The physiological significance of this sperm modification in enhancing sperm AR response, which required at least 3 days of T residence in order for the sperm to gain a complete AR response, was also elucidated. Mol. Reprod. Dev. 69: 356–363, 2004. © 2004 Wiley‐Liss, Inc.
Expression of HSP70/HSC70 in swine blastocysts: Effects of oxidative and thermal stress
Authors: Bernardini Chiara , Fantinati Paolo , Zannoni Augusta , Forni Monica , Tamanini Carlo , Bacci Maria Laura 
Published: August 2004

AbstractStress proteins are induced in response to a wide range of biological and physicochemical stresses; HSC70 (constitutive) and HSP70 (inducible) belong to the HSP70 stress protein family. The present study aimed at investigating whether environmental stress, particularly thermal and oxidative stress, is involved in modulating HSP70/HSC70 expression in in vitro porcine embryos from two/four cell stage to blastocyst. For oxidative stress, embryos were cultured at 38.5°C under a 5% O2–5% CO2 atmosphere or 5% CO2 in air (approximately 20% O2); for thermal stress, embryos were cultured at 38.5°C under 5% O2, 5% CO2, and exposed to heat shock (1 hr at 42°C). At the end of culture, embryos were analysed by Western blotting, using specific antibodies discriminating HSP70 from HSC70. Embryos cultured under 20% O2 showed HSC70 levels significantly higher (P < 0.005) than embryos cultured under 5% O2, while heat shocked embryos presented HSP70 levels higher (P < 0.01) than control group. In addition, the developmental rate of embryos was negatively affected by the higher oxygen tension (P < 0.05). Our data indicate that porcine embryos express both HSP70 and HSC70 and could differentially respond to both oxidative and heat stress by up‐regulating HSC70 and HSP70, respectively. Mol. Reprod. Dev. 69: 303–307, 2004. © 2004 Wiley‐Liss, Inc.
Transcription factor sox‐2 inhibits co‐activator stimulated transcription
Authors: Bernadt Cory T. , Nowling Tamara , Rizzino Angie 
Published: August 2004

AbstractPrevious studies have shown that transcription of the fibroblast growth factor‐4 (FGF‐4) gene by early embryonic cells is dependent upon a powerful distal enhancer located 3 kb downstream of the transcription start site within the untranslated region of the last exon. The transcription factors Sox‐2 and Oct‐3 cooperatively bind to critical cis‐regulatory elements within the enhancer to synergistically activate transcription. Moreover, the co‐activator p300 can mediate the synergistic activity of Sox‐2 and Oct‐3, and p300 associates with the FGF‐4 enhancer in vivo. Embryonal carcinoma (EC) cells have been used extensively as a model system to study the regulation of the FGF‐4 gene during early development. Recently, it has been suggested that suboptimal levels of Sox‐2 expression in F9 EC cells limit the transcription of the FGF‐4 gene. The studies presented in this report argue that Sox‐2 levels are not limiting in F9 EC cells. Moreover, overexpression of Sox‐2 in F9 EC cells decreases FGF‐4 promoter activity. In addition, overexpression of Sox‐2 in these cells inhibits activation by the co‐activators p300, CBP, and OCA‐B in a manner that requires the transactivation domain of Sox‐2. These findings suggest that Sox‐2 levels in F9 EC cells are regulated carefully to avoid interference with the transcription of critical genes. Mol. Reprod. Dev. 69: 260–267, 2004. © 2004 Wiley‐Liss, Inc.
A mass spectrometric “Western blot” to evaluate the correlations between histone methylation and histone acetylation
Authors: Zhang Kangling , Siino Joseph S. , Jones Patrick R. , Yau Peter M. , Bradbury E. Morton 
Published: August 2004

AbstractHistone acetylation, methylation, and phosphorylation occur predominantly in the unstructured N‐terminal domains or histone “tails”. These modifications and others comprise a “histone code” that directly facilitates or antagonizes association of regulatory proteins with nucleosomes to mediate changes in chromatin structure and activity. Methylation of histone H3 outside of the tail region at lysine 79 has been reported for a variety of species ranging from yeast to humans and in some gene‐specific cases appears to be associated with active chromatin and transcription. Whether methylation of lysine 79 is associated with other post‐translational modifications of the H3 tail is unknown. Using mass spectrometric relative quantitation, a mass spectrometric “Western blot”, we compare methylation at lysines 4, 9, and 79 with acetylation of human histone H3. We find that the total levels of lysine 4 and 79 methylation (combined mono‐, di‐, and trimethylation) in the H3 population increase with the degree of H3 tail acetylation. The total amount of lysine 4 methylation increases progressively from less than 10% in the nonacetylated H3 to greater than 90% in the penta‐acetylated H3. In addition, significant levels of lysine 4 trimethylation also occur in combination with the penta‐acetylated H3 species. In contrast, the level of H3 lysine 9 trimethylation is greatest for the monoacetylated species while H3 lysine 9 acetylation occurs predominantly in hyperacetylated (tetra‐ and penta‐acetylated) H3 isoforms. Together, these results indicate that methylation of lysine 4 and 79 as well as the switch from lysine 9 methylation to acetylation are coordinated synchronously with H3 hyperacetylation as marks of active chromatin.
Protein identification and tracking in two‐dimensional electrophoretic gels by minimal protein identifiers
Authors: Mattow Jens , Schmidt Frank , Höhenwarter Wolfgang , Siejak Frank , Schaible Ulrich E. , Kaufmann Stefan H.E. 
Published: August 2004

AbstractProtein identification by matrix‐assisted laser desorption/ionization mass‐spectrometry peptide mass fingerprinting (MALDI‐MS PMF) represents a cornerstone of proteomics. However, it often fails to identify low‐molecular‐mass proteins, protein fragments, and protein mixtures reliably. To overcome these limitations, PMF can be complemented by tandem mass spectrometry and other search strategies for unambiguous protein identification. The present study explores the advantages of using a MALDI‐MS‐based approach, designated minimal protein identifier (MPI) approach, for protein identification. This is illustrated for culture supernatant (CSN) proteins of Mycobacterium tuberculosis H37Rv after separation by two‐dimensional gel electrophoresis (2‐DE). The MPI approach takes into consideration that proteins yield characteristic peptides upon proteolytic cleavage. In this study, peptide mixtures derived from tryptic protein cleavage were analyzed by MALDI‐MS and the resulting spectra were compared with template spectra of previously identified counterparts. The MPI approach allowed protein identification by few protein‐specific signature peptide masses and revealed truncated variants of mycobacterial elongation factor EF‐Tu, previously not identified by PMF. Furthermore, the MPI approach can be employed to track proteins in 2‐DE gels, as demonstrated for the 14 kDa antigen, the 10 kDa chaperone, and the conserved hypothetical protein Rv0569 of M. tuberculosis H37Rv. Furthermore, it is shown that the power of the MPI approach strongly depends on distinct factors, most notably on the complexity of the proteome analyzed and accuracy of the mass spectrometer used for peptide mass determination.