Inhibition of vascular endothelial growth factor-induced angiogenesis by scopoletin through interrupting the autophosphorylation of VEGF receptor 2 and its downstream signaling pathways

2011 ◽  
Vol 54 (1-2) ◽  
pp. 18-28 ◽  
Author(s):  
Rong Pan ◽  
Yue Dai ◽  
Xing-Hua Gao ◽  
Dan Lu ◽  
Yu-Feng Xia
2016 ◽  
Vol 40 (6) ◽  
pp. 1570-1577 ◽  
Author(s):  
Jie Wei ◽  
Hua Jiang ◽  
Hongrui Gao ◽  
Guangjie Wang

Background/Aims: Prior studies demonstrate that hypoxia inducible factor subtype 1α (HIF-1α) in retinal tissues is involved in development of diabetic retinopathy (DR). In this report, we particularly examined the role played by mammalian target of rapamycin (mTOR) in regulating expression of HIF-1α and its downstream pathway, namely vascular endothelial growth factor (VEGF). Methods: Streptozotocin (STZ) was systemically injected to induce hyperglycemia in rats. ELISA and Western Blot analysis were employed to determine the levels of HIF-1α and VEGF as well as expression of mTOR pathways in retinal tissues of control rats and STZ rats. Results: Our results show that HIF-1α and VEGF as well as VEGF receptor subtype 2 (VEGFR-2) were increased in STZ rats. Also, the protein expression of p-mTOR, mTOR-mediated phosphorylation of 4E-binding protein 4 (4E-BP1), p70 ribosomal S6 protein kinase 1 (S6K1) pathways were amplified in diabetic retina compared with controls. Blocking mTOR by using rapamycin significantly attenuated activities of HIF-1α and VEGF signaling pathways. Conclusion: Our data for the first time revealed specific signaling pathways engaged in the development of DR, including the activation of mTOR and HIF-1α -VEGF mechanism. Targeting one or more of these signaling molecules may present new opportunities for treatment and management of DR often observed in clinics.


2012 ◽  
Vol 32 (5) ◽  
pp. 884-895 ◽  
Author(s):  
Fabricio Simão ◽  
Aline S Pagnussat ◽  
Ji Hae Seo ◽  
Deepti Navaratna ◽  
Wendy Leung ◽  
...  

Resveratrol may be a powerful way of protecting the brain against a wide variety of stress and injury. Recently, it has been proposed that resveratrol not only reduces brain injury but also promotes recovery after stroke. But the underlying mechanisms are unclear. Here, we tested the hypothesis that resveratrol promotes angiogenesis in cerebral endothelial cells and dissected the signaling pathways involved. Treatment of cerebral endothelial cells with resveratrol promoted proliferation, migration, and tube formation in Matrigel assays. Consistent with these pro-angiogenic responses, resveratrol altered endothelial morphology resulting in cytoskeletal rearrangements of β-catenin and VE-cadherin. These effects of resveratrol were accompanied by activation of phosphoinositide 3 kinase (PI3-K)/Akt and Mitogen-Activated Protein Kinase (MAPK)/ERK signaling pathways that led to endothelial nitric oxide synthase upregulation and increased nitric oxide (NO) levels. Subsequently, elevated NO signaling increased vascular endothelial growth factor and matrix metalloproteinase levels. Sequential blockade of these signaling steps prevented resveratrol-induced angiogenesis in cerebral endothelial cells. These findings provide a mechanistic basis for the potential use of resveratrol as a candidate therapy to promote angiogenesis and neurovascular recovery after stroke.


2004 ◽  
Vol 286 (3) ◽  
pp. L539-L545 ◽  
Author(s):  
Altaf S. Kazi ◽  
Shidan Lotfi ◽  
Elena A. Goncharova ◽  
Omar Tliba ◽  
Yassine Amrani ◽  
...  

In severe asthma, cytokines and growth factors contribute to the proliferation of smooth muscle cells and blood vessels, and to the increased extracellular matrix deposition that constitutes the process of airway remodeling. Vascular endothelial growth factor (VEGF), which regulates vascular permeability and angiogenesis, also modulates the function of nonendothelial cell types. In this study, we demonstrate that VEGF induces fibronectin secretion by human airway smooth muscle (ASM) cells. In addition, stimulation of ASM with VEGF activates ERK, but not p38MAPK, and fibronectin secretion is ERK dependent. Both ERK activation and fibronectin secretion appear to be mediated through the VEGF receptor flt-1, as evidenced by the effects of the flt-1-specific ligand placenta growth factor. Finally, we demonstrate that ASM cells constitutively secrete VEGF, which is increased in response to PDGF, transforming growth factor-β, IL-1β, and PGE2. We conclude that ASM-derived VEGF, through modulation of the extracellular matrix, may play an important role in airway remodeling seen in asthma.


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