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Find video protocols related to scientific articles indexed in Pubmed.
[Preliminary study of combining T2-weighted imaging, diffusion weighted imaging and dynamic contrast enhanced-magnetic resonance imaging for diagnosing prostatic central gland cancer].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 11-18-2014
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To explore the value of combining T2-weighted imaging (T2WI), diffusion weighted imaging (DWI) and dynamic contrast enhanced-magnetic resonance imaging (DCE-MRI) for qualitatively diagnosing central gland prostate cancer (CGPCa) as a gold standard with pathologic findings.
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A novel DNA-binding protein, PhaR, plays a central role in the regulation of polyhydroxyalkanoate accumulation and granule formation in the haloarchaeon Haloferax mediterranei.
Appl. Environ. Microbiol.
PUBLISHED: 10-26-2014
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Polyhydroxyalkanoates (PHAs) are synthesized and assembled as PHA granules that undergo well-regulated formation in many microorganisms. However, this regulation remains unclear in haloarchaea. In this study, we identified a PHA granule-associated regulator (PhaR) that negatively regulates the expression of both its own gene and the granule structural gene phaP in the same operon (phaRP) in Haloferax mediterranei. Chromatin immunoprecipitation and quantitative PCR (ChIP-qPCR) assays demonstrated a significant interaction between the PhaR and the phaRP promoter in vivo. Scanning mutagenesis of the phaRP promoter revealed a specific cis-element as the possible binding position of the PhaR. The haloarchaeal homologs of the PhaR contain a novel conserved domain that belongs to a swapped-hairpin barrel fold family found in AbrB-like proteins. Amino acid substitution indicated that this AbrB-like domain is critical for the repression activity of PhaR. In addition, the phaRP promoter had a weaker activity in the PHA-negative strains, implying a function of the PHA granules in titration of the PhaR. Moreover, the H. mediterranei strain lacking phaR was deficient in PHA accumulation and produced granules with irregular shapes. Interestingly, the PhaR itself can promote PHA synthesis and granule formation in a PhaP-independent manner. Collectively, our results demonstrated that the haloarchaeal PhaR is a novel bi-functional protein, which plays the central role in the regulation of PHA accumulation and granule formation in H. mediterranei.
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Hybrid elastin-like polypeptide-polyethylene glycol (ELP-PEG) hydrogels with improved transparency and independent control of matrix mechanics and cell ligand density.
Biomacromolecules
PUBLISHED: 08-20-2014
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Hydrogels have been developed as extracellular matrix (ECM) mimics both for therapeutic applications and basic biological studies. In particular, elastin-like polypeptide (ELP) hydrogels, which can be tuned to mimic several biochemical and physical characteristics of native ECM, have been constructed to encapsulate various types of cells to create in vitro mimics of in vivo tissues. However, ELP hydrogels become opaque at body temperature because of ELP's lower critical solution temperature behavior. This opacity obstructs light-based observation of the morphology and behavior of encapsulated cells. In order to improve the transparency of ELP hydrogels for better imaging, we have designed a hybrid ELP-polyethylene glycol (PEG) hydrogel system that rapidly cross-links with tris(hydroxymethyl) phosphine (THP) in aqueous solution via Mannich-type condensation. As expected, addition of the hydrophilic PEG component significantly improves the light transmittance. Coherent anti-Stokes Raman scattering (CARS) microscopy reveals that the hybrid ELP-PEG hydrogels have smaller hydrophobic ELP aggregates at 37 °C. Importantly, this hydrogel platform enables independent tuning of adhesion ligand density and matrix stiffness, which is desirable for studies of cell-matrix interactions. Human fibroblasts encapsulated in these hydrogels show high viability (>98%) after 7 days of culture. High-resolution confocal microscopy of encapsulated fibroblasts reveals that the cells adopt a more spread morphology in response to higher RGD ligand concentrations and softer gel mechanics.
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Association of rs12979860 and rs8099917 polymorphisms in IL28B with SVR in hepatic allograft recipients with HCV recurrence undergoing PEG-IFN/RBV therapy: A meta-analysis.
Hum. Immunol.
PUBLISHED: 06-05-2014
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The association of rs12979860 and rs8099917 single nucleotide polymorphisms (SNPs) in interleukin-28B (IL28B) with sustained virological response (SVR) in hepatic allograft recipients undergoing treatment with PEGylated interferon (PEG-IFN) plus ribavirin (RBV) for recurrent hepatitis C virus (HCV) infection remains inconclusive. We therefore performed a meta-analysis to estimate this association. A search of the literature published prior to November 1, 2013, was conducted using various databases. Eleven eligible studies were included in the meta-analysis. The pooled results revealed that rs12979860 genotype CC in the recipient, donor, and recipient/donor pair was significantly related to high SVR in the recipients (recipient: odds ratio [OR]=3.06, 95% confidence interval [CI]=2.18-4.30; donor: OR=2.65, 95% CI=1.83-3.85; recipient/donor pair: OR=6.05, 95% CI=3.16-11.58). A similar association was observed with rs8099917 genotype TT (recipient: OR=3.84, 95% CI=2.37-6.22; donor: OR=2.44, 95% CI=1.12-5.28; recipient/donor pair: OR=5.43, 95% CI=2.51-11.75). These results suggest that rs12979860 genotype CC and rs8099917 genotype TT contribute to a high SVR in the recipient after antiviral treatment.
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Minimally oxidized LDL inhibits macrophage selective cholesteryl ester uptake and native LDL-induced foam cell formation.
J. Lipid Res.
PUBLISHED: 06-02-2014
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Scavenger receptor-mediated uptake of oxidized LDL (oxLDL) is thought to be the major mechanism of foam cell generation in atherosclerotic lesions. Recent data has indicated that native LDL is also capable of contributing to foam cell formation via low-affinity receptor-independent LDL particle pinocytosis and selective cholesteryl ester (CE) uptake. In the current investigation, Cu(2+)-induced LDL oxidation was found to inhibit macrophage selective CE uptake. Impairment of selective CE uptake was significant with LDL oxidized for as little as 30 min and correlated with oxidative fragmentation of apoB. In contrast, LDL aggregation, LDL CE oxidation, and the enhancement of scavenger receptor-mediated LDL particle uptake required at least 3 h of oxidation. Selective CE uptake did not require expression of the LDL receptor (LDL-R) and was inhibited similarly by LDL oxidation in LDL-R(-/-) versus WT macrophages. Inhibition of selective uptake was also observed when cells were pretreated or cotreated with minimally oxidized LDL, indicating a direct inhibitory effect of this oxLDL on macrophages. Consistent with the effect on LDL CE uptake, minimal LDL oxidation almost completely prevented LDL-induced foam cell formation. These data demonstrate a novel inhibitory effect of mildly oxidized LDL that may reduce foam cell formation in atherosclerosis.
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One-pot Synthesis of Elastin-like Polypeptide Hydrogels with Grafted VEGF-Mimetic Peptides.
Biomater Sci
PUBLISHED: 04-15-2014
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Immobilization of growth factors to polymeric matrices has been a common strategy in the design of tissue engineering scaffolds to promote tissue regeneration, which requires complex cell signaling events with the surrounding matrix. However, the use of large protein growth factors in polymeric scaffolds is often plagued by immunogenicity, short in vivo half-lives, and reduced bioactivity. To address these concerns, we develop a single-step, cell-compatible strategy to tether small, growth-factor-mimetic peptides into a protein-engineered hydrogel with tunable biomaterial properties. Specifically, we covalently immobilize the QK peptide, an angiogenic peptide mimicking the receptor-binding region of vascular endothelial growth factor (VEGF), within tunable elastin-like polypeptide (ELP) hydrogels that include a cell-adhesive RGD sequence. Using a cell-compatible, amine-reactive crosslinker, we conducted a one-pot synthesis to simultaneously encapsulate cells while precisely controlling the QK grafting density (10 nM - 100 ?M) in the ELP hydrogels without altering other material properties. Fluorescence analysis of fluor-labeled QK peptides demonstrated that the conjugation efficiency to ELP hydrogels was >75% and that covalent immobilization effectively eliminates all QK diffusion. Compared with pristine ELP hydrogels, human umbilical vein endothelial cell (HUVEC) proliferation was significantly enhanced on ELP hydrogels immobilized with 10 nM or 1 ?M QK. Moreover, upon encapsulation within tethered QK-ELP hydrogels, HUVEC spheroids maintained near 100% viability and demonstrated significantly more three-dimensional outgrowth compared to those supplemented with soluble QK peptide at the same concentration. These results encourage the further development of protein-engineered scaffolds decorated with growth-factor-mimetic peptides to provide long-term biological signals using this versatile, single-step synthesis.
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Avidity-controlled hydrogels for injectable co-delivery of induced pluripotent stem cell-derived endothelial cells and growth factors.
J Control Release
PUBLISHED: 04-11-2014
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To translate recent advances in induced pluripotent stem cell biology to clinical regenerative medicine therapies, new strategies to control the co-delivery of cells and growth factors are needed. Building on our previous work designing Mixing-Induced Two-Component Hydrogels (MITCHs) from engineered proteins, here we develop protein-polyethylene glycol (PEG) hybrid hydrogels, MITCH-PEG, which form physical gels upon mixing for cell and growth factor co-delivery. MITCH-PEG is a mixture of C7, which is a linear, engineered protein containing seven repeats of the CC43 WW peptide domain (C), and 8-arm star-shaped PEG conjugated with either one or two repeats of a proline-rich peptide to each arm (P1 or P2, respectively). Both 20kDa and 40kDa star-shaped PEG variants were investigated, and all four PEG-peptide variants were able to undergo a sol-gel phase transition when mixed with the linear C7 protein at constant physiological conditions due to noncovalent hetero-dimerization between the C and P domains. Due to the dynamic nature of the C-P physical crosslinks, all four gels were observed to be reversibly shear-thinning and self-healing. The P2 variants exhibited higher storage moduli than the P1 variants, demonstrating the ability to tune the hydrogel bulk properties through a biomimetic peptide-avidity strategy. The 20kDa PEG variants exhibited slower release of encapsulated vascular endothelial growth factor (VEGF), due to a decrease in hydrogel mesh size relative to the 40kDa variants. Human induced pluripotent stem cell-derived endothelial cells (hiPSC-ECs) adopted a well-spread morphology within three-dimensional MITCH-PEG cultures, and MITCH-PEG provided significant protection from cell damage during ejection through a fine-gauge syringe needle. In a mouse hindlimb ischemia model of peripheral arterial disease, MITCH-PEG co-delivery of hiPSC-ECs and VEGF was found to reduce inflammation and promote muscle tissue regeneration compared to a saline control.
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Role of Nogo?A in the regulation of hepatocellular carcinoma SMMC?7721 cell apoptosis.
Mol Med Rep
PUBLISHED: 02-18-2014
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Nogo-A has been identified as an inhibitor of neurite outgrowth specific to the central nervous system. However, little is known about the role of Nogo-A in hepatocellular carcinoma (HCC), the most common primary malignant tumor with a high mortality rate. This study aimed to investigate the role of endogenous Nogo-A in human liver cancer cells. Reverse transcription polymerase chain reaction was used to detect the expression of Nogo-A in four liver cancer cell lines. A lentivirus vector was then constructed to mediate RNA interference (RNAi) targeting of Nogo?A (LV?Nogo-A?siRNA) and was confirmed to successfully suppress the expression of the Nogo-A gene in SMMC-7721 cells. Furthermore, Nogo-A was observed to be highly expressed in liver cancer cell lines. RNAi of Nogo-A using the LV?Nogo-A?siRNA construct significantly decreased Nogo-A protein expression and specifically inhibited the growth of SMMC-7721 cells. This growth inhibitory effect may be attributed to an increase in G2/M phase arrest and apoptosis in SMMC-7721 cells containing Nogo-A?siRNA. The results of this study demonstrate that Nogo-A may represent a novel therapeutic target for the treatment of liver cancer, in addition to its potent roles in neural systems.
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Avidity-controlled delivery of angiogenic peptides from injectable molecular-recognition hydrogels.
Tissue Eng Part A
PUBLISHED: 02-03-2014
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Peptide mimics of growth factors represent an emerging class of therapeutic drugs due to high biological specificity and relative ease of synthesis. However, maintaining efficacious therapeutic dosage at the therapy site has proven challenging owing to poor intestinal permeability and short circulating half-lives in the blood stream. In this work, we present the affinity immobilization and controlled release of QK, a vascular endothelial growth factor (VEGF) mimetic peptide, from an injectable mixing-induced two-component hydrogel (MITCH). The MITCH system is crosslinked by reversible interactions between WW domains and complementary proline-rich peptide modules. Fusion of the QK peptide to either one or two units of the proline-rich sequence creates bifunctional peptide conjugates capable of specific binding to MITCH while preserving their angiogenic bioactivity. Presenting two repeats of the proline-rich sequence increases the binding enthalpy 2.5 times due to avidity effects. Mixing of the drug conjugates with MITCH components results in drug encapsulation and extended release at rates consistent with the affinity immobilization strength. Human umbilical vein endothelial cells (HUVECs) treated with the soluble drug conjugates exhibit morphogenetic events of VEGF receptor 2 signal transduction followed by cell migration and organization into networks characteristic of early angiogenesis. In a three-dimensional model where HUVECs were cultured as spheroids in a matrix of collagen and fibronectin, injection of drug-releasing MITCH resulted in significantly more cell outgrowth than drugs injected in saline. This ability to sustain local drug availability is ideal for therapeutic angiogenesis applications, where spatiotemporal control over drug distribution is a key requirement for clinical success.
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Ectopic osteogenesis of allogeneic bone mesenchymal stem cells loading on ?-tricalcium phosphate in canines.
Plast. Reconstr. Surg.
PUBLISHED: 01-29-2014
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Bone mesenchymal stem cells are progenitor cells for mesenchymal tissues. The objective of this study was to evaluate the subcutaneous ectopic osteogenesis of allogeneic bone mesenchymal stem cells, which were loaded on ?-tricalcium phosphate in canines without immunosuppressive therapy.
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Loss of caveolin-1 and adiponectin induces severe inflammatory lung injury following LPS challenge through excessive oxidative/nitrative stress.
Am. J. Physiol. Lung Cell Mol. Physiol.
PUBLISHED: 01-17-2014
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Excessive reactive oxygen/nitrogen species have been associated with the onset, progression, and outcome of sepsis, both in preclinical and clinical studies. However, the signaling pathways regulating oxidative/nitrative stress in the pathogenesis of sepsis-induced acute lung injury and acute respiratory distress syndrome are not fully understood. Employing the novel mouse model with genetic deletions of both caveolin-1 (Cav1) and adiponectin (ADPN) [double knockout (DKO) mice], we have demonstrated the critical role of Cav1 and ADPN signaling cross talk in regulating oxidative/nitrative stress and resulting inflammatory lung injury following LPS challenge. In contrast to the inhibited inflammatory lung injury in Cav1(-/-) mice, we observed severe lung inflammation and markedly increased lung vascular permeability in DKO mice in response to LPS challenge. Accordingly, the DKO mice exhibited an 80% mortality rate following a sublethal dose of LPS challenge. At basal state, loss of Cav1 and ADPN resulted in a drastic increase of oxidative stress and resultant nitrative stress in DKO lungs. Scavenging of superoxide by pretreating the DKO mice with MnTMPYP (a superoxide dismutase mimetic) restored the inflammatory responses to LPS challenge including reduced lung myeloperoxidase activity and vascular permeability. Thus oxidative/nitrative stress collectively modulated by Cav1 and ADPN signalings is a critical determinant of inflammatory lung injury in response to LPS challenge.
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Targeted delivery to cartilage is critical for in vivo efficacy of insulin-like growth factor 1 in a rat model of osteoarthritis.
PUBLISHED: 01-07-2014
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Acute articular injuries lead to an increased risk of progressive joint damage and osteoarthritis (OA), and no therapies are currently available to repair or protect the injured joint tissue. Intraarticular delivery of therapeutic proteins has been limited by their rapid clearance from the joint space and lack of retention within cartilage. The aim of this study was to test whether targeted delivery to cartilage by fusion with a heparin-binding domain would be sufficient to prolong the in vivo function of the insulin-like growth factor 1 (IGF-1).
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Temperate pine barrens and tropical rain forests are both rich in undescribed fungi.
PLoS ONE
PUBLISHED: 01-01-2014
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Most of fungal biodiversity on Earth remains unknown especially in the unexplored habitats. In this study, we compared fungi associated with grass (Poaceae) roots from two ecosystems: the temperate pine barrens in New Jersey, USA and tropical rain forests in Yunnan, China, using the same sampling, isolation and species identification methods. A total of 426 fungal isolates were obtained from 1600 root segments from 80 grass samples. Based on the internal transcribed spacer (ITS) sequences and morphological characteristics, a total of 85 fungal species (OTUs) belonging in 45 genera, 23 families, 16 orders, and 6 classes were identified, among which the pine barrens had 38 and Yunnan had 56 species, with only 9 species in common. The finding that grass roots in the tropical forests harbor higher fungal species diversity supports that tropical forests are fungal biodiversity hotspots. Sordariomycetes was dominant in both places but more Leotiomycetes were found in the pine barrens than Yunnan, which may play a role in the acidic and oligotrophic pine barrens ecosystem. Equal number of undescribed fungal species were discovered from the two sampled ecosystems, although the tropical Yunnan had more known fungal species. Pine barrens is a unique, unexplored ecosystem. Our finding suggests that sampling plants in such unexplored habitats will uncover novel fungi and that grass roots in pine barrens are one of the major reservoirs of novel fungi with about 47% being undescribed species.
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[Relationship between mRNA expression of MnSOD and manganese neurotoxicity].
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi
PUBLISHED: 12-28-2013
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To investigate the relationship between mRNA expression of manganese superoxide dismutase (MnSOD) and manganese neurotoxicity.
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Dissection of the transcriptional regulator GlpR, the promoter elements, and the post-transcriptional processing involved in the fructose-induced activation of the phosphoenolpyruvate-dependent sugar phosphotransferase system in Haloferax mediterranei.
Appl. Environ. Microbiol.
PUBLISHED: 12-13-2013
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Among all known archaeal strains, the phosphoenolpyruvate-dependent phosphotransferase system (PTS) for fructose utilization is primarily used by haloarchaea that thrive in hypersaline environments, whereas the molecular details of the regulation of the archaeal PTS under fructose induction remain unclear. In this study, we present a comprehensive examination of the regulatory mechanism of the fructose-PTS (HFX_1559-HFX_1563) in the haloarchaeon Haloferax mediterranei. With gene knockout-complementation, microarray analysis and ChIP-qPCR, we revealed that GlpR (HFX_1565) is the indispensable activator, which specifically binds to the PTS promoter (PPTS) during fructose induction. Further promoter scanning mutation indicated that three sites located at the upstream of the H. mediterranei PPTS, which are conserved in most haloarchaeal PPTS, are found to be involved in this induction. Interestingly, two PTS transcripts (named T8 and T17) with different 5 UTR lengths were observed, and the promoter or 5 UTR swap experiments indicated that the shorter 5 UTR was most likely generated from the longer one. Notably, the translation efficiency of the transcript with this shorter 5 UTR was significantly higher, and the ratio of T8 (with the shorter 5 UTR) to T17 increased during fructose induction, implying that a post-transcriptional mechanism is also involved in PTS activation. With these insights into the molecular regulation of the haloarchaeal PTS, we have proposed a working model of haloarchaea in response to environmental fructose.
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Designing ECM-mimetic Materials Using Protein Engineering.
Acta Biomater
PUBLISHED: 11-20-2013
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The natural extracellular matrix (ECM), with its multitude of evolved cell-instructive and cell-responsive properties, provides inspiration and guidelines for the design of engineered biomaterials. One strategy to create ECM-mimetic materials is the modular design of protein-based engineered ECM (eECM) scaffolds. This modular design strategy involves combining multiple protein domains with different functionalities into a single, modular polymer sequence, resulting in a multifunctional matrix with independent tunability of the individual domain functions. These eECMs often enable decoupled control over multiple material properties for fundamental studies of cell-matrix interactions. In addition, since the eECMs are frequently composed entirely of bioresorbable amino acids, these matrices have immense clinical potential for a variety of regenerative medicine applications. This brief review demonstrates how fundamental knowledge gained from structure-function studies of native proteins can be exploited in the design of novel protein-engineered biomaterials. While the field of protein-engineered biomaterials has existed for over 20 years, the community is only now beginning to fully explore the diversity of functional peptide modules that can be incorporated into these materials. We have chosen to highlight recent examples that either (1) demonstrate exemplary use as matrices with cell-instructive and cell-responsive properties or (2) demonstrate outstanding creativity in terms of novel molecular-level design and macro-level functionality.
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Lipoxin A4 ameliorates cerebral ischaemia/reperfusion injury through upregulation of nuclear factor erythroid 2-related factor 2.
Neurol. Res.
PUBLISHED: 07-22-2013
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Lipoxin A4 (LXA4) is a potent anti-inflammatory mediator that exerts a neuroprotective effect following cerebral ischaemia/reperfusion (I/R) injury. However, little is known about the underlying mechanisms. Upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) is generally considered to reduce cerebral I/R injury. Nuclear factor erythroid 2-related factor 2 can induce haeme oxygenase-1 (HO-1) and glutathione (GSH) expression to combat increased oxidative stress. The present study aimed to investigate the effects of Nrf2 signalling on LXA4-mediated neuroprotection.
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Coicenals A-D, four new diterpenoids with new chemical skeletons from the plant pathogenic fungus Bipolaris coicis.
Org. Lett.
PUBLISHED: 07-22-2013
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Coicenals A-C (1-3) possessing a previously undescribed 10-(sec-butyl)-6-hydroxy-1,7,9-trimethyl-1,6,7,8,9,9a-hexahydro-1,4-methanobenzo[d]oxepin-2(4H)-ylidene)acetaldehyde skeleton and coicenal D (4) with a new 2-(sec-butyl)-5-hydroxy-1,6,8-trimethyl-2,5,6,7,8,8a-hexahydro-1H-4a,1-(epoxymethano)naphthalen-10-ylidene)acetaldehyde skeleton were isolated from the solid culture of the plant pathogenic fungus Bipolaris coicis. The absolute configurations in 1 and 4 were assigned by electronic circular dichroism (ECD) calculations. Compounds 1 and 2 were transformed into 4 and 5 by treatment with acetyl chloride, respectively. Compounds 1-4 showed moderate inhibitory activity against NO release with IC50 values of 16.34 ± 1.12, 23.55 ± 1.37, 10.82 ± 0.83, and 54.20 ± 2.82 ?M, respectively.
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A rice virescent-yellow leaf mutant reveals new insights into the role and assembly of plastid caseinolytic protease in higher plants.
Plant Physiol.
PUBLISHED: 06-26-2013
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The plastidic caseinolytic protease (Clp) of higher plants is an evolutionarily conserved protein degradation apparatus composed of a proteolytic core complex (the P and R rings) and a set of accessory proteins (ClpT, ClpC, and ClpS). The role and molecular composition of Clps in higher plants has just begun to be unraveled, mostly from studies with the model dicotyledonous plant Arabidopsis (Arabidopsis thaliana). In this work, we isolated a virescent yellow leaf (vyl) mutant in rice (Oryza sativa), which produces chlorotic leaves throughout the entire growth period. The young chlorotic leaves turn green in later developmental stages, accompanied by alterations in chlorophyll accumulation, chloroplast ultrastructure, and the expression of chloroplast development- and photosynthesis-related genes. Positional cloning revealed that the VYL gene encodes a protein homologous to the Arabidopsis ClpP6 subunit and that it is targeted to the chloroplast. VYL expression is constitutive in most tissues examined but most abundant in leaf sections containing chloroplasts in early stages of development. The mutation in vyl causes premature termination of the predicted gene product and loss of the conserved catalytic triad (serine-histidine-aspartate) and the polypeptide-binding site of VYL. Using a tandem affinity purification approach and mass spectrometry analysis, we identified OsClpP4 as a VYL-associated protein in vivo. In addition, yeast two-hybrid assays demonstrated that VYL directly interacts with OsClpP3 and OsClpP4. Furthermore, we found that OsClpP3 directly interacts with OsClpT, that OsClpP4 directly interacts with OsClpP5 and OsClpT, and that both OsClpP4 and OsClpT can homodimerize. Together, our data provide new insights into the function, assembly, and regulation of Clps in higher plants.
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Surgical resection should be taken into consideration for the treatment of small gastric gastrointestinal stromal tumors.
World J Surg Oncol
PUBLISHED: 06-25-2013
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The National Comprehensive Cancer Network (NCCN) recommends conservative follow-up for gastric gastrointestinal stromal tumors (GISTs) less than 2 cm. The aim of the present study was to investigate the clinical and pathological features of small gastric GISTs, re-evaluate the risk potential, and discuss the treatment strategy of small gastric GISTs.
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GAPDH is critical for superior efficacy of female bone marrow-derived mesenchymal stem cells on pulmonary hypertension.
Cardiovasc. Res.
PUBLISHED: 06-25-2013
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Pulmonary arterial hypertension, a chronic lung disease, remains an unacceptable prognosis despite significant advances in conventional therapies. Stem cell therapy represents a novel and effective modality. This study was aimed to add new insight in gender differences of bone marrow-derived mesenchymal stem cells on therapy against pulmonary arterial hypertension and the underlying mechanism.
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Typification and phylogenetic study of Phyllosticta ampelicida and P. vaccinii.
Mycologia
PUBLISHED: 05-24-2013
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Phyllosticta ampelicida, the causal agent of black rot of grape, and P. vaccinii, the pathogen of early rot of cranberry, are neotypified and epitypified respectively by strains from American Type Culture Collection (ATCC). Morphological characteristics of these cultures are described and compared with type specimens and the original descriptions. Based on phylogeny inferred from DNA sequences of internal transcribed spacer (ITS), actin (ACT), translation elongation factor 1-alpha (TEF1) and glyceraldehyde-3-phosphate dehydrogenase (GPDH), traditionally defined P. ampelicida (teleomorph Guignardia bidwellii) is revealed to be a species complex including P. ampelicida sensu stricto, typified in this study, and two additional species, one of which is described as new P. parthenocissi. Our results did not support an anamorph/teleomorph connection between P. vaccinii and G. vaccinii in that they represent different species. Multilocus sequence data from the neotype and epitype were generated and deposited in GenBank.
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Expression and prognostic value of Ars2 in hepatocellular carcinoma.
Int. J. Clin. Oncol.
PUBLISHED: 05-12-2013
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Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in China. Arsenic resistance protein 2 (Asr2) was reported to be important for microRNA (miR) biogenesis, and its depletion could reduce the levels of several miRs, including miR-21, which is over-expressed in HCC. We hypothesized that Ars2 is also overexpressed in HCC and may be involved in the biological properties of HCC.
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[The application of sentinel lymph node detection in thyroid cancer].
Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi
PUBLISHED: 05-02-2013
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Thyroid cancer is more common in thyroid diseases, because of its slow growth and good prognosis, different scholars have different views on lymph node dissection. During the study of definition and positioning methods of sentinel lymph node biopsy, discuss the necessity of cervical node dissection and the application of cleaning scope in thyroid cancer surgery.
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Silica-based cerium (III) chloride nanoparticles prevent the fructose-induced glycation of ?-crystallin and H2O 2-induced oxidative stress in human lens epithelial cells.
Arch. Pharm. Res.
PUBLISHED: 03-27-2013
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This study aimed to investigate whether silica-cerium (III) chloride (CeCl3) nanoparticles could inhibit the formation of advanced glycation end-products (AGEs) and reduce oxidative stress. Silica-CeCl3 nanoparticles were synthesised by adsorption and embedment with micro-silica materials, forming uniform nanoparticles with a diameter of approximately 130 nm. Chaperone activity assays and AGEs formation assays, and intracellular reactive assays were adopted in this study to evaluate CeCl3 nanoparticles effect. UV-visible spectrometry showed that silica-CeCl3 nanoparticles at low concentrations rapidly formed tentatively stable conjugations with ?-crystallin, greatly enhancing the chaperone activity of ?-crystallin. Moreover, silica-CeCl3 nanoparticles markedly inhibited the fructose-induced glycation of ?-crystallin, showing an advantage over the control drugs aminoguanidine and carnosine. Silica-CeCl3 nanoparticles also reduced intracellular reactive oxygen species production and restored glutathione levels in H2O2-treated human lens epithelial cells. These findings suggest that silica-CeCl3 may be used as a novel agent for the prevention of cataractogenesis.
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Characterization of genes for chitin catabolism in Haloferax mediterranei.
Appl. Microbiol. Biotechnol.
PUBLISHED: 03-21-2013
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Chitin is the second most abundant natural polysaccharide after cellulose. But degradation of chitin has never been reported in haloarchaea. In this study, we revealed that Haloferax mediterranei, a metabolically versatile haloarchaeon, could utilize colloidal or powdered chitin for growth and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) accumulation, and the gene cluster (HFX_5025-5039) for the chitin catabolism pathway was experimentally identified. First, reverse transcription polymerase chain reaction results showed that the expression of the genes encoding the four putative chitinases (ChiAHme, ChiBHme, ChiCHme, and ChiDHme, HFX_5036-5039), the LmbE-like deacetylase (DacHme, HFX_5027), and the glycosidase (GlyAHme, HFX_5029) was induced by colloidal or powdered chitin, and chiA Hme, chiB Hme, and chiC Hme were cotranscribed. Knockout of chiABC Hme or chiD Hme had a significant effect on cell growth and PHBV production when chitin was used as the sole carbon source, and the chiABCD Hme knockout mutant lost the capability to utilize chitin. Knockout of dac Hme or glyA Hme also decreased PHBV accumulation on chitin. These results suggested that ChiABCDHme, DacHme, and GlyAHme were indeed involved in chitin degradation in H. mediterranei. Additionally, the chitinase assay showed that each chitinase possessed hydrolytic activity toward colloidal or powdered chitin, and the major product of colloidal chitin hydrolysis by ChiABCDHme was diacetylchitobiose, which was likely further degraded to monosaccharides by DacHme, GlyAHme, and other related enzymes for both cell growth and PHBV biosynthesis. Taken together, this study revealed the genes and enzymes involved in chitin catabolism in haloarchaea for the first time and indicated the potential of H. mediterranei as a whole-cell biocatalyst in chitin bioconversion.
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XRCC1 Arg399Gln polymorphism and bladder cancer risk: updated meta-analyses based on 5767 cases and 6919 controls.
Exp. Biol. Med. (Maywood)
PUBLISHED: 03-13-2013
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Previous reports implicate XRCC1 Arg399Gln polymorphism as a possible risk factor for several cancers. Published meta-analyses have been conducted on the association of XRCC1 Arg399Gln polymorphism with susceptibility to bladder cancer, and have generated conflicting results. The present study aimed to derive a more precise estimation of the relationship. Updated meta-analyses assessing the association of XRCC1 Arg399Gln polymorphism with bladder cancer were conducted and subgroup analyses on ethnicity, smoking status and source of controls were further performed. Eligible studies were identified for the period up to May 2012. A total of 19 case-control studies comprising 5767 cases and 6919 controls were lastly selected for analysis. The overall data failed to indicate significant associations between XRCC1 Arg399Gln polymorphism and bladder cancer risk (Gln/Gln versus Arg/Arg: odds ratio (OR) = 0.97; 95% CI = 0.85-1.10; dominant model: OR = 1.02; 95% CI = 0.94-1.09; recessive model: OR = 0.95; 95% CI = 0.84-1.07). In subgroup analyses stratified by ethnicity, smoking status and source of controls, respectively, similar results were obtained. In conclusion, the results of the present study suggest that XRCC1 Arg399Gln polymorphism might not modify the susceptibility to bladder cancer. Further large and well-designed studies are needed to confirm this conclusion.
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3-Anhydro-6-hydroxy-ophiobolin A, a new sesterterpene inhibiting the growth of methicillin-resistant Staphylococcus aureus and inducing the cell death by apoptosis on K562, from the phytopathogenic fungus Bipolaris oryzae.
Bioorg. Med. Chem. Lett.
PUBLISHED: 02-28-2013
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A new ophiobolin derivative, 3-anhydro-6-hydroxy-ophiobolin A (1), as well as two known ophiobolin derivatives 3-anhydro-ophiobolin A (2) and 3-anhydro-6-epi-ophiobolin A (3) were isolated from the PDB culture of a phytopathogenic fungus Bipolaris oryzae. The structure of 1 was elucidated through 2D NMR and other spectroscopic techniques. Compound 1 exhibited strong antimicrobial activity against Bacille Calmette-Guerin, Bacillus subtilis, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus with MIC value of 12.5 ?g/mL, and potent antiproliferative activity against cell lines HepG2 and K562 with IC50 of 6.49 ?M and 4.06 ?M, respectively. Further studies on the cytotoxicity of compound 1 against K562 cells demonstrated that it induced apoptosis, observed by flow cytometric method. Preliminary structure-activity relationships of these ophiobolins and the mechanism of apoptosis induced by 1 were analyzed.
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Circumscription of the anthracnose pathogens Colletotrichum lindemuthianum and C. nigrum.
Mycologia
PUBLISHED: 02-28-2013
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The anthracnose pathogen of common bean (Phaseolus vulgaris) is usually identified as Colletotrichum lindemuthianum, while anthracnose of potato (Solanum tuberosum), peppers (Capsicum annuum), tomato (S. lycopersicum) and several other crop plants is often attributed to C. coccodes. In order to study the phylogenetic relationships of these important pathogens, we conducted a multigene analysis (ITS, ACT, TUB2, CHS-1, GAPDH) of strains previously identified as C. lindemuthianum, C. coccodes and other related species, as well as representative species of the major Colletotrichum species complexes. Strains of C. lindemuthianum belonged to a single clade; we selected an authentic specimen as lectotype, and an appropriate specimen and culture from the CBS collection to serve as epitype. Two clades were resolved within C. coccodes s. lat. One clade included the ex-neotype strain of C. coccodes on Solanum, while an epitype was selected for C. nigrum, which represents the oldest name of the second clade, which occurs on Capsicum, Solanum, as well as several other host plants. Furthermore, we recognized C. lycopersici as a synonym of C. nigrum, and C. biologicum as a synonym of C. coccodes.
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Investigation of tumor suppressing function of CACNA2D3 in esophageal squamous cell carcinoma.
PLoS ONE
PUBLISHED: 02-22-2013
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Deletion of 3p is one of the most frequent genetic alterations in esophageal squamous cell carcinoma (ESCC), suggesting the existence of one or more tumor suppressor genes (TSGs) within these regions. In this study, one TSG, CACNA2D3 at 3p21.1, was characterized.
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Multiple propionyl coenzyme A-supplying pathways for production of the bioplastic poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in Haloferax mediterranei.
Appl. Environ. Microbiol.
PUBLISHED: 02-22-2013
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Haloferax mediterranei is able to accumulate the bioplastic poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with more than 10 mol% 3-hydroxyvalerate (3HV) from unrelated carbon sources. However, the pathways that produce propionyl coenzyme A (propionyl-CoA), an important precursor of 3HV monomer, have not yet been determined. Bioinformatic analysis of H. mediterranei genome indicated that this strain uses multiple pathways for propionyl-CoA biosynthesis, including the citramalate/2-oxobutyrate pathway, the aspartate/2-oxobutyrate pathway, the methylmalonyl-CoA pathway, and a novel 3-hydroxypropionate pathway. Cofeeding of pathway intermediates and inactivating pathway-specific genes supported that these four pathways were indeed involved in the biosynthesis of 3HV monomer. The novel 3-hydroxypropionate pathway that couples CO2 assimilation with PHBV biosynthesis was further confirmed by analysis of (13)C positional enrichment in 3HV. Notably, (13)C metabolic flux analysis showed that the citramalate/2-oxobutyrate pathway (53.0% flux) and the 3-hydroxypropionate pathway (30.6% flux) were the two main generators of propionyl-CoA from glucose. In addition, genetic perturbation on the transcriptome of the ?phaEC mutant (deficient in PHBV accumulation) revealed that a considerable number of genes in the four propionyl-CoA synthetic pathways were significantly downregulated. We determined for the first time four propionyl-CoA-supplying pathways for PHBV production in haloarchaea, particularly including a new 3-hydroxypropionate pathway. These results would provide novel strategies for the production of PHBV with controllable 3HV molar fraction.
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Loss of sorting nexin 27 contributes to excitatory synaptic dysfunction by modulating glutamate receptor recycling in Downs syndrome.
Nat. Med.
PUBLISHED: 02-01-2013
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Sorting nexin 27 (SNX27), a brain-enriched PDZ domain protein, regulates endocytic sorting and trafficking. Here we show that Snx27(-/-) mice have severe neuronal deficits in the hippocampus and cortex. Although Snx27(+/-) mice have grossly normal neuroanatomy, we found defects in synaptic function, learning and memory and a reduction in the amounts of ionotropic glutamate receptors (NMDA and AMPA receptors) in these mice. SNX27 interacts with these receptors through its PDZ domain, regulating their recycling to the plasma membrane. We demonstrate a concomitant reduced expression of SNX27 and CCAAT/enhancer binding protein ? (C/EBP?) in Downs syndrome brains and identify C/EBP? as a transcription factor for SNX27. Downs syndrome causes overexpression of miR-155, a chromosome 21-encoded microRNA that negatively regulates C/EBP?, thereby reducing SNX27 expression and resulting in synaptic dysfunction. Upregulating SNX27 in the hippocampus of Downs syndrome mice rescues synaptic and cognitive deficits. Our identification of the role of SNX27 in synaptic function establishes a new molecular mechanism of Downs syndrome pathogenesis.
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NDRG2 is a novel p53-associated regulator of apoptosis in C6-originated astrocytes exposed to oxygen-glucose deprivation.
PLoS ONE
PUBLISHED: 01-17-2013
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N-myc downstream-regulated gene 2 (NDRG2) has been documented to be a pro-differentiative and anti-proliferative gene in cancer research. Our previous study found a significant NDRG2 up-regulation in reactive astrocytes of penumbra after transient focal cerebral ischemia, which was parallel to the enhancement of TUNEL-positive signals. However, it is still uncertain whether NDRG2 participates in cellular apoptosis induced by ischemia-reperfusion injury in brain. In this study, we investigated the role of NDRG2 in cellular apoptosis induced by oxygen-glucose deprivation (OGD) in IL-6-differentiated C6 glioma cells. The results showed that NDRG2 was up-regulated and translocated from the cytoplasm to the nucleus after OGD exposure. NDRG2 over-expression exhibited an anti-proliferative effect and increased the Bax/Bcl-2 ratio after OGD exposure, while NDRG2 silencing promoted the cellular proliferation and attenuated the up-regulation of Bax/Bcl-2 ratio. The pro-apoptotic effect of p53 was verified by the results in which p53 silencing greatly reduced the percentage of OGD-induced apoptotic cells. p53 silencing also reduced the OGD-induced NDRG2 up-regulation. However, over-expression of p53 did not further improve the NDRG2 up-regulation. In conclusion, NDRG2 is a p53-associated regulator of apoptosis in C6-originated astrocytes after OGD exposure. These findings bring insight to the roles of NDRG2 in ischemic-hypoxic injury and provide potential targets for future clinical therapies on stroke.
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Aberrant expression of GATA binding protein 6 correlates with poor prognosis and promotes metastasis in cholangiocarcinoma.
Eur. J. Cancer
PUBLISHED: 01-11-2013
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GATA6, a zinc-finger transcription factor, functions as a tumour promoter or suppresser according to different tumour origins. We investigated the clinical significance of GATA6 and its role in invasion and metastasis in cholangiocarcinoma (CCA).
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Genetic diversity and population structure of rice pathogen Ustilaginoidea virens in China.
PLoS ONE
PUBLISHED: 01-01-2013
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Rice false smut caused by the fungal pathogen Ustilaginoidea virens is becoming a destructive disease throughout major rice-growing countries. Information about its genetic diversity and population structure is essential for rice breeding and efficient control of the disease. This study compared the genome sequences of two U. virens isolates. Three SNP-rich genomic regions were identified as molecular markers that could be used to analyze the genetic diversity and population structure of U. virens in China. A total of 56 multilocus sequence types (haplotypes) were identified out of 162 representative isolates from 15 provinces covering five major rice-growing areas in China. However, the phylogeny, based on sequences at individual SNP-rich regions, strongly conflicted with each other and there were significant genetic differences between different geographical populations. Gene flow between the different geographical populations and genetic differentiation within each geographical population were also detected. In addition, genetic recombination and genetic isolation resulting from geographic separation was also found.
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A systematically combined genotype and functional combination analysis of CYP2E1, CYP2D6, CYP2C9, CYP2C19 in different geographic areas of mainland China--a basis for personalized therapy.
PLoS ONE
PUBLISHED: 01-01-2013
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The cytochrome P450 is the major enzyme involved in drug metabolism. Single CYP genotypes and metabolic phenotypes have been widely studied, but no combination analysis has been conducted in the context of specific populations and geographical areas. This study is the first to systematically analyze the combined genotypes and functional combinations of 400 samples of major CYP genes--CYP2E1, CYP2D6, CYP2C9, and CYP2C19 in four geographical areas of mainland China. 167 different genotype combinations were identified, of which 25 had a greater than 1% frequency in the Chinese Han population. In addition, phenotypes of the four genes for each sample were in line with the predictions of previous studies of the four geographical areas. On the basis of the genotype classification, we were able to produce a systemic functional combinations analysis for the population. 25 of the combinations detected had at least two non-wild phenotypes and four showed a frequency above 1%. A bioinformatics analysis of the relationship between particular drugs and multi-genes was conducted. This is the first systematic study to analyze genotype combinations and functional combinations across whole Chinese population and could make a significant contribution in the field of personalized medicine and therapy.
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Annexin A2 promotes the migration and invasion of human hepatocellular carcinoma cells in vitro by regulating the shedding of CD147-harboring microvesicles from tumor cells.
PLoS ONE
PUBLISHED: 01-01-2013
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It has been reported that Annexin A2 (ANXA2) is up-regulated in hepatocellular carcinoma (HCC), but the roles of ANXA2 in the migration and invasion of HCC cells have not been determined. In this study, we found that ANXA2-specific siRNA (si-ANXA2) significantly inhibited the migration and invasion of HCC cells co-cultured with fibroblasts in vitro. In addition, the production of MMP-2 by fibroblasts cultured in supernatant collected from si-ANXA2-transfected HCC cells was notably down-regulated. ANXA2 was also found to be co-localized and co-immunoprecipitated with CD147. Further investigation revealed that the expression of ANXA2 in HCC cells affected the shedding of CD147-harboring membrane microvesicles, acting as a vehicle for CD147 in tumor-stromal interactions and thereby regulating the production of MMP-2 by fibroblasts. Together, these results suggest that ANXA2 enhances the migration and invasion potential of HCC cells in vitro by regulating the trafficking of CD147-harboring membrane microvesicles.
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Nascent HDL formation in hepatocytes and role of ABCA1, ABCG1, and SR-BI.
J. Lipid Res.
PUBLISHED: 12-20-2011
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To study the mechanisms of hepatic HDL formation, we investigated the roles of ABCA1, ABCG1, and SR-BI in nascent HDL formation in primary hepatocytes isolated from mice deficient in ABCA1, ABCG1, or SR-BI and from wild-type (WT) mice. Under basal conditions, in WT hepatocytes, cholesterol efflux to exogenous apoA-I was accompanied by conversion of apoA-I to HDL-sized particles. LXR activation by T0901317 markedly enhanced the formation of larger HDL-sized particles as well as cellular cholesterol efflux to apoA-I. Glyburide treatment completely abolished the formation of 7.4 nm diameter and greater particles but led to the formation of novel 7.2 nm-sized particles. However, cells lacking ABCA1 failed to form such particles. ABCG1-deficient cells showed similar capacity to efflux cholesterol to apoA-I and to form nascent HDL particles compared with WT cells. Cholesterol efflux to apoA-I and nascent HDL formation were slightly but significantly enhanced in SR-BI-deficient cells compared with WT cells under basal but not LXR activated conditions. As in WT but not in ABCA1-deficient hepatocytes, 7.2 nm-sized particles generated by glyburide treatment were also detected in ABCG1-deficient and SR-BI-deficient hepatocytes. Our data indicate that hepatic nascent HDL formation is highly dependent on ABCA1 but not on ABCG1 or SR-BI.
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[Karyotype analysis of amniotic fluid cells and comparison of chromosomal abnormality rate during second trimester].
Zhonghua Fu Chan Ke Za Zhi
PUBLISHED: 12-20-2011
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To investigate the karyotypes of amniotic fluid cells and compare the incidence of chromosomal abnormality as well as to evaluate the clinical significance of abnormal karyotypes.
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Mitochondrial genome sequence of the bluegill sunfish (Lepomis macrochirus).
Mitochondrial DNA
PUBLISHED: 12-15-2011
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The bluegill sunfish (Lepomis macrochirus) belongs to Lepomis genera of the family Centrarchidae, which is an economically important freshwater species in China. This study presents the complete mitochondrial genome of L. macrochirus, which is the first complete sequence from sunfish species. L. macrochirus mitochondrial DNA is 16,489 bp long, with the genome organization and gene order being identical to that of the typical vertebrate.
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[Recent progress in the study of reduction-sensitive drug carriers].
Yao Xue Xue Bao
PUBLISHED: 11-30-2011
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With rapid and efficient drug release, few side effects and excellent biodegradable properties, the reduction-sensitive carriers is not only the new hot point in the field of pharmaceutical research, but also the most promising intelligent drug carrier on clinical application. This paper reviews the latest research of reduction-sensitive drug and gene carriers, including the mechanisms of drug release and the synthesis of the reduction-sensitive conjugates, reduction-sensitive nano polymer micelles, nano vesicles, nano hollow microspheres, nano liposomes, as well as the characteristics and advantages of various kinds of carrier system. It will provide a theoretical basis for its further application.
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Phylogeny of Chaetothyriaceae in northern Thailand including three new species.
Mycologia
PUBLISHED: 11-28-2011
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In a recent study unusual taxa of epiphyllous ascomycota belonging to Chaetothyriaceae (Eurotiomycetes) were collected in northern Thailand. This family is poorly understood due to morphological confusion and lack of phylogenetic studies. This paper deals with three new species, Ceramothyrium thailandicum, Chaetothyrium brischofiacola and Phaeosaccardinula ficus, which are fully described and illustrated. A DNA sequence analyses of LSU and ITS rDNA genes shows that the new species cluster in the Chaetothyriaceae. This paper adds six sequences for Chaetothyriaceae to GenBank, providing much needed data for the family.
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Application of the Apn2/MAT locus to improve the systematics of the Colletotrichum gloeosporioides complex: an example from coffee (Coffea spp.) hosts.
Mycologia
PUBLISHED: 11-15-2011
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To improve phylogenetic resolution of the Colletotrichum gloeosporioides species complex we developed and tested the performance of a new set of primers for the Apn2/MAT locus with a case study of 22 isolates. These were isolated mainly from coffee plants and represent six divergent and well characterized species within the C. gloeosporioides complex. Following previous studies on this locus, we have generated sequence data from an expanded region (> 4600 bp), revealing increased phylogenetic informativeness when compared to other commonly used markers such as ITS, ?-tub2 and GS. Within the Apn2/MAT locus the ApMAT marker alone was almost as informative in terms of phylogenetic resolution as a seven-gene concatenated dataset. Our results further revealed that gene-tree discordance may come to be a common issue in resolving evolutionary relationships in the C. gloeosporioides complex, highlighting the importance of multilocus approaches. The use of state-of-the-art data analysis techniques and a highly informative dataset as employed here may abate this issue and hopefully assist in disentangling the C. gloeosporioides complex.
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Aquapeziza: a new genus from freshwater and its morphological and phylogenetic relationships to Pezizaceae.
Mycologia
PUBLISHED: 11-10-2011
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An investigation of freshwater fungi on submerged wood in southwestern China led to the discovery of a new discomycete species from a small stream in Yunnan Province. The taxon is characterized morphologically by its combined characters of epigenous, white ascomata, ovoid, amyloid asci and multi-guttulate, single-celled, smooth, globose ascospores. Because the taxon cannot be accommodated in any known genus based on morphological characters and molecular data (28S and ITS rDNA sequences) a new genus and species Aquapeziza globispora is proposed to accommodate it. The new genus is circumscribed and a description and illustrations of the new species are provided. Relationships of Aquapeziza in Pezizaceae are inferred from 28S and ITS rDNA sequence analyses.
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[Altitudinal patterns of flower plant biomass on alpine and subalpine meadow in Balang Mountains].
Ying Yong Sheng Tai Xue Bao
PUBLISHED: 08-11-2011
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A field survey was conducted to study the altitudinal patterns of flower plant biomass on alpine and subalpine meadow in Wolong Nature Reserve in Balang Mountains, and the soil factors were analyzed. With the increase of altitude, the aboveground biomass, including the biomass of flower-fruit, stem, and leaf, varied in unimodal and peaked at 3500 m a. s. l., the belowground biomass varied in U-shape, the soil acidity and the contents of soil hydrolyzable N and total K increased significantly, whereas the contents of soil organic matter, total N, and available P had a significant decrease. The aboveground biomass of the flower plants increased significantly with increasing soil pH and soil total N and available K contents, and the belowground biomass of the plants increased significantly with increasing soil organic matter and available P contents but decreased significantly with increasing soil total K and hydrolyzable N contents.
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Comparative genomics study of polyhydroxyalkanoates (PHA) and ectoine relevant genes from Halomonas sp. TD01 revealed extensive horizontal gene transfer events and co-evolutionary relationships.
Microb. Cell Fact.
PUBLISHED: 08-08-2011
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Halophilic bacteria have shown their significance in industrial production of polyhydroxyalkanoates (PHA) and are gaining more attention for genetic engineering modification. Yet, little information on the genomics and PHA related genes from halophilic bacteria have been disclosed so far.
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Genetic engineering of Ketogulonigenium vulgare for enhanced production of 2-keto-L-gulonic acid.
J. Biotechnol.
PUBLISHED: 07-10-2011
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Folate derivatives are crucial growth factors for Ketogulonigenium vulgare which is used in mixed culture with Bacillus megaterium for the industrial production of 2-keto-L-gulonic acid (2-KGA), the precursor of L-ascorbic acid (L-AA) or vitamin C (Vc). To improve the growth and 2-KGA production, five genes involved in folate biosynthesis identified in a folate gene cluster from Lactococcus lactis MG1363, including folB, folKE, folP, folQ and folC, were over-expressed in K. vulgare. Intracellular folate concentration in the recombinant strain harboring folate biosynthesis genes cluster under the control of P(sdh) (sorbose dehydrogenase gene sdh promoter from K. vulgare) was 8 times higher than that of the wildtype K. vulgare DSM 4025 (P<0.001). In shake flask studies, the cell density and 2-KGA production of the recombinant K. vulgare Rif (pMCS2PsdhfolBC) were increased by 18% (P<0.001) and 14% (P<0.001), respectively, under a relatively stable pH 7 condition. In fermentor studies, enhancements around 25% cell density (P<0.001) and approximately 35% 2-KGA productivity (P<0.001) were observed in comparison with the controls without over-expressing the folate biosynthesis genes. This was the first successful study of metabolic engineering on K. vulgare for enhanced 2-KGA production.
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Fine mapping of qPAA8, a gene controlling panicle apical development in rice.
J Integr Plant Biol
PUBLISHED: 06-27-2011
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In rice, one detrimental factor influencing single panicle yield is the frequent occurrence of panicle apical abortion (PAA) under unfavorable climatic conditions. Until now, no detailed genetic information has been available to avoid PAA in rice breeding. Here, we show that the occurrence of PAA is associated with the accumulation of excess hydrogen peroxide. Quantitative trait loci (QTLs) mapping for PAA in an F(2) population derived from the cross of L-05261 (PAA line) × IRAT129 (non-PAA variety) identified seven QTLs over a logarithm of the odd (LOD) threshold of 2.5, explaining approximately 50.1% of phenotypic variance for PAA in total. Five of the QTLs with an increased effect from L-05261, were designated as qPAA3-1, qPAA3-2, qPAA4, qPAA5 and qPAA8, and accounted for 6.8%, 5.9%, 4.2%, 13.0% and 12.2% of phenotypic variance, respectively. We found that the PAA in the early heading plants was mainly controlled by qPAA8. Subsequently, using the sub-populations specific for qPAA8 based on marker-assisted selection, we further narrowed qPAA8 to a 37.6-kb interval delimited by markers RM22475 and 8-In112. These results are beneficial for PAA gene clone.
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Ars2 is overexpressed in human cholangiocarcinomas and its depletion increases PTEN and PDCD4 by decreasing microRNA-21.
Mol. Carcinog.
PUBLISHED: 06-23-2011
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Due to the lack of effective diagnostic tools, most patients with cholangiocarcinoma (CCA) have no chance of surgical resection. Ars2 is a protein that was reported to be important for microRNA (miR) biogenesis, and its depletion can reduce the levels of several miRs, including miR-21, which is overexpressed in CCAs. We hypothesized that Ars2 was also present in CCAs and could be an early diagnostic marker. In our experiments, Ars2, PTEN, PDCD4, and miR-21 were evaluated in 18 CCAs and paired normal tissues. ShArs2, miR-21 mimics, and Ars2 were transfected into CCA and bile duct epithelial cells either alone or together. Cell proliferation, tumorigenicity analysis and expression changes of Ars2, PTEN, PDCD4, and miR-21 were evaluated. We found that both Ars2 and miR-21 were overexpressed, with 95% sensitivity and 100% specificity, and an ROC of 0.995 in distinguishing between CCAs and paired normal tissues by qRT-PCR. PTEN and PDCD4 were reversed in immunohistochemistry, but no difference was observed using qRT-PCR. The knockdown of Ars2 in CCA cells decreased the level of miR-21, inhibited cell proliferation and prevented tumor formation in nude mice. Ars2 knockdown also led to an increase in both PTEN and PDCD4 protein levels. Both proteins decreased when the miR-21 mimic was con-transfected. However, the overexpression of Ars2 alone could not get the opposite results. Based on our data, we conclude that Ars2 is overexpressed in human CCA and may be a diagnostic marker. Ars2 depletion increases PTEN and PDCD4 protein levels via the reduction of miR-21.
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Fyn requires HnRNPA2B1 and Sam68 to synergistically regulate apoptosis in pancreatic cancer.
Carcinogenesis
PUBLISHED: 06-03-2011
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The Src family kinase Fyn, heterogenous nuclear ribonucleoprotein (HnRNP) A2B1 and Sam68 are thought to be associated with the metastasis of tumors, but their roles in the regulation of apoptosis remain unclear. This study investigated the role of Fyn and its potential relationship with HnRNPA2B1 and Sam68 in the regulation of apoptosis in pancreatic cancer. Experimental design. We examined both the activity of Fyn and the expression of HnRNPA2B1 in human pancreatic cancer tissues and systematically investigated the apoptotic mechanisms induced by Fyn activity using multiple experimental approaches.
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[Relationship between MnSOD polymorphisms and susceptibility of chronic poisoning exposed to manganism occupationally].
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi
PUBLISHED: 05-31-2011
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To study the relationship between polymorphisms of MnSOD and the susceptibility of chronic poisoning exposed to manganism occupationally.
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Vascular and micro-environmental influences on MSC-coral hydroxyapatite construct-based bone tissue engineering.
Biomaterials
PUBLISHED: 05-23-2011
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Bone tissue engineering (BTE) has been demonstrated an effective approach to generate bone tissue and repair bone defect in ectopic and orthotopic sites. The strategy of using a prevascularized tissue-engineered bone grafts (TEBG) fabricated ectopically to repair bone defects, which is called live bone graft surgery, has not been reported. And the quantitative advantages of vascularization and osteogenic environment in promoting engineered bone formation have not been defined yet. In the current study we generated a tissue engineered bone flap with a vascular pedicle of saphenous arteriovenous in which an organized vascular network was observed after 4 weeks implantation, and followed by a successful repaire of fibular defect in beagle dogs. Besides, after a 9 months long term observation of engineered bone formation in ectopic and orthotopic sites, four CHA (coral hydroxyapatite) scaffold groups were evaluated by CT (computed tomography) analysis. By the comparison of bone formation and scaffold degradation between different groups, the influences of vascularization and micro-environment on tissue engineered bone were quantitatively analyzed. The results showed that in the first 3 months vascularization improved engineered bone formation by 2 times of non-vascular group and bone defect micro-environment improved it by 3 times of ectopic group, and the CHA-scaffold degradation was accelerated as well.
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[Effect of lipoxin A(4) on lipopolysaccharide-induced endothelial hyperpermeability in human umbilical vein endothelial cell].
Zhonghua Fu Chan Ke Za Zhi
PUBLISHED: 05-18-2011
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To explore whether lipoxin A(4) (LXA(4))could prevent lipopolysaccharide (LPS)-induced human umbilical vein endothelial cells (HUVEC) monolayer hyperpermeability and its possible mechanism.
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The amsterdam declaration on fungal nomenclature.
IMA Fungus
PUBLISHED: 05-17-2011
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The Amsterdam Declaration on Fungal Nomenclature was agreed at an international symposium convened in Amsterdam on 19-20 April 2011 under the auspices of the International Commission on the Taxonomy of Fungi (ICTF). The purpose of the symposium was to address the issue of whether or how the current system of naming pleomorphic fungi should be maintained or changed now that molecular data are routinely available. The issue is urgent as mycologists currently follow different practices, and no consensus was achieved by a Special Committee appointed in 2005 by the International Botanical Congress to advise on the problem. The Declaration recognizes the need for an orderly transitition to a single-name nomenclatural system for all fungi, and to provide mechanisms to protect names that otherwise then become endangered. That is, meaning that priority should be given to the first described name, except where that is a younger name in general use when the first author to select a name of a pleomorphic monophyletic genus is to be followed, and suggests controversial cases are referred to a body, such as the ICTF, which will report to the Committee for Fungi. If appropriate, the ICTF could be mandated to promote the implementation of the Declaration. In addition, but not forming part of the Declaration, are reports of discussions held during the symposium on the governance of the nomenclature of fungi, and the naming of fungi known only from an environmental nucleic acid sequence in particular. Possible amendments to the Draft BioCode (2011) to allow for the needs of mycologists are suggested for further consideration, and a possible example of how a fungus only known from the environment might be described is presented.
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Effect of lipoxin A4 on lipopolysaccharide-induced endothelial hyperpermeability.
ScientificWorldJournal
PUBLISHED: 05-10-2011
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Excessive oxidative stress, decreased antioxidant capacity, and enhanced cellular calcium levels are initial factors that cause endothelial cell (EC) hyperpermeability, which represents a crucial event in the pathogenesis of pre-eclampsia. Lipoxin A4 (LXA4) strongly attenuated lipopolysaccharide (LPS)-induced hyperpermeability through maintaining the normal expression of VE-cadherin and â-catenin. This effect was mainly mediated by a specific LXA4 receptor. LXA4 could also obviously inhibit LPS-induced elevation of the cellular calcium level and up-regulation of the transient receptor potential protein family C 1, an important calcium channel in ECs. At the same time, LXA4 strongly blocked LPS-triggered reactive oxidative species production, while it promoted the expression of the NF-E2 related factor 2 (Nrf2) protein. Our findings demonstrate that LXA4 could prevent the EC hyperpermeability induced by LPS in human umbilical vein endothelial cells (HUVECs), under which the possible mechanism is through Nrf2 as well as Ca2+-sensitive pathways.
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[Effects of agonist and antagonist of cysteinyl leukotriene receptors on differentiation of rat glioma C6 cells].
Zhejiang Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 04-14-2011
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To investigate the role of cysteinyl leukotriene (CysLT) receptors in the differentiation of rat glioma C6 cells.
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[Construction of HEK293 cell lines expressing hCysLT? receptor and its application in screening of antagonists].
Zhejiang Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 04-14-2011
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To construct HEK293 cell lines stably expressing hCysLT(2) receptor, and to evaluate its application in screening of synthetic compounds with antagonist activity.
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Human chorionic gonadotropin (hCG) regulation of galectin-3 expression in endometrial epithelial cells and endometrial stromal cells.
Acta Histochem.
PUBLISHED: 03-15-2011
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Previous investigations on galectin-3 (gal-3) have focused mainly on its role in some malignant tumors. It was believed that gal-3 plays important roles in cell proliferation, apoptosis and adhesion in many cell types. Recently, gal-3 has been recognized as a factor related to endometrial receptivity in the human endometrium and trophoblast during embryo implantation. Human chorionic gonadotropin (hCG) is a specific embryonic hormone providing a signal from the embryo involved in preparing the receptive endometrium for embryo implantation. The current study aimed to determine whether hCG regulates gal-3 expression in endometrial cells. Our results showed that expression of gal-3 in both endometrial epithelial cells (EECs) and endometrial stromal cells (ESCs) could be regulated by hCG in an intricate manner. These results indicate that gal-3 might be regulated by hCG in preparing the endometrium for embryonic implantation.
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Nuclear translocation of MRP1 contributes to multidrug resistance of mucoepidermoid carcinoma.
Oral Oncol.
PUBLISHED: 03-14-2011
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Multidrug resistance-related protein 1 (MRP1 or ABCC1), a membrane-bound energy-dependent efflux transporter, is overexpressed in several kinds of multidrug-resistant cell lines and related to multidrug-resistance (MDR) of various cancers. In this study, we investigated whether MRP1 was involved in the chemoresistance of mucoepidermoid carcinoma (MEC). We demonstrated that down-regulation of MRP1 in MC3/5FU, a drug-resistant MEC cell line, by RNA interference increased the drug sensitivity of the cells to 5-fluorouracil, doxorubicin, pharmorubicin, bleomycin-A5, cis-platinum and taxol. However, no significant quantitative difference of MRP1 mRNA and protein expression was found between MC3/5FU cells and its parental cell line (MC3) as determined by RT-PCR and Western blot. Interestingly, MRP1 was translocated from the cytoplasmic membrane of the MC3 cells to the nuclei of MC3/5FU cells as revealed by indirect immunofluorescence staining. Furthermore, MRP1 down-regulation mainly decreased the nuclear expression of MRP1 rather than the cytoplasmic membrane expression. Our results suggested that MRP1 was involved in the chemoresistance of MEC and MRP1 may confer drug-resistance by a mechanism associated with its nuclear translocation.
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Lipoxin A4 and its analog suppress hepatocellular carcinoma via remodeling tumor microenvironment.
Cancer Lett.
PUBLISHED: 03-10-2011
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Macrophages play an important role in tumor inflammatory microenvironment, lipoxin (LX), the stop signal for inflammation, has been extensively studied preclinically for its anti-inflammatory or inflammatory pro-resolving effect. Here, we showed that LXA(4) could promote the apoptosis and inhibit the proliferation, migration and angiogenesis of HepG2 hepatocarcinoma cells stimulated by lipopolysaccharide (LPS) or activated macrophage-conditioned media (ACM). Moreover, BML-111, the analog of LXA(4), effectively inhibited the proliferation, invasion and angiogenesis of tumor in H22 hepatocarcinoma cell bearing mice. These results showed that LXA(4) could be a possible candidate for liver cancer therapy, and blocking the activation of macrophages would be an effective drug target.
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Scavenger receptor SR-BI in macrophage lipid metabolism.
Atherosclerosis
PUBLISHED: 03-07-2011
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To investigate the mechanisms by which macrophage scavenger receptor BI (SR-BI) regulates macrophage cholesterol homeostasis and protects against atherosclerosis.
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Conditional deletion of NRSF in forebrain neurons accelerates epileptogenesis in the kindling model.
Cereb. Cortex
PUBLISHED: 02-21-2011
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Neuron-restrictive silencer factor (NRSF), also known as repressor element-1 silencing transcription factor, is a transcriptional repressor that plays important roles in embryonic development and neurogenesis. Recent findings show that NRSF is upregulated after seizures activity however, the link between NRSF and epileptogenesis remains poorly understood. To investigate the role of NRSF in epilepsy, we employed a Cre-loxp system to specifically delete NRSF in excitatory neurons of the postnatal mouse forebrain. In the kindling model of epileptogenesis, conditional NRSF knockout (NRSF-cKO) mice exhibited dramatically accelerated seizure progression and prolonged afterdischarge duration compared with control mice. Moreover, seizures activity-induced mossy fiber sprouting was enhanced in the NRSF-cKO mice. The degree of upregulation of Fibroblast growth factor 14 and Brain-derived neurotrophic factor (BDNF) following kainic acid-induced status epilepticus was significantly increased in the cortex of NRSF-cKO mice compared with control mice. Furthermore, the derepression of BDNF was associated by activation of PLC? and PI(3)K signaling pathways. These findings indicate that NRSF functions as an intrinsic repressor of limbic epileptogenesis.
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Deficiency of sorting nexin 27 (SNX27) leads to growth retardation and elevated levels of N-methyl-D-aspartate receptor 2C (NR2C).
Mol. Cell. Biol.
PUBLISHED: 02-07-2011
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Phox (PX) domain-containing sorting nexins (SNXs) are emerging as important regulators of endocytic trafficking. Sorting nexin 27 (SNX27) is unique, as it contains a PDZ (Psd-95/Dlg/ZO1) domain. We show here that SNX27 is primarily targeted to the early endosome by interaction of its PX domain with PtdIns(3)P. Although targeted ablation of the SNX27 gene in mice did not significantly affect growth and survival during embryonic development, SNX27 plays an essential role in postnatal growth and survival. N-Methyl-d-aspartate (NMDA) receptor 2C (NR2C) was identified as a novel SNX27-interacting protein, and this interaction is mediated by the PDZ domain of SNX27 and the C-terminal PDZ-binding motif of NR2C. Increased NR2C expression levels, together with impaired NR2C endocytosis in SNX27(-/-) neurons, indicate that SNX27 may function to regulate endocytosis and/or endosomal sorting of NR2C. This is consistent with a role of SNX27 as a general regulator for sorting of membrane proteins containing a PDZ-binding motif, and its absence may alter the trafficking of these proteins, leading to growth and survival defects.
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Pancreas-sparing duodenectomy with regional lymphadenectomy for pTis and pT1 ampullary carcinoma.
Surgery
PUBLISHED: 02-04-2011
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The role of pancreas-sparing duodenectomy (PSD) in the treatment of ampullary carcinoma (Amp Ca) with local lymph node metastasis remains controversial. The aim of this study was to investigate the feasibility, safety, and long-term prognosis of PSD with regional lymphadenectomy in the treatment of early-stage (pTis/pT1) Amp Ca with or without regional lymph node metastasis.
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Exposed hydroxyapatite particles on the surface of photo-crosslinked nanocomposites for promoting MC3T3 cell proliferation and differentiation.
Acta Biomater
PUBLISHED: 01-25-2011
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We present a systematic study for investigating the role of exposed hydroxyapatite (HA) nanoparticles in influencing surface characteristics and mouse pre-osteoblastic MC3T3-E1 cell behavior using nanocomposites prepared by photo-crosslinking poly(?-caprolactone) diacrylate (PCLDA) with HA. PCLDA530 and PCLDA2000 synthesized from poly(?-caprolactone) diol precursors with nominal molecular weights of 530 and 2000 g mol(-1) were used as the polymer matrices. Crosslinked PCLDA530 was amorphous while crosslinked PCLDA2000 was semi-crystalline. Crosslinked PCLDA/HA composites with different compositions of HA (10%, 20% and 30%) as well as crosslinked PCLDAs were characterized in terms of their composition-dependent physicochemical properties. The tensile, compressive and shear moduli were greatly enhanced by incorporating HA nanoparticles with the polymer matrices. The disk surfaces of original crosslinked PCLDA/HA nanocomposites were removed by cutting using a blade to expose HA nanoparticles that were embedded in the polymer substrates. The composition of HA was much higher on the cut surface, particularly in semi-crystalline crosslinked PCLDA2000/HA nanocomposites. The surface characteristics of original and cut crosslinked PCLDA/HA nanocomposites were compared and correlated with cell behavior on these nanocomposites. MC3T3-E1 cell attachment, proliferation and differentiation were significantly enhanced when the HA composition was increased in original crosslinked PCLDA/HA nanocomposites due to more bioactive HA, higher surface stiffness and rougher topography. More exposed HA on the surface of cut semi-crystalline PCLDA2000/HA nanocomposites resulted in improved hydrophilicity and significantly better MC3T3 cell attachment, proliferation and differentiation compared with the original surfaces. This study suggests that HA nanoparticles may not be fully exploited in polymer/HA nanocomposites where the top polymer surface covers the particles. The removal of this polymer layer can generate more desirable surfaces and osteoconductivity for bone repair and regeneration.
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Identification of proteins interacting with human SP110 during the process of viral infections.
Med Chem
PUBLISHED: 01-13-2011
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Human SP110 plays an important role in resisting intracellular pathogens, and hence has become an important drug target for preventing intracellular pathogen diseases, such as tuberculosis, hepatic veno-occlusive disease, and intracellular cancers. Unfortunately, so far little is known about the interactions of SP110 with the other proteins in a cell, which is considered to be the key for revealing its action mechanism and mediated pathway. Using both the genetic and structural analyses as well as the segment-docking approach, we have identified two proteins: the human remodeling and spacing factor 1 (RSF1) and the activating transcription factor 7 interacting protein (ATF7IP). They are very likely interacting with human SP110 during the process of viral infections. Owing to the close relationship of RSF1 with the chromatin remodeling and ATF7IP with the chromatin formation, it is logical to infer that human SP110 may be involved in the chromatin remodeling and formation as well. These findings may provide useful insights into the development of new drugs for treating and preventing intracellular pathogen diseases.
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Spatial-temporal expression of NDRG2 in rat brain after focal cerebral ischemia and reperfusion.
Brain Res.
PUBLISHED: 01-08-2011
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N-myc downstream regulated gene 2 (NDRG2) was reported to be widely expressed in the nervous system. However, the expression and potential role of NDRG2 in focal cerebral ischemia brain remain unclear. Herein, we investigated spatial-temporal expression of NDRG2 in the rat brain following transient focal cerebral ischemia. Male Sprague-Dawley rats underwent a 120-min transient occlusion of middle cerebral artery. Rats were killed and brain samples were harvested at 4, 12, 24, and 72h after reperfusion. Expression of NDRG2 in the brain was determined by reverse transcriptase-polymerase chain reaction (RT-PCR), Western blot analysis and immunohistochemical staining. Cellular apoptosis was assessed by TUNEL staining. The results showed that NDRG2 was expressed on cells with an astrocytes-like morphology in ischemic penumbra. NDRG2 mRNA and protein expression began to increase at 4h after reperfusion and peaked at 24h in the ischemic penumbra. By using immunofluorescence, NDRG2 signals were co-localized with GFAP-positive astrocytes, and NDRG2 expression in astrocytes translocated from a cytoplasm to a nuclear localization at 24h after reperfusion. Double immunofluorescent staining for TUNEL and NDRG2 showed that some NDRG2 signals co-localized with TUNEL-positive cells, and that the apoptotic cells increased with enhancement of NDRG2-positive signals. In conclusion, NDRG2 expression is up-regulated in ischemic penumbra following transient focal cerebral ischemia. NDRG2 expression in astrocytes may play important pathological roles in cell apoptosis after stroke.
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[The role of apoptosis in the stress-related changes of intestinal mucosa barrier following traumatic brain injury].
Zhonghua Nei Ke Za Zhi
PUBLISHED: 12-18-2010
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To investigate the role of epithelial cell apoptosis in the stress-related changes of intestinal mucosa barrier following traumatic brain injury.
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Gender-specific prognostic markers of patients with gallbladder cancer after surgical resection.
Am Surg
PUBLISHED: 12-15-2010
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The aim of this study was to elucidate gender-specific markers for postresectional long-term survival of gallbladder cancer (GBC) based on a cohort of Chinese patients. Clinicopathological records of 81 patients (27 males and 54 females) after surgical resection for GBC were reviewed retrospectively. The influence of each variable on survival was determined using the Kaplan-Meier method and log-rank test. For females, Cox regression analysis was also adopted. Univariate analysis showed that the absence of lymph node and distant metastases, differentiation grade, and curative resection were associated with prolonged survival for all males, whereas tumor size, differentiation grade, and the presence of lymph node metastases influenced the overall or disease-free survival of patients after curative resection (all P < 0.05). On the other hand, Nevin stage was an independent marker for both overall survival for all females and overall and disease-free survival for female patients who underwent curative resection. Additionally, resection type and differentiation grade were of independent prognostic significance for different subgroups of females (all P < 0.05). Our data suggested that tumor-related factors affect prognosis of both male and female patients with GBC after resection. Of these factors, tumor differentiation status might be more significant for males, but Nevin stage had a stronger predictive potential for females.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.