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Find video protocols related to scientific articles indexed in Pubmed.
Transcriptional bypass of regioisomeric ethylated thymidine lesions by T7 RNA polymerase and human RNA polymerase II.
Nucleic Acids Res.
PUBLISHED: 11-19-2014
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Alkylative damage to DNA can be induced by environmental chemicals, endogenous metabolites and some commonly prescribed chemotherapeutic agents. The regioisomeric N3-, O(2)- and O(4)-ethylthymidine (N3-, O(2)- and O(4)-EtdT, respectively) represent an important class of ethylated DNA lesions. Using nonreplicative double-stranded vectors containing an N3-EtdT, O(2)-EtdT or O(4)-EtdT at a defined site in the template strand, herein we examined the effects of these lesions on DNA transcription mediated by single-subunit T7 RNA polymerase or multisubunit human RNA polymerase II in vitro and in human cells. We found that O(4)-EtdT is highly mutagenic and exclusively induces the misincorporation of guanine opposite the lesion, whereas N3-EtdT and O(2)-EtdT display promiscuous miscoding properties during transcription. In addition, N3-EtdT and O(2)-EtdT were found to inhibit strongly DNA transcription in vitro and in certain human cells. Moreover, N3-EtdT, but not O(2)-EtdT or O(4)-EtdT, is an efficient substrate for transcription-coupled nucleotide excision repair. These findings provide new important insights into how these alkylated DNA lesions compromise the flow of genetic information, which may help to understand the risk of these lesions in living cells.
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Pirenzepine Inhibits Myopia in Guinea Pig Model by Regulating the Balance of MMP-2 and TIMP-2 Expression and Increased Tyrosine Hydroxylase Levels.
Cell Biochem. Biophys.
PUBLISHED: 11-13-2014
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In this study, we investigated the effects and mechanism of action of pirenzepine in a guinea pig model of myopia induced by exposure to monochromatic light. It was observed that pirenzepine inhibited the increase of diopter and extension of ocular axial length. Immunohistochemistry staining showed that the number of tyrosine hydroxylase (TH)-positive cells in pirenzepine group was significantly higher compared to the other treatment groups pointing to a highly positive correlation between TH expression levels and the diopter and axial length change. RT-PCR analysis further showed that pirenzepine treatment reduced the expression of matrix metalloproteinase (MMP-2) and enhanced the expression of tissue inhibitors of metalloproteinase (TIMP-2) compared to the other treatment and control groups. To conclude, we demonstrate that pirenzepine may improve the prognosis of monochromatic light-induced myopia in guinea pigs, possibly by both regulating the balance of MMP-2 and TIMP-2 in sclera and increasing the TH expression in retina.
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AcCystatin, an immunoregulatory molecule from Angiostrongylus cantonensis, ameliorates the asthmatic response in an aluminium hydroxide/ovalbumin-induced rat model of asthma.
Parasitol. Res.
PUBLISHED: 11-05-2014
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Epidemiological surveys have demonstrated that helminth infections are negatively related to atopic diseases, including asthma. Defining and characterising specific helminth molecules that have excellent immunomodulatory capacities as potential therapeutics for the treatment or prophylaxis of allergic manifestations are of great interest. AcCystatin, a cystatin protease inhibitor of Angiostrongylus cantonensis, is a homologue of other nematode cystatins with immunoregulatory properties. Here, we aim to determine the effects of AcCystatin on an ovalbumin/aluminium hydroxide (OVA/Al[OH]3)-induced rat model of asthma. Wistar rats were randomly divided into four groups, including a control group, an OVA/Al[OH]3-induced asthma group, a group receiving AcCystatin immunisation prior to OVA/Al[OH]3-induced asthma and a group receiving AcCystatin treatment after OVA/Al[OH]3-induced asthma. The numbers of eosinophils, basophils, neutrophils, lymphocytes and monocytes in the peripheral blood and of eosinophils in the bronchoalveolar lavage fluid (BALF) were counted for each animal. The expression levels of the cytokines interferon-?, interleukin (IL) 4, IL-5, IL-6, IL-10, IL17A and tumour necrosis factor receptor-? in BALF, of OVA-specific immunoglobulin E in BALF and serum and of the chemokines eotaxin-1, eotaxin-2, eotaxin-3, MCP-1 and MCP-3 in lung tissue were measured. In addition, the degree of peribronchial and perivascular inflammation and the intensity of goblet cell metaplasia were qualitatively evaluated. The sensitised/challenged rats developed an extensive cell inflammatory response of the airways. AcCystatin administration significantly reduced the cellular infiltrate in the perivascular and peribronchial lung tissues and reduced both goblet mucous production and eosinophil infiltration. The rats that were treated with AcCystatin before or after sensitisation with OVA showed significant decreases in eotaxin-1, eotaxin-3 and MCP-1 expression in the lung tissue. The production of IL-4, IL-5, IL-6 and IL-17A and of OVA-specific IgE antibodies was also significantly reduced in AcCystatin-treated rats compared with untreated asthmatic rats. The AcCystatin treatment was associated with a significant increase in IL-10 levels. Our present findings provide the first demonstration that AcCystatin is an effective agent in the prevention and treatment of the airway inflammation associated with asthma.
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From Ergolines to Indoles: Improved Inhibitors of the Human H3 Receptor for the Treatment of Narcolepsy.
ChemMedChem
PUBLISHED: 09-26-2014
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Ergolines were recently identified as a novel class of H3 receptor (H3R) inverse agonists. Although their optimization led to drug candidates with encouraging properties for the treatment of narcolepsy, brain penetration remained low. To overcome this issue, ergoline 1 ((6aR,9R,10aR)-4-(2-(dimethylamino)ethyl)-N-phenyl-9-(pyrrolidine-1-carbonyl)-6,6a,8,9,10,10a-hexahydroindolo[4,3-fg]quinoline-7(4H)-carboxamide)) was transformed into a series of indole derivatives with high H3R affinity. These new molecules were profiled by simultaneous determination of their brain receptor occupancy (RO) levels and pharmacodynamic (PD) effects in mice. These efforts culminated in the discovery of 15?m ((R)-1-isopropyl-5-(1-(2-(2-methylpyrrolidin-1-yl)ethyl)-1H-indol-4-yl)pyridin-2(1H)-one), which has an ideal profile showing a strong correlation of PD effects with RO, and no measurable safety liabilities. Its desirably short duration of action was confirmed by electroencephalography (EEG) measurements in rats.
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Arsenite binds to the RING finger domains of RNF20-RNF40 histone E3 ubiquitin ligase and inhibits DNA double-strand break repair.
J. Am. Chem. Soc.
PUBLISHED: 09-09-2014
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Arsenic is a widespread environmental contaminant. However, the exact molecular mechanisms underlying the carcinogenic effects of arsenic remain incompletely understood. Core histones can be ubiquitinated by RING finger E3 ubiquitin ligases, among which the RNF20-RNF40 heterodimer catalyzes the ubiquitination of histone H2B at lysine 120. This ubiquitination event is important for the formation of open and biochemically accessible chromatin fiber that is conducive for DNA repair. Herein, we found that arsenite could bind directly to the RING finger domains of RNF20 and RNF40 in vitro and in cells, and treatment with arsenite resulted in substantially impaired H2B ubiquitination in multiple cell lines. Exposure to arsenite also diminished the recruitment of BRCA1 and RAD51 to laser-induced DNA double-strand break (DSB) sites, compromised DNA DSB repair in human cells, and rendered cells sensitive toward a radiomimetic agent, neocarzinostatin. Together, the results from the present study revealed, for the first time, that arsenite may exert its carcinogenic effect by targeting cysteine residues in the RING finger domains of histone E3 ubiquitin ligase, thereby altering histone epigenetic mark and compromising DNA DSB repair. Our results also suggest arsenite as a general inhibitor for RING finger E3 ubiquitin ligases.
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New maltol glycosides from Flos Sophorae.
J Nat Med
PUBLISHED: 09-01-2014
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Three new maltol glycosides, designated soyamalosides A (1), B (2), and C (3), together with eight known compounds (4-11), were obtained from a 70 % EtOH extract of Flos Sophorae. Their structures were elucidated by chemical and spectroscopic methods. Of the known compounds, this is the first report of 4-6, 9, and 11 in the Sophora genus. Compounds 2, 3, and 10 showed significant protective effects against antimycin A-induced L6 cell injury.
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Linalool, derived from Cinnamomum camphora (L.) Presl leaf extracts, possesses molluscicidal activity against Oncomelania hupensis and inhibits infection of Schistosoma japonicum.
Parasit Vectors
PUBLISHED: 08-29-2014
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Schistosomiasis japonicum remains a considerable economic and public health concern in China, the Philippines and Indonesia. Currently available measures to control the unique intermediate host Oncomelania hupensis are frequently associated with severe side effects. Previous studies have demonstrated that linalool-rich extracts from various plants exhibited promising biological activities including cytotoxic, anti-microbial and anti-parasitic properties.
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Profiling the T-cell receptor repertoire of patient with pleural tuberculosis by high-throughput sequencing.
Immunol. Lett.
PUBLISHED: 08-27-2014
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Pleural tuberculosis (PLTB), a major cause of morbidity and mortality, is the most common extrapulmonary manifestation of active Mycobacterium tuberculosis (Mtb) in developing countries. Gamma delta T-cell receptor (TCR) repertoire of peripheral blood mononuclear cells (PBMCs) and pleural effusion mononuclear cells (PEMCs) and beta TCR repertoire from peripheral blood mononuclear cells (PBMCs) have been reported. However, a detailed different characteristic of beta TCR repertoire of mononuclear cells isolated from peripheral blood and pleural fluid in the immune response to Mtb infection should be further revealed. The TCR ?-chain (TRB) from PBMCs and PEMCs from an untreated pleural tuberculosis patient was sequenced by the Illumina sequencing platform. A total of 96,758 and 124,130 unique complementarity-determining region 3 (CDR3) sequences were identified at the nucleotide level, encoding 69,488 and 99,095 peptide sequences, respectively. TCR profiling showed that TRBV20-1 family and TRBV20-1/TRBJ1-5 gene combination had a dominant expression in PEMCs, but not in PBMCs. Expansive expression of common CDR3 clonotypes was observed in PEMCs. CDR3 spectratyping analysis showed that few TRBV families had a significantly skewed pattern, with one peak or a few prominent peaks in the PBMCs. By contrast, some TRBV families showed oligoclonal or clonal expansion in the PEMCs. Here, we firstly profiled the TRB repertoire differences of PBMCs and PEMCs from one PLTB patient using high-throughput sequencing. And this study may provide new insight for the detailed and efficient study of TCR repertoire of PEMCs in the future.
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Local delivery of minocycline-loaded PEG-PLA nanoparticles for the enhanced treatment of periodontitis in dogs.
Int J Nanomedicine
PUBLISHED: 08-18-2014
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Rapid local drug clearance of antimicrobials is a major drawback for the treatment of chronic periodontitis. In the study reported here, minocycline-loaded poly(ethylene glycol)-poly(lactic acid) nanoparticles were prepared and administered locally for long drug retention and enhanced treatment of periodontitis in dogs.
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Analysis of fluorescent ceramide and sphingomyelin analogs: a novel approach for in vivo monitoring of sphingomyelin synthase activity.
Lipids
PUBLISHED: 08-10-2014
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A novel sensitive high-performance liquid chromatography-fluorescence detection (HPLC-FLD) method was developed for real-time monitoring of relative sphingomyelin synthase (SMS) activity based on the measurement of a fluorescent ceramide (Cer) analog and its metabolite, a fluorescent sphingomyelin (CerPCho) analog, in plasma. Analyses were conducted using HPLC-FLD following a protein precipitation procedure. The chromatographic separations were carried out on an Agilent C18 RP column (150 × 4.6 mm, 5 ?m) based on a methanol-0.1 % trifluoroacetic acid aqueous solution (88:12, by vol) elution at a flow-rate of 1 mL/min. The limit of quantification in plasma was 0.05 ?M for both the fluorescent Cer analog and its metabolite. Significant differences in the fluorescent Cer analog and its metabolite concentration ratio at 5 min were found between vehicle control group and three D2 (a novel SMS inhibitor) dose groups (P < 0.05). Dose-dependent effects (D2 doses: 0, 2.5, 5, 10 mg/kg) were observed. Our method could be used to detect relative SMS activity in biochemical assays and to screen potential SMS inhibitors in vivo. D2 was found to be a potent SMS inhibitor in vivo, and may have a potential antiatherosclerotic effect, which is under further study. D609 was also selected as another model SMS inhibitor to validate our newly developed method.
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Effects of Tet-mediated Oxidation Products of 5-Methylcytosine on DNA Transcription in vitro and in Mammalian Cells.
Sci Rep
PUBLISHED: 08-07-2014
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5-methylcytosine (5-mC) is a well-characterized epigenetic regulator in mammals. Recent studies showed that Ten-eleven translocation (Tet) proteins can catalyze the stepwise oxidation of 5-mC to produce 5-hydroxymethylcytosine (5-HmC), 5-formylcytosine (5-FoC) and 5-carboxylcytosine (5-CaC). The exciting discovery of these novel cytosine modifications has stimulated substantial research interests about their roles in epigenetic regulation. Here we systematically examined the effects of the oxidized 5-mC derivatives on the efficiency and fidelity of DNA transcription using a recently developed competitive transcription and adduct bypass assay. Our results showed that, when located on the transcribed strand, 5-FoC and 5-CaC exhibited marginal mutagenic and modest inhibitory effects on DNA transcription mediated by single-subunit T7 RNA polymerase or multi-subunit human RNA polymerase II in vitro and in human cells. 5-HmC displayed relatively milder blocking effects on transcription, and no mutant transcript could be detectable for 5-HmC in vitro or in cells. The lack of considerable mutagenic effects of the oxidized 5-mC derivatives on transcription was in agreement with their functions in epigenetic regulation. The modest blocking effects on transcription suggested that 5-FoC and 5-CaC may function in transcriptional regulation. These findings provided new evidence for the potential functional interplay between cytosine methylation status and transcription.
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New terpenoid glycosides obtained from Rosmarinus officinalis L. aerial parts.
Fitoterapia
PUBLISHED: 07-26-2014
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Five new terpenoid glycosides, named as officinoterpenosides A1 (1), A2 (2), B (3), C (4), and D (5), together with 11 known ones, (1S,4S,5S)-5-exo-hydrocamphor 5-O-?-d-glucopyranoside (6), isorosmanol (7), rosmanol (8), 7-methoxyrosmanol (9), epirosmanol (10), ursolic acid (11), micromeric acid (12), oleanolic acid (13), niga-ichigoside F1 (14), glucosyl tormentate (15), and asteryunnanoside B (16), were obtained from the aerial parts of Rosmarinus officinalis L. Their structures were elucidated by chemical and spectroscopic methods (UV, IR, HRESI-TOF-MS, 1D and 2D NMR). Among the new ones, 1 and 2, 3 and 4 are diterpenoid and triterpenoid glycosides, respectively; and 5 is a normonoterpenoid. For the known ones, 6 was isolated from the Rosmarinus genus first, and 15, 16 were obtained from this species for the first time.
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Endothelium-dependent and -independent relaxation of rat aorta induced by extract of Schizophyllum commune.
Phytomedicine
PUBLISHED: 07-25-2014
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Schizophyllum commune (SC) is widely consumed by Chinese, especially in southern part of China. The aim of the present study was to assess the extract of SC on vascular tone and the mechanisms involved. Experiments were performed on aorta of 18-week-old male Sprague-Dawley rats. Dried SC was extracted with 50% ethanol, 90% ethanol and deionized water, respectively. The effects of SC on the isometric tension of rat aortic rings were measured. Protein expression for the endothelial nitric oxide synthase (eNOS) was also determined in the primarily cultured rat aortic arterial endothelial cells (RAECs). The results showed that the water extract of SC induced a marked relaxation in aortic rings with or without endothelium. After the pretreatments of N(?)-nitro-l-arginine methyl ester, indomethacin, RP-cAMP, and methylene blue, the SC-induced relaxation was significantly decreased. In addition, the contraction due to Ca(2+) influx and intracellular Ca(2+) release was also inhibited by SC. Furthermore, expression of the eNOS protein was significantly elevated in RAECs after treatment of SC. In conclusion, the water extract of SC induces an endothelium-dependent and -independent relaxation in rat aorta. The relaxing effect of SC involves the modulation of NO-cGMP-dependent pathways, PGI2-cAMP-depedent pathways, Ca(2+) influx though calcium channels and intracellular Ca(2+) release.
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A Review of Recent Research Progress on the Astragalus Genus.
Molecules
PUBLISHED: 07-22-2014
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Astragalus L., is one of the largest genuses of flowering plants in the Leguminosae family. Roots of A. membranaceus Bge. var. mongholicus (Bge.) Hsiao, A. membranaceus (Fisch.) Bge. and its processed products are listed in the China Pharmacopeia for "qi deficiency" syndrome treatment. However, more and more researches on other species of Astragalus have been conducted recently. We summarize the recent researches of Astragalus species in phytochemistry and pharmacology. More than 200 constituents, including saponins and flavonoids, obtained from 46 species of Astragalus genus were collected for this article. In pharmacological studies, crude extracts of Astragalus, as well as isolated constituents showed anti-inflammatory, immunostimulant, antioxidative, anti-cancer, antidiabetic, cardioprotective, hepatoprotective, and antiviral activities. The goal of this article is to provide an overview of chemical and pharmacological studies on the Astragalus species over the last 10 years, which could be of value to new drug or food supplement research and development.
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Corticosterone mitigates the stress response in an animal model of PTSD.
J Psychiatr Res
PUBLISHED: 07-18-2014
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Activation of glucocorticoid receptor signaling in the stress response to traumatic events has been implicated in the pathogenesis of stress-associated psychiatric disorders such as post-traumatic stress disorder (PTSD). Elevated startle response and hyperarousal are hallmarks of PTSD, and are generally considered to evince fear (DSM V). To further examine the efficacy of corticosterone in treating hyperarousal and elevated fear, the present study utilized a learned helplessness stress model in which rats are restrained and subjected to tail shock for three days. These stressed rats develop a delayed long-lasting exaggeration of the acoustic startle response (ASR) and retarded body weight growth, similar to symptoms of PTSD patients (Myers et al., 2005; Speed et al., 1989). We demonstrate that both pre-stress and post-stress administration of corticosterone (3 mg/kg/day) mitigates a subsequent exaggeration of the ASR measured 14 days after cessation of the stress protocol. Furthermore, the mitigating efficacy of pre-stress administration of corticosterone (3 mg/kg/day for three days) appeared to last significantly longer, up to 21 days after the cessation of the stress protocol, in comparison to that of post-stress administration of corticosterone. However, pre-stress administration of corticosterone at 0.3 mg/kg/day for three days did not mitigate stress-induced exaggeration of the ASR measured at both 14 and 21 days after the cessation of the stress protocol. In addition, pre-stress administration of corticosterone (3 mg/kg/day for three days) mitigates the retardation of body weight growth otherwise resulting from the stress protocol. Congruently, co-administration of the corticosterone antagonist RU486 (40 mg/kg/day for three days) with corticosterone (3 mg/kg/day) prior to stress diminished the mitigating efficacy of the exogenous corticosterone on exaggerated ASR and stress-retarded body weight. The relative efficacy of pre versus post administration of corticosterone and high versus low dose of corticosterone on stress-induced exaggeration of innate fear response and stress-retarded body weight growth indicate that exogenous corticosterone administration within an appropriate time window and dosage are efficacious in diminishing traumatic stress induced pathophysiological processes. Clinical implications associated with the efficacy of prophylactic and therapeutic corticosterone therapy for mitigating symptoms of PTSD are discussed, particularly in relation to diminishing hyperarousal and exaggerated innate fear response.
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IKK? negatively regulates ASC-dependent inflammasome activation.
Nat Commun
PUBLISHED: 07-17-2014
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The inflammasomes are multiprotein complexes that activate caspase-1 in response to infections and stress, resulting in the secretion of pro-inflammatory cytokines. Here we report that I?B kinase ? (IKK?) is a critical negative regulator of apoptosis-associated specklike protein containing a C-terminal caspase-activation-andrecruitment (CARD) domain (ASC)-dependent inflammasomes. IKK? controls the inflammasome at the level of the adaptor ASC, which interacts with IKK? in the nucleus of resting macrophages in an IKK? kinase-dependent manner. Loss of IKK? kinase activity results in inflammasome hyperactivation. Mechanistically, the downstream nuclear effector IKK-related kinase (IKKi) facilitates translocation of ASC from the nucleus to the perinuclear area during inflammasome activation. ASC remains under the control of IKK? in the perinuclear area following translocation of the ASC/IKK? complex. Signal 2 of NLRP3 activation leads to inhibition of IKK? kinase activity through the recruitment of PP2A, allowing ASC to participate in NLRP3 inflammasome assembly. Taken together, these findings reveal a IKKi-IKK?-ASC axis that serves as a common regulatory mechanism for ASC-dependent inflammasomes.
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The differential regulation of human ACT1 isoforms by Hsp90 in IL-17 signaling.
J. Immunol.
PUBLISHED: 07-14-2014
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IL-17 is a proinflammatory cytokine implicated in the pathogenesis of autoimmune diseases including psoriasis. ACT1 is an essential adaptor molecule in the IL-17 signaling pathway. A missense single nucleotide polymorphism (rs33980500; SNP-D10N) that resulted in the substitution of an asparagine for an aspartic acid at position 10 of ACT1 (ACT1-D10N) is associated with psoriasis susceptibility. Due to alternative splicing in humans, SNP-D10N encodes two mutated ACT1 proteins, ACT1-D10N and ACT1-D19N. Although both ACT1 isoforms are Hsp90 client proteins, the nine additional amino acids in ACT1-D19N provide an additional Hsp90 binding site that is absent in ACT1-D10N. Therefore, whereas ACT1-D10N is a dead protein that is unable to transduce IL-17 signals for gene expression, ACT1-D19N is fully responsive to IL-17. Intriguingly, the two ACT1 isoforms are differentially expressed in ACT1(D10N/D10N) fibroblasts and T cells. Fibroblasts express both isoforms equally, enabling ACT1-D19N to compensate for the loss of ACT1-D10N function. ACT1(D10N/D10N) T cells, however, express predominantly ACT1-D10N. Lacking this compensatory mechanism, ACT1(D10N/D10N) T cells behave like ACT1-deficient T cells, exhibiting a dysregulated and hyperactive Th17 phenotype with overproduction of IL-22 and IL-17. The hyperactive Th17 response combined with fully responsive fibroblasts likely synergized to contribute to psoriasis susceptibility in SNP-D10N patients.
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A novel mouse model of Campylobacter jejuni gastroenteritis reveals key pro-inflammatory and tissue protective roles for Toll-like receptor signaling during infection.
PLoS Pathog.
PUBLISHED: 07-01-2014
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Campylobacter jejuni is a major source of foodborne illness in the developed world, and a common cause of clinical gastroenteritis. Exactly how C. jejuni colonizes its host's intestines and causes disease is poorly understood. Although it causes severe diarrhea and gastroenteritis in humans, C. jejuni typically dwells as a commensal microbe within the intestines of most animals, including birds, where its colonization is asymptomatic. Pretreatment of C57BL/6 mice with the antibiotic vancomycin facilitated intestinal C. jejuni colonization, albeit with minimal pathology. In contrast, vancomycin pretreatment of mice deficient in SIGIRR (Sigirr(-/-)), a negative regulator of MyD88-dependent signaling led to heavy and widespread C. jejuni colonization, accompanied by severe gastroenteritis involving strongly elevated transcription of Th1/Th17 cytokines. C. jejuni heavily colonized the cecal and colonic crypts of Sigirr(-/-) mice, adhering to, as well as invading intestinal epithelial cells. This infectivity was dependent on established C. jejuni pathogenicity factors, capsular polysaccharides (kpsM) and motility/flagella (flaA). We also explored the basis for the inflammatory response elicited by C. jejuni in Sigirr(-/-) mice, focusing on the roles played by Toll-like receptors (TLR) 2 and 4, as these innate receptors were strongly stimulated by C. jejuni. Despite heavy colonization, Tlr4(-/-)/Sigirr(-/-) mice were largely unresponsive to infection by C. jejuni, whereas Tlr2(-/-)/Sigirr(-/-) mice developed exaggerated inflammation and pathology. This indicates that TLR4 signaling underlies the majority of the enteritis seen in this model, whereas TLR2 signaling had a protective role, acting to promote mucosal integrity. Furthermore, we found that loss of the C. jejuni capsule led to increased TLR4 activation and exaggerated inflammation and gastroenteritis. Together, these results validate the use of Sigirr(-/-) mice as an exciting and relevant animal model for studying the pathogenesis and innate immune responses to C. jejuni.
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C/EBP? promotes angiogenesis through secretion of IL-6, which is inhibited by genistein, in EGFRvIII-positive glioblastoma.
Int. J. Cancer
PUBLISHED: 05-13-2014
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To study the mechanisms underlying the IL-6-promoted angiogenic microenvironment in EGFRvIII-positive glioblastoma, VEGF expression in EGFRvIII positive/negative tumors was determined by optical molecular imaging. Next, the HUVEC tube formation assay, Western blot, qPCR, RNA silencing, chromatin immuno-precipitation, luciferase reporter, and ELISA assays were performed to examine the role of IL-6 and C/EBP? in the formation of the angiogenic microenvironment in EGFRvIII-positive tumors. Finally, in vitro and in vivo genistein treatment experiments were conducted to challenge the interaction between the IL-6 promoter and C/EBP?. Optical imaging revealed greater VEGF expression in EGFRvIII-positive tumor-bearing mice, suggesting an angiogenic microenvironment. In vitro experiments demonstrated that C/EBP?-mediated regulation of IL-6 was indispensable for maintenance of this angiogenic microenvironment. In contrast, genistein-mediated up-regulation of CHOP impeded C/EBP? interaction with the IL-6 promoter, thus disturbing the angiogenic microenvironment. This more malignant microenvironment in EGFRvIII glioblastoma is generated, at least in part, by greater VEGF, IL-6, and C/EBP? expression. Interaction of C/EBP? with the IL-6 promoter maintains this angiogenic microenvironment, while disturbance of this dynamically balanced interaction inhibits EGFRvIII tumor proliferation by reducing both VEGF and IL-6 expression. © 2014 Wiley Periodicals, Inc.
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The large-scale investigation of gene expression in Leymus chinensis stigmas provides a valuable resource for understanding the mechanisms of poaceae self-incompatibility.
BMC Genomics
PUBLISHED: 05-09-2014
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Many Poaceae species show a gametophytic self-incompatibility (GSI) system, which is controlled by at least two independent and multiallelic loci, S and Z. Until currently, the gene products for S and Z were unknown. Grass SI plant stigmas discriminate between pollen grains that land on its surface and support compatible pollen tube growth and penetration into the stigma, whereas recognizing incompatible pollen and thus inhibiting pollination behaviors. Leymus chinensis (Trin.) Tzvel. (sheepgrass) is a Poaceae SI species. A comprehensive analysis of sheepgrass stigma transcriptome may provide valuable information for understanding the mechanism of pollen-stigma interactions and grass SI.
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Association between thrombelastography system and vascular obstructions and hemorrhage: a two-year follow-up study of elderly Chinese patients.
Ann. Clin. Lab. Sci.
PUBLISHED: 05-06-2014
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This study was designed to test the hypothesis that prior thrombelastography (TEG) indices are associated with subsequent vascular obstructions and hemorrhage events in aged populations, as well as to obtain knowledge about the distribution of TEG indices in elderly Chinese patients.
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Determination of purine contents in different parts of pork and beef by high performance liquid chromatography.
Food Chem
PUBLISHED: 05-02-2014
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Determination of adenine, hypoxanthine, guanine and xanthine in different parts of pork and beef using high performance liquid chromatography was described. Chromatographic separation was carried out on Waters Atlantis T3 column (4.6mm×250mm×5?m) with column temperature at 30°C. The mobile phase contained 99% 10.0mmol/L ammonium formate solution at pH 3.6 and 1.0% methanol. Chromatography was achieved at a flow rate of 1.0mL/min and detection wavelength at 254nm. The results indicated that total purine amounts in pork rump and beef sirloin were higher than those in other parts (P<0.05). The principal purine bases were hypoxanthine and adenine, and hypoxanthine content was the most highest in all samples (P<0.05). As pork rump and beef sirloin contain considerable amounts of total purine and uricogenic purine base, we suggest that excess consumption of them be avoid, whereas pork loin chop and beef rib eye are more suitable for a low-purine diet.
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?-N-methylation of damaged DNA-binding protein 2 (DDB2) and its function in nucleotide excision repair.
J. Biol. Chem.
PUBLISHED: 04-21-2014
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DDB2 exhibits a high affinity toward UV-damaged DNA, and it is involved in the initial steps of global genome nucleotide excision repair. Mutations in the DDB2 gene cause the genetic complementation group E of xeroderma pigmentosum, an autosomal recessive disease manifested clinically by hypersensitivity to sunlight exposure and an increased predisposition to skin cancer. Here we found that, in human cells, the initiating methionine residue in DDB2 was removed and that the N-terminal alanine could be methylated on its ?-amino group in human cells, with trimethylation being the major form. We also demonstrated that the ?-N-methylation of DDB2 is catalyzed by the N-terminal RCC1 methyltransferase. In addition, a methylation-defective mutant of DDB2 displayed diminished nuclear localization and was recruited at a reduced efficiency to UV-induced cyclobutane pyrimidine dimer foci. Moreover, loss of this methylation conferred compromised ATM (ataxia telangiectasia mutated) activation, decreased efficiency in cyclobutane pyrimidine dimer repair, and elevated sensitivity of cells toward UV light exposure. Our study provides new knowledge about the posttranslational regulation of DDB2 and expands the biological functions of protein ?-N-methylation to DNA repair.
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MyD88-dependent interplay between myeloid and endothelial cells in the initiation and progression of obesity-associated inflammatory diseases.
J. Exp. Med.
PUBLISHED: 04-21-2014
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Low-grade systemic inflammation is often associated with metabolic syndrome, which plays a critical role in the development of the obesity-associated inflammatory diseases, including insulin resistance and atherosclerosis. Here, we investigate how Toll-like receptor-MyD88 signaling in myeloid and endothelial cells coordinately participates in the initiation and progression of high fat diet-induced systemic inflammation and metabolic inflammatory diseases. MyD88 deficiency in myeloid cells inhibits macrophage recruitment to adipose tissue and their switch to an M1-like phenotype. This is accompanied by substantially reduced diet-induced systemic inflammation, insulin resistance, and atherosclerosis. MyD88 deficiency in endothelial cells results in a moderate reduction in diet-induced adipose macrophage infiltration and M1 polarization, selective insulin sensitivity in adipose tissue, and amelioration of spontaneous atherosclerosis. Both in vivo and ex vivo studies suggest that MyD88-dependent GM-CSF production from the endothelial cells might play a critical role in the initiation of obesity-associated inflammation and development of atherosclerosis by priming the monocytes in the adipose and arterial tissues to differentiate into M1-like inflammatory macrophages. Collectively, these results implicate a critical MyD88-dependent interplay between myeloid and endothelial cells in the initiation and progression of obesity-associated inflammatory diseases.
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An insight into the key genes and biological functions associated with insulin resistance in adipose tissue with microarray technology.
Mol Med Rep
PUBLISHED: 04-08-2014
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In the present study, the key genes and biological functions associated with insulin resistance were investigated by comparing the gene expression profiles of adipose tissue obtained from insulin?sensitive and insulin?resistant patients. The gene expression data set GSE20950 was downloaded from the Gene Expression Omnibus, including 39 adipose tissue samples obtained from insulin?sensitive and insulin?resistant patients undergoing gastric bypass surgery. Adipose samples were divided into two groups (the insulin?sensitive and insulin?resistant groups) and the differentially expressed genes (DEGs) were screened out with packages of R. The interactions among DEGs were retrieved with Osprey and functional enrichment analysis was performed with the WebGestalt system. Information regarding the interaction network and enriched biological functions was combined to construct a functional interaction network. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was then conducted using the Database for Annotation, Visualization and Integrated Discovery. A total of 170 DEGs were detected in the insulin?sensitive group, 8 downregulated and 162 upregulated. Response to glucose stimulus was the most significantly over?represented functional term. The focal adhesion pathway was identified to be significant in the genes of the functional interaction network. The present study revealed key biological functions and DEGs in adipose tissues associated with insulin resistance, which may facilitate the development of novel therapies for insulin resistance and diabetes.
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A new rotavirus VP6-based foreign epitope presenting vector and immunoreactivity of VP4 epitope chimeric proteins.
Viral Immunol.
PUBLISHED: 04-04-2014
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The VP6, the group antigenic rotavirus (RV), is highly conserved and the most abundant, constituting about 39% of the viral structure proteins by weight. The high degree of identity (>87%-99%) in the primary amino acid sequences suggests VP6-based vaccines could potentially provide heterotypic protection. Although some efforts have been made toward producing recombinant rotavirus VP6 vaccines, the native VP6 is still unsatisfactory as an optimal vaccine. The major neutralizing antigenic epitopes that exist on VP4 or VP7 are not on the native VP6, and as a vector the native VP6 lacks insertion sites that can be used for insertion of foreign epitopes. In this study, a new foreign epitope presenting system using VP6 as a vector (VP6F) was constructed on the outer surface of the vector six sites that could be used for insertion of the foreign epitopes created. Using this system, three VP6-based VP4 epitope chimeric proteins were constructed. Results showed that these chimeric proteins reacted with anti-VP6 and -VP4 antibodies, and elicited antibodies against VP6 and VP4 in guinea pigs. Antibodies against VP6F or antibodies against the chimeric proteins neutralized RV Wa and SA11 infection in vitro. It is optimistic that the limitation for using the native VP6 as a vaccine candidate or vector will be solved with our proposed approach. It is expected that this VP6-based epitope presenting system and the VP6-based VP4 epitope chimeric proteins will be valuable for and contribute to the development of novel RV vaccines and vaccine vectors.
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Analysis of 116 cases of rectal cancer treated by transanal local excision.
World J Surg Oncol
PUBLISHED: 03-25-2014
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The purpose of this research was to evaluate the therapeutic effects and prognostic factors of transanal local excision (TAE) for rectal cancer.
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IRAK4 dimerization and trans-autophosphorylation are induced by Myddosome assembly.
Mol. Cell
PUBLISHED: 03-03-2014
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Trans-autophosphorylation is among the most prevalent means of protein kinase activation, yet its molecular basis is poorly defined. In Toll-like receptor and interleukin-1 receptor signaling pathways, the kinase IRAK4 is recruited to the membrane-proximal adaptor MyD88 through death domain (DD) interactions, forming the oligomeric Myddosome and mediating NF-?B activation. Here we show that unphosphorylated IRAK4 dimerizes in solution with a KD of 2.5 ?M and that Myddosome assembly greatly enhances IRAK4 kinase domain (KD) autophosphorylation at sub-KD concentrations. The crystal structure of the unphosphorylated IRAK4(KD) dimer captures a conformation that appears to represent the actual trans-autophosphorylation reaction, with the activation loop phosphosite of one IRAK4 monomer precisely positioned for phosphotransfer by its partner. We show that dimerization is crucial for IRAK4 autophosphorylation in vitro and ligand-dependent signaling in cells. These studies identify a mechanism for oligomerization-driven allosteric autoactivation of IRAK4 that may be general to other kinases activated by autophosphorylation.
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Reaction analysis and visualization of ReaxFF molecular dynamics simulations.
J. Mol. Graph. Model.
PUBLISHED: 03-02-2014
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ReaxFF MD (Reactive Force Field Molecular Dynamics) is a promising method for investigating complex chemical reactions in relatively larger scale molecular systems. The existing analysis tools for ReaxFF MD lack the capability of capturing chemical reactions directly by analyzing the simulation trajectory, which is critical in exploring reaction mechanisms. This paper presents the algorithms, implementation strategies, features, and applications of VARxMD, a tool for Visualization and Analysis of Reactive Molecular Dynamics. VARxMD is dedicated to detailed chemical reaction analysis and visualization from the trajectories obtained in ReaxFF MD simulations. The interrelationships among the atoms, bonds, fragments, species and reactions are analyzed directly from the three-dimensional (3D) coordinates and bond orders of the atoms in a trajectory, which are accomplished by determination of atomic connectivity for recognizing connected molecular fragments, perception of bond types in the connected fragments for molecules or radicals, indexing of all these molecules or radicals (chemical species) based on their 3D coordinates and recognition of bond breaking or forming in the chemical species for reactions. Consequently, detailed chemical reactions taking place between two sampled frames can be generated automatically. VARxMD is the first tool specialized for reaction analysis and visualization in ReaxFF MD simulations. Applications of VARxMD in ReaxFF MD simulations of coal and HDPE (high-density polyethylene) pyrolysis show that VARxMD provides the capabilities in exploring the reaction mechanism in large systems with complex chemical reactions involved that are difficult to access manually.
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Effects of voltage-gated K+ channel on cell proliferation in multiple myeloma.
ScientificWorldJournal
PUBLISHED: 02-26-2014
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To study the effects and underlying mechanisms of voltage-gated K(+) channels on the proliferation of multiple myeloma cells.
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Telomere length - a cellular aging marker for depression and Post-traumatic Stress Disorder.
Med. Hypotheses
PUBLISHED: 02-24-2014
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Telomeres play a central role in cell fate and aging by adjusting the cellular response to both biological and psychological stress. Human telomeres are regions of tandem TTAGGG repeats at chromosomal ends that protect chromosomes from degradation, fusion, and recombination. They are made up of approximately 1000-2500 copies of the repeated DNA sequence. Over time, at each cell division, the telomere ends become shorter. Thus, telomere length (TL) has been considered a cellular marker for age-related diseases. In addition to biochemical stressors such as oxidation and inflammation, psychosocial traumatic stress has also been linked to shorter telomeres. TL is significantly inversely correlated with long-term depression, even after controlling for age. Average TL in depressed subjects, who were above the median of lifetime depression, was 281 base pairs shorter than that in controls, corresponding to approximately 7years of accelerated cell aging. Several recent studies have also demonstrated an inverse relationship between leukocyte telomere length (LTL) and the risk of PTSD. TL was inversely correlated with the duration of caregiving and PTSD. Here, we focus on the discussion of findings in studies of the relationships between stress-related disorders (e.g., depression and PTSD) and telomeres. We also present direct evidence that TL is associated with traumatic stress, depression, and PTSD, and hypothesize that traumatic stress affects not only mental disorders but also cellular aging. The nature of this relationship between stress and TL warrants further evaluation in psychiatry.
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Generation, transmission and infectiosity of chicken MDV aerosols under experimental conditions.
Vet. Microbiol.
PUBLISHED: 01-25-2014
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To further investigate the airborne infection mechanism of Marek's disease virus (MDV), a MDV aerosol infection model was established, and the generation, transmission and infectiosity of MDV aerosols were monitored in this study. Two positive/negative pressure isolators, in which SPF chickens were raised, were connected with a closed conduit. Two repetitive trials, Trial 1 (T1) and Trial 2 (T2) were carried out for objective assessment. Air samples were collected using the AGI-30 sampler. Viral DNA in air samples and feather follicle samples were detected using real-time quantitative PCR (QRT-PCR). MDV in air and blood samples was detected by indirect immunofluorescence assay (IFA). In chickens of isolator A (MDV inoculation group), MDV was detected in feather follicles in 100% of the tested chickens at 6 days post inoculation (dpi) in both trials; and MDV was isolated from blood samples at 9-10 dpi. MDV DNA was detected in air samples from isolator A at 12 dpi in T1 and 14 dpi in T2 and concentration of aerosolized MDV DNA was peaked at 3.84 × 10(6)copies/m(3) air at 40 dpi in T1, and 6.17 × 10(5)copies/m(3) air at 38 dpi in T2, respectively. Infectious MDV (cell culture) was isolated from isolator A at 17 in T1 and 19 dpi in T2, respectively. MDV aerosol in Isolator B was almost same as isolator A. Viremia was detected in isolator B at 26-30 dpi. The incidence of viremia in isolator B reached 70% at 3 months post inoculation. These results demonstrated that infected chicken could discharge virus, the MDV could form aerosols and infect neighboring chickens. Understanding the mechanism of generation and infection of MDV aerosols is helpful to prevent and control MD.
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Structure of the unique SEFIR domain from human interleukin 17 receptor A reveals a composite ligand-binding site containing a conserved ?-helix for Act1 binding and IL-17 signaling.
Acta Crystallogr. D Biol. Crystallogr.
PUBLISHED: 01-20-2014
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Interleukin 17 (IL-17) cytokines play a crucial role in mediating inflammatory and autoimmune diseases. A unique intracellular signaling domain termed SEFIR is found within all IL-17 receptors (IL-17Rs) as well as the key adaptor protein Act1. SEFIR-mediated protein-protein interaction is a crucial step in IL-17 cytokine signaling. Here, the 2.3 Å resolution crystal structure of the SEFIR domain of IL-17RA, the most commonly shared receptor for IL-17 cytokine signaling, is reported. The structure includes the complete SEFIR domain and an additional ?-helical C-terminal extension, which pack tightly together to form a compact unit. Structural comparison between the SEFIR domains of IL-17RA and IL-17RB reveals substantial differences in protein topology and folding. The uniquely long insertion between strand ?C and helix ?C in IL-17RA SEFIR is mostly well ordered, displaying a helix (?CC'ins) and a flexible loop (CC'). The DD' loop in the IL-17RA SEFIR structure is much shorter; it rotates nearly 90° with respect to the counterpart in the IL-17RB SEFIR structure and shifts about 12?Å to accommodate the ?CC'ins helix without forming any knots. Helix ?C was identified as critical for its interaction with Act1 and IL-17-stimulated gene expression. The data suggest that the heterotypic SEFIR-SEFIR association via helix ?C is a conserved and signature mechanism specific for IL-17 signaling. The structure also suggests that the downstream motif of IL-17RA SEFIR together with helix ?C could provide a composite ligand-binding surface for recruiting Act1 during IL-17 signaling.
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Correlation between miR-23a and onset of hepatocellular carcinoma.
Clin Res Hepatol Gastroenterol
PUBLISHED: 01-10-2014
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To clarify the role of miR-23a in the onset and development of hepatocarcinoma on the cellular, genetic and molecular levels.
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Vasodilatory effect of 14,15-epoxyeicosatrienoic acid on mesenteric arteries in hypertensive and aged rats.
Prostaglandins Other Lipid Mediat.
PUBLISHED: 01-04-2014
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The objective of this study was to investigate the 14,15-epoxyeicosatrienoic acid (14,15-EET)-induced vasodilatations as well as the underlying signaling pathways in rat mesenteric arteries from young, adult and old normotensive (WKY) and hypertensive rats. Protein expressions for prostaglandin EP(1-4) receptors, large conductance Ca(2+)-activated K(+) (BK(Ca)) channels, and adenylate cyclase (AC) were determined together with 14,15-EET-induced vasodilatations in primary- versus secondary-branches of the mesenteric artery. Responses to 14,15-EET were greater in the smaller secondary- versus primary-branches (and also more sensitive with lower EC50) and were reduced in vessels from old (80 weeks) rats as well as from vessels from the spontaneous hypertensive rats (SHR). Regardless of age or hypertension responses to 14,15-EET were inhibited by the EP2 antagonist AH6809, BK(Ca) channel inhibitor iberiotoxin, or 3',5'-cyclic monophosphate (cAMP)-protein kinase A (PKA) pathway antagonists. These data indicate 14,15-EET-induced vasodilatation is mediated via the activation of EP2 receptors and opening of BK(Ca) channels. The expressions of the EP2 receptor and AC were markedly reduced in vessels from SHR as well as old rats, whereas BK(Ca) expression was reduced in old WKY and SHR, but not adult SHR. Furthermore, expression of the p53 protein, an indicator of cell senescence and apoptosis, was elevated in adult and old SHR as well as in old WKY. In summary, attenuated 14,15-EET-induced vasodilatation in mesenteric arteries from old normotensive WKY as well as adult and old SHR is associated with reduced expression of EP2 receptors and AC.
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Carex diaoluoshanica (Carex sect. Lageniformes, Cyperaceae), a new species from Hainan, China.
PLoS ONE
PUBLISHED: 01-01-2014
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Carex diaoluoshanica, a new species of Carex sect. Lageniformes from Hainan, China, is described and illustrated. The new species is similar to C. breviscapa but differs in having wider leaves with the leaf base gradually narrowed, 5-10 cm long and petiolelike, culms subfiliform, with only two spikes, the lateral female spikes from near the culm base.
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Cadherin-11 in renal cell carcinoma bone metastasis.
PLoS ONE
PUBLISHED: 01-01-2014
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Bone is one of the common sites of metastases from renal cell carcinoma (RCC), however the mechanism by which RCC preferentially metastasize to bone is poorly understood. Homing/retention of RCC cells to bone and subsequent proliferation are necessary steps for RCC cells to colonize bone. To explore possible mechanisms by which these processes occur, we used an in vivo metastasis model in which 786-O RCC cells were injected into SCID mice intracardially, and organotropic cell lines from bone, liver, and lymph node were selected. The expression of molecules affecting cell adhesion, angiogenesis, and osteolysis were then examined in these selected cells. Cadherin-11, a mesenchymal cadherin mainly expressed in osteoblasts, was significantly increased on the cell surface in bone metastasis-derived 786-O cells (Bo-786-O) compared to parental, liver, or lymph node-derived cells. In contrast, the homing receptor CXCR4 was equivalently expressed in cells derived from all organs. No significant difference was observed in the expression of angiogenic factors, including HIF-1?, VEGF, angiopoeitin-1, Tie2, c-MET, and osteolytic factors, including PTHrP, IL-6 and RANKL. While the parental and Bo-786-O cells have similar proliferation rates, Bo-786-O cells showed an increase in migration compared to the parental 786-O cells. Knockdown of Cadherin-11 using shRNA reduced the rate of migration in Bo-786-O cells, suggesting that Cadherin-11 contributes to the increased migration observed in bone-derived cells. Immunohistochemical analysis of cadherin-11 expression in a human renal carcinoma tissue array showed that the number of human specimens with positive cadherin-11 activity was significantly higher in tumors that metastasized to bone than that in primary tumors. Together, these results suggest that Cadherin-11 may play a role in RCC bone metastasis.
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Transcriptome analysis reveals common and distinct mechanisms for sheepgrass (Leymus chinensis) responses to defoliation compared to mechanical wounding.
PLoS ONE
PUBLISHED: 01-01-2014
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Herbivore grazing is a multiple-component process that includes wounding, defoliation, and saliva deposition. Despite the extensive published research on mechanical wounding and defoliation, no analysis to identify the genes that specify defoliation and mechanical wounding has been performed. Moreover, the influence of the expression of these genes on plant regrowth after defoliation remains poorly understood.
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Therapeutic role of ursolic acid on ameliorating hepatic steatosis and improving metabolic disorders in high-fat diet-induced non-alcoholic fatty liver disease rats.
PLoS ONE
PUBLISHED: 01-01-2014
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Non-alcoholic fatty liver disease (NAFLD) is one of the most prevalent liver diseases around the world, and is closely associated with obesity, diabetes, and insulin resistance. Ursolic acid (UA), an ubiquitous triterpenoid with multifold biological roles, is distributed in various plants. This study was conducted to investigate the therapeutic effect and potential mechanisms of UA against hepatic steatosis in a high-fat diet (HFD)-induced obese non-alcoholic fatty liver disease (NAFLD) rat model.
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Pathogenic pseudorabies virus, China, 2012.
Emerging Infect. Dis.
PUBLISHED: 01-01-2014
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In 2012, an unprecedented large-scale outbreak of disease in pigs in China caused great economic losses to the swine industry. Isolates from pseudorabies virus epidemics in swine herds were characterized. Evidence confirmed that the pathogenic pseudorabies virus was the etiologic agent of this epidemic.
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IRAK-1 bypasses priming and directly links TLRs to rapid NLRP3 inflammasome activation.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 12-30-2013
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Pathogenic infections and tissue injuries trigger the assembly of inflammasomes, cytosolic protein complexes that activate caspase-1, leading to cleavage of pro-IL-1? and pro-IL-18 and to pyroptosis, a proinflammatory cell death program. Although microbial recognition by Toll-like receptors (TLRs) is known to induce the synthesis of the major caspase-1 substrate pro-IL-1?, the role of TLRs has been considered limited to up-regulation of the inflammasome components. During infection with a virulent microbe, TLRs and nucleotide-binding oligomerization domain-like receptors (NLRs) are likely activated simultaneously. To examine the requirements and outcomes of combined activation, we stimulated TLRs and a specific NLR, nucleotide binding and oligomerization, leucine-rich repeat, pyrin domain-containing 3 (NLRP3), simultaneously and discovered that such activation triggers rapid caspase-1 cleavage, leading to secretion of presynthesized inflammatory molecules and pyroptosis. This acute caspase-1 activation is independent of new protein synthesis and depends on the TLR-signaling molecule IL-1 receptor-associated kinase (IRAK-1) and its kinase activity. Importantly, Listeria monocytogenes induces NLRP3-dependent rapid caspase-1 activation and pyroptosis, both of which are compromised in IRAK-1-deficient macrophages. Our results reveal that simultaneous sensing of microbial ligands and virulence factors by TLRs and NLRP3, respectively, leads to a rapid TLR- and IRAK-1-dependent assembly of the NLRP3 inflammasome complex, and that such activation is important for release of alarmins, pyroptosis, and early IFN-? production by memory CD8 T cells, all of which could be critical for early host defense.
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IL-4 Derived from Non-T Cells Induces Basophil- and IL-3-independent Th2 Immune Responses.
Immune Netw
PUBLISHED: 11-20-2013
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How Th2 immunity develops in vivo remains obscure. Basophils have been considered key innate cells producing IL-4, a cytokine essential for Th2 immunity. Increasing evidence suggests that basophils are dispensable for the initiation of Th2 immunity. In this study, we revisited the role of basophils in Th2 immune responses induced by various types of adjuvants. Mice deficient in IL-3 or IL-3 receptor, in which basophil lymph node recruitment is completely abolished, fully developed wild type level Th2 CD4 T cell responses in response to parasite antigen or papain immunization. Similar finding was also observed in mice where basophils are inducibly ablated. Interestingly, IL-4-derived from non-T cells appeared to be critical for the generation of IL-4-producing CD4 T cells. Other Th2 promoting factors including IL-25 and thymic stromal lymphopoietin (TSLP) were dispensable. Therefore, our results suggest that IL-3- and basophil-independent in vivo Th2 immunity develops with the help of non-T cell-derived IL-4, offering an additional mechanism by which Th2 type immune responses arise in vivo.
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Contemporary epidemiology of gout and hyperuricemia in community elderly in Beijing.
Int J Rheum Dis
PUBLISHED: 09-30-2013
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To evaluate the prevalence and risk factors of gout and hyperuricemia in an elderly community cohort in Beijing.
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Morphologic characteristics and proliferation of rabbit corneal stromal cells onto complexes of collagen-chitosan-sodium hyaluronate under simulated microgravity.
Invest. Ophthalmol. Vis. Sci.
PUBLISHED: 09-28-2013
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We investigated the morphologic characteristics and proliferation of rabbit corneal stromal cells (CSCs) onto scaffolds under simulated microgravity.
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Prediction of outcomes in crescentic IgA nephropathy in a multicenter cohort study.
J. Am. Soc. Nephrol.
PUBLISHED: 09-12-2013
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Crescentic IgA nephropathy (IgAN), defined as >50% crescentic glomeruli on kidney biopsy, is one of the most common causes of rapidly progressive GN. However, few studies have characterized this condition. To identify risk factors and develop a prediction model, we assessed data from patients?14 years old with crescentic IgAN who were followed ?12 months. The discovery cohort comprised 52 patients from one kidney center, and the validation cohort comprised 61 patients from multiple centers. At biopsy, the mean serum creatinine (SCr) level ± SD was 4.3±3.4 mg/dl, and the mean percentage of crescents was 66.4%±15.8%. The kidney survival rates at years 1, 3, and 5 after biopsy were 57.4%±4.7%, 45.8%±5.1%, and 30.4%±6.6%, respectively. Multivariate Cox regression revealed initial SCr as the only independent risk factor for ESRD (hazard ratio [HR], 1.32; 95% confidence interval [CI], 1.10 to 1.57; P=0.002). Notably, the percentage of crescents did not associate independently with ESRD. Logistic regression showed that the risk of ESRD at 1 year after biopsy increased rapidly at SCr>2.7 mg/dl and reached 90% at SCr>6.8 mg/dl (specificity=98.5%, sensitivity=64.6% for combined cohorts). In both cohorts, patients with SCr>6.8 mg/dl were less likely to recover from dialysis. Analyses in additional cohorts revealed a similar association between initial SCr and ESRD in patients with antiglomerular basement membrane disease but not ANCA-associated systemic vasculitis. In conclusion, crescentic IgAN has a poor prognosis, and initial SCr concentration may predict kidney failure in patients with this disease.
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Identification of novel ?-n-methylation of CENP-B that regulates its binding to the centromeric DNA.
J. Proteome Res.
PUBLISHED: 08-26-2013
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The eukaryotic centromere is an essential chromatin region required for accurate segregation of sister chromatids during cell division. Centromere protein B (CENP-B) is a highly conserved protein which can bind to the 17-bp CENP-B box on the centromeric DNA. In this study, we found that CENP-B could be ?-N-methylated in human cells. We also showed that the level of the ?-N-methylation was stimulated in cells in response to a variety of extracellular stimuli, including increased cell density, heat shock, and arsenite treatment, although the methylation level was not altered upon metaphase arrest. We identified N-terminal RCC1 methyltransferase (NRMT) as a major enzyme required for the CENP-B methylation. Additionally, we found that chromatin-bound CENP-B was primarily trimethylated and ?-N-trimethylation could enhance CENP-Bs binding to CENP-B box in cells. Our study also expands the function of protein ?-N-methylation that has been known for decades and whose function remains largely unexplored.
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Translesion synthesis of 8,5-cyclopurine-2-deoxynucleosides by DNA polymerases ?, ?, and ?.
J. Biol. Chem.
PUBLISHED: 08-21-2013
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Reactive oxygen species can give rise to a battery of DNA damage products including the 8,5-cyclo-2-deoxyadenosine (cdA) and 8,5-cyclo-2-deoxyguanosine (cdG) tandem lesions. The 8,5-cyclopurine-2-deoxynucleosides are quite stable lesions and are valid and reliable markers of oxidative DNA damage. However, it remains unclear how these lesions compromise DNA replication in mammalian cells. Previous in vitro biochemical assays have suggested a role for human polymerase (Pol) ? in the insertion step of translesion synthesis (TLS) across the (5S) diastereomers of cdA and cdG. Using in vitro steady-state kinetic assay, herein we showed that human Pol ? and a two-subunit yeast Pol ? complex (REV3/REV7) could function efficiently in the insertion and extension steps, respectively, of TLS across S-cdA and S-cdG; human Pol ? and Pol ? could also extend past these lesions, albeit much less efficiently. Results from a quantitative TLS assay showed that, in human cells, S-cdA and S-cdG inhibited strongly DNA replication and induced substantial frequencies of mutations at the lesion sites. Additionally, Pol ?, Pol ?, and Pol ?, but not Pol ?, had important roles in promoting replication through S-cdA and S-cdG in human cells. Based on these results, we propose a model for TLS across S-cdA and S-cdG in human cells, where Pol ? and/or Pol ? carries out nucleotide insertion opposite the lesion, whereas Pol ? executes the extension step.
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Application of RIFLE criteria in patients with multiple myeloma with acute kidney injury: a 15-year retrospective, single center, cohort study.
Leuk. Lymphoma
PUBLISHED: 08-20-2013
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Although there have been numerous studies of patients with multiple myeloma (MM) and acute kidney injury (AKI), the results from these studies have varied greatly because of inconsistent definitions of AKI. The RIFLE criteria, which were designed to standardize the staging of AKI, have been extensively validated worldwide, but rarely in patients with MM. We retrospectively analyzed the natural history of 78 patients with MM and AKI between July 1995 and December 2010. RIFLE criteria, solely on the basis of the serum creatinine standard, were applied to stage the severity of AKI as risk, injury or failure. Among patients at the risk, injury and failure stage, the chemotherapy response rates were 54.5%, 63.6% and 39.3% (p = 0.26), and the renal response rates were 72.7%, 90.9% and 30.4%, respectively (p < 0.001). Severity of AKI predicted renal response but not chemotherapy response. Older age (odds ratio [OR] = 1.04, p = 0.01), hypercalcemia (OR = 2.57, p = 0.01) and reversibility of renal insufficiency (OR = 3.35 for no vs. yes, p < 0.001) were independent prognostic factors associated with survival. Severity of AKI staged by RIFLE class (OR = 2.04, failure stage vs. risk and injury stages. p = 0.06) was associated with marginally better long-term outcome. The RIFLE criteria may play a critical role in the early prevention and management of AKI in this population.
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SIGIRR, a negative regulator of TLR/IL-1R signalling promotes Microbiota dependent resistance to colonization by enteric bacterial pathogens.
PLoS Pathog.
PUBLISHED: 08-01-2013
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Enteric bacterial pathogens such as enterohemorrhagic E. coli (EHEC) and Salmonella Typhimurium target the intestinal epithelial cells (IEC) lining the mammalian gastrointestinal tract. Despite expressing innate Toll-like receptors (TLRs), IEC are innately hypo-responsive to most bacterial products. This is thought to prevent maladaptive inflammatory responses against commensal bacteria, but it also limits antimicrobial responses by IEC to invading bacterial pathogens, potentially increasing host susceptibility to infection. One reason for the innate hypo-responsiveness of IEC is their expression of Single Ig IL-1 Related Receptor (SIGIRR), a negative regulator of interleukin (IL)-1 and TLR signaling. To address whether SIGIRR expression and the innate hypo-responsiveness of IEC impacts on enteric host defense, Sigirr deficient (-/-) mice were infected with the EHEC related pathogen Citrobacter rodentium. Sigirr -/- mice responded with accelerated IEC proliferation and strong pro-inflammatory and antimicrobial responses but surprisingly, Sigirr -/- mice proved dramatically more susceptible to infection than wildtype mice. Through haematopoietic transplantation studies, it was determined that SIGIRR expression by non-haematopoietic cells (putative IEC) regulated these responses. Moreover, the exaggerated responses were found to be primarily dependent on IL-1R signaling. Whilst exploring the basis for their susceptibility, Sigirr -/- mice were found to be unusually susceptible to intestinal Salmonella Typhimurium colonization, developing enterocolitis without the typical requirement for antibiotic based removal of competing commensal microbes. Strikingly, the exaggerated antimicrobial responses seen in Sigirr -/- mice were found to cause a rapid and dramatic loss of commensal microbes from the infected intestine. This depletion appears to reduce the ability of the microbiota to compete for space and nutrients (colonization resistance) with the invading pathogens, leaving the intestine highly susceptible to pathogen colonization. Thus, SIGIRR expression by IEC reflects a strategy that sacrifices maximal innate responsiveness by IEC in order to promote commensal microbe based colonization resistance against bacterial pathogens.
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Spontaneous loss of tolerance of autoreactive B cells in Act1-deficient rheumatoid factor transgenic mice.
J. Immunol.
PUBLISHED: 07-31-2013
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Self-reactive B cells in BALB/c AM14 transgenic (Tg) rheumatoid factor mice are not subject to central or peripheral tolerization. Instead, they remain at a stage of "clonal ignorance"; that is, they do not proliferate and differentiate into Ab-forming cells. However, the immunoregulatory mechanisms that prevent autoantibody production in these mice remain unclear. In this study, we show that crossing AM14 Tg mice to a mouse strain deficient in Act1, a molecule involved in the regulation of BAFF-R and CD40-signaling in B cells, results in spontaneous activation of AM14 Tg B cells and production of AM14-specific Abs. Three- to 5-mo-old AM14 Tg Act1(-/-) mice showed significant expansion of AM14 Tg B cells, including a 2- to 3-fold increase in the spleen and cervical lymph nodes compared with AM14 Tg Act1(+/+) mice. Furthermore, in the presence of endogenous self-Ag (IgH(a) congenic background), AM14 Tg Act1(-/-) B cells were spontaneously activated and differentiated into Ab-forming cells. In contrast with previous studies using AM14 Tg MLR.Fas(lpr) mice, we found that a significant number of AM14 Tg cells AM14 Tg Act1(-/-) mice displayed phenotypic characteristics of germinal center B cells. Anti-CD40L treatment significantly limited the expansion and activation of AM14 Tg Act1(-/-) B cells, suggesting that CD40L-mediated signals are required for the retention of these cells. Our results support the important role of Act1 in the regulation of self-reactive B cells and reveal how Act1 functions to prevent the production of autoantibodies.
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Activation of neutrophils by autocrine IL-17A-IL-17RC interactions during fungal infection is regulated by IL-6, IL-23, ROR?t and dectin-2.
Nat. Immunol.
PUBLISHED: 07-23-2013
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Here we identified a population of bone marrow neutrophils that constitutively expressed the transcription factor ROR?t and produced and responded to interleukin 17A (IL-17A (IL-17)). IL-6, IL-23 and ROR?t, but not T cells or natural killer (NK) cells, were required for IL-17 production in neutrophils. IL-6 and IL-23 induced expression of the receptors IL-17RC and dectin-2 on neutrophils, and IL-17RC expression was augmented by activation of dectin-2. Autocrine activity of IL-17A and its receptor induced the production of reactive oxygen species (ROS), and increased fungal killing in vitro and in a model of Aspergillus-induced keratitis. Human neutrophils also expressed ROR?t and induced the expression of IL-17A, IL-17RC and dectin-2 following stimulation with IL-6 and IL-23. Our findings identify a population of human and mouse neutrophils with autocrine IL-17 activity that probably contribute to the etiology of microbial and inflammatory diseases.
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Release of nonmuscle myosin II from the cytosolic domain of tumor necrosis factor receptor 2 is required for target gene expression.
Sci Signal
PUBLISHED: 07-18-2013
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Tumor necrosis factor-? (TNF-?) elicits its biological activities through activation of TNF receptor 1 (TNFR1, also known as p55) and TNFR2 (also known as p75). The activities of both receptors are required for the TNF-?-induced proinflammatory response. The adaptor protein TNFR-associated factor 2 (TRAF2) is critical for either p55- or p75-mediated activation of nuclear factor ?B (NF-?B) and mitogen-activated protein kinase (MAPK) signaling, as well as for target gene expression. We identified nonmuscle myosin II (myosin) as a binding partner of p75. TNF-?-dependent signaling by p75 and induction of target gene expression persisted substantially longer in cells deficient in myosin regulatory light chain (MRLC; a component of myosin) than in cells replete in myosin. In resting endothelial cells, myosin was bound constitutively to the intracellular region of p75, a region that overlaps with the TRAF2-binding domain, and TNF-? caused the rapid dissociation of myosin from p75. At early time points after exposure to TNF-?, p75 activated Rho-associated kinase 1 (ROCK1). Inhibition of ROCK1 activity blocked TNF-?-dependent phosphorylation of MRLC and the dissociation of myosin from p75. ROCK1-dependent release of myosin was necessary for the TNF-?-dependent recruitment of TRAF2 to p75 and for p75-specific activation of NF-?B and MAPK signaling. Thus, our findings have revealed a previously uncharacterized, noncanonical regulatory function of myosin in cytokine signaling.
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IL-17 family: cytokines, receptors and signaling.
Cytokine
PUBLISHED: 07-16-2013
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The interleukin 17 (IL-17) family, a subset of cytokines consisting of IL-17A-F, plays crucial roles in host defense against microbial organisms and in the development of inflammatory diseases. Although IL-17A is the signature cytokine produced by T helper 17 (Th17) cells, IL-17A and other IL-17 family cytokines have multiple sources ranging from immune cells to non-immune cells. The IL-17 family signals via their correspondent receptors and activates downstream pathways that include NF?B, MAPKs and C/EBPs to induce the expression of anti-microbial peptides, cytokines and chemokines. The proximal adaptor Act1 is a common mediator during the signaling of all IL-17 cytokines so far and is thus involved in IL-17 mediated host defense and IL-17-driven autoimmune conditions. This review will give an overview and recent updates on the IL-17 family, the activation and regulation of IL-17 signaling as well as diseases associated with this cytokine family.
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Act1 mediates IL-17-induced EAE pathogenesis selectively in NG2+ glial cells.
Nat. Neurosci.
PUBLISHED: 07-10-2013
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Interleukin 17 (IL-17) is a signature cytokine of Th17 cells. We previously reported that deletion of NF-?B activator 1 (Act1), the key transducer of IL-17 receptor signaling, from the neuroectodermal lineage in mice (neurons, oligodendrocytes and astrocytes) results in attenuated severity of experimental autoimmune encephalomyelitis (EAE). Here we examined the cellular basis of this observation. EAE disease course was unaffected by deletion of Act1 in neurons or mature oligodendrocytes, and Act1 deletion in astrocytes only modestly affected disease course. Deletion of Act1 in NG2(+) glia resulted in markedly reduced EAE severity. Furthermore, IL-17 induced characteristic inflammatory mediator expression in NG2(+) glial cells. IL-17 also exhibited strong inhibitory effects on the maturation of oligodendrocyte lineage cells in vitro and reduced their survival. These data identify NG2(+) glia as the major CNS cellular target of IL-17 in EAE. The sensitivity of oligodendrocyte lineage cells to IL-17-mediated toxicity further suggests a direct link between inflammation and neurodegeneration in multiple sclerosis.
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Association of STAT4 gene polymorphism with increased susceptibility of rheumatoid arthritis in a northern Chinese Han subpopulation.
Int J Rheum Dis
PUBLISHED: 06-19-2013
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Several studies have reported STAT4 polymorphism is strongly associated with increased susceptibility to rheumatoid arthritis (RA). However, a study from China showed no association between STAT4 and RA susceptibility in a Chinese Han subpopulation. Since the northern Hans are known to be genetically different from the southern Hans, the aim of this study was to investigate the association of STAT4 polymorphism with RA in a large cohort of a northern Chinese Han subpopulation.
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HuR is required for IL-17-induced Act1-mediated CXCL1 and CXCL5 mRNA stabilization.
J. Immunol.
PUBLISHED: 06-14-2013
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IL-17, a major inflammatory cytokine plays a critical role in the pathogenesis of many autoimmune inflammatory diseases. In this study, we report a new function of RNA-binding protein HuR in IL-17-induced Act1-mediated chemokine mRNA stabilization. HuR deficiency markedly reduced IL-17-induced chemokine expression due to increased mRNA decay. Act1-mediated HuR polyubiquitination was required for the binding of HuR to CXCL1 mRNA, leading to mRNA stabilization. Although IL-17 induced the coshift of Act1 and HuR to the polysomal fractions in a sucrose gradient, HuR deficiency reduced the ratio of translation-active/translation-inactive IL-17-induced chemokine mRNAs. Furthermore, HuR deletion in distal lung epithelium attenuated IL-17-induced neutrophilia. In summary, HuR functions to couple receptor-proximal signaling to posttranscriptional machinery, contributing to IL-17-induced inflammation.
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LcSAIN1, a novel salt-induced gene from sheepgrass, confers salt stress tolerance in transgenic Arabidopsis and rice.
Plant Cell Physiol.
PUBLISHED: 05-20-2013
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Previously, we identified >1,500 genes that were induced by high salt stress in sheepgrass (Leymus chinensis, Gramineae: Triticeae) when comparing the changes in their transcription levels in response to high salt stress by next-generation sequencing. Among the identified genes, a gene of unknown function (designated as Leymus chinensis salt-induced 1, LcSAIN1) showed a high sequence identity to its homologs from wheat, Hordeum vulgare and Oryza sativa, but LcSAIN1 and its homologs produce hypothetical proteins with no conserved functional domains. Transcription of the LcSAIN1 gene was up-regulated by various stresses. The overexpression of LcSAIN1 in Arabidopsis and rice increased the greening rate of cotyledons, the fresh weight, root elongation, plant height and the plant survival rate when compared with control plants and conferred a tolerance against salt stress. Subcellular localization analysis indicated that LcSAIN1 is localized predominantly in the nucleus. Our results show that the LcSAIN1 gene might play an important positive modulation role in increasing the expression of transcription factors (MYB2 and DREB2A) and functional genes (P5CS and RAB18) in transgenic plants under salt stress and that it augments stress tolerance through the accumulation of compatible solutes (proline and soluble sugar) and the alleviation of changes in reactive oxygen species. The LcSAIN1 gene could be a potential resource for engineering salinity tolerance in important crop species.
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Proteins differentially expressed in conidia and mycelia of the entomopathogenic fungus Metarhizium anisopliae sensu stricto.
Can. J. Microbiol.
PUBLISHED: 05-14-2013
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Metarhizium anisopliae is a well-characterized entomopathogenic fungus that attacks a variety of insects. Its conidia are involved in its propagation and also in its infection of host insects. To investigate the protein expression profiles and to identify the proteins related to development and pathogenesis, we performed a comparative proteomic analysis of the conidia and mycelia of an M. anisopliae strain (Ma1291). The analysis used 2-dimensional gel electrophoresis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. We detected 898 ± 37 protein spots in conidia and 1072 ± 24 in mycelia of strain Ma1291. A comparison of the 2 protein-expression profiles indicated that only 28% of protein spots were common to both developmental stages. Finally, we identified 30 proteins (19 from conidia and 11 from mycelia). The identified proteins exclusive to conidia were those involved in protective processes, appressorium formation, and degradation of the host cuticle (protease PR1H). The identified proteins exclusive to mycelia included major proteins participating in biosynthetic and energy metabolism, such as UTP-glucose-1-phosphate uridylyltransferase and heat shock protein 70. This research provides the first proteomic analysis of different developmental stages of M. anisopliae, and the results should facilitate clarification of the molecular basis of these epigenetic variations.
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Transcription factor Krüppel-like factor 2 plays a vital role in endothelial colony forming cells differentiation.
Cardiovasc. Res.
PUBLISHED: 05-10-2013
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Endothelial colony forming cells (ECFCs) participate in post-natal vasculogenesis. We previously reported that vascular endothelial growth factor (VEGF) promotes human ECFC differentiation through AMP-activated protein kinase (AMPK) activation. However, the mechanisms underlying transcriptional regulation of ECFC differentiation still remain largely elusive. Here, we investigated the role of transcription factor Krüppel-like factor 2 (KLF2) in the regulation of ECFC function.
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Re-evaluation of the classification system for membranoproliferative glomerulonephritis.
Contrib Nephrol
PUBLISHED: 05-08-2013
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In recent years, significant advances have been made in understanding the pathogenesis and etiology of membranoproliferative glomerulonephritis (MPGN). A new classification system based on pathological immunofluorescence findings has been proposed to replace the traditional clinical classification system in order to better identify the underlying causes of MPGN and to provide guidance for more individualized treatment. We conducted a retrospective survey of the MPGN patients treated in our hospital from 2000 to 2012 and report here the validation of this new classification system in this cohort. A total of 34 patients were diagnosed with MPGN, including 25 males and 9 females. There were 3 cases of secondary MPGN, including 1 case due to monoclonal gammopathy of undetermined significance (MGUS) and 2 cases related to hepatitis B virus (HBV) infection. Clinical presentations included nephrotic syndrome (76.5%), microscopic hematuria (79.4%), hypocomplementemia (58.8%), renal insufficiency (82.4%), hypertension (100%), and peripheral edema (100%). All patients were treated with prednisone and immunosuppressive agents, mainly cyclophosphamide. During follow-up (median 6 months, range 3-47 months), 4 patients were lost to follow-up and 2 patients progressed to end-stage renal disease. In Western countries the main cause of secondary MPGN was hepatitis C virus or HBV infection, here however we report 2 cases related to HBV infection. MGUS-associated MPGN was less frequent in the Chinese cohort. Future studies should be designed to evaluate the association of the new classification system and clinical outcomes of MPGN.
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Tacrolimus combined with corticosteroids in idiopathic membranous nephropathy: a randomized, prospective, controlled trial.
Contrib Nephrol
PUBLISHED: 05-08-2013
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Although idiopathic membranous nephropathy (IMN) is the most common cause of adult-onset nephrotic syndrome, the management of IMN remains controversial. The aim of this prospective study was to compare the efficacy and drug safety of tacrolimus with that of cyclophosphamide (CTX; control group) in IMN patients receiving corticosteroid therapy. A total of 100 IMN patients with nephrotic syndrome were randomly assigned to receive a combination of corticosteroid therapy and either CTX or tacrolimus. During a follow-up period of at least 18 months, the remission rate after 2 months in the tacrolimus group was 65.1%, which was higher than that of the CTX group (44.2%) (p = 0.02). The mean time to partial or complete remission was 2.20 months in the tacrolimus group and 3.92 months in the CTX group (p < 0.001). We also found significantly greater improvements in the serum albumin levels in the tacrolimus group compared with the CTX group at the 2-month (p = 0.003) and 3-month time points (p = 0.01). The serum creatinine levels remained stable in both groups. Although remission was quicker and more common in the tacrolimus group (compared with the CTX group) before 3 months, there was no superiority of tacrolimus after 6 months. Glucose intolerance, urinary tract infections, and pneumonia were the major side effects observed in this study. All of the side effects were mild and controlled, and there were fewer side effects in the tacrolimus group compared with the CTX group, indicating a better treatment tolerance in the tacrolimus group.
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Treatment and prognosis of primary focal segmental glomerulosclerosis.
Contrib Nephrol
PUBLISHED: 05-08-2013
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This study aimed to analyze the treatment, clinical outcomes, and risk factors that affect the prognosis of patients with primary focal segmental glomerulosclerosis (FSGS) and to provide theoretical evidence for various treatment options in these patients. The study reviewed the clinical, laboratory, and pathological data of 168 patients with primary FSGS treated at Ruijin Hospital between January 2002 and October 2011. Of these patients, 108 were male (64.3%) and 60 were female (35.7%). The median age of disease onset was 38 years (range 12-78 years). The median case history was 10 months (range 4 days to 30 years). The mean proteinuria level was 2.3 ± 0.6 g/day. 75 (44.6%) patients had nephrotic syndrome. The mean serum creatinine was 108.1 ± 8.9 ?mol/l. Over a follow-up period of 25.3 ± 11.4 months, end-stage renal failure occurred in 4 patients, and all 4 survived. In the group treated with angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, the following factors were identified as risk factors for experiencing a 50% increase in serum creatinine over the baseline: a baseline eGFR <60 ml/min, proteinuria >1 g/day during the follow-up period, glomerular sclerosis >grade 1, and tubulointerstitial lesions >stage 1. In the group treated with steroids, patients who achieved a stable remission had better preserved renal function and milder glomerular sclerosis than steroid-dependent patients (p < 0.01). Steroid-resistant FSGS patients had a worse histological severity of glomerular sclerosis than steroid-dependent patients (p < 0.01). The prognosis of FSGS was correlated with the amount of proteinuria, the level of serum creatinine, and the severity of glomerular sclerosis and tubulointerstitial lesions. Steroids may be more effective in those who have better preserved renal function and milder glomerular sclerosis.
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Increased risk of treatment failure and end-stage renal disease in familial focal segmental glomerular sclerosis.
Contrib Nephrol
PUBLISHED: 05-08-2013
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Focal segmental glomerular sclerosis (FSGS) is one of the most important causes of end-stage renal disease (ESRD). The pathogenesis, clinical manifestation, pathological changes and treatment of FSGS differ in patients with and without a family history of the disease. Few studies have compared familial FSGS (FFSGS) and sporadic FSGS (SFSGS). The aim of this study was to assess the clinical and pathological features and the prognosis of FSGS in patients with and without a family history of the disease.
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Changing spectrum of biopsy-proven primary glomerular diseases over the past 15 years: a single-center study in China.
Contrib Nephrol
PUBLISHED: 05-08-2013
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The prevalence of chronic kidney disease (CKD) is reported to be 10.8-11.8% of the Chinese population. With economic development and longer life expectancy, the spectrum of CKD etiology has kept changing. Primary glomerular diseases (PGD) are still the most common renal diseases in China. To investigate the changing pattern of PGD in China, we retrospectively analyzed consecutive native renal biopsies performed in our hospital from 1997 to 2011. The patients were grouped according to a 3-year interval, 1997-1999 (period 1), 2000-2002 (period 2), 2003-2005 (period 3), 2006-2008 (period 4), 2009-2011 (period 5), and divided into three age groups (<20, 20-59, and ?60 years old). 8,909 qualified cases were enrolled in this study. Among 8,909 specimens, 6,337 (71.13%) were diagnosed as PGD, while this prevalence decreased significantly from 77.61% in 1997-1999 to 66.73% in 2006-2008. IgA nephropathy (IgAN) was the most common PGD (36.66%), without any significant difference in the 5 periods (p = 0.185). IgAN was the most common PGD both in patients between the 20- to 59-year-old group (45.58%) and <20-year-old group (19.29%) as well. Membranous nephropathy (MN) was the most frequently found PGD in patients at age ?60 years (39.64%). The frequency of MN was increased significantly from 6.48% in 1997-1999 to 22.79% in 2009-2011 (p < 0.001). The proportion of elderly patients increased significantly from 3.18% in 1997-1999 to 15.21% in 2009-2011 (p < 0.001). The prevalence of endocapillary proliferative glomerulonephritis (EnPGN) has decreased since 1997. PGD has remained the most common renal disease in China, although with a descending trend. The spectrum of PGD is different in different age groups. The frequency of EnPGN has decreased significantly, while that of MN has increased significantly.
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An ACT1 mutation selectively abolishes interleukin-17 responses in humans with chronic mucocutaneous candidiasis.
Immunity
PUBLISHED: 04-13-2013
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Patients with inborn errors of interleukin-17F (IL-17F) or IL-17RA display chronic mucocutaneous candidiasis (CMC). We report a biallelic missense mutation (T536I) in the adaptor molecule ACT1 in two siblings with CMC. The mutation, located in the SEFIR domain, abolished the homotypic interaction of ACT1 with IL-17 receptors, with no effect on homodimerization. The patients fibroblasts failed to respond to IL-17A and IL-17F, and their T cells to IL-17E. By contrast, healthy individuals homozygous for the common variant D10N, located in the ACT1 tumor necrosis factor receptor-associated factor-interacting domain and previously associated with psoriasis, had impaired, but not abolished, responses to IL-17 cytokines. SEFIR-independent interactions of ACT1 with other proteins, such as CD40, heat shock protein 70 (HSP70) and HSP90, were not affected by the T536I mutation. Overall, human IL-17A and IL-17F depend on ACT1 to mediate protective mucocutaneous immunity. Moreover, other ACT1-dependent IL-17 cytokines seem to be largely redundant in host defense.
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Overexpression of sheepgrass R1-MYB transcription factor LcMYB1 confers salt tolerance in transgenic Arabidopsis.
Plant Physiol. Biochem.
PUBLISHED: 04-09-2013
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Sheepgrass [Leymus chinensis (Trin.) Tzvel.] is a dominant, rhizomatous grass that has extensive plasticity in adapting to various harsh environments. Based on data from 454 high-throughput sequencing (GS FLX) exposure to salt stress, an unknown functional MYB-related gene LcMYB1 was identified from sheepgrass. Tissue specific expression profiles showed that the LcMYB1 gene was expressed ubiquitously in different tissues, with higher expression levels observed in the rhizome and panicle. The expression of LcMYB1 was induced obviously by high salt, drought and abscisic acid and was induced slightly by cold. A fusion protein of LcMYB1 with green fluorescent protein (GFP) was localized to the nucleus, and yeast one-hybrid analysis indicated that LcMYB1 was an activator of transcriptional activity. LcMYB1-overexpressing plants were more tolerant to salt stress than WT plants. The amounts of proline and soluble sugars were higher in transgenic Arabidopsis than in WT plants under salt stress conditions. The overexpression of LcMYB1 enhanced the expression levels of P5CS1 and inhibited other salt stress response gene markers. These findings demonstrate that LcMYB1 influences the intricate salt stress response signaling networks by promoting different pathways than the classical DREB1A- and MYB2-mediated signaling pathway. Additionally, LcMYB1 is a promising gene resource for improving salinity tolerance in crops.
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The role of Epstein-Barr virus (EBV) and cytomegalovirus (CMV) in immune thrombocytopenia.
Hematology
PUBLISHED: 03-22-2013
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Although Epstein-Barr virus (EBV) and cytomegalovirus (CMV) are known to trigger immune thrombocytopenia (ITP), the manifestations of EBV and CMV in ITP spleen tissues continue to be poorly understood.
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Two novel potent ?-amylase inhibitors from the family of acarviostatins isolated from the culture of Streptomyces coelicoflavus ZG0656.
Chem. Biodivers.
PUBLISHED: 03-16-2013
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Two novel aminooligosaccharides were separated from the culture filtrate of Streptomyces coelicoflavus ZG0656. Their chemical structures were determined by acidic hydrolysis, electrospray-ionization tandem mass spectrometry (ESI-MS/MS), and NMR spectroscopy. The compounds were named acarviostatins III0(-1) and III23 according to the nomenclature of this group of metabolites. The two novel acarviostatins were both mixed noncompetitive inhibitors of porcine pancreatic ?-amylase (PPA). The inhibition constants (K(i)) for acarviostatins III0(-1) and III23 were 0.009 and 0.026 ?M, respectively, 151 and 52 times more potent than acarbose.
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Nascent endothelium initiates Th2 polarization of asthma.
J. Immunol.
PUBLISHED: 02-20-2013
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Asthma airway remodeling is linked to Th2 inflammation. Angiogenesis is a consistent feature of airway remodeling, but its contribution to pathophysiology remains unclear. We hypothesized that nascent endothelial cells in newly forming vessels are sufficient to initiate Th2-inflammation. Vascular endothelial (VE)-cadherin is a constitutively expressed endothelial cell adhesion molecule that is exposed in its monomer form on endothelial tip cells prior to adherens junction formation. Abs targeted to VE-cadherin monomers inhibit angiogenesis by blocking this adherens junction formation. In this study, VE-cadherin monomer Ab reduced angiogenesis in the lungs of the allergen-induced murine asthma model. Strikingly, Th2 responses including, IgE production, eosinophil infiltration of the airway, subepithelial fibrosis, mucus metaplasia, and airway-hyperreactivity were also attenuated by VE-cadherin blockade, via mechanisms that blunted endothelial IL-25 and proangiogenic progenitor cell thymic stromal lymphopoietin production. The results identify angiogenic responses in the origins of atopic inflammation.
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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.