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1.
It has been described that A disintegrin and metalloproteinase (ADAM10) may involve in the physiopathology of prion diseases, but the direct molecular basis still remains unsolved. In this study, we confirmed that ADAM10 was able to cleave recombinant human prion protein in vitro. Using immunoprecipitation tests (IP) and immunofluorescent assays (IFA), reliable molecular interaction between the native cellular form of PrP (PrPC) and ADAM10 was observed not only in various cultured neuronal cell lines but also in brain homogenates of healthy hamsters and mice. Only mature ADAM10 (after removal of its prodomain) molecules showed the binding activity with the native PrPC. Remarkably more prion protein (PrP)-ADAM10 complexes were detected in the membrane fraction of cultured cells. In the scrapie-infected SMB cell model, the endogenous ADAM10 levels, especially the mature ADAM10, were significantly decreased in the fraction of cell membrane. IP and IFA tests of prion-infected SMB-S15 cells confirmed no detectable PrP-ADAM10 complex in the cellular lysates and PrP-ADAM10 co-localization on the cell surface. Furthermore, we demonstrated that the levels of ADAM10 in the brain homogenates of scrapie agent 263K-infected hamsters and agent ME7-infected mice were also almost diminished at the terminal stage, showing time-dependent decreases during the incubation period. Our data here provide the solid molecular basis for the endoproteolysis of ADAM10 on PrP molecules and interaction between ADAM10 and PrPC. Obvious loss of ADAM10 during prion infection in vitro and in vivo highlights that ADAM10 may play essential pathophysiological roles in prion replication and accumulation.  相似文献   

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Development of drug resistance is a challenging problem in cancer chemotherapy. It has been shown that basic fibroblast growth factor (bFGF) plays an important role in an epigenetic mechanism of drug resistance. We have isolated a bFGF binding peptide P7 with inhibitory activity against bFGF-induced proliferation of human gastric cancer cells by screening a phage display library. In this study, we found that P7 peptide also has efficacy of reversing bFGF-induced resistance to Adriamycin (ADM) in human gastric cancer cells. Further investigations with SGC-7901 cells revealed that inhibition of Akt activation triggered by bFGF, and reversal of bFGF-induced up-regulation of Bcl-2 and XIAP and down-regulation of Bax, contribute to P7 peptide counteracting the anti-apoptotic effect of bFGF, and further reversing bFGF-induced resistance to ADM. The results suggested that the bFGF-binding peptide may have therapeutic potential of drug resistance in gastric cancer.  相似文献   

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The current large-scale meta-analysis was performed to reach a reliable conclusion on the association between X-ray repair cross-complementing 1 (xrcc1) rs1799782 and the development of lung cancer. Studies that investigated the association between rs1799782 and lung cancer risk were identified by searching PubMed. We calculated odds ratio (OR) with corresponding 95 % confidence interval (CI) for Trp/Trp vs Arg/Arg, Trp/Trp + Arg/Trp vs Arg/Arg, and Trp/Trp vs Arg/Trp + Arg/Arg contrast models. Combining all 25 studies, we yielded three summary ORs: 1.07 (95 % CI 0.92–1.23) for Trp/Trp vs Arg/Arg, 0.93 (95 % CI 0.87–1.00) for Trp/Trp + Arg/Trp vs Arg/Arg, and 1.08 (95 % CI 0.94–1.25) for Trp/Trp vs Arg/Trp + Arg/Arg, suggesting rs1799782 was not associated with overall risk of lung cancer. Strikingly, a significantly deceased risk was found among Caucasian populations (Trp/Trp + Arg/Trp vs Arg/Arg, OR = 0.86, 95 % CI 0.76–0.97). This study confirms that xrcc1 rs1799782 may lower the risk of lung cancer among Caucasians.  相似文献   

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[14C]Glutamic acid and [3H]GABA were injected into the lateral ventricle of mouse and then [14C]GABA and [3H]GABA in synaptosomes isolated from the animals were analysed. The [14C]GABA was interpreted to be newly synthesized GABA from [14C]glutamic acid while the [3H]GABA to be newly taken up GABA. We have obtained the following results: (1) when the animals were pretreated with aminooxyacetic acid and thus the GABA content in synaptosomes increased to about 2 times of the control level, only the [3H]GABA was enhanced to 3 times of the control level without any change of [14C]GABA, (2) the release of [14C]GABA from synaptosomes by high K+ depolarization was 1.5 times greater than that of [3H]GABA, (3) the releases of both [14C]GABA and [3H]GABA were increased in the presence of cold GABA,l-2,4-diaminobutyric acid or γ-amino-β-hydroxybutyric acid, but only slightly increased in the presence of β-alanine. These results would suggest that newly synthesized GABA and newly taken up GABA localized individually in different pools, which might localize either in different nerve terminals or separately in the same nerve terminal.  相似文献   

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To investigate the expression of TNF-α, IFN-γ, TGF-β, and IL-4 in the spinal tuberculous focus and its relationship with the lesions type, severity, and bone destruction. The pathological samples of patients with spinal tuberculosis (TB) were divided into hyperplasia group and necrosis group according to their intra-operative and post-operative pathological findings. Normal bone tissues were taken as the control group. Pathology and expression of TNF-α, IFN-γ, TGF-β, and IL-4 in different tissues were compared among these three groups using immunohistochemical staining, quantitative image analysis, and measurement of bone tissue. 286 granulomas observed in the 14 samples in the hyperplasia group, which included 84 necrotizing and 202 non-necrotizing granulomas. As for the 20 samples in the necrosis group, there were 356 necrotizing and 186 non-necrotizing granulomas among all the 542 granulomas. The proportion of necrotizing granulomas in the necrosis group was significantly higher than that of the hyperplasia group. By inter-group comparison, expression of TNF-α, IFN-γ of granulomas in the hyperplasia group was significantly higher than that of the necrosis group, while the expression of TGF-β, IL-4 of granulomas in the necrosis group was significantly higher than that of the hyperplasia group. Also, expression of IFN-γ of non-necrotizing granulomas was significantly higher than that of necrotizing granulomas in the hyperplasia group, and expression of TGF-β in necrotizing granulomas was significantly higher than that of non-necrotizing granulomas in the necrosis group. The lesions were mainly bone resorption in the hyperplasia group, whereas mostly necrotic bones accompanied by local fibrosis in the necrosis group. Expression levels of TNF-α, IFN-γ in the hyperplasia group have a positive correlation to bone loss, whereas expression levels of TGF-β, IL-4 in the necrosis group have a positive correlation to the bone formation. The high expressions of TNF-α, IFN-γ in the spinal tuberculous focus were associated with protective immune cells. TGF-β and IL-4 were related to allergic lesions, fibrosis and osteogenesis. Expression imbalance of TNF-α, IFN-γ, TGF-β, and IL-4 might aggravate the allergy of TB.  相似文献   

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Different wound dressings with antibacterial property have been surveyed and one among them is bacterial cellulose (BC). Since the BC does not have antibacterial property, the biologically produced silver nanoparticles (SNPs) were impregnated into the BC. For the BC production, Hestrin–Schramm broth was used. Formation of the BC was proven by enzymatic hydrolysis. For SNPs production, the bacterial supernatant was treated with AgNO3 and formation of SNPs was monitored through spectrophotometer, TEM and XRD. For impregnation of SNPs into the BC, the cleaned membrane was placed in the bacterial supernatant that contained 1 mmol of AgNO3. The antibacterial assay was done for the BC/SNPs. Enzymatic hydrolysis proved the presence of the BC. Spectrophotometer and XRD results showed the formation of SNPs. TEM analysis revealed the presence of SNPs with sizes around 5–100 nm. SEM micrographs showed the impregnation of SNPs into the BC. Antibacterial test exhibited the antibacterial activity of the BC/SNPs.  相似文献   

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A protocol to obtain full-length cDNA using a SuperScript® Full-Length cDNA Library Construction Kit II (Invitrogen, United States) was developed, and a high quality cDNA library of meristem tissue of finger millet panicle (Eleusine coracana (L.) Gaertn) was constructed. The titer of the constructed cDNA library was 3.01 × 105 CFU/mL, the average length of the insert was approximately 1070 base pairs, and the average efficiency of insertion of cDNA fragments was 99.5%. The sequencing of randomly selected clones created cDNA library was carried out. The cDNA sequences of clones were identified by BLAST search. The cDNA library analysis and selective sequencing indicate good functionality and full size of cDNA inserts of the clones. The constructed cDNA library from meristematic tissue of finger millet panicle is a good and reliable source for isolation and identification of key genes of metabolism and development of meristem as well for creation of new genetic markers for genetic research and molecular selection.  相似文献   

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Destruction of the connective tissue matrix (CTM) and angiogenesis are the two processes playing a key role in tumor progression. Matrix metalloproteinases (MMPs) play a leading role in processes of tissue destruction. Tissue collagenases MMP-1 and MT1-MMP hydrolyze fibrillar collagens constituting the base of CTM and enable tumor invasion. Gelatinases A and B (MMP-2 and MMP-9) hydrolyze type IV collagen which is the main component of basal membranes and contribute to the development of metastases. Endogenous activators and inhibitors are involved in the regulation of expression and activity of these enzymes. MMP-9 was shown to release vascular endothelial growth factor (VEGF), the principal inductor of angiogenesis, bound to CTM. Angiotensin-converting enzyme (ACE) is involved in the induction of VEGF synthesis and stimulation of endothelial cell proliferation mediated by angiotensin II (AII) and its type 1 receptor (AT1R). Experiments reported in the present article addressed the distinctive features of expression of key degradation and angiogenesis enzymes in squamous cell carcinoma (SCC) of the cervix. MMP-1, MT1-MMP, MMP-2, and MMP-9 and their endogenous regulators TIMP-1 and TIMP-2, as well as ACE, were the objects of research. Experiments were performed with clinical specimens including tumor tissue samples, for which presence or absence of metastasis to regional lymph nodes was taken into account, and morphologically normal tissue samples. Increased expression of MMP-1, MT1-MMP, and MMP-9 and decreased expression of TIMP-1 and TIMP-2 were shown to make the principal contribution to the destructive (invasive) potential of cervical carcinomas; the effect of changes in MMP-2 expression was less pronounced. Dramatically increased expression of MMP-1 and MMP-9 was evident in metastasizing tumors. ACE activity in tumor samples was generally higher than activity in normal tissue. Substantial expression of MMP-1, MMP-2, MMP-9, and ACE was detected in morphologically normal tissue adjacent to the tumor; this can contribute to increased destructive potential of a tumor. The data reported are important for understanding the mechanisms of tumor progression, have prognostic value, and may affect the choice of individual therapeutic strategy for the patients.  相似文献   

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MapReduce is a programming model to process a massive amount of data on cloud computing. MapReduce processes data in two phases and needs to transfer intermediate data among computers between phases. MapReduce allows programmers to aggregate intermediate data with a function named combiner before transferring it. By leaving programmers the choice of using a combiner, MapReduce has a risk of performance degradation because aggregating intermediate data benefits some applications but harms others. Now, MapReduce can work with our proposal named the Adaptive Combiner for MapReduce (ACMR) to automatically, smartly, and trainer for getting a better performance without any interference of programmers. In experiments on seven applications, MapReduce can utilize ACMR to get the performance comparable to the system that is optimal for an application.  相似文献   

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Endothelial inflammation plays major roles in all phases of the atherosclerotic process, the leading cause of death by cardiovascular disease. Both innate immunity and endothelial adhesion molecules contribute to endothelial inflammation. In this work, we applied multiple antibodies (Abs) to measure changes in expression levels of six proteins in response to inflammatory stimulation. These six proteins include toll-like receptor 2 (TLR2) and toll-like receptor 4 (TLR4) representing innate immunity and four endothelial adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), E-selectin, and P-selectin. We observed two different types of dynamic behaviors among these proteins upon inflammatory stimulation. Increased expression of toll-like receptor 2 (TLR2), P-selectin, E-selectin, and TLR4 peaked relatively early (after 4 h of stimulation) while VCAM-1, and ICAM-1 showed a more gradual and consistent increase in expression with stimulatory time. The magnitude of this increase was significantly greater for VCAM-1 and ICAM-1. The multiplexed detection developed in this study using fluorophore-conjugated primary Abs provides an approach for live cell and in vivo imaging of endothelium inflammation for quantitative characterization of multiple proteins within a network.  相似文献   

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Suppression of myostatin (MSTN) is associated with skeletal muscle atrophy and insulin resistance. However, the mechanisms by which MSTN regulates insulin resistance are not well known. We have explored the signaling pathways through which MSTN regulates insulin resistance in diet-induced obese rats using a polyclonal antibody for MSTN. The anti-MSTN polyclonal antibody significantly improved insulin resistance and whole-body insulin sensitivity, decreased MSTN protein expression in muscle samples by 39 % in diet-induced obese rats. Furthermore, the anti-MSTN polyclonal antibody significantly enhanced PI3K activity (140 %), Akt phosphorylation (86 %), GLUT4 protein expression (23 %), the phosphorylation of mTOR (21 %), and inhibited the phosphorylation of FoxO1 (57 %), but did not affect the phosphorylation of GSK-3β. Thus, suppression of MSTN by the anti-MSTN polyclonal antibody reverses insulin resistance of diet-induced obesity via MSTN/PI3K/Akt/mTOR and MSTN/PI3K/Akt/FoxO1 signaling pathways.  相似文献   

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Experimental results are presented for the verification of the first adsorption step of the ‘adsorbed template’ biogeochemical cycle, a simple model for a primitive prebiotic replication system. The adsorption of Poly-C, Poly-U, Poly-A, Poly-G, and 5′-AMP, 5′-GMP, 5′-CMP and 5′-UMP onto gypsum was studied. It was found that under the conditions of the experiment, the polymers have a very high affinity for the mineral surface, while the monomers adsorb much less efficiently.  相似文献   

18.
Heme oxygenase (HO) represents an intrinsic antiinflammatory system based on its ability to inhibit expression of proinflammatory cytokines. The constitutive isoform heme oxygenase-2 (HO-2) has high expression and activity in cerebral microvascular endothelial cells (CMVEC). This study was undertaken to evaluate the role of HO-2 in regulation of TLR4/MyD88-dependent signaling and to study the effect of HO-2 on the expression and secretion of the proinflammatory cytokines tumor necrosis factor α (TNF-α) and Interleukin-6 (IL6) in CMVEC. HO-2 short hairpin RNA (shRNA) and HO-2 overexpression plasmids were used to observe the effect of HO-2 on proinflammatory cytokines in CMVEC in vitro, and the results showed that the messenger RNA (mRNA) and protein levels of TNF-α and IL6 were increased and decreased, respectively, compared with control groups. LPS-stimulated TNF-α and IL6 mRNA and protein were also reduced in CMVEC treated with an inhibitor of TLR4 signaling, CLI-095, or HO-2 overexpression. CLI-095 and HO-2 overexpression both reduced TLR4 expression in CMVEC, and HO-2 shRNA blocked these effects of CLI-095. CLI-095 and HO-2 overexpression potently suppressed TLR4/MyD88-dependent proinflammatory cytokine expression in CMVEC. These results suggest that HO-2 plays an important role in protecting CMVEC against cytokine-mediated inflammation.  相似文献   

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The insulin-like growth factor-1 (IGF-1) signaling pathway is strongly associated with the risk of various cancers, and its inhibition has emerged as a potent anticancer strategy. Accumulating evidence from in vitro studies has shown that curcumin is a potent inhibitor of the IGF-1 signaling pathway. However, direct evidence that curcumin modulates IGF-1-induced tumorigenesis in a physiological system has not been reported. Therefore, in this study, we assessed the anticarcinogenic activity of curcumin on skin cancer by using BK5.IGF-1 transgenic (Tg) mice that overexpress IGF-1 in the skin epidermis. In 7,12-dimethylbenz(a)anthracene (DMBA)-tetradecanoyl phorbol-13-acetate (TPA) two-stage skin carcinogenesis, a curcumin diet (0.02% wt/wt) fed for 14 wk remarkably reduced mouse skin tumor multiplicity by 53%, epidermal hyperplasia and proliferation compared to the control diet group. TPA-induced phosphorylation of Akt, S6 kinase (S6K), and eukaryotic translation initiation factor 4E-binding protein 1 (4EBP1) in mouse skin was lower in the curcumin group than in the control group. Curcumin treatment inhibited IGF-1-induced phosphorylation of the IGF-1 receptor, insulin receptor substrate-1, Akt, S6K, and 4EBP1 in the mouse keratinocyte cell line, C50 in a dose-dependent manner. Taken together, these data suggest that curcumin exerts significant anticarcinogenic activity in skin cancer through the inhibition of IGF-1 signaling.  相似文献   

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Knowledge about the presence and ecological significance of bacteria and archaea in the deep-sea environments has been well recognized, but the eukaryotic microorganisms, such as fungi, have rarely been reported. The present study investigated the composition and abundance of fungal community in the deep-sea sediments of the Pacific Ocean. In this study, a total of 1,947 internal transcribed spacer (ITS) regions of fungal rRNA gene clones were recovered from five sediment samples at the Pacific Ocean (water depths ranging from 5,017 to 6,986 m) using three different PCR primer sets. There were 16, 17, and 15 different operational taxonomic units (OTUs) identified from fungal-universal, Ascomycota-, and Basidiomycota-specific clone libraries, respectively. Majority of the recovered sequences belonged to diverse phylotypes of Ascomycota (25 phylotypes) and Basidiomycota (18 phylotypes). The multiple primer approach totally recovered 27 phylotypes which showed low similarities (≤97 %) with available fungal sequences in the GenBank, suggesting possible new fungal taxa occurring in the deep-sea environments or belonging to taxa not represented in the GenBank. Our results also recovered high fungal LSU rRNA gene copy numbers (3.52?×?106 to 5.23?×?107copies/g wet sediment) from the Pacific Ocean sediment samples, suggesting that the fungi might be involved in important ecological functions in the deep-sea environments.  相似文献   

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