874 resultados para expression of power
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Leber hereditary optic neuropathy (LHON) is the most extensively studied mitochondrial disease, with the majority of the cases being caused by one of three primary mitochondrial DNA (mtDNA) mutations. Incomplete disease penetrance and gender bias are two
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Iron is required for many microbes and pathogens for their survival and proliferation including Leishmania which cause leishmaniasis. Leishmaniasis is an increasingly serious infectious disease with a wide spectrum of clinical manifestations. These range from localized cutaneous leishmaniasis (CL) lesions to a lethal visceral form. Certain strains such as BALB/c mice fail to control L. major infection and develop progressive lesions and systemic disease. These mice are thought to be a model of non-healing forms of the human disease such as kala-azar or diffuse cutaneous leishmaniasis. Progression of disease in BALB/c mice has been associated with the anemia, in last days of their survival, the progressive anemia is considered to be one of the reasons of their death. Ferroportin (Fpn), a key regulator of iron homeostasis is a conserved membrane protein that exports iron across the duodenal enterocytes as well as macrophages and hepatocytes into the blood circulation. Fpn has also critical influence on survival and proliferation of many microorganisms whose growth is dependent upon iron, thus preparation of Fpn is needed to study the role of iron in immune responses and pathogenesis of micoorganisms. To prepare and characterize a recombinant ferroportin, total RNA was extracted from Indian zebrafish duodenum, and used to synthesize cDNA by RT-PCR. PCR product was first cloned in Topo TA vector and then subcloned into the GFP expression vector pEGFP–N1. The final resulted plasmid (pEGFP-ZFpn) was used for expression of FPN-EGFP protein in Hek 293T cells. The expression was confirmed by fluorescence microscopy and flow cytometery. Recombinant Fpn was further characterized by submission of its predicted amino acid sequences to the TMHMM V2.0 prediction server (hidden Markov model), NetOGlyc 3.1 server and NetNGlyc 3.1 server. Data emphasised that obtained Fpn from indian zebrafish contained eight transmembrane domains with N- and C-termini inside the cytoplasm and harboured 78 mucin-type glycosylated amino acid. The results indicate that the prepared and characterized recombinant Fpn protein has no membrane topology difference compared to other Fpn described by other researcher. Our next aim was to deliver recombinant plasmid (pEGFP-ZFpn) to entrocyte cells. However, naked therapeutic genes are rapidly degraded by nucleases, showing poor cellular uptake, nonspecificity to the target cells, and low transfection efficiency. The development of safe and efficient gene carriers is one of the prerequisites for the success of gene therapy. Chitosan and alginate 139 polymers were used for oral gene carrier because of their biodegradability, biocompatibility and their mucoadhesive and permeability-enhancing properties in the gut. Nanoparticles comprising Alginate/Chitosan polymers were prepared by pregel preparation method. The resulting nanoparticles had a loading efficiency of 95% and average size of 188 nm as confirmed by PCS method and SEM images had showed spherical particles. BALB/c mice were divided to three groups. The first and second group were fed with chitosan/alginate nanoparticles containing the pEGFP-ZFpn and pEGFP plasmid, respectively (30 μgr/mice) and the third group (control) didn’t get any nanoparticles. The result showed BALB/c mice infected by L.major, resulted in higher hematocryte and iron level in pEGFP-ZFpn fed mice than that in other groups. Consentration of cytokines determined by ELISA showed lower levels of IL-4 and IL-10 and higher levels of IFN-γ/IL-4 and IFN-γ/IL-10 ratios in pEGFP-ZFpn fed mice than that in other groups. Morover more limited increase of footpad thickness and significant reduction of viable parasites in lymph node was seen in pEGFP-ZFpn fed mice. The results showed the first group exhibited a highr hematocryte and iron compared to the other groups. These data strongly suggests the in vivo administration of chitosan/alginate nanoparticles containing pEGFP-ZFpn suppress Th2 response and may be used to control the leishmaniasis .
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Learning and memory play an important role in morphine addiction. Status epilepticus (SE) can impair the spatial and emotional learning and memory. However, little is known about the effects of SE on morphine-induced conditioned place preference (CPP). Th
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Long term potentiation in hippocampus, evoked by high-frequency stimulation, is mediated by two major glutamate receptor subtypes, alpha-amino-3-hydroxyl-5-methyl-4-isoxazole propionate receptors and N-methyl-D-aspartate receptors. Receptor subunit compos
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Neuregulin-1 (Nrg-1)(1) gene has been considered as a schizophrenia susceptibility gene. In order to observe the association of Nrg-1 gene with schizophrenia, the study was designed to investigate the effect of anti-psychotic treatment on the Nrg-1 mRNA e
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Vascular endothelial growth factor (VEGF) plays an important role in normal and pathological angiogenesis. VEGF receptors (VEGFRs, including VEGFR-1, VEGFR-2, and VEGFR-3) and neuropilins (NRPs, including NRP-1 and NRF-2) are high-affinity receptors for V
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Vascular endothelial growth factor (VEGF) and its receptor VEGFR-2 play important roles in mitogenesis and chemotaxis of endothelial cells. In normal human skin, VEGF is expressed and secreted by epidermal keratinocytes. Emerging data suggest that keratin
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In this paper, a new thermal model based on the Fourier series solution of heat conduction equation has been introduced in detail. 1-D and 2-D Fourier series thermal models have been programmed in MATLAB/Simulink. Compared with the traditional finite-difference thermal model and equivalent RC thermal network, the new thermal model can provide high simulation speed with high accuracy, which has been proved to be more favorable in dynamic thermal characterization on power semiconductor switches. The complete electrothermal simulation models of insulated gate bipolar transistor (IGBT) and power diodes under inductive load switching condition have been successfully implemented in MATLAB/Simulink. The experimental results on IGBT and power diodes with clamped inductive load switching tests have verified the new electrothermal simulation model. The advantage of Fourier series thermal model over widely used equivalent RC thermal network in dynamic thermal characterization has also been validated by the measured junction temperature.© 2010 IEEE.
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Large tumor suppressor (Lats) is a Ser/Thr kinase, and it presents an important function in tumor suppression. lats was originally identified in Drosophila and recently in mammals. In mammals, it contains two homologues, lats1 and lats2. In the present study, lats1 and lats2 were characterized from zebrafish (Danio rerio), which is the first report of lats in a nonmammalian vertebrate. The primary structure, genomic organization, and phylogenesis of lats from different species were studied, and the results suggest that lats1 is the direct descendant of invertebrate lats, whereas lats2 is formed by genome duplication. In zebrafish, both lats genes are maternally expressed, while they show distinctly different expression profiles during gastrulation. lats1 is almost ubiquitously expressed through development, and lats2 is more prominently expressed in the non-neural ectoderm region of zebrafish gastrula. Most intriguingly, as revealed by cell tracing and gene expression analysis, morpholino-mediated knockdown of either lats1 or lats2 led to obvious defects of cell migration in gastrulation, indicating the functional significance of lats in gastrulation movements. Developmental Dynamics 238:28502859, 2009. (C) 2009 Wiley-Liss, Inc.
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The double-stranded RNA (dsRNA)-dependent protein kinase (PKR) belongs to the eIF2 alpha kinase family and plays a critical role in interferon (IFN)-mediated antiviral response. Recently, in Japanese flounder (Paralichthys olivaceus), a PKR gene has been identified. In this study, we showed that PoPKR localized to the cytoplasm, and the dsRNA-binding motifs (dsRBMs) played a determinative role in protein localization. In cultured FEC cells, PoPKR was detected at a low level of constitutive expression but was highly induced after treatment with UV-inactivated grass carp hemorrhagic virus, active SMRV and Poly I:C although with different expression kinetics. In flounder, PoPKR was ubiquitously distributed in all tested tissues, and SMRV infection resulted in significant upregulation at mRNA and protein levels. In order to reveal the role of PoPKR in host antiviral response, its expression upon exposure to various inducers was characterized and further compared with that of PoHRI, which is another eIF2 alpha kinase of flounder. Interestingly, expression comparison revealed that all inducers stimulated upregulation of PoHRI in cultured flounder embryonic cells and fish, with a similar kinetics to PoPKR but to a less extent. These results suggest that, during antiviral immune response, both flounder eIF2 alpha kinases might play similar roles and that PoPKR is the predominant kinase. (C) 2009 National Natural Science Foundation of China and Chinese Academy of Sciences. Published by Elsevier Limited and Science in China Press. All rights reserved.
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In adaptation to new environments, organisms may accumulate mutations within encoding sequences to modify protein characteristics or acquire mutations within regulatory sequences to alter gene expression levels. With the development of antifreeze capability as the example, this study presents the evidence that change in gene expression level is probably the most important mechanism for adaptive evolution in a green alga Chlorella vulgaris. C. vulgaris NJ-7, an isolate from Antarctica, possesses an 18S rRNA sequence identical to that of a temperate isolate, SAG211-11b/UTEX259, but shows much higher freeze tolerance than the later isolate. The chromosomal DNA/cDNA of four antifreeze genes, namely hiC6, hiC12, rpl10a and hsp70, from the two isolates of C. vulgaris were cloned and sequenced, and very few variations of deduced amino acid sequences were found. In contrast, the transcription of hiC6, hiC12 and rpl10a was greatly intensified in NJ-7 compared to that in UTEX259, which is correlated to the significantly enhanced freeze tolerance of the Antarctica isolate. (C) 2009 National Natural Science Foundation of China and Chinese Academy of Sciences. Published by Elsevier Limited and Science in China Press. All rights reserved.
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Teleost vitellogenins (VTGs) are large multidomain apolipoproteins, traditionally considered to be estrogen-responsive precursors of the major egg yolk proteins, expressed and synthesized mainly in hepatic tissue. The inducibility of VTGs has made them one of the most frequently used in vivo and in vitro biomarkers of exposure to estrogen-active substances. A significant level of zebrafish vtgAo1, a major estrogen responsive form, has been unexpectedly found in heart tissue in our present studies. Our studies on zebrafish cardiomyopathy, caused by adrenergic agonist treatment, suggest a similar protective function of the cardiac expressed vtgAo1. We hypothesize that its function is to unload surplus intracellular lipids in cardiomyocytes for "reverse triglyceride transportation" similar to that found in lipid transport proteins in mammals. Our results also demonstrated that zebrafish vtgAo1 mRNA expression in heart can be suppressed by both (x-adrenergic agonist, phenylephrine (PE) and beta-adrenergic agonist, isoproterenol (ISO). Furthermore, the strong stimulation of zebrafish vtgAo1 expression in plasma induced by the beta-adrenergic antagonist, MOXIsylyl, was detected by Enzyme-Linked ImmunoSorbent Assay (ELISA). Such stimulation cannot be suppressed by taMOXIfen, an antagonist to estrogen receptors. Thus, Our present data indicate that the production of teleost VTG in vivo can be regulated not only by estrogenic agents, but by adrenergic signals as well. (c) 2009 Elsevier Inc. All rights reserved.
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Natural killer (NK) cell enhancing factor (NKEF) belongs to the newly defined peroxiredoxin (Prx) family. Its functions are to enhance NK cell cytotoxicity and to protect DNA and proteins from oxidative damage. In this study, a partial cDNA sequence of carp NKEF-B was isolated from thymus cDNA library. Subsequently, the full-length cDNA of carp NKEF-B was obtained by means of 3' and 5' RACE, respectively. The full-length cDNA of carp NKEF-B was 1022 bp, consisting of a 73 bp 5'-terminal untranslated region (UTR), a 355 bp T-terminal UTR, and a 594 bp open reading frame coding for a protein of 197 amino acids. Carp NKEF-B contained two consensus Val-Cys-Pro (VCP) motifs and three consensus cysteine (Cys-51, Cys-70 and Cys-172) residues. Sequence comparison showed that the deduced amino acid sequence of carp NKEF-B had an overall similarity of 74-96% to that of other species homologues. Phylogenetic analysis revealed that carp NKEF-B forms a cluster with other known teleost NKEF-Bs. Then, by PCR we obtained a 5.1 -k long genomic DNA of carp NKEF-B containing six exons and five introns. Realtime RT-PCR results showed that carp NKEF-B gene was predominantly detected in kidney and head kidney under un-infected conditions. Whereas under SVCV-infection condition, the expression of NKEF-B gene was significantly increased in blood cells, gill, intestine and spleen, but maintained in liver, and decreased significantly in kidney and head kidney. Finally, the rNKEF-B was constructed and expressed in Escherichia coli. By using an antibody against carp rNKEF-B, immunohistochemical study further indicated that NKEF-B positive cells are mainly some RBCs and a few epithelial cells in gill and intestine, and that under SVCV-infection condition, these positive cells or positive products in their cytoplasm were mainly increased in gill and spleen sections of carp. The results obtained in the present study will help to understand the function of NKEF-B in teleost innate immunity. (C) 2008 Elsevier Ltd. All rights reserved.
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Teleost vitellogenins (VTGs) are large multidomain apolipoproteins and traditionally considered as the estrogen responsive precursors of the major egg yolk proteins. We identified five clones encoding VTGs, about 16% of the random EST clones from our constructed cDNA library from Chinese rare minnow liver tissue treated with 17 beta-estradiol (E2). Full-length vtgAo1 has been obtained based on the sequence information of four partial cDNA inserts by RACE. The inducibility of the vtgAo1 expression in liver by E2 was confirmed by RT-PCR. The presence of vtgAo1 transcripts have been observed primarily in liver. However. a significant level of the vtgAo1 was found in an unexpected location, heart, particularly in atrial cells by RT-PCR and whole mount in situ hybridization analyses. The vtgAo1 mRNA expression in heart and liver tissue could be suppressed by both alpha-adrenergic agonist, phenylephrine (PE) and beta-adrenergic agonist, isoproterenol (ISO). The expression of VTG in the heart observed in the present studies suggested it may provide protection from surplus intracellular lipids in fish cardiomyocytes as triglyceride transport proteins do in mammals. The results also indicated that the production of teleost vtg in vivo can be regulated by riot only estrogenic agents, but adrenergic signals as well. (c) 2008 Elsevier B.V. All rights reserved.
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The pathogenic process of highly pathogenic avian influenza virus (HPAIV) infection is poorly understood. To explore the differential expression of kidney genes as a result of HPAIV infection, two cDNA libraries were constructed from uninfected and infected kidneys by suppression subtractive hybridization (SSH). Fifteen genes including IFN-stimulated genes (ISG12), lymphocyte antigen 6 complex locus E gene (LY6E), matrix Gla protein gene (MGP), lysozyme gene, haemopoiesis related membrane protein I gene, KIAA1259, MGC68696, G6pe-prov protein gene (G6PC), MGC4504, alcohol dehydrogenase gene (ADH), glutathione S-transferase gene (GST), sodium-dependent high-affinity dicarboxylate transporter gene (SDCT), Synaptotagmin XV (SytXV) and two novel genes were found significantly up-regulated or dramatically suppressed. Differential expression of these genes was further identified by Northern blot. Functional analysis indicated that the regulation of their expression might contribute to the pathogenic process of HPAIV infection. In contrast, the increased expression of three IFN-stimulated genes named ISG12, LY6E, and haemopoiesis related membrane protein 1 gene might reflect host defense responses. Further study showed that ISG12 protein failed to directly interact with NS1 protein of HPAIV which expressed simultaneously in the organs where HPAIV replication occurred, by use of BacterioMatch two-hybrid system. Therefore, our findings may provide new insights into understanding the molecular mechanism underlying the pathophysiological process of HPAIV infection in chicken. (c) 2007 Elsevier Ltd. All rights reserved.