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 Double-Stranded RNA-Binding Protein Regulates Vascular Endothelial Growth Factor mRNA Stability, Translation, and Breast Cancer Angiogenesis

2007 ◽  
Vol 28 (2) ◽  
pp. 772-783 ◽  
Author(s):  
Frank Vumbaca ◽  
Kathryn N. Phoenix ◽  
Daniel Rodriguez-Pinto ◽  
David K. Han ◽  
Kevin P. Claffey
Keyword(s):  
Breast Cancer ◽  
Mrna Stability ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Vascular Endothelial ◽  
Vegf Mrna ◽  
Double Stranded Rna ◽  
Hypoxic Conditions ◽  
Endothelial Growth Factor

ABSTRACT Vascular endothelial growth factor (VEGF) is a key angiogenic factor expressed under restricted nutrient and oxygen conditions in most solid tumors. The expression of VEGF under hypoxic conditions requires transcription through activated hypoxia-inducible factor 1 (HIF-1), increased mRNA stability, and facilitated translation. This study identified double-stranded RNA-binding protein 76/NF90 (DRBP76/NF90), a specific isoform of the DRBP family, as a VEGF mRNA-binding protein which plays a key role in VEGF mRNA stability and protein synthesis under hypoxia. The DRBP76/NF90 protein binds to a human VEGF 3′ untranslated mRNA stability element. RNA interference targeting the DRBP76/NF90 isoform limited hypoxia-inducible VEGF mRNA and protein expression with no change in HIF-1-dependent transcriptional activity. Stable repression of DRBP76/NF90 in MDA-MB-435 breast cancer cells demonstrated reduced polysome-associated VEGF mRNA levels under hypoxic conditions and reduced mRNA stability. Transient overexpression of the DRBP76/NF90 protein increased both VEGF mRNA and protein levels synthesized under normoxic and hypoxic conditions. Cells with stable repression of the DRBP76/NF90 isoform showed reduced tumorigenic and angiogenic potential in an orthotopic breast tumor model. These data demonstrate that the DRBP76/NF90 isoform facilitates VEGF expression by promoting VEGF mRNA loading onto polysomes and translation under hypoxic conditions, thus promoting breast cancer growth and angiogenesis in vivo.

scholarly journals Vascular Endothelial Growth Factor Signaling in Models of Oxygen-Induced Retinopathy: Insights Into Mechanisms of Pathology in Retinopathy of Prematurity

2021 ◽  
Vol 9 ◽  
Author(s):  
Aniket Ramshekar ◽  
M. Elizabeth Hartnett
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Retinopathy Of Prematurity ◽  
Neuronal Development ◽  
Growth Factor Signaling ◽  
Vascular Endothelial ◽  
Vegf Signaling ◽  
Oxygen Induced Retinopathy ◽  
Retinal Angiogenesis ◽  
Endothelial Growth Factor

Retinopathy of prematurity (ROP) is a leading cause of blindness in children worldwide. Blindness can occur from retinal detachment caused by pathologic retinal angiogenesis into the vitreous, termed intravitreal neovascularization (IVNV). Although agents that interfere with the bioactivity of vascular endothelial growth factor (VEGF) are now used to treat IVNV, concerns exist regarding the identification of optimal doses of anti-VEGF for individual infants and the effect of broad VEGF inhibition on physiologic angiogenesis in external organs or in the retina of a preterm infant. Therefore, it is important to understand VEGF signaling in both physiologic and pathologic angiogenesis in the retina. In this manuscript, we review the role of receptors that interact with VEGF in oxygen-induced retinopathy (OIR) models that represent features of ROP pathology. Specifically, we discuss our work regarding the regulation of VEGFR2 signaling in retinal endothelial cells to not only reduce severe ROP but also facilitate physiologic retinal vascular and neuronal development.

scholarly journals C-Abl Is Required for the Development of Hyperoxia-Induced Retinopathy

2001 ◽  
Vol 193 (12) ◽  
pp. 1383-1392 ◽  
Author(s):  
Irene Nunes ◽  
Rosemary D. Higgins ◽  
Lucia Zanetta ◽  
Peter Shamamian ◽  
Stephen P. Goff
Keyword(s):  
Mrna Expression ◽  
Retinal Neovascularization ◽  
Mrna Levels ◽  
Vascular Endothelial ◽  
Wild Type ◽  
Vegf Mrna ◽  
Nonreceptor Tyrosine Kinase ◽  
Kinase C ◽  
Endothelial Growth Factor ◽  
Inspired Oxygen

The requirement for the nonreceptor tyrosine kinase c-abl in the pathogenesis of retinopathy of prematurity (ROP) was examined using the mouse model for ROP and c-abl–deficient mice. Hyperoxia-induced retinal neovascularization was observed in wild-type and heterozygous mice but animals that were homozygous null for c-abl did not develop a vasoproliferative retinopathy in response to hyperoxia. Two gene products, endothelin-1 (ET-1) and vascular endothelial growth factor (VEGF), have been implicated in the pathogenesis of ROP. The mRNA expression of ET-1 and VEGF was assessed in mice maintained in normoxia and in hyperoxia-exposed mice. ET-1 mRNA levels were unchanged in wild-type mice throughout the hyperoxia treatment, suggesting that ET-1 mRNA expression is not regulated by the increase in inspired oxygen. In wild-type mice maintained in room air, VEGF mRNA levels rose threefold from postnatal day 6 (P6) to P17. When wild-type mice were treated with the hyperoxia regimen, a fivefold decrease in VEGF mRNA expression was observed from P7 to P16. However, retinal VEGF expression in hyperoxia-treated homozygous null mice did not decrease and remained at control levels. These data suggest that c-abl is required for the hyperoxia-induced retinal neovascularization and hyperoxia-induced decrease in VEGF mRNA levels.

Osteoblast expression of vascular endothelial growth factor is modulated by the extracellular microenvironment

2001 ◽  
Vol 280 (1) ◽  
pp. C72-C80 ◽  
Author(s):  
Jason A. Spector ◽  
Babak J. Mehrara ◽  
Joshua A. Greenwald ◽  
Pierre B. Saadeh ◽  
Douglas S. Steinbrech ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Lactate Concentration ◽  
Vascular Endothelial ◽  
Acidic Ph ◽  
Vegf Mrna ◽  
Hypoxic Conditions ◽  
Extracellular Microenvironment ◽  
Endothelial Growth Factor ◽  
Elevated Lactate

Angiogenesis, the formation of new blood vessels, is crucial to the process of fracture healing. Vascular disruption after osseous injury results in an acidic, hypoxic wound environment. We have previously shown that osteoblasts can produce vascular endothelial growth factor (VEGF) in response to a variety of stimuli. In this study we examined pH and lactate concentration, two components of the putative fracture extracellular microenvironment, and determined their relative contribution to regulation of rat calvarial osteoblast VEGF production under both normoxic and hypoxic conditions. Our results demonstrate that pH and lactate concentration do independently affect osteoblast VEGF mRNA and protein production. Acidic pH (7.0) significantly decreased VEGF production, under normoxic and hypoxic conditions ( P < 0.05), compared with neutral pH (7.4). This decrease was primarily transcriptionally regulated, because the rate of VEGF mRNA degradation was unchanged at pH 7.0 vs. 7.4. Similarly, an elevated lactate concentration (22 mM) also depressed osteoblast elaboration of VEGF at both neutral and acidic pH ( P < 0.001). Furthermore, the effects of increasing acidity and elevated lactate appeared to be additive.

scholarly journals Transcription of Inflammatory Cytokine TNFα is Upregulated in Retinal Angiogenesis under Hyperoxia

2016 ◽  
Vol 39 (2) ◽  
pp. 573-583
Author(s):  
Yuxi Feng ◽  
Shalini Gross ◽  
Anupriya Chatterjee ◽  
Yumei Wang ◽  
Jihong Lin ◽  
...  
Keyword(s):  
Underlying Mechanism ◽  
Vascular Endothelial ◽  
Vascular Morphology ◽  
Oxygen Induced Retinopathy ◽  
Avascular Zone ◽  
Deep Layers ◽  
Retinal Angiogenesis ◽  
Model C ◽  
Endothelial Growth Factor ◽  
Angiopoietin 1

Background/Aims: Hypoxia induces angiogenesis while hyperoxia promotes vasoregression in the retina. We investigated herein the effect of prolonged hyperoxia on retinal angiogenesis and the underlying mechanism in an oxygen-induced retinopathy (OIR) model. Methods: Vascular morphology was quantified in whole-mount retina from the mice subjected to the conventional OIR model (c-OIR) or the OIR model with prolonged hyperoxia (p-OIR). Expressions of genes related to angiogenesis were determined by real-time PCR. Results: p-OIR retinas showed few intraretinal neovascular tufts at the border of avascular zones, lacking preretinal neovascularization, whereas c-OIR retinas had numerous preretinal neovascularizations. p-OIR retinas demonstrated outgrowth of capillaries in the deep layers despite persistent hyperoxia and possess a larger avascular zone compared with the c-OIR retinas. The capillaries in the p-OIR retinas were well-formed in contrast to those in the c-OIR retinas. p-OIR retinas expressed significantly higher TNFα (∼4 fold) than c-OIR retinas. The expression of vascular endothelial growth factor, Erythropoietin, Angiopoietin 1 and 2 remained unchanged. Conclusion: Our data demonstrate that TNFα transcription is increased in hyperoxia-promoted retinal angiogenesis, implicating it, in association with low VEGF levels, as a possible proponent in retinal angiogenesis under hyperoxia.

scholarly journals Evogliptin, a dipeptidyl peptidase-4 inhibitor, attenuates pathological retinal angiogenesis by suppressing vascular endothelial growth factor-induced Arf6 activation

2020 ◽  
Vol 52 (10) ◽  
pp. 1744-1753
Author(s):  
Songyi Seo ◽  
Mi-Kyung Kim ◽  
Ryul-I Kim ◽  
Yeongju Yeo ◽  
Koung Li Kim ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Diabetic Retinopathy ◽  
Growth Factor ◽  
Dipeptidyl Peptidase ◽  
Inhibitory Effect ◽  
Retinal Neovascularization ◽  
Vegf Receptor ◽  
Vascular Endothelial ◽  
Dipeptidyl Peptidase 4 ◽  
Endothelial Growth Factor

Abstract Dipeptidyl peptidase-4 (DPP-4) inhibitors are used for the treatment of type 2 diabetes mellitus (DM). Recent studies have shown that beyond their effect in lowing glucose, DPP-4 inhibitors mitigate DM-related microvascular complications, such as diabetic retinopathy. However, the mechanism by which pathological retinal neovascularization, a major clinical manifestation of diabetic retinopathy, is inhibited is unclear. This study sought to examine the effects of evogliptin, a potent DPP-4 inhibitor, on pathological retinal neovascularization in mice and elucidate the mechanism by which evogliptin inhibits angiogenesis mediated by vascular endothelial growth factor (VEGF), a key factor in the vascular pathogenesis of proliferative diabetic retinopathy (PDR). In a murine model of PDR, an intravitreal injection of evogliptin significantly suppressed aberrant retinal neovascularization. In human endothelial cells, evogliptin reduced VEGF-induced angiogenesis. Western blot analysis showed that evogliptin inhibited the phosphorylation of signaling molecules associated with VEGF-induced cell adhesion and migration. Moreover, evogliptin substantially inhibited the VEGF-induced activation of adenosine 5′-diphosphate ribosylation factor 6 (Arf6), a small guanosine 5′-triphosphatase (GTPase) that regulates VEGF receptor 2 signal transduction. Direct activation of Arf6 using a chemical inhibitor of Arf-directed GTPase-activating protein completely abrogated the inhibitory effect of evogliptin on VEGF-induced activation of the angiogenic signaling pathway, which suggests that evogliptin suppresses VEGF-induced angiogenesis by blocking Arf6 activation. Our results provide insights into the molecular mechanism of the direct inhibitory effect of the DPP-4 inhibitor evogliptin on pathological retinal neovascularization. In addition to its glucose-lowering effect, the antiangiogenic effect of evogliptin could also render it beneficial for individuals with PDR.

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