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1.
  总被引:4,自引:0,他引:4  
It has become obvious that a better understanding and potential elucidation of the nucleolar phosphoprotein B23 involving in functional interrelationship between nuclear organization and gene expression. In present study, protein B23 expression were investigated in the regenerative hepatocytes at different periods (at days 0, 1, 2, 3, 4, 7) during liver regeneration after partial hepatectomy on the rats with immunohistochemistry and Western blot analysis. Another experiment was done with immunolabeling methods and two-dimensional (2-D) gel electrophoresis for identification of B23 in the regenerating hepatocytes and HepG2 cells (hepatoblastoma cell line) after sequential extraction with detergents, nuclease, and salt. The results showed that its expression in the hepatocytes had a locative move and quantitative change during the process of liver regeneration post-operation. Its immunochemical localization in the hepatocytes during the process showed that it moved from nucleoli of the hepatocytes in the stationary stage to nucleoplasm, cytoplasm, mitotic spindles, and mitotic chromosomes of the hepatocytes in the regenerating livers. It was quantitatively increased progressively to peak level at day 3 post-operation and declined gradually to normal level at day 7. It was detected in nuclear matrix protein (NMP) composition extracted from the regenerating hepatocytes and HepG2 cells and identified with isoelectric point (pI) value of 5.1 and molecular weight of 40 kDa. These results indicated that B23 was a proliferate shuttle protein involving in cell cycle and cell proliferation associated with nuclear matrix.  相似文献   

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  总被引:2,自引:0,他引:2  
The nonchromatin structure or nuclear matrix in developing spermatogenic cells of the rat was studied using a biochemical fractionation in concert with resinless section electron microscopy. Observations demonstrated that the nuclear matrix of spermatogenic cells consisted of a three-dimensional network of filaments of variable thicknesses. In spermatogonia and spermatocytes the nuclear matrix consisted of relatively thin filaments, while that of round spermatids consisted of a thicker interconnecting network of filament. In elongating spermatids, the interior of the nuclear matrix consisted of a network of dense filaments bounded by a peripheral lamina. The protein composition of the nuclear matrix in spermatogenic cells was examined by high-resolution two-dimensional gel electrophoresis and correlated with morphological changes characteristic of each stage. The results showed that the proteins of nuclear matrix changed in a cell stage-specific manner. These stage-specific changes corresponded to the major transitions of chromatin structure and function during spermatogenesis. Furthermore, immunocytochemical and immunoblotting analysis of DNA topoisomerase II (topo II) revealed that this enzyme exhibited stage-specific variations and was associated with the nuclear matrix. These results suggest that the nuclear matrix in spermatogenic cells may be involved in mediating DNA modifications and maintaining nuclear organization during spermatogenesis. Mol. Reprod. Dev. 59:314-321, 2001.  相似文献   

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A 70% partial hepatectomy (70%PHx) induces cell proliferation until the original mass of the liver is restored. Mitochondria are involved directly in the process of liver regeneration (LR); however, their role in the early phase of LR is not clear. In an attempt to identify mitochondrial proteins that are correlated with the early phase of LR, we obtained a mitochondrial fraction via Nycodenz(R) density gradient centrifugation and subcellular proteomic analysis was performed. The mitochondrial proteins were separated by two-dimensional gel electrophoresis and identified by mass spectrometry. Compared to the sham-operation control group, 3 proteins were up-regulated and 22 proteins were down-regulated at 24 h after 70%PHx. We identified 22 differentially expressed proteins that were associated with carbohydrate metabolism, lipid metabolism, the respiratory chain and oxidation-phosphorylation, biotransformation and other metabolic pathways. Prohibitin, a proliferation-regulating protein that was down-regulated at 24 h after PHx, was analyzed by applying RNAi (PHBi) with BRL-3A. This demonstrated a decreased mitochondrial membrane potential, implying a potential role in maintaining mitochondrial integrity. These results indicated that hepatic mitochondrial adaptations to LR after 70%PHx affect various cellular metabolic pathways, which advances our knowledge of the role of mitochondria in the early phase of LR.  相似文献   

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Reale  M.  Frydas  S.  Barbacane  R.C.  Placido  F.C.  Cataldo  I.  Conti  P.  Vacalis  D.  Trakatellis  A.  Anogianakis  G.  Felaco  M.  Di Giocchino  M. 《Molecular and cellular biochemistry》1998,185(1-2):1-5
Effects of selenium deficiency, induced by thioacetamide, were investigated in rats. Thioacetamide (0.3 g/L) given in drinking water, as expected, caused a significant loss of selenium from the liver. It was accompanied by liver cirrhosis and a significant increase in the liver weight as well as liver to body weight ratio. A significant loss of selenium from spleen was also accompanied by an increase in its weight. Weights of lungs, testis and kidney, however, were not affected by thioacetamide and there was no change in their selenium content. Plasma levels of selenium were significantly reduced in the thioacetamide treated group. All these changes were confirmed to be due to selenium deficiency caused by thioacetamide, as supplementation with selenium reversed these changes. The mode of action of selenium is unknown but may involve anti-oxidant defense mechanisms.  相似文献   

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Membrane and membrane-associated proteins are rich in known or potential pharmaceutical drug targets for carcinogenesis. In order to systemically analyze membrane proteins of human breast cancer, we isolated membrane from MCF-7 cells by sequential extraction by washing with three different buffers, namely, phosphate buffer (5 mM, pH 8.0), Tris (40 mM, pH 9.5), and sodium carbonate (100 mM pH 11). The extracted proteins were separated by two-dimensional gel electrophoresis (2-DE) using cup-loading and were then analyzed by peptide mass fingerprinting (PMF). A total of 137 spots from the gels of the three procedures were successfully identified. They corresponded to 79 distinct proteins. Among them, 22 exclusive proteins belonging to each washing procedure were also found, including P-glycoprotein, endoplasmin, Stress-70 protein, ADAM 10, protein disulfide isomerase, and glutamate receptor. These results indicate phosphate buffer to be the most beneficial for enrichment of peripheral membrane proteins, and sodium carbonate is beneficial for the presentation of integral membrane proteins but usually with poor resolution. The reference maps and identified proteins will serve as a basis for the further investigation of breast cancer, especially the proteomic comparison among different cell types of breast cancer, or among the different stages in the drug interfering process of the MCF-7 cell line.  相似文献   

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小鼠肝大部分切除(partial hepatectomy,PH)实验是研究肝再生的一个重要的实验。本文以C57小鼠为例,对肝大部分切除实验做了较为详细的介绍。实验结果显示,在术后的1~8天,小鼠的肝脏体重比值逐渐增加,在术后的7~10天里可以达到原来肝重的90%以上,10天以后肝细胞停止分裂。正常情况下,实施肝大部分切除后,小鼠的存活率可以达到90%以上。该模型的建立为研究肝脏再生的细胞和分子生物学机制奠定了基础。  相似文献   

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汤莉  杨超  尹蕾  边富宁  王晓璐  高智勇  王爱国 《四川动物》2012,31(1):132-134,138,177
目的建立一种简易、高效的小鼠2/3肝切除方法。方法取3月龄健康昆明小鼠,进行肝顺次结扎切除手术,观察术后小鼠生存和肝组织再生状况。结果通过顺次结扎切除左小叶和中央小叶,可在15min内完成小鼠2/3肝脏切除手术,术后成活率为90%,术后42h时可见肝组织再生,术后7d肝脏可恢复75%以上的肝组织原质量。结论通过分叶顺次肝切除术,可准确量化肝脏切除的程度,简便易行、成功率高,为肝再生的机理研究提供了理想的动物模型。  相似文献   

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Host cell proteins (HCP) are a problematic set of impurities in downstream processing (DSP) as they behave most similarly to the target protein during separation. Approaching DSP with the knowledge of HCP separation behavior would be beneficial for the production of high purity recombinant biologics. Therefore, this work was aimed at characterizing the separation behavior of complex mixtures of HCP during a commonly used method: anion‐exchange chromatography (AEX). An additional goal was to evaluate the performance of a statistical methodology, based on the characterization data, as a tool for predicting protein separation behavior. Aqueous two‐phase partitioning followed by two‐dimensional electrophoresis provided data on the three physicochemical properties most commonly exploited during DSP for each HCP: pI (isoelectric point), molecular weight, and surface hydrophobicity. The protein separation behaviors of two alternative expression host extracts (corn germ and E. coli) were characterized. A multivariate random forest (MVRF) statistical methodology was then applied to the database of characterized proteins creating a tool for predicting the AEX behavior of a mixture of proteins. The accuracy of the MVRF method was determined by calculating a root mean squared error value for each database. This measure never exceeded a value of 0.045 (fraction of protein populating each of the multiple separation fractions) for AEX. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1453–1463, 2016  相似文献   

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Host cell proteins (HCPs) constitute a major group of impurities for biologic drugs produced using cell culture technology. HCPs are required to be closely monitored and adequately removed in the downstream process. However, HCPs are a complex mixture of proteins with significantly diverse molecular and immunological properties. An overall understanding of the composition of HCPs and changes in their molecular properties upon changes in upstream and harvest process conditions can greatly facilitate downstream process design. This article describes the use of a comparative proteomic profiling method viz. two‐dimensional difference gel electrophoresis (2D‐DIGE) to examine HCP composition in the harvest stream of CHO cell culture. The effect of upstream process parameters such as cell culture media, bioreactor control strategy, feeding strategy, and cell culture duration/cell viability on HCP profile was examined using this technique. Among all the parameters studied, cell viability generated the most significant changes on the HCP profile. 2D‐DIGE was also used to compare the HCP differences between monoclonal antibody producing and null cell cultures. The HCP species in production cell culture was found to be well represented in null cell culture, which confirms the suitability of using the null cell culture for immunoassay reagent generation. 2D‐DIGE is complimentary to the commonly used HCP immunoassay. It provides a direct comparison of the changes in HCP composition under different conditions and can reveal properties (pI, MW) of individual species, whereas the immunoassay sensitively quantifies total HCP amount in a given sample. Biotechnol. Bioeng. 2010; 105: 306–316. © 2009 Wiley Periodicals, Inc.  相似文献   

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To obtain more information on the elements of chemical communication in the migratory locust (Locusta migratoria) (Orthoptera: Acrididae), we have searched for additional odorant-binding proteins (OBPs) and for volatiles in the feces that could represent potential semiochemicals for this species. A two-dimensional electrophoretic (2DE) analysis of an antennal extract showed only three closely positioned spots that were recognized by the antiserum against locust OBP. Three genes were also identified using PCR and 5'RACE-PCR approaches, encoding isoforms differing from each other for a single amino acid substitution. The gas-chromatographic-electroantennogram (GC-EAD) headspace analysis of a feces sample revealed the presence of several compounds that elicited dose-dependent electrophysiological responses in the antennae of both sexes. Most of these compounds are different from those identified in the feces of the desert locust (Schistocerca gregaria) and reported to be behaviorally active. Ligand-binding experiments performed with such volatiles and recombinant OBP did not show affinity, thus indicating that the binding pocket of OBP requires larger molecules than those so far identified.  相似文献   

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Liver regeneration is regulated by several factors, including growth factors, cytokines, and post-translational modifications of several proteins. It is suggested that transglutaminase 2 (TG2) and ornithine decarboxylase (ODC) are involved in liver regeneration. To investigate the role of TG2 and ODC activities in regenerating liver, we used retinoic acid (RA), an inducer of TG2 and a suppressor of ODC. Regenerating rat liver was prepared by 70% partial hepatectomy (PH). Rats were sacrificed at 1, 2, 3, 4, and 6 days after surgery. RA was intraperitoneally injected immediately after PH. TG2 and ODC activities and products (epsilon-(gamma-glutamyl) lysine isopeptide (Gln-Lys) and polyamines, respectively) were examined at the indicated times. In RA-treated rat, DNA synthesis and ODC activity declined and the peak shifted to 2 days after PH, whereas TG2 activity increased at 1 day after PH. At that time, protein-polyamine, especially the protein-spermidine (SPD) bond, transiently decreased, whereas the formation of the Gln-Lys bond increased after PH. These results suggested that in regenerating liver, enhanced the formation of Gln-Lys bonds catalyzed by TG2 led to reduced DNA synthesis, whereas when ODC produced newly synthesized SPD, the inhibition of Gln-Lys bond production by the preferential formation of protein-SPD bonds led to an increase in DNA synthesis.  相似文献   

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Liver stem/progenitor cells play a key role in liver development and maybe also in liver cancer development. In our previous study a population of c-Kit-(CD45/TER119)- liver stem/progenitor cells in mouse fetal liver, was successfully sorted with large amount (10(6)-10(7)) by using immuno-magnetic microbeads. In this study, the sorted liver stem/progenitor cells were used for proteomic study. Proteins of the sorted liver stem/progenitor cells and unsorted fetal liver cells were investigated using two-dimensional electrophoresis. A two-dimensional proteome map of liver stem/progenitor cells was obtained for the first time. Proteins that exhibited significantly upregulation in liver stem/progenitor cells were identified by peptide mass fingerprinting and peptide sequencing. Nineteen protein spots corresponding to 12 different proteins were identified as showing significant upregulation in liver stem/progenitor cells and seem to play important roles in such cells in cell metabolism, cell cycle regulation, and stress. An interesting finding is that most of the upregulated proteins were overexpressed in various cancers (11 of 12, including 6 in human hepatocellular carcinoma (HCC)) and involved in cancer development as reported in previous studies. Some of the identified proteins were validated by real-time PCR, Western blotting, and immunostaining. Taken together, the data presented provide a significant new protein-level insight into the biology of liver stem/progenitor cells, a key population of cells that might be also involved in liver cancer development.  相似文献   

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