|Endothelial Wnt/β-catenin signaling inhibits glioma angiogenesis and normalizes tumor blood vessels by inducing PDGF-B expression. |
Reis, M; Czupalla, CJ; Ziegler, N; Devraj, K; Zinke, J; Seidel, S; Heck, R; Thom, S; Macas, J; Bockamp, E; Fruttiger, M; Taketo, MM; Dimmeler, S; Plate, KH; Liebner, S
The Journal of experimental medicine
Endothelial Wnt/β-catenin signaling is necessary for angiogenesis of the central nervous system and blood-brain barrier (BBB) differentiation, but its relevance for glioma vascularization is unknown. In this study, we show that doxycycline-dependent Wnt1 expression in subcutaneous and intracranial mouse glioma models induced endothelial Wnt/β-catenin signaling and led to diminished tumor growth, reduced vascular density, and normalized vessels with increased mural cell attachment. These findings were corroborated in GL261 glioma cells intracranially transplanted in mice expressing dominant-active β-catenin specifically in the endothelium. Enforced endothelial β-catenin signaling restored BBB characteristics, whereas inhibition by Dkk1 (Dickkopf-1) had opposing effects. By overactivating the Wnt pathway, we induced the Wnt/β-catenin-Dll4/Notch signaling cascade in tumor endothelia, blocking an angiogenic and favoring a quiescent vascular phenotype, indicated by induction of stalk cell genes. We show that β-catenin transcriptional activity directly regulated endothelial expression of platelet-derived growth factor B (PDGF-B), leading to mural cell recruitment thereby contributing to vascular quiescence and barrier function. We propose that reinforced Wnt/β-catenin signaling leads to inhibition of angiogenesis with normalized and less permeable vessels, which might prove to be a valuable therapeutic target for antiangiogenic and edema glioma therapy.
|Development and evaluation of an antibody capture ELISA for detection of IgG to Epstein-Barr virus in oral fluid samples. |
C Sheppard, B Cohen, N Andrews, H Surridge
Journal of virological methods
The development of an EBV IgG antibody capture ELISA (GACELISA) for detection of EBV viral capsid antigen specific IgG in oral fluids is described. The assay was optimised and evaluated using paired serum and oral fluid samples from healthy laboratory staff (n=82) and oral fluids collected either for routine measles, mumps, and rubella testing (n=629) or for an epidemiological study of atopic dermatitis (n=252). Statistical analysis by mixture modelling was used to determine the GACELISA cut-off and to estimate the sensitivity and specificity of the assay. Sensitivity and specificity was also assessed by comparing the results of immunofluorescence assay for EBV specific IgG in serum with those of GACELISA in 82 matching oral fluids. Compared to serum immunofluorescence assay, oral fluid GACELISA was found to have a sensitivity of 82.2 and 88.9% specificity with these samples. Mixture modelling, predicted the GACELISA to be 88.4% sensitive and of 99.4% specific. The prevalence of antibody to EBV in oral fluids was found to be 73.8% in laboratory staff, 34.4--73.9% in measles, mumps, and rubella patients and 22.2% in atopic dermatitis study participants. A robust, reliable and reproducible EBV GACELISA has been developed which will be a useful tool for epidemiological investigations.