Wnt 10b activates the CCN2 promoter in NIH 3T3 fibroblasts through the Smad response element

Wnt proteins elevate expression of the CCN family. For example, Wnt10b induces the fibrogenic pro-adhesive molecule connective tissue growth factor (CTGF, CCN2) in NIH 3T3 fibroblasts. Wnt10b activates the CCN2 minimal promoter. In this report, we map the Wnt10b response element in the CCN2 minimal promoter to the previously identified Smad response element. These results suggest that Wnts may cross-talk with the Smad signaling pathway to induce fibrotic responses in fibroblasts

WNT-1 Signaling Inhibits Apoptosis by Activating β-Catenin/T Cell Factor–Mediated Transcription

Wnt signaling plays a critical role in development and oncogenesis. Although significant progress has been made in understanding the downstream signaling cascade of Wnt signaling, little is known regarding Wnt signaling modification of the cell death machinery. Given that numerous oncogenes transform cells by providing cell survival function, we hypothesized that Wnt signaling may inhibit apoptosis. Here, we report that cells expressing Wnt-1 were resistant to cancer therapy–mediated apoptosis. Wnt-1 signaling inhibited the cytochrome c release and the subsequent caspase-9 activation induced by chemotherapeutic drugs, including both vincristine and vinblastine. Furthermore, we found that Wnt-1–mediated cell survival was dependent on the activation of β-catenin/T cell factor (Tcf) transcription. Inhibition of β-catenin/Tcf transcription by expression of the dominant-negative mutant of Tcf-4 blocked Wnt-1–mediated cell survival and rendered cells sensitive to apoptotic stimuli. These results provide the first demonstration that Wnt-1 inhibits cancer therapy–mediated apoptosis and suggests that Wnt-1 may exhibit its oncogenic potential through a mechanism of anti-apoptosis

Wnt signaling promotes oncogenic transformation by inhibiting c-Myc–induced apoptosis

Aberrant activation of the Wnt/β-catenin signaling pathway is associated with numerous human cancers and often correlates with the overexpression or amplification of the c-myc oncogene. Paradoxical to the cellular transformation potential of c-Myc is its ability to also induce apoptosis. Using an inducible c-MycER expression system, we found that Wnt/β-catenin signaling suppressed apoptosis by inhibiting c-Myc–induced release of cytochrome c and caspase activation. Both cyclooxygenase 2 and WISP-1 were identified as effectors of the Wnt-mediated antiapoptotic signal. Soft agar assays showed that neither c-Myc nor Wnt-1 alone was sufficient to induce cellular transformation, but that Wnt and c-Myc coordinated in inducing transformation. Furthermore, coexpression of Wnt-1 and c-Myc induced high-frequency and rapid tumor growth in nude mice. Extensive apoptotic bodies were characteristic of c-Myc–induced tumors, but not tumors induced by coactivation of c-Myc and Wnt-1, indicating that the antiapoptotic function of Wnt-1 plays a critical role in the synergetic action between c-Myc and Wnt-1. These results elucidate the molecular mechanisms by which Wnt/β-catenin inhibits apoptosis and provide new insight into Wnt signaling-mediated oncogenesis

A study on the cavitating flow around an elliptical disk-shaped cavitator for non-body-of-revolution underwater vehicles

Supercavitation has been recently presented as an effective method for the drag reduction of underwater vehicles. However, maintaining the supercavitating state requires a lot of energy, making vehicles difficult to control. Therefore, it is necessary to design an underwater vehicle with low drag in the fully wetted state while being able to move at ultra-high speed in the supercavitating state. In this study, a detachable fairing design for underwater vehicles is proposed, which has the advantage of increasing the total voyage and avoiding the problem of difficult steering in the supercavitating state. On the other hand, the study of non-body-of-revolution (non-BOR) has become a prevalent area of interest in the shape design of underwater vehicles. The cavity generated by an elliptical disk-shaped cavitator is studied numerically. It is found that the cavity profile on the cross-section near the cavitator is approximately elliptical. The cavity length of an elliptical disk-shaped cavitator is almost the same as that of a disk-shaped cavitator when they have the same inflow area. Based on these two characteristics, the parameters of the internal elliptical disk-shaped cavitator are optimized, which provides a promising strategy for the issue of cavitators increasing drag in a fully wetted state

Prediction and identification of mouse cytotoxic T lymphocyte epitopes in Ebola virus glycoproteins

<p>Abstract</p> <p>Background</p> <p>Ebola viruses (EBOVs) cause severe hemorrhagic fever with a high mortality rate. At present, there are no licensed vaccines or efficient therapies to combat EBOV infection. Previous studies have shown that both humoral and cellular immune responses are crucial for controlling Ebola infection. CD8⁺ T cells play an important role in mediating vaccine-induced protective immunity. The objective of this study was to identify H-2^d-specific T cell epitopes in EBOV glycoproteins (GPs).</p> <p>Results</p> <p>Computer-assisted algorithms were used to predict H-2^d-specific T cell epitopes in two species of EBOV (<it>Sudan</it> and <it>Zaire</it>) GP. The predicted peptides were synthesized and identified in BALB/c mice immunized with replication-deficient adenovirus vectors expressing the EBOV GP. Enzyme-linked immunospot assays and intracellular cytokine staining showed that the peptides RPHTPQFLF (<it>Sudan</it> EBOV), GPCAGDFAF and LYDRLASTV (<it>Zaire</it> EBOV) could stimulate splenoctyes in immunized mice to produce large amounts of interferon-gamma.</p> <p>Conclusion</p> <p>Three peptides within the GPs of two EBOV strains were identified as T cell epitopes. The identification of these epitopes should facilitate the evaluation of vaccines based on the Ebola virus glycoprotein in a BALB/c mouse model.</p

Influenza virus induced cell-cell fusion. MDCK cells were infected with the viruses at MOI of 0.1 or 0.001 in the presence of 1 µg/ml TPCK-trypsin.

<p>After adsorption for 1 h at 37°C, the inocula were removed and the cultures were washed 3 times. The cells were incubated for the indicated times at 37°C in the maintenance media. At the indicated time, the cells were processed for indirect immunofluorescence assay, and the infected cells were detected with polyclonal antisera to whole viruses. (A) MOI at 0.1, 3 h p.i. (B) MOI at 0.1, 6 h p.i. (C) MOI at 0.001, 12 h p.i.</p

Impact of different NA on initiation of influenza virus infection.

<p>MDCK cells were infected at an MOI of 0.001 in the presence of 1 µg/ml TPCK-trypsin. After adsorption for 1 h at 37°C, the inocula were removed and the cultures were washed 3 times. The cells were incubated at 37°C for 6 h. At the indicated time, the cells were processed for immunofluorescence, and the infected cells were detected with polyclonal antisera to whole viruses. (A) Fluorescence images of the infected cells at 6 h p.i. Fluorescent photomicrographs showing the intracellular expression of virus protein in cell culture. The FITC-fluorescence signal was expressed as the infected cells. (B) Volocity Demo software analysis of the ratios of infected cells according to the Fig. 5A. *, statistical significance (<i>p</i><0.05) (C) Flow-cytometric analysis of virus-infected cells at 6 h p.i. MDCK cells (2×10⁶) in suspension were incubated with PBS or anti-PR8 antibodies on ice. Then the FITC-conjugated IgG secondary antibodies were added. After washing, the cells were fixed and the number of infected cells was determined by flow cytometric analysis. *, statistical significance (<i>p</i><0.05).</p

Virus elution in <i>vitro</i>.

<p>50 µl two-fold dilutions of virus containing the HA titers of 1∶128 was incubated with 50 µl 0.5% chicken erythrocytes in microtiter plates at 4°C for 1 h. Then microtiter plates were incubated at 37°C, and the reduction of HA titers was measured periodically for 8 h.</p

Pathogenicity of recombinant viruses in BALB/c mice.

<p>Survival rates (A) and bodyweight changes (B) after challenge with the viruses. BALB/c mice were intranasally inoculated with rPR8-H5N1NA, rPR8-H9N2NA, rPR8-H1N1NA or PR8-wt virus at 1×10^6.5 EID₅₀. The survival rates and bodyweights of five mice in each group were measured daily from the date of challenge to 14 days after challenge. Values represent mean ± SD of each group of mice.</p

Alignment of the deduced amino acid sequences of the NA genes from the influenza virus strains A/Chicken/Jiangsu/7/2002(H9N2), A/California/04/2009 (H1N1), A/chicken/Henan/12/2004 (H5N1) and PR8 (H1N1).

<p>Alignment of the deduced amino acid sequences of the NA genes from the influenza virus strains A/Chicken/Jiangsu/7/2002(H9N2), A/California/04/2009 (H1N1), A/chicken/Henan/12/2004 (H5N1) and PR8 (H1N1).</p