scholarly journals Novel role of p66Shc in ROS-dependent VEGF signaling and angiogenesis in endothelial cells

2012 ◽  
Vol 302 (3) ◽  
pp. H724-H732 ◽  
Author(s):  
Jin Oshikawa ◽  
Seok-Jo Kim ◽  
Eiji Furuta ◽  
Cristiana Caliceti ◽  
Gin-Fu Chen ◽  
...  
Keyword(s):  
Critical Role ◽  
Adaptor Protein ◽  
Tube Formation ◽  
Vegf Receptor ◽  
Kinase Activation ◽  
Vegf Signaling ◽  
Rac1 Activity ◽  
Interfering Rna ◽  
Endothelial Growth Factor

p66Shc, a longevity adaptor protein, is demonstrated as a key regulator of reactive oxygen species (ROS) metabolism involved in aging and cardiovascular diseases. Vascular endothelial growth factor (VEGF) stimulates endothelial cell (EC) migration and proliferation primarily through the VEGF receptor-2 (VEGFR2). We have shown that ROS derived from Rac1-dependent NADPH oxidase are involved in VEGFR2 autophosphorylation and angiogenic-related responses in ECs. However, a role of p66Shc in VEGF signaling and physiological responses in ECs is unknown. Here we show that VEGF promotes p66Shc phosphorylation at Ser36 through the JNK/ERK or PKC pathway as well as Rac1 binding to a nonphosphorylated form of p66Shc in ECs. Depletion of endogenous p66Shc with short interfering RNA inhibits VEGF-induced Rac1 activity and ROS production. Fractionation of caveolin-enriched lipid raft demonstrates that p66Shc plays a critical role in VEGFR2 phosphorylation in caveolae/lipid rafts as well as downstream p38MAP kinase activation. This in turn stimulates VEGF-induced EC migration, proliferation, and capillary-like tube formation. These studies uncover a novel role of p66Shc as a positive regulator for ROS-dependent VEGFR2 signaling linked to angiogenesis in ECs and suggest p66Shc as a potential therapeutic target for various angiogenesis-dependent diseases.

scholarly journals Rap1 promotes VEGFR2 activation and angiogenesis by a mechanism involving integrin αvβ3

Blood ◽  
2011 ◽  
Vol 118 (7) ◽  
pp. 2015-2026 ◽  
Author(s):  
Sribalaji Lakshmikanthan ◽  
Magdalena Sobczak ◽  
Changzoon Chun ◽  
Angela Henschel ◽  
Jillian Dargatz ◽  
...  
Keyword(s):  
Integrin Αvβ3 ◽  
In Vivo Model ◽  
Vegf Receptor ◽  
Dependent Manner ◽  
Vascular Endothelial ◽  
Kinase Activation ◽  
Vegf Signaling ◽  
Endothelial Growth Factor

Abstract Vascular endothelial growth factor (VEGF) acting through VEGF receptor 2 (VEGFR2) on endothelial cells (ECs) is a key regulator of angiogenesis, a process essential for wound healing and tumor metastasis. Rap1a and Rap1b, 2 highly homologous small G proteins, are both required for angiogenesis in vivo and for normal EC responses to VEGF. Here we sought to determine the mechanism through which Rap1 promotes VEGF-mediated angiogenesis. Using lineage-restricted Rap1-knockout mice we show that Rap1-deficiency in endothelium leads to defective angiogenesis in vivo, in a dose-dependent manner. Using ECs obtained from Rap1-deficient mice we demonstrate that Rap1b promotes VEGF-VEGFR2 kinase activation and regulates integrin activation. Importantly, the Rap1b-dependent VEGF-VEGFR2 activation is in part mediated via integrin αvβ3. Furthermore, in an in vivo model of zebrafish angiogenesis, we demonstrate that Rap1b is essential for the sprouting of intersomitic vessels, a process known to be dependent on VEGF signaling. Using 2 distinct pharmacologic VEGFR2 inhibitors we show that Rap1b and VEGFR2 act additively to control angiogenesis in vivo. We conclude that Rap1b promotes VEGF-mediated angiogenesis by promoting VEGFR2 activation in ECs via integrin αvβ3. These results provide a novel insight into the role of Rap1 in VEGF signaling in ECs.

scholarly journals Endothelial Semaphorin 3fb regulates Vegf pathway-mediated angiogenic sprouting

2021 ◽  
Author(s):  
Charlene Watterston ◽  
Rami Halabi ◽  
Sarah McFarlane ◽  
Sarah J Childs
Keyword(s):  
Growth Factor ◽  
Critical Role ◽  
Developmental Time ◽  
Vegf Receptor ◽  
Growth Factor Signaling ◽  
Actin Assembly ◽  
Vegf Signaling ◽  
Vessel Growth ◽  
Vegf Pathway ◽  
Endothelial Growth Factor

Vessel growth integrates diverse extrinsic signals with intrinsic signaling cascades to coordinate cell migration and sprouting morphogenesis. The pro-angiogenic effects of Vascular Endothelial Growth Factor (VEGF) are carefully controlled during sprouting to generate an efficiently patterned vascular network. We identify crosstalk between VEGF signaling and that of the secreted ligand Semaphorin 3fb (Sema3fb), one of two zebrafish paralogs of mammalian Sema3F. The sema3fb gene is expressed by endothelial cells in actively sprouting vessels. Loss of sema3fb results in abnormally wide and stunted intersegmental vessel artery sprouts. Although the sprouts initiate at the correct developmental time, they have a reduced migration speed. These sprouts have persistent filopodia and abnormally spaced nuclei suggesting dysregulated control of actin assembly. sema3fb mutants show simultaneously higher expression of pro-angiogenic (VEGF receptor 2 (vegfr2) and delta-like 4 (dll4)) and anti-angiogenic (soluble VEGF receptor 1 (svegfr1)/ soluble Fms Related Receptor Tyrosine Kinase 1 (sflt1)) pathway components. We show increased phospho-ERK staining in migrating angioblasts, consistent with enhanced Vegf activity. Reducing Vegfr2 kinase activity in sema3fb mutants rescues angiogenic sprouting. Our data suggest that Sema3fb plays a critical role in promoting endothelial sprouting through modulating the VEGF signaling pathway, acting as an autocrine cue that modulates intrinsic growth factor signaling.

scholarly journals Endothelial Semaphorin 3fb regulates Vegf pathway-mediated angiogenic sprouting

PLoS Genetics ◽  
2021 ◽  
Vol 17 (8) ◽  
pp. e1009769
Author(s):  
Charlene Watterston ◽  
Rami Halabi ◽  
Sarah McFarlane ◽  
Sarah J. Childs
Keyword(s):  
Growth Factor ◽  
Critical Role ◽  
Developmental Time ◽  
Vegf Receptor ◽  
Growth Factor Signaling ◽  
Actin Assembly ◽  
Vegf Signaling ◽  
Vessel Growth ◽  
Vegf Pathway ◽  
Endothelial Growth Factor

Vessel growth integrates diverse extrinsic signals with intrinsic signaling cascades to coordinate cell migration and sprouting morphogenesis. The pro-angiogenic effects of Vascular Endothelial Growth Factor (VEGF) are carefully controlled during sprouting to generate an efficiently patterned vascular network. We identify crosstalk between VEGF signaling and that of the secreted ligand Semaphorin 3fb (Sema3fb), one of two zebrafish paralogs of mammalian Sema3F. The sema3fb gene is expressed by endothelial cells in actively sprouting vessels. Loss of sema3fb results in abnormally wide and stunted intersegmental vessel artery sprouts. Although the sprouts initiate at the correct developmental time, they have a reduced migration speed. These sprouts have persistent filopodia and abnormally spaced nuclei suggesting dysregulated control of actin assembly. sema3fb mutants show simultaneously higher expression of pro-angiogenic (VEGF receptor 2 (vegfr2) and delta-like 4 (dll4)) and anti-angiogenic (soluble VEGF receptor 1 (svegfr1)/ soluble Fms Related Receptor Tyrosine Kinase 1 (sflt1)) pathway components. We show increased phospho-ERK staining in migrating angioblasts, consistent with enhanced Vegf activity. Reducing Vegfr2 kinase activity in sema3fb mutants rescues angiogenic sprouting. Our data suggest that Sema3fb plays a critical role in promoting endothelial sprouting through modulating the VEGF signaling pathway, acting as an autocrine cue that modulates intrinsic growth factor signaling.

scholarly journals An Inside View: VEGF Receptor Trafficking and Signaling

Physiology ◽  
2012 ◽  
Vol 27 (4) ◽  
pp. 213-222 ◽  
Author(s):  
Michael Simons
Keyword(s):  
Control Systems ◽  
Biological Function ◽  
Critical Role ◽  
Vegf Receptor ◽  
Vascular Endothelial ◽  
Receptor Endocytosis ◽  
Vegf Signaling ◽  
Adult Organism ◽  
Endothelial Growth Factors

Vascular endothelial growth factors (VEGF) and their receptors play a central role in the development of cardiovascular system and in vasculature-related processes in the adult organism. Given the critical role of this signaling cascade, intricate control systems have evolved to regulate its function. A new layer of added complexity has been the demonstration of the importance of endocytosis and intracellular trafficking of VEGF receptors in the regulation of VEGF signaling. In this review, we consider an evolving link between VEGF receptor endocytosis, trafficking, and signaling and their biological function.

scholarly journals Role of Vascular Endothelial Growth Factor (VEGF) in Human Embryo Implantation: Clinical Implications

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 253
Author(s):  
Xi Guo ◽  
Hong Yi ◽  
Tin Chiu Li ◽  
Yu Wang ◽  
Huilin Wang ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Recurrent Miscarriage ◽  
Embryo Implantation ◽  
Critical Role ◽  
Angiogenic Factor ◽  
Vascular Endothelial ◽  
Underlying Mechanisms ◽  
Endothelial Growth Factor

Vascular endothelial growth factor (VEGF) is a well-known angiogenic factor that plays a critical role in various physiological and pathological processes. VEGF also contributes to the process of embryo implantation by enhancing embryo development, improving endometrial receptivity, and facilitating the interactions between the developing embryo and the endometrium. There is a correlation between the alteration of VEGF expression and reproductive failure, including recurrent implantation failure (RIF) and recurrent miscarriage (RM). In order to clarify the role of VEGF in embryo implantation, we reviewed recent literature concerning the expression and function of VEGF in the reproductive system around the time of embryo implantation and we provide a summary of the findings reported so far. We also explored the effects and the possible underlying mechanisms of action of VEGF in embryo implantation.

scholarly journals Suppression of eNOS-derived superoxide by caveolin-1: a biopterin-dependent mechanism

2011 ◽  
Vol 301 (3) ◽  
pp. H903-H911 ◽  
Author(s):  
Kanchana Karuppiah ◽  
Lawrence J. Druhan ◽  
Chun-an Chen ◽  
Travis Smith ◽  
Jay L. Zweier ◽  
...  
Keyword(s):  
Gene Silencing ◽  
Oxidase Activity ◽  
Molecular Mechanisms ◽  
Critical Role ◽  
Caveolin 1 ◽  
Calcium Calmodulin Dependent ◽  
Enos Uncoupling ◽  
Nadph Oxidation ◽  
Interfering Rna

In the vasculature, nitric oxide (NO) is generated by endothelial NO synthase (eNOS) in a calcium/calmodulin-dependent reaction. In the absence of the requisite eNOS cofactor tetrahydrobiopterin (BH4), NADPH oxidation is uncoupled from NO generation, leading to the production of superoxide. Although this phenomenon is apparent with purified enzyme, cellular studies suggest that formation of the BH4 oxidation product, dihydrobiopterin, is the molecular trigger for eNOS uncoupling rather than BH4 depletion alone. In the current study, we investigated the effects of both BH4 depletion and oxidation on eNOS-derived superoxide production in endothelial cells in an attempt to elucidate the molecular mechanisms regulating eNOS oxidase activity. Results demonstrated that pharmacological depletion of endothelial BH4 does not result in eNOS oxidase activity, whereas BH4 oxidation gave rise to significant eNOS-oxidase activity. These findings suggest that the endothelium possesses regulatory mechanisms, which prevent eNOS oxidase activity from pterin-free eNOS. Using a combination of gene silencing and pharmacological approaches, we demonstrate that eNOS-caveolin-1 association is increased under conditions of reduced pterin bioavailability and that this sequestration serves to suppress eNOS uncoupling. Using small interfering RNA approaches, we demonstrate that caveolin-1 gene silencing increases eNOS oxidase activity to 85% of that observed under conditions of BH4 oxidation. Moreover, when caveolin-1 silencing was combined with a pharmacological inhibitor of AKT, BH4 depletion increased eNOS-derived superoxide to 165% of that observed with BH4 oxidation. This study identifies a critical role of caveolin-1 in the regulation of eNOS uncoupling and provides new insight into the mechanisms through which disease-associated changes in caveolin-1 expression may contribute to endothelial dysfunction.

scholarly journals Adenosine triphosphate is a critical determinant for VEGFR signal during hypoxia

2016 ◽  
Vol 311 (6) ◽  
pp. C985-C995 ◽  
Author(s):  
Abdullah Al Mamun ◽  
Hisaki Hayashi ◽  
Miho Sakima ◽  
Motohiko Sato
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Signal Propagation ◽  
Tube Formation ◽  
Activation Process ◽  
Vegf Receptor ◽  
Vegf Mrna ◽  
Critical Determinant ◽  
Hypoxia Exposure ◽  
Vegf Signaling

Hypoxia induces angiogenesis through the VEGF signaling pathway; however, signal propagation of VEGF in hypoxia is not fully understood. In this study, we examined alterations in VEGF signaling during hypoxia conditions and its determinant in endothelial cells. To analyze VEGF signaling during hypoxia, human umbilical vein endothelial cells (HUVECs) were exposed to 3 h of hypoxia (1% O2) followed by 3 h of reoxygenation or 12 h of hypoxia. Hypoxia induced expression of VEGF mRNA, but it was not associated with an increase in tube formation by HUVECs. During 3 h of hypoxia, VEGF-induced phosphorylation of VEGF receptor-2 (VEGFR-2) and downstream molecules were significantly inhibited without a change in VEGFR-2 expression, but it was completely restored after reoxygenation. VEGF-mediated VEGFR-2 phosphorylation is associated with a reduction in cellular ATP in hypoxia conditions (65.93 ± 8.32% of normoxia, means ± SE, P < 0.01). Interestingly, attenuation of VEGFR-2 phosphorylation was restored by addition of ATP to prepared membranes from cells that underwent 3 h of hypoxia. In contrast to 3 h of hypoxia, exposure of cells to 12 h of hypoxia decreased VEGFR-2 expression and VEGF-mediated VEGFR-2 phosphorylation. The magnitude of VEGFR-2 phosphorylation was not fully restored by addition of ATP to prepared membranes from cells exposed to 12 h of hypoxia. These data indicate that ATP is an important determinant of VEGF signaling in hypoxia and suggest that the activation process of VEGFR-2 was modified by sustained hypoxia. These observations contribute to our understanding of signal alterations in VEGF in endothelial cells during hypoxia.

scholarly journals Scl isoforms act downstream of etsrp to specify angioblasts and definitive hematopoietic stem cells

Blood ◽  
2010 ◽  
Vol 115 (26) ◽  
pp. 5338-5346 ◽  
Author(s):  
Xi Ren ◽  
Gustavo A. Gomez ◽  
Bo Zhang ◽  
Shuo Lin
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Critical Role ◽  
Vascular Endothelial ◽  
Hematopoietic Stem ◽  
Vegf Signaling ◽  
Endothelial Growth Factor ◽  
Endothelial Development ◽  
Definitive Hematopoiesis ◽  
Runx1 Expression

Abstract Recent lineage studies suggest that hematopoietic stem cells (HSCs) may be derived from endothelial cells. However, the genetic hierarchy governing the emergence of HSCs remains elusive. We report here that zebrafish ets1-related protein (etsrp), which is essential for vascular endothelial development, also plays a critical role in the initiation of definitive hematopoiesis by controlling the expression of 2 stem cell leukemia (scl) isoforms (scl-α and scl-β) in angioblasts. In etsrp morphants, which are deficient in endothelial and HSC development, scl-α alone partially rescues angioblast specification, arterial-venous differentiation, and the expression of HSC markers, runx1 and c-myb, whereas scl-β requires angioblast rescue by fli1a to restore runx1 expression. Interestingly, when vascular endothelial growth factor (Vegf) signaling is inhibited, HSC marker expression can still be restored by scl-α in etsrp morphants, whereas the rescue of arterial ephrinb2a expression is blocked. Furthermore, both scl isoforms partially rescue runx1 but not ephrinb2a expression in embryos deficient in Vegf signaling. Our data suggest that downstream of etsrp, scl-α and fli1a specify the angioblasts, whereas scl-β further initiates HSC specification from this angioblast population, and that Vegf signaling acts upstream of scl-β during definitive hematopoiesis.

scholarly journals Punicalagin protects H9c2 cardiomyocytes from doxorubicin-induced toxicity through activation of Nrf2/HO-1 signaling

2019 ◽  
Vol 39 (5) ◽  
Author(s):  
Mingfang Ye ◽  
Linlin Zhang ◽  
Yuanming Yan ◽  
Huizhong Lin
Keyword(s):  
Wide Spectrum ◽  
Critical Role ◽  
Antitumor Agent ◽  
Cytochrome C Release ◽  
Beneficial Effects ◽  
H9c2 Cardiomyocytes ◽  
Underlying Mechanisms ◽  
Interfering Rna

Abstract Doxorubicin (DOX) is a wide-spectrum antitumor agent, but its clinical application is largely limited by its cardiotoxicity. Therefore, identification of effective agents against DOX-induced cardiotoxicity is of critical importance. The present study aimed to determine the beneficial role of punicalagin (PUN), a polyphenol isolated from pomegranate, in DOX-induced cardiotoxicity in vitro and explored the underlying mechanisms. H9c2 cardiomyocytes were pretreated with different concentrations (50, 100 and 200 μM) of PUN prior to DOX exposure. The results showed that PUN pretreatment significantly increased cell viability, inhibited lactate dehydrogenase (LDH) release and suppressed cell apoptosis induced by DOX. Additionally, PUN pretreatment attenuated the loss of mitochondrial membrane potential and cytochrome c release. Besides, PUN further enhanced the expression of nuclear Nrf2 and HO-1 in DOX-treated H9c2 cells, and the aforementioned beneficial effects of PUN were partially abolished by small interfering RNA (siRNA)-mediated Nrf2 knockdown. Hence, our findings clearly revealed that PUN might be a promising agent for alleviating the cardiotoxicity of DOX, and Nrf2/HO-1 signaling might serve a critical role during this process.

scholarly journals Vimentin filaments drive migratory persistence in polyploidal cancer cells

2020 ◽  
Vol 117 (43) ◽  
pp. 26756-26765
Author(s):  
Botai Xuan ◽  
Deepraj Ghosh ◽  
Joy Jiang ◽  
Rachelle Shao ◽  
Michelle R. Dawson
Keyword(s):  
Cancer Cells ◽  
Cancer Progression ◽  
Structural Integrity ◽  
Single Cell Analysis ◽  
Critical Role ◽  
Critical Function ◽  
Rna Knockdown ◽  
Interfering Rna ◽  
The Impact

Polyploidal giant cancer cells (PGCCs) are multinucleated chemoresistant cancer cells found in heterogeneous solid tumors. Due in part to their apparent dormancy, the effect of PGCCs on cancer progression has remained largely unstudied. Recent studies have highlighted the critical role of PGCCs as aggressive and chemoresistant cancer cells, as well as their ability to undergo amitotic budding to escape dormancy. Our recent study demonstrated the unique biophysical properties of PGCCs, as well as their unusual migratory persistence. Here we unveil the critical function of vimentin intermediate filaments (VIFs) in maintaining the structural integrity of PGCCs and enhancing their migratory persistence. We performed in-depth single-cell analysis to examine the distribution of VIFs and their role in migratory persistence. We found that PGCCs rely heavily on their uniquely distributed and polarized VIF network to enhance their transition from a jammed to an unjammed state to allow for directional migration. Both the inhibition of VIFs with acrylamide and small interfering RNA knockdown of vimentin significantly decreased PGCC migration and resulted in a loss of PGCC volume. Because PGCCs rely on their VIF network to direct migration and to maintain their enlarged morphology, targeting vimentin or vimentin cross-linking proteins could provide a therapeutic approach to mitigate the impact of these chemoresistant cells in cancer progression and to improve patient outcomes with chemotherapy.

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