Breast cancer has a relatively high mortality rate in women due to recurrence and metastasis. Increasing evidence has identified a rare population of cells with stem cell-like properties in breast cancer. These cells, termed cancer stem cells (CSCs), which have the capacity for self-renewal and differentiation, contribute significantly to tumor progression, recurrence, drug resistance and metastasis.
View Article and Find Full Text PDFIntroduction: A definitive diagnosis of Creutzfeldt-Jakob disease (CJD) can only be made by neuropathologic examination and demonstration of typical pathologic changes and the pathologic prion protein in central nervous tissues. This study investigated the diagnostic sensitivity and specificity of the microtubule-association protein tau in cerebrospinal fluid (CSF) from Chinese patients with sporadic CJD.
Methods: Two hundred two CSF samples from clinically suspected patients with sporadic CJD were analyzed for tau protein by enzyme-linked immunosorbent assay and for the signal transduction regulatory protein 14-3-3 protein by immunoblot.
Prion protein (PrP) is able to bind with tubulin and to interfere with the formation of microtubule. To investigate the influence of accumulation of cytosolic PrP in cytoplasm on microtubule, plasmid pcDNA3.1-PrP23-230 expressing human PrP23-230 was introduced into HeLa cells.
View Article and Find Full Text PDFBackground: Phospho-tau deposition has been described in a rare genetic human prion disease, Gerstmann-Sträussler-Scheinker syndrome, but is not common neuropathological picture for other human and animal transmissible spongiform encephalopathies (TSEs). This study investigated the possible changes of tau and phosphorylated tau (p-tau, at Ser396, Ser404, and Ser202/Thr205) in scrapie experimental animals.
Methods: The profiles of tau and p-tau (p-tau, at Ser396, Ser404, and Ser202/Thr205) in the brain tissues of agents 263K- or 139A-infected hamsters were evaluated by Western blots and real-time PCR.
Different neurodegenerative disorders like prion disease, is caused by protein misfolding conformers. Reverse-transfected cytosolic prion protein (PrP) and PrP expressed in the cytosol have been shown to be neurotoxic. To investigate the possible mechanism of neurotoxicity due to accumulation of PrP in cytosol, a PrP mutant lacking the signal and GPI (CytoPrP) was introduced into the SH-SY5Y cell.
View Article and Find Full Text PDFIn human prion diseases, phosphorylated-tau deposition has been described in a rare genetic form, Gerstmann-Straussler-Scheinker disease, but is not considered part of the neuropathological picture of Creutzfeldt-Jakob disease. To investigate the possible changes of tau and phosphorylated tau (Ser396/Ser404) in transmissible spongiform encephalopathies (TSEs), the expressions and transcriptions of above biological factors in the brain tissues of 263K- and 139A-infected hamsters were evaluated by Western blots and Real Time PCR, respectively, followed by quantitative analyses of immunoblot images and relative transcriptional levels compared with normal animals. The contents of total tau increased, but phosphorylated tau at Ser396 and Ser404 decreased, regardless of the types of scrapie agents and clinical incubations.
View Article and Find Full Text PDFManganese may play some roles in the pathogenesis of prion diseases. In this study, recombinant human wild-type (WT) PrP and PrP mutants with deleted or inserted octarepeats were exposed to manganese, and their biochemical and biophysical characteristics were evaluated by proteinase K (PK) digestion, sedimentation experiments, transmission electron microscopy and circular dichroism. It demonstrated that incubation of manganese remarkably increased PK-resistances, protein aggregations and beta-sheet contents of the PrPs.
View Article and Find Full Text PDFObjective: To study the circulation, distribution, and genomic diversity of HPVs in common warts in Beijing area of China.
Methods: Forty eight patients with pathologically diagnosed common warts were screened for the presence of HPV with HPV type-specific PCR and direct sequencing analysis. The genomic diversity of HPVs prevalent in Chinese patients was analyzed based on LCR.
Transmissible spongiform encephalopathies (TSEs), or prion diseases, are fatal neurodegenerative disorders caused by an infectious agent termed a prion, which can convert normal cellular prion protein (PrP(C)) into a pathologically misfolded isoform (PrP(Sc)). Taking advantage of protein misfolding cyclic amplification (PMCA), a series of experiments was conducted to investigate the possible influences of pyridine nucleotides on the propagation activities of hamster-adapted scrapie agents 263K and 139A in vitro using normal hamster brain homogenates and recombinant hamster PrP as the substrates. The results showed that PrP(Sc) from both scrapie agent 263K- and 139A-infected brains propagated more efficiently in PMCA with the addition of reduced NADPH, showing an obvious dose-dependent enhancement.
View Article and Find Full Text PDFTransmissible spongiform encephalopathies (TSEs), or prion diseases, are transmissible neurodegenerative disorders of protein conformation. This group of diseases is caused by infectious agents, termed prions, which can convert normal conformation (PrP(C)) into misfolded protein (PrP(Sc)). The infectivity of non-neuronal tissues has been wildly addressed, but the propagating features and the biochemical properties of prion generated from these tissues are only partially settled.
View Article and Find Full Text PDFTo explore the possible molecular interaction between CK2 and PrP, the full length sequences of human CK2alpha and CK2beta genes were amplified with RT-PCR using the mRNA from cell line SH-SY5Y as the template, and then the fusion proteins HIS-CK2alpha and GST-HIS-CK2beta were expressed in E. coli. The interaction between CK2 and PrP was evaluated with immunoprecipitation and pull-down assays.
View Article and Find Full Text PDFIn order to establish an amplification system in vitro with which the PrP(Sc) is able to convert PrP(C) into proteinase K-resistant isoform infinitely and whether this system is more efficient than conventional protein misfolding cyclic amplification (PMCA), scrapie strain 263K-infected hamster's brain homogenate and homologous normal brain homogenate were prepared, respectively. A new methodology, namely serial PMCA, was utilized to reveal the continuous propagation ability of PrP(Sc). Totally 8 rounds of serial PMCA were proceeded and each round contained 48 cycles of alternative sonication and incubation.
View Article and Find Full Text PDFIn order to study the physicochemical characteristics of cytosolic PrP (CytoPrP) and evaluate its possible influence on cell viability, a recombinant plasmid expressing human CytoPrP eukaryoticly was constructed and transfected into human neuroblastoma cell line SH-SY5Y transiently. Proteinase-resistant activities of CytoPrP were evaluated by a proteinase K (PK) digestion and cytotoxic effects of CytoPrP were tested by MTT assay and Trypan Blue cell-counting. The presence of CytoPrP in cytoplasm after transfection was controlled by the presence of protease inhibitor.
View Article and Find Full Text PDFTo establish a new Western blotting assay for PrP(Sc) detection, we optimized the Western blotting assay with a precipitation procedure of streptomycin sulfate. After digestion with PK, 10% scrapie infected hamster brain homogenates were incubated with 60 mmol/L streptomycin and the precipitated PrP(Sc) was recovered by centrifugation. The enrichment of PrP(Sc) by streptomycin sulfate precipitation was evaluated using Western blotting assay.
View Article and Find Full Text PDFObjective: To establish a sandwich ELISA method for detecting vascular endothelial growth factor (VEGF) in sera of population and the patients with hepatocellular carcinoma (HCC).
Methods: Full length and two truncated human VEGF cDNA sequences were amplified from a commercial plasmid pBLAST49-hVEGF by PCR and inserted into the prokaryotic-expression plasmid pET-32a or pGEX-2T. Various VEGF proteins were expressed and purified from E.
To address the possible alteration of casein kinase 2 (CK2) in transmissible spongiform encephalopathies (TSEs), the levels and patterns of CK2 in the brain tissues of hamsters or C57BL mice inoculated intracerebrally with scrapie agents 263K or 139A were evaluated by Western blots, followed by quantitative analysis. Specific semi-quantitative RT-PCR for evaluating the mRNA transcripts of CK2 subunits was performed in parallel. Compared with normal animals, the levels of CK2alpha and CK2beta in the brains of infected hamsters and mice were significantly decreased, regardless of which scrapie agent was.
View Article and Find Full Text PDFGliosis of glial fibrillary acidic protein (GFAP) associated astrocytes is considered to be one of the hallmarks of transmissible spongiform encephalopathies (TSEs). In the present study, remarkable GFAP-PrP(Sc) or GFAP-PrP(C) complexes were separately detected in the brain homogenates of 263 K (Scrapie)-infected or normal hamsters by co-immunoprecipitation assay. To get more exact molecular evidences for interaction between prion protein (PrP) and GFAP, various recombinant PrP or GFAP proteins were expressed using prokaryotic-expressing and in vitro translation system.
View Article and Find Full Text PDFMicrotubule associated protein tau is considered to play roles in some types of human transmissible spongiform encephalopathies (TSE). In this study, the full-length and several truncated human tau proteins were expressed from E. coli and purified.
View Article and Find Full Text PDFMicrotubule dynamics is essential for many vital cellular processes such as in intracellular transport, metabolism, and cell division. Some evidences demonstrate that PrP may associate with microtubular cytoskeleton and its major component, tubulin. In the present study, the molecular interaction between PrP and tubulin was confirmed using pull-down assays, immunoprecipitation and ELISA.
View Article and Find Full Text PDFZhonghua Shi Yan He Lin Chuang Bing Du Xue Za Zhi
September 2007
Objective: To study the potential interaction between PrP protein and glial fibrillary acidic protein (GFAP) and identify the binding region within PrP with GFAP.
Methods: The supernatant of healthy and scrapie-infected hamsters' brain homogenate was prepared, while various recombinant PrP or GFAP proteins were expressed using prokaryotic-expressing or in-vitro translation system. The possible molecular interaction between PrP proteins and GFAP was tested by Pull-down and immunoprecipitation assays.
Zhonghua Shi Yan He Lin Chuang Bing Du Xue Za Zhi
September 2007
Objective: Generation and Identification of Phage Engineering Antibodies Library against Hamster Prion Protein.
Methods: Fab antibodies were identified and confirmed. BALB/c mice were immuned with PrP proteins.
Zhonghua Shi Yan He Lin Chuang Bing Du Xue Za Zhi
September 2007
Objective: The present study was conducted to understand the effects of PrP in different octapeptide repeats on proliferation of HeLa cells.
Methods And Results: Mutant PrPs with octapeptide repeat insertion were transiently expressed in HeLa cells and their results of MTT assay showed stronger cytotoxic effect on the proliferation of cells than wild-type PrP. Annexin V/PI assay also demonstrated that the expression of mutant PrPs was much easier to induce apoptosis than wild-type in HeLa cells.
In order to further study the potential interaction between PrP protein and the tubulin and identify the binding region in PrP with tubulin, native tubulin was extracted from rabbit brian tissues, while various recombinant PrP proteins were expressed and purified. The possible molecular interaction between various PrP fusion proteins and tubulin was tested by pull-down and immunoprecipitation assays. Remarkable molecular interaction between the full length PrP and tubulin was observed by pull-down and immunoprecipitation assays.
View Article and Find Full Text PDFMed Microbiol Immunol
December 2007
Two strains of Fab monoclonal antibodies (mAbs) against prion protein, designated as IV-66 and IV-78, were selected from the phage display libraries. The gene sequences encoding the light kappa chain and heavy Fd chain of IV-78 were inserted into a baculovirus expression cassette vector for mouse IgG expression. Western blot, Dot-ELISA and immunoprecipitation confirmed that these Fab and IgG mAbs reacted well with the recombinant hamster and human PrP proteins expressed in prokaryotic and in mammalian cells and PrP(Sc) from scrapie-infected hamsters.
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