scholarly journals PLD1-dependent PKCγ activation downstream to Src is essential for the development of pathologic retinal neovascularization

Blood ◽  
2010 ◽  
Vol 116 (8) ◽  
pp. 1377-1385 ◽  
Author(s):  
Qiuhua Zhang ◽  
Dong Wang ◽  
Venkatesh Kundumani-Sridharan ◽  
Laxmisilpa Gadiparthi ◽  
Dianna A. Johnson ◽  
...  
Keyword(s):  
Tube Formation ◽  
Dominant Negative ◽  
Retinal Neovascularization ◽  
Endothelial Cell Migration ◽  
Microvascular Endothelial Cell ◽  
Dominant Negative Mutant ◽  
Vascular Endothelial ◽  
Retinal Angiogenesis ◽  
Microvascular Endothelial ◽  
Endothelial Growth Factor

Abstract Vascular endothelial growth factor (VEGF) appears to be an important mediator of pathologic retinal angiogenesis. In understanding the mechanisms of pathologic retinal neovascularization, we found that VEGF activates PLD1 in human retinal microvascular endothelial cells, and this event is dependent on Src. In addition, VEGF activates protein kinase C-γ (PKCγ) via Src-dependent PLD1 stimulation. Inhibition of Src, PLD1, or PKCγ via pharmacologic, dominant negative mutant, or siRNA approaches significantly attenuated VEGF-induced human retinal microvascular endothelial cell migration, proliferation, and tube formation. Hypoxia also induced Src-PLD1-PKCγ signaling in retina, leading to retinal neovascularization. Furthermore, siRNA-mediated down-regulation of VEGF inhibited hypoxia-induced Src-PLD1-PKCγ activation and neovascularization. Blockade of Src-PLD1-PKCγ signaling via the siRNA approach also suppressed hypoxia-induced retinal neovascularization. Thus, these observations demonstrate, for the first time, that Src-dependent PLD1-PKCγ activation plays an important role in pathologic retinal angiogenesis.

Knockdown of Nrf2 inhibits angiogenesis by downregulating VEGF expression through PI3K/Akt signaling pathway in cerebral microvascular endothelial cells under hypoxic conditions

2018 ◽  
Vol 96 (4) ◽  
pp. 475-482 ◽  
Author(s):  
Yujing Huang ◽  
Ying Mao ◽  
Huiying Li ◽  
Guangxun Shen ◽  
Guangxian Nan
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Ischemic Stroke ◽  
Growth Factor ◽  
Signaling Pathway ◽  
Akt Signaling ◽  
Tube Formation ◽  
Vascular Endothelial ◽  
Akt Signaling Pathway ◽  
Microvascular Endothelial ◽  
Endothelial Growth Factor

Ischemic stroke is a major cerebrovascular disease resulting from a transient or permanent local reduction of cerebral blood flow. Angiogenesis plays an important role in cerebral microvascular repair after ischemic stroke. This study aimed at investigating the effect of NF-E2-related factor 2 (Nrf2) on the angiogenesis of mouse cerebral microvascular endothelial bEnd.3 cells in a hypoxic environment. We found that Nrf2 expression was temporarily increased in hypoxia-induced bEnd.3 cells. Knockdown of Nrf2 inhibited the proliferation, migration, as well as tube formation in hypoxia-induced bEnd.3 cells. Meanwhile, vascular endothelial growth factor and PI3K/Akt signaling pathways were identified to be regulated by Nrf2 in hypoxia-induced bEnd.3 cells. It was found that silencing of Nrf2 downregulated the expression levels of NAD(P)H:quinine oxidoreductase-1, vascular endothelial growth factor, p-Akt, and heme oxygenase-1 in hypoxia-induced bEnd.3 cells. Data suggested that hypoxia induced the transient increase of Nrf2, which plays a key role in the angiogenesis of cerebral microangiogenesis, and that Nrf2 regulates the proliferation, migration, as well as tube formation likely through PI3K/Akt signaling pathway in hypoxia-induced bEnd.3 cells. Our study provides proof of concept for the modulation of Nrf2, so as to tilt the balance toward angiogenesis, representing a therapeutic strategy for hypoxia or ischemia disorders such as stroke.

scholarly journals A Fairy Chemical Suppresses Retinal Angiogenesis as a HIF Inhibitor

Biomolecules ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1405
Author(s):  
Deokho Lee ◽  
Yukihiro Miwa ◽  
Jing Wu ◽  
Chiho Shoda ◽  
Heonuk Jeong ◽  
...  
Keyword(s):  
Hypoxia Inducible Factor ◽  
Inhibitory Effect ◽  
Retinal Neovascularization ◽  
Vascular Endothelial ◽  
Vegf Mrna ◽  
Oxygen Induced Retinopathy ◽  
Hypoxic Conditions ◽  
Chronic Therapy ◽  
Retinal Angiogenesis ◽  
Endothelial Growth Factor

Neovascular retinal degeneration is a leading cause of blindness in advanced countries. Anti-vascular endothelial growth factor (VEGF) drugs have been used for neovascular retinal diseases; however, anti-VEGF drugs may cause the development of chorioretinal atrophy in chronic therapy as they affect the physiological amount of VEGF needed for retinal homeostasis. Hypoxia-inducible factor (HIF) is a transcription factor inducing VEGF expression under hypoxic and other stress conditions. Previously, we demonstrated that HIF was involved with pathological retinal angiogenesis in murine models of oxygen-induced retinopathy (OIR), and pharmacological HIF inhibition prevented retinal neovascularization by reducing an ectopic amount of VEGF. Along with this, we attempted to find novel effective HIF inhibitors. Compounds originally isolated from mushroom-forming fungi were screened for prospective HIF inhibitors utilizing cell lines of 3T3, ARPE-19 and 661W. A murine OIR model was used to examine the anti-angiogenic effects of the compounds. As a result, 2-azahypoxanthine (AHX) showed an inhibitory effect on HIF activation and suppressed Vegf mRNA upregulation under CoCl2-induced pseudo-hypoxic conditions. Oral administration of AHX significantly suppressed retinal neovascular tufts in the OIR model. These data suggest that AHX could be a promising anti-angiogenic agent in retinal neovascularization by inhibiting HIF activation.

scholarly journals Cancer-derived small extracellular vesicles promote angiogenesis by heparin-bound, bevacizumab-insensitive VEGF, independent of vesicle uptake

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Song Yi Ko ◽  
WonJae Lee ◽  
Hilary A. Kenny ◽  
Long H. Dang ◽  
Lee M. Ellis ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Stromal Cells ◽  
Tube Formation ◽  
Endothelial Cell Migration ◽  
Tumor Xenograft ◽  
Vascular Endothelial ◽  
Heparin Interaction ◽  
Endothelial Growth Factor ◽  
Vegf Isoforms ◽  
Tumor Xenograft Growth

Abstract Cancer-derived small extracellular vesicles (sEVs) induce stromal cells to become permissive for tumor growth. However, it is unclear whether this induction solely occurs through transfer of vesicular cargo into recipient cells. Here we show that cancer-derived sEVs can stimulate endothelial cell migration and tube formation independently of uptake. These responses were mediated by the 189 amino acid isoform of vascular endothelial growth factor (VEGF) on the surface of sEVs. Unlike other common VEGF isoforms, VEGF189 preferentially localized to sEVs through its high affinity for heparin. Interaction of VEGF189 with the surface of sEVs profoundly increased ligand half-life and reduced its recognition by the therapeutic VEGF antibody bevacizumab. sEV-associated VEGF (sEV-VEGF) stimulated tumor xenograft growth but was not neutralized by bevacizumab. Furthermore, high levels of sEV-VEGF were associated with disease progression in bevacizumab-treated cancer patients, raising the possibility that resistance to bevacizumab might stem in part from elevated levels of sEV-VEGF.

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