ABSTRACT
Tumor progression is intimately associated with the vasculature, as tumor proliferation induces angiogenesis and tumor cells metastasize to distant organs via blood vessels. However, whether tumor invasion is associated with blood vessels remains unknown. As glioblastoma (GBM) is featured by aggressive invasion and vascular abnormalities, we characterized the onset of vascular remodeling in the diffuse tumor infiltrating zone by establishing new spontaneous GBM models with robust invasion capacity. Normal brain vessels underwent a gradual transition to severely impaired tumor vessels at the GBM periphery over several days. Increasing vasodilation from the tumor periphery to the tumor core was also found in human GBM. The levels of vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR2) showed a spatial correlation with the extent of vascular abnormalities spanning the tumor-invading zone. Blockade of VEGFR2 suppressed vascular remodeling at the tumor periphery, confirming the role of VEGF-VEGFR2 signaling in the invasion-associated vascular transition. As angiopoietin-2 (ANGPT2) was expressed in only a portion of the central tumor vessels, we developed a ligand-independent tunica interna endothelial cell kinase 2 (Tie2)-activating antibody that can result in Tie2 phosphorylation in vivo. This agonistic anti-Tie2 antibody effectively normalized the vasculature in both the tumor periphery and tumor center, similar to the effects of VEGFR2 blockade. Mechanistically, this antibody-based Tie2 activation induced VE-PTP-mediated VEGFR2 dephosphorylation in vivo. Thus, our study reveals that the normal-to-tumor vascular transition is spatiotemporally associated with GBM invasion and may be controlled by Tie2 activation via a novel mechanism of action.
Subject(s)
Glioblastoma , Humans , Glioblastoma/pathology , Vascular Endothelial Growth Factor A/metabolism , Vascular Remodeling , Signal Transduction , Vascular Endothelial Growth FactorsABSTRACT
Tetralogy of Fallot is rarely associated with partially anomalous pulmonary venous connection. Unidentified partially anomalous pulmonary venous connection, however, might increase the risk of pulmonary valve replacement in repaired tetralogy of Fallot patients. Here, we present a case of a 19-year-old male who received a correction of tetralogy of Fallot 18 years ago and a rare type of partially anomalous pulmonary venous connection with levoatrial cardinal vein was identified during the follow-up period. The anomalous pulmonary veins were connected to the left hepatic vein and the right superior caval vein. Performing a pulmonary valve replacement, partially anomalous pulmonary venous connection was also corrected with a new approach using the venous plexus between the hepatic veins.
Subject(s)
Heart Defects, Congenital , Pulmonary Veins , Scimitar Syndrome , Tetralogy of Fallot , Adult , Heart Defects, Congenital/complications , Humans , Male , Pulmonary Veins/abnormalities , Pulmonary Veins/surgery , Scimitar Syndrome/complications , Scimitar Syndrome/diagnostic imaging , Scimitar Syndrome/surgery , Tetralogy of Fallot/complications , Tetralogy of Fallot/surgery , Vena Cava, Superior/surgery , Young AdultABSTRACT
BACKGROUND: Pueraria lobata is used in traditional Asian medicine to treat cardiovascular diseases, diarrhea, diabetes mellitus, and diabetic complications such as diabetic retinopathy. Oxidative stress in retinal pigment epithelial cells is implicated in the pathogenesis of retinopathy and age-related macular degeneration (AMD). Here, we evaluated whether the P. lobata extract can prevent cell death and decrease membrane permeability in oxidative stress-induced human retinal pigment epithelial cells. METHODS: The effects of P. lobata extract on hydrogen peroxide- (H2O2-) induced oxidative stress were investigated using 2',7'-dichlorofluorescin diacetate, western blotting, and immunohistochemistry in human retinal pigment epithelial cells. The effects of puerarin, daidzein, and daidzin isolated from P. lobata extract were also studied by determining cell death, reactive oxygen species (ROS) generation, and p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) phosphorylation. RESULTS: Our results showed that the P. lobata extract inhibited ROS generation, suppressed the disruption of zonula occludens-1 (ZO-1), and reduced membrane permeability in H2O2-induced human retinal pigment epithelial cells. Additionally, the P. lobata extract prevented the inhibition of p38 MAPK and JNK phosphorylation. CONCLUSION: Our findings suggest that the P. lobata extract has the potential to prevent AMD development by inhibiting the mechanism underlying oxidative stress-mediated ocular disorders.