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Bin Zhou

Publications and source records attributed to Bin Zhou.

104 records · Page 6Linked to original sources
PubMed2003

Requirement of the p130CAS-Crk coupling for metastasis suppressor KAI1/CD82-mediated inhibition of cell migration.

KAI1/CD82 protein is a member of the tetraspanin superfamily and has been rediscovered as a cancer metastasis suppressor. The mechanism of KAI1/CD82-mediated suppression of cancer metastasis remains to be established. In this study, we found that migration of the metastatic prostate cancer cell line Du145 was substantially inhibited when KAI1/CD82 was expressed. The expression of focal adhesion kinase (FAK) and Lyn, a Src family tyrosine kinase and substrate of FAK, was up-regulated at both RNA and protein levels upon KAI1/CD82 expression. The activation of FAK and Lyn, however, remained unchanged in Du145-KAI1/CD82 cells. As a downstream target of FAK-Lyn signaling, the p130CAS (Crk-associated substrate) protein was decreased upon the expression of KAI1/CD82. Consequently, less p130CAS-CrkII complex, which functions as a "molecular switch" in cell motility, was formed in Du145-KAI1/CD82 cells. To confirm that the p130CAS-CrkII complex is indeed important for the motility inhibition by KAI1/CD82, overexpression of p130CAS in Du145-KAI1/CD82 cells increased the formation of p130CAS-CrkII complex and largely reversed the KAI1/CD82-mediated inhibition of cell motility. Taken together, our studies indicate the following: 1) signaling of FAK-Lyn-p130CAS-CrkII pathway is altered in KAI1/CD82-expressing cells, and 2) p130CAS-CrkII coupling is required for KAI1/CD82-mediated suppression of cell motility.

Antigens, CD↗
PubMed2003

Naturally occurring human IgM antibody that binds B7-DC and potentiates T cell stimulation by dendritic cells.

A human IgM Ab, serum-derived human IgM 12 (sHIgM12), is identified that binds mouse and human dendritic cells (DC), inducing dramatic immunopotentiation following treatment of the mouse DC in vitro. Competition, transfection, and knockout studies identified the ligand on mouse DC as the costimulatory molecule family member B7-DC. Potent T cell responses are stimulated by Ag-pulsed DC treated with the sHIgM12 Ab in vitro and upon adoptive transfer of Ab-treated Ag-pulsed DC into animals. The multivalent structure of pentameric IgM provides the potential for cross-linking cell surface targets, endowing the soluble Abs with biological potential not normally associated with immune function. The ability of the sHIgM12 Ab to potentiate the immune response is dependent on the multimeric structure of IgM, as bivalent monomers do not retain this property. Furthermore, pretreatment of DC with IgM monomers blocks subsequent potentiation by intact IgM pentamers, an indication that cross-linking of B7-DC on the cell surface is critical for potentiation of Ag presentation. These findings imply that, in addition to known costimulatory roles, B7-DC can function as a receptor for signals delivered by cells expressing B7-DC ligands.

Adjuvants, Immunologic↗
PubMed2003

[A study on the construction of allelic ladders for 4 short tandem repeat loci (D7S817, D10S1432, D10S1213 and D18S865) and their genetic polymorphism in two Chinese populations].

OBJECTIVE: To produce standard allelic ladders for four STR loci(D7S817, D10S1432, D10S1213 and D18S865) by recombined plasmids and use them in the research of genetic polymorphism. METHODS: After being amplified by PCR, different STR allelic fragments were isolated from the polyacryramide gel. The STR allelic fragments were eluted into distilled water and reamplified by PCR to obtain purified allelic fragments. Next, the purified allelic fragments were subcloned individually into the PUC plasmid vectors, and the size and structure of the inserts were confirmed by the analysis of their DNA sequences. Then we transfected the PUC plasmid vectors into E. coli DH5 alpha cells, worked on selective culture, and finally, mixed the alleles of the four STR loci respectively. RESULTS: The standard allelic ladders for four new loci (D7S817, D10S1432, D10S1213 and D18S865) were obtained, with which the genetic polymorphisms of four new loci in Chinese Hans and Dongxiang ethnic groups were studied. CONCLUSION: The standard STR allelic ladders acquired by this method are of high value in forensic practice, and they are applicable to the analysis of genetic polymorphism.

Alleles↗
PubMed2003

[DNA-based technique and species identification].

The species identification plays a key role in forensic analysis. Generally, three methods have been applied for this purpose, they are morphologic-based, serologic-based and DNA-based techniques. This review mainly discussed the DNA-based technique and evaluate it's value in species identification of forensic science.

Animals↗
PubMed2003

[Cell behavior of periodontal ligament cells cultured on commercially pure titanium].

OBJECTIVE: To study the cell behavior of periodontal ligament cells (PDLCs) cultured on commercially pure titanium (cpTi) by cell morphology, cell counting and osteoclin (OC) immunofluorescent staining. METHODS: 1 x 10(5)/ml PDLCs in 2 ml culture medium were seeded on cpTi discs fixed in 24-well culture plates. Morphological study of cell attachment was observed by scanning electron microscope (SEM) and fluorescence microscopy. Cell adhesion was analyzed by MTT at 0.5, 1, 2, 4 hours respectively. OC was directly observed by immunofluorescent staining. RESULTS: PDLCs could attach and spread on cpTi discs. SEM showed that PDLCs had pseudopod-like protuberance. PDLCs showed different attaching phase and reached saturation in cell number at the early stage. The cells and ECM could express OC 7 days later. CONCLUSION: PDLCs show a regular, dynamic pattern in early stage and they can keep proliferating and differentiating on CpTi in vitro. It was indicated that the biological function of PDLCs around dental implant should be reconsidered.

Cells, Cultured↗
PubMed2002

Purification and molecular identification of the human hyaluronan receptor for endocytosis.

The clearance of hyaluronan (HA) and chondroitin sulfates from the circulating blood and lymph in the body is mediated by the membrane-bound HA receptor for endocytosis (HARE). Previously, we found that two HARE species of approximately 175 kDa and approximately 300 kDa are abundant in the sinusoidal endothelial cells in rat liver, spleen, and lymph nodes (Zhou et al. [2000], J. Biol. Chem., 275, 37733-37741). In the present study, immunocytochemical analysis of human tissues showed a similar pattern with abundant expression of HARE in the sinusoidal endothelial cells of human liver, spleen, and lymph nodes. The two human HARE proteins were immunoaffinity-purified from human spleen. Each protein was recognized in western blots using several anti-rat HARE monoclonal antibodies and was able to bind 125I-HA specifically. In nonreducing SDS-PAGE, these two human HARE species migrated at approximately 190 kDa and approximately 315 kDa; both proteins are approximately 15 kDa larger than the corresponding rat HAREs, although the de-N-glycosylated core proteins are essentially the same mass. After reduction, the human 190-kDa HARE gave a single 196-kDa species, which was not seen in the approximately 315-kDa HARE after reduction. The reduced approximately 315-kDa HARE yielded two major proteins at approximately 250 kDa and approximately 220 kDa. We determined the sequence of the human 190-kDa HARE cDNA based on analysis of internal tryptic peptides, as well as RT-PCR and 5' RACE analyses using human spleen and lymph node cDNA libraries. The human gene that encodes HARE is on chromosome 12.

Amino Acid Sequence↗
PubMed2002

Human antibodies against spores of the genus Bacillus: a model study for detection of and protection against anthrax and the bioterrorist threat.

A naive, human single-chain Fv (scFv) phage-display library was used in bio-panning against live, native spores of Bacillus subtilis IFO 3336 suspended in solution. A direct in vitro panning and enzyme-linked immunosorbent assay-based selection afforded a panel of nine scFv-phage clones of which two, 5B and 7E, were chosen for further study. These two clones differed in their relative specificity and affinity for spores of B. subtilis IFO 3336 vs. a panel of spores from 11 other Bacillus species/strains. A variety of enzyme-linked immunosorbent assay protocols indicated these scFv-phage clones recognized different spore epitopes. Notably, some spore epitopes markedly changed between the free and microtiter-plate immobilized state as revealed by antibody-phage binding. An additional library selection procedure also was examined by constructing a Fab chain-shuffled sublibrary from the nine positive clones and by using a subtractive panning strategy to remove crossreactivity with B. licheniformis 5A24. The Fab-phage clone 52 was improved compared with 5B and was comparable to 7E in binding B. subtilis IFO 3336 vs. B. licheniformis 5A24, yet showed a distinctive crossreactivity pattern with other spores. We also developed a method to directly detect individual spores by using fluorescently labeled antibody-phage. Finally, a variety of "powders" that might be used in deploying spores of B. anthracis were examined for antibody-phage binding. The strategies described provide a foundation to discover human antibodies specific for native spores of B. anthracis that can be developed as diagnostic and therapeutic reagents.

Anthrax↗
PubMed2002

Regulation of the murine Nfatc1 gene by NFATc2.

NFAT proteins play a key role in the inducible expression of cytokine genes in T lymphocytes. NFATc1 and NFATc2 are the predominant NFAT family members in the peripheral immune system. NFATc2 is found abundantly in the cytoplasm of resting T cells, whereas Nfatc1 expression is induced during T cell activation. To investigate Nfatc1 regulation, we characterized the structure of the murine Nfatc1 gene and its 5'-flanking region. A 290-bp sequence proximal to the transcription start site is highly conserved between mouse and human and possesses both basal and inducible promoter activities. Multiple binding sites for transcription factors were identified within this region, including a consensus NFAT-binding site. This promoter segment was cyclosporin A-sensitive, and mutation of the NFAT site abrogated inducible promoter activity and inhibited formation of an inducible DNA x protein complex containing NFATc2 in primary T cells. Overexpression of NFATc2 increased inducible Nfatc1 promoter activity, whereas this inducibility was attenuated in NFATc2(-/-) splenocytes. This study suggests that pre-existing NFATc2 contributes to the subsequent induction of Nfatc1 during T cell activation.

Animals↗
PubMed2002

Molecular cloning and functional expression of the rat 175-kDa hyaluronan receptor for endocytosis.

We recently purified the rat liver hyaluronan receptor for endocytosis (HARE) and found abundant expression of 175- and approximately 300-kDa HARE species in sinusoidal endothelial cells of the liver, spleen, and lymph nodes. We report herein the first cloning and functional expression of the rat 175-kDa HARE. Peptide sequences were obtained from the purified 175-kDa HARE, and degenerate oligonucleotide primers were designed for reverse transcription-polymerase chain reaction and cDNA cloning. Results of 5'-rapid amplification of cDNA ends, Northern analysis, N-terminal sequence, and antibody reactivity analyses indicated the absence of mRNA directly encoding the 175-kDa HARE. This protein is most likely derived from a larger precursor. Accordingly, we constructed an artificial 4.7-kb cDNA encoding the 1431 amino acid 175-kDa HARE. The predicted type I membrane protein has a mass of 156,393 Da and a pI of 7.86. The 175-kDa HARE cDNA, fused to the N-terminal leader sequence of the Ig kappa-chain, was transfected transiently into COS-7 cells and stably into SK-Hep-1 cells, respectively, to assess hyaluronan or hyaluronic acid (HA)-binding activity and endocytosis. In both cases, HARE expression and HA-binding activity were detected. Furthermore, stable SK-175HARE cells demonstrated specific endocytosis of (125)I-HA and receptor recycling. Fluorescence-activated cell sorting analysis confirmed that recombinant HARE was expressed on the cell surface and that fluorescent HA uptake was inhibited by a specific blocking monoclonal antibody against HARE. Additionally, HARE was substantially colocalized with clathrin, but not with internalized HA that was delivered to lysosomes. The results confirm that recombinant 175-kDa HARE is an authentic endocytic receptor for HA and that this receptor can function independently of the approximately 300-kDa HARE. HARE is the first functionally identified member of a protein family that shares a similar organization of Fasciclin, epidermal growth factor-like, Xlink, and transmembrane domains.

Amino Acid Sequence↗
PubMed2002

[Establishment and applications of the spatial database of land resources information in Anshun, Guizhou Province].

For the purpose of managing and processing land resources and environment information, a spatial database of land information in Anshun City, Guizhou Province, which involved present data and the investigated information by remote sensing, was established under the supporting of PAMAP GIS 4.2. The spatial database could provide the functionality of querying for spatial data and its associated attributes, conversion between the different data formats, mapping the digital terrain, fast and accurate analysis on soil resources, land assessment and management application, and soil erosion risk mapping. The establishment of this spatial database was expected to play an important role in territorial planning, agricultural sustainable development, spatial assessment of ecological environment, and so on.

Databases as Topic↗
PubMed2002

[Preparation of calcium phosphate coatings on surfaces of commercially pure titanium induced by simulated body fluid].

All samples were divided into three groups and subjected to three different surface treatments, i.e. untreated group, group etched with mixed acid of 1:1 HCl and H2SO4 followed by immersion in 6N NaOH solution at 60 degrees C for 24 h and group etched with mixed acid of 1:1 HCl and H2SO4 followed by immersion in 6N NaOH solution at 60 degrees C for 24 h then heated at 600 degrees C for 1 h. After soaked in simulated body fluid for two weeks, a thin calcium phosphate coatings was precipitated on the surfaces of the two treated samples. Results of SEM and EDX showed that calcium phosphate coatings on the surfaces of the titanium samples etched and heated were more even than the titanium samples etched without heating. The analysis of XRD demonstrated the main component of calcium phosphate coating was hydroxyapatite.

Body Fluids↗
PubMed2002

[Microbiological eco-regulation in Vc two-step fermentation].

The growth and interaction of Gluconobacter axydans and Bacillus megaterium in Vc two step fermentation have been studied. The results showed that there is a kind of coordinate symbiosis between G. axydans and B. megaterium during the fermentation, which could promoted 2-Keto-L-gulonic acid (2KGA) synthesis. The efficiency on the synbiosis would vary as the conditions of fermentation were different and were improved by the environmental factors.

Bacillus megaterium↗
PubMedDate not supplied

Measurements of NO2, SO2, O3, benzene and toluene using differential optical absorption spectroscopy (DOAS) in Shanghai, China.

NO2, SO2, O3, benzene, and toluene were measured in Taopu industry park of Shanghai during the period June to August 2003 by differential optical absorption spectroscopy (DOAS) technique. The daily average concentrations of SO2, NO2, and O3 ranged from 5.7 ppb to 40 ppb, 22 ppb to 123 ppb, and 10.6 ppb to 23 ppb respectively. SO2 and NO2 concentrations were found to depend on wind direction. The diurnal variation of NO2 concentrations had two peaks due to traffic emission. Our DOAS measurements of NO2, SO2 and O3 were compared with the conventional measurement instruments (API automatic monitoring instrument). The concept of a percent difference (PD) and linear regression methods were employed to study the difference between DOAS and API instruments. The correlation analysis between PD values and meteorological parameters and analysis of abnormal higher absolute PD values indicated that the lower visibility induced the bad compatibility between the two systems. The results showed that both systems exhibited strong compatibility with good correlation, therefore the DOAS system is able to provide reliable information on distribution patterns of major air pollutants. Average benzene and toluene concentrations were 1.4 and 8.0 ppb respectively.

Air Pollutants↗