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Wei Cao

Publications and source records attributed to Wei Cao.

At least 19 recordsLinked to original sources
PubMed2006

Innate immune functions of plasmacytoid dendritic cells.

Plasmacytoid dendritic cells (pDCs) are specialized immune cells capable of producing large amounts of type I interferon (IFN) and other proinflammatory cytokines in response to viral infections. To date, a multicomponent cytoplasmic transductional-transcriptional complex and a spatiotemporal mechanism have been revealed in pDCs that mediate the rapid and robust IFN production after Toll-like receptor activation. Multiple regulatory mechanisms involving surface receptors, intracellular and exogenous factors as well as virally encoded molecules have been shown to modulate the IFN responses in these cells. The unique innate immune functions of pDCs are crucial both in infectious diseases and in autoimmune diseases. The recent research progress provides an in-depth understanding of the biology of pDCs and a sensible basis for future therapeutic interventions.

Animals↗
PubMed2006

Exploring a possible way to synthesize novel better antioxidants based on vitamin E: a DFT study.

The promoting effect of heterocyclic ring and heteroatom on the antioxidant properties of vitamin E has been investigated systemically by using density functional theory. The calculated results show that the heteroatom plays a more important role in promoting the antioxidant properties than the heterocyclic ring, indicating that replacing O atom by S or Se is impossible to synthesize the novel better antioxidants. Furthermore, the bond dissociation enthalpy (BDE) and ionization potential (IP) of the corresponding molecules are decreased dramatically when the O atom is replaced by NH. In addition, the calculated results also reveal that reducing the atom number of heterocyclic ring is an ideal way to synthesize novel antioxidants with better antioxidant activity than vitamin E.

Amines↗
PubMed2006

Plasmacytoid dendritic cell-specific receptor ILT7-Fc epsilonRI gamma inhibits Toll-like receptor-induced interferon production.

Immunoglobulin-like transcripts are a family of inhibitory and stimulatory cell surface immune receptors. Transcripts for one member of this family, ILT7, are selectively expressed in human plasmacytoid dendritic cells (pDCs). We demonstrate here that ILT7 protein associates with the signal adapter protein Fc epsilonRI gamma to form a receptor complex. Using an anti-ILT7 monoclonal antibody, we show that ILT7 is expressed specifically on human pDCs, but not on myeloid dendritic cells or other peripheral blood leukocytes. Cross-linking of ILT7 resulted in phosphorylation of Src family kinases and Syk kinase and induced a calcium influx in freshly isolated pDCs, which was blocked by Src family and Syk kinases inhibitors, thus indicating the activation of an immunoreceptor-based tyrosine activation motif-mediated signaling pathway. ILT7 cross-linking on CpG or influenza virus-stimulated primary pDCs inhibited the transcription and secretion of type I interferon and other cytokines. Therefore, the ILT7-Fc epsilonRI gamma receptor complex negatively regulates the innate immune functions of human pDCs.

Dendritic Cells↗
PubMed2006

Structural analysis of water-soluble glucans from the root of Angelica sinensis (Oliv.) Diels.

Two water-soluble glucans (designated APS-1cI and APS-1cII) were extracted from the roots of Angelica sinensis (Oliv.) Diels and further purified by anion-exchange and gel-filtration chromatography. Their molecular weights were determined to be 1.7 x 10(5) and 3.9 x 10(4)Da, respectively. The structures of the purified glucans were investigated by a combination of chemical and instrumental analysis, such as methylation analysis, periodate oxidation, GC-MS, as well as FTIR and NMR spectroscopy ((1)H, (13)C, H-H COSY, HSQC, HMBC, TOCSY and NOESY). The data obtained indicated that APS-1cI was a linear alpha-glucan composed of only (1-->6)-alpha-D-Glcp, and APS-1cII had a repeating unit consisting of (1-->4)-alpha-D-Glcp and (1-->6)-alpha-D-Glcp in a molar ratio of 4:1. Such glucans isolated from A. sinensis (Oliv.) Diels have not been previously reported.

Angelica sinensis↗
PubMed2006

Gammadelta T cells recognize tumor cells via CDR3delta region.

The principles governing gammadelta T cell specificity and diversity remain unclear due to lack of detailed structural analysis. To elucidate key structural basis of the specificity of gammadelta TCR for tumors, we analyzed the binding activities of synthesized TCR Vdelta2 CDR3 peptides derived from tumor infiltrating lymphocyte (TIL) s in ovarian epithelial carcinoma (OEC) via biospecific interaction analysis approach, enzyme immunoassay and immunofluorescence assays. Besides, we used human CDR3delta grafted-Ig to repeat major tests. We found that synthesized OEC-derived CDR3delta peptides could bind specifically to tumor cell lines and tissues. CDR3delta-graft Ig showed a similar binding specificity with CDR3delta peptides, suggesting the determinant role of CDR3delta in antigen binding. Moreover, CDR3delta peptide-mediated binding specificity was blocked by pre-incubation with same peptide, which decreased the cytotoxicity of gammadelta T cells to OEC cells in vitro. Our finding indicates that CDR3delta peptide could mimic antigen-binding specificity of gammadelta TCR. Our strategy provides a novel, simple and convenient approach to investigate the binding activity and function of gammadelta TCR.

Antigen Presentation↗
PubMed2006

The ortho hydroxy-amino group: another choice for synthesizing novel antioxidants.

Four ortho hydroxy-amino derivatives have been designed based on the structures of flavonoids to explore the effect of the ortho hydroxy-amino group on the antioxidant properties of molecules, and their bond dissociation enthalpies (BDE), ionization potentials (IP), the highest occupied molecular orbitals (HOMO), and spin densities have been calculated. The results reveal that the ortho hydroxy-amino group plays an important role in promoting the antioxidant properties of molecules because of its lowering effect on BDE, IP, and spin density. The derivatives with ortho hydroxy-amino group show stronger antioxidant activity than the derivatives with mono hydroxy or ortho dihydroxy group. Thus, the ortho hydroxy-amino group can be used as another potential functional group to synthesize novel antioxidants as guessed.

Amino Acids↗
PubMed2006

Determination of AKF-PD in whole blood of rat by HPLC-UV.

An HPLC-UV method was developed and validated for the determination of AKF-PD in whole blood of rat. Phenacetin was chosen as the internal standard, and the separation was achieved on a C18 column with methanol and 0.02 M phosphate buffer (pH 3.2) as mobile phase. The obtained calibration graphs were linear (r = 0.9999, n = 9) in the range of 0.203-52.0 microg ml(-1). The low limit of quantitation was 0.203 microg ml(-1). This method can be used to study the pharmacokinetics of AKF-PD in rat.

Animals↗
PubMed2006

Flow injection-chemiluminescence determination of phenol using potassium permanganate and formaldehyde system.

It is found that phenol can react with potassium permanganate in the acidic medium and produce chemiluminescence, which is greatly enhanced by formaldehyde. The optimum conditions for this chemiluminescent reaction are in detail studied using a flow injection system. The experiments indicate that under optimum conditions, the chemiluminescence intensity is linearly related to the concentration of phenol in the range 5.0x10(-9) to 1.0x10(-6)gmL-1 with a detection limit (3sigma) of 3x10(-9)gmL-1. The relative standard deviation is 1.2% for 4.0x10(-7)gmL-1 phenol solution in 11 repeated measurements. This method has the advantages of simple operation, fast response and high sensitivity. The method is successfully applied to the determination of phenol in the waste water.

Flow Injection Analysis↗
PubMed2006

Polymorphism of Xeroderma Pigmentosum group G and the risk of lung cancer and squamous cell carcinomas of the oropharynx, larynx and esophagus.

We investigated the effects of XPG His1104Asp polymorphism (rs17655) on the risk of lung cancer and squamous cell carcinomas of the oropharynx, larynx and esophagus (SCCOLE). This population-based case-control study involves 611 new cases of lung cancer, 601 new cases of oropharyngeal, laryngeal and esophageal cancers, and 1,040 cancer-free controls. The XPG polymorphism was assayed by PCR-RFLP method for 497 lung cancer cases, 443 cases of oropharyngeal, laryngeal and esophageal cancers and 912 controls. Binary and polytomous unconditional logistic regression models were fitted to assess the main effects and the effect modifications between the polymorphism and environmental exposures. With the adjustment for potential confounders, the XPG Asp1104Asp genotype was inversely associated with lung cancer (odds ratio [OR] = 0.62, 95% confidence limits [CL] = 0.38, 1.0) and SCCOLE (OR = 0.47, 95% CL = 0.27, 0.82), with the combined His1104His and His1104Asp genotypes as the referent. With subjects having genotype Asp1104Asp and no tobacco smoking exposure as the common referent, the ORs on lung cancer were 13 (95% CL = 4.4, 37) for heavy tobacco smoking (>20 pack-years), 1.9 (95% CL = 0.78, 4.5) for having at least one copy of 1104His, and 23 (95% CL = 9.5, 56) for the joint effect, respectively. Compared to non-smokers with the Asp1104Asp genotype, the adjusted OR on SCCOLE for heavy smokers (>20 pack-years) having at least one copy of 1104His was 8.0 (95% CL = 2.7, 24). Similarly, compared to non-drinkers with the Asp1104Asp genotype, the adjusted OR on SCCOLE for heavy drinkers (> or =3 drinks/day) with at least one copy of 1104His was 10 (95% CL = 2.7, 38). In conclusion, our study suggests that the XPG Asp1104Asp genotype may be associated with decreased susceptibility to lung cancer and SCCOLE.

Adenocarcinoma↗
PubMed2006

A combined treatment TNF-alpha/doxorubicin alleviates the resistance of MCF-7/Adr cells to cytotoxic treatment.

The efficiency of anticancer therapy is often restricted by the development of drug resistance. Here, we report that the doxorubicin (DOX)-resistant MCF-7/Adr cells were more resistant to DOX-treatment than MCF-7 cells. However, an alternative treatment of DOX/TNF-alpha enhanced the cytotoxic effect in multidrug resistant MCF-7/Adr cell line. Treatment of cells with TNF-alpha following doxorubicin (DOX) resulted in a decrease of the activated Rel A/p65 in nuclei. Histone deacetylase 1 (HDAC1) was found to interact with Rel A/p65 in the complex, suggesting that HDAC1 is involved in mediating nuclear export of Rel A/p65. The combined treatment of TNF-alpha/DOX also resulted in a significant decrease of mRNA levels of anti-apoptotic genes, such as the cellular inhibitor of apoptosis-1 (c-IAP1), and the long isoform of B cell leukemia/lymphoma x gene (Bcl-xL), leading to efficient induction of caspase-8 cleavage and cell death. In previous work, we demonstrated that TNF-alpha promotes DOX-induced cell death and anti-cancer effect through downregulation of p21 in p53-deficient tumor cells. Thus, we proposed that alternative administration of TNF-alpha and DOX may be a new and efficient therapeutic strategy for patients that develop resistance to cytotoxic treatment.

Antibiotics, Antineoplastic↗
PubMed2006

Human plasmacytoid predendritic cells activate NK cells through glucocorticoid-induced tumor necrosis factor receptor-ligand (GITRL).

Plasmacytoid dendritic cell precursors (pDCs) are professional type I interferon-producing cells, a critical cell type in regulating innate and adaptive immune responses. By microarray gene expression analysis, we found that pDCs activated by virus or CpG-ODN preferentially express the ligand for the glucocorticoid-induced tumor necrosis factor receptor (GITRL), which was confirmed by reverse transcriptase-polymerase chain reaction (RT-PCR) and flow cytometry analysis. Using the same approaches, we found GITR is expressed by activated natural killer (NK) cells and T cells. We show that pDCs activated by CpG-ODN promote NK cell cytotoxicity and interferon (IFN)-gamma production through type I IFNs and GITRL. Using a GITRL-transfected cell line, we further demonstrate that GITRL promotes NK cell cytotoxicity and IFN-gamma production in synergy with interleukin-2 (IL-2), IFN-alpha, and NKG2D triggering. We also demonstrated that pDCs localized in close contact to NK cells in T-cell areas of the tonsils, and a subpopulation of the pDCs expressed GITRL. This study reveals a novel function of GITR/GITRL in pDC-mediated coactivation of NK cells.

Base Sequence↗
PubMed2006

17beta-estradiol (betaE2) protects human retinal Müller cell against oxidative stress in vitro: evaluation of its effects on gene expression by cDNA microarray.

17beta-estradiol (betaE(2)) is an effective neuroprotectant against hydrogen peroxide (H(2)O(2))-induced retinal neuronal cell death and light-induced photoreceptor degeneration. Müller cells are the principal macroglia responsible for supporting retinal neuronal survival, information processing and removing metabolic waste. However, the role of betaE(2) on human Müller cells is unclear. In this study, the effects of betaE(2) on human Müller cell survival and gene expression were examined. Our data revealed that betaE(2) is able to increase human Müller cell viability after exposure to H(2)O(2) through inhibition of apoptosis. Microarray analysis revealed significant changes in the expression of 69 genes (total of 21,324 genes screened) in cultured human Müller cells 6 h after betaE(2) treatment. Four of the betaE(2)-responsive genes [thrombospondin 1 (TSP1), mitogen-activated protein kinase kinase kinase 3 (MAP3K3), large conductance calcium-activated potassium channel beta2 subunit (KCNMB2), and SRY (sex-determining region Y)-box 11 (SOX11)] were validated by both real-time qRT-PCR and semi-quantitative RT-PCR. Interestingly, exposure of human Müller cells to betaE(2) increased pigment epithelium-derived factor (PEDF) gene expression as measured by both RT-PCR and real time qRT-PCR. Our data demonstrate, for the first time, that betaE(2) protects cultured human Müller cells against H(2)O(2)-induced cell death through the inhibition of apoptosis. This protective effect may operate through regulation of genes, such as TSP1, MAP3K3, SOX11, TSP1, and PEDF, and may in turn exert an important role in protecting retinal neurons.

Antioxidants↗
PubMed2006

Evaluation of 99mTc labeled diadenosine tetraphosphate as an atherosclerotic plaque imaging agent in experimental models.

The potential of 99mTc labeled P1, P4-di (adenosine-5')-tetraphosphate (Ap4A) for imaging experimental atherosclerotic plaques was evaluated in New Zealand white (NZW) rabbits. To label the 99mTc to Ap4A, stannous tartrate solution was used. 99mTc-Ap4A was purified on a Sephadex G-25 column. The radiochemistry purities of 99mTc-Ap4A were 85% to 91%. Biodistribution study revealed 99mTc-Ap4A cleared from blood rapidly. Thirty min after 99mTc-Ap4A administrated on NZW atherosclerotic rabbits, lesion to blood (target/blood, T/B) ratio was 3.17 +/- 1.27, and lesions to normal (target/non-target, T/NT) ratio was 5.23 +/- 1.87. Shadows of atherosclerotic plaques were clearly visible on radioautographic film. Aortas with atherosclerotic plaques also could be seen on ex vivo gamma camera images. Atherosclerotic abdominal aortas were clearly visible on in vivo images 15 min to 3 h after 99mTc-Ap4A administration. 99mTc-labeled Ap4A can be used for rapid noninvasive detection of experimental atherosclerotic plaque.

Animals↗
PubMed2006

Neuroprotection of insulin against oxidative stress-induced apoptosis in cultured retinal neurons: involvement of phosphoinositide 3-kinase/Akt signal pathway.

In order to investigate the neuroprotection of insulin in retinal neurons, we used retinal neuronal culture as a model system to study the protective effects of insulin against H2O2-induced cytotoxicity and apoptotic death. Primary retinal neuronal cultures were grown from retinas of 0-2-day old Sprague-Dawley rats. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay. Apoptotic cell death was evaluated by the TdT-mediated digoxigenin-dUTP nick-end labeling assay, and by DNA laddering analysis. Phosphoinositide 3-kinase (PI3K) activity was measured using phosphoinositide 4,5-bisphophate and [gamma-32P]ATP as substrate. Western blot analysis with anti-phospho-Akt (pS473) antibody was performed to examine the level of phosphorylated Akt. We observed that treatment with 100 microM H2O2 for 24 h significantly decreased cell viability and induced apoptotic death of retinal neurons, and that pretreatment with 10 nM insulin significantly inhibited or attenuated H2O2-induced cytotoxicity and apoptosis. Pretreatment with LY294002, a specific PI3K inhibitor, abolished the cytoprotective effect of insulin. Insulin also strongly activated both PI3K and the downstream effector Akt. These results suggest that insulin protects retinal neurons from oxidative stress-induced apoptosis and that the PI3K/Akt signal pathway is involved in insulin-mediated retinal neuroprotection.

Animals↗
PubMed2006

Salutary effect of pigment epithelium-derived factor in diabetic nephropathy: evidence for antifibrogenic activities.

Diabetic nephropathy is a major complication of diabetes and a leading cause of end-stage renal diseases in the U.S. Pigment epithelium-derived factor (PEDF) is a potent angiogenic inhibitor that has been extensively studied in diabetic retinopathy. Recently, we reported that PEDF is expressed at high levels in normal kidneys and that PEDF levels are decreased in kidneys of streptozotocin (STZ)-induced diabetic rats. In the present study, we injected STZ-diabetic rats with an adenovirus expressing PEDF (Ad-PEDF) to evaluate its effects in diabetes. The results showed that increased expression of PEDF in the kidney in response to Ad-PEDF delivery significantly alleviated microalbuminuria in early stages of diabetes. Administration of Ad-PEDF was found to prevent the overexpression of two major fibrogenic factors, transforming growth factor-beta (TGF-beta)1 and connective tissue growth factor (CTGF), and to significantly reduce the production of an extracellular matrix (ECM) protein in the diabetic kidney. Moreover, PEDF upregulated metalloproteinase-2 expression in diabetic kidney, which is responsible for ECM degradation. In cultured human mesangial cells, PEDF significantly inhibited the overexpression of TGF-beta1 and fibronectin induced by angiotensin II. PEDF also blocked the fibronectin production induced by TGF-beta1 through inhibition of Smad3 activation. These findings suggest that PEDF functions as an endogenous anti-TGF-beta and antifibrogenic factor in the kidney. A therapeutic potential of PEDF in diabetic nephropathy is supported by its downregulation in diabetes; its prevention of the overexpression of TGF-beta, CTGF, and ECM proteins in diabetic kidney; and its amelioration of proteinuria in diabetic rats following Ad-PEDF injection.

Adenoviridae↗
PubMed2006

[Comparative study of uptake and washout of 99mTcn(NOEt)2 with 99mTc-MIBI in human nasopharyngeal carcinoma cell line CNE].

OBJECTIVE: To determine the cellular kinetics of 99mTc-bis {N-ethoxy-N-ethyl dithiocarbamato-nitrido [N(NOEt)2]} in human nasopharyngeal carcinoma CNE cells line and to compare it with the cellular kinetics of 99mTc-methoxyisobutylisonitrile (MIBI) in the same conditions; to define the possible clinical application value of 99mTcN(NOEt)2 in nasopharyngeal carcinoma imaging. METHOD: 99mTcN(NOEt)2 or 99mTc-MIBI were incubated with CNE cells at 37degrees C, 22 degrees C, at different time points after incubation, the uptake and washout characteristics of radiotracers in CNE cells were investigated and compared. RESULT: The maximum uptake ratio of 99mTcN(NOEt)2 in CNE cells was 43.15%, that of 99mTc-MIBI was 11.08% (P < 0.01). The uptake of 99mTcN(NOEt)2 after 5 min incubation in CNE cells was 63% of total uptake, uptake of 99mTc-MIBI was 48% of total uptake (P < 0.05); 1 h after removal of the unbound tracer, 63.92% of the total uptake of 99TcN(NOEt)2 was retained in the CNE cells, 53. 97% of 99mTc-MIBI was retained (P < 0.05); not like 99mTc-MIBI, the cellular kinetics of 99mTcN (NOEt)2 were similar at 37 degrees C and 22 degrees C ( P > 0.05). CONCLUSION: 99mTcN(NOEt)2 may be a gamma imaging agent better than 99mTc-MIBI for nasopharyngeal carcinoma imaging. 99mTcN(NOEt)2 is a potential human nasopharyngeal carcinoma imaging agent.

Cell Line, Tumor↗
PubMed2006

[Isolation and characterization of a facultative anaerobic aniline-degrading bacterium].

An aniline-degrading bacterium (designated strain AN29) was isolated from dyeing wastewater process (anaerobic baffled reactor, ABR) with the capability of utilizing aniline as sole carbon source and nitrogen source. It was identified as Pseudomonas sp. based upon the phenotypic properties and a partial analysis of the 16S rDNA. The strain could degrade aniline under the aerobic and anaerobic conditions, the optimal initial pH 6.5 - 8.0, a temperature of 37 degrees C, and initial aniline concentrations of 500 - 2 000 mg/L with maximum concentration of 4 000 mg/L respectively.

Aerobiosis↗