scholarly journals Elements of the Endomucin Extracellular Domain Essential for VEGF-Induced VEGFR2 Activity

Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1413
Author(s):  
Zhengping Hu ◽  
Issahy Cano ◽  
Kahira L. Saez-Torres ◽  
Michelle E. LeBlanc ◽  
Magali Saint-Geniez ◽  
...  
Keyword(s):  
Extracellular Domain ◽  
Tube Formation ◽  
Vegf Receptor ◽  
Type I ◽  
Downstream Signaling ◽  
Transmembrane Glycoprotein ◽  
Glycosylation Sites ◽  
Domain Truncation ◽  
Endothelial Functions ◽  
Endothelial Growth Factor

Endomucin (EMCN) is the type I transmembrane glycoprotein, mucin-like component of the endothelial cell glycocalyx. We have previously shown that EMCN is necessary for vascular endothelial growth factor (VEGF)-induced VEGF receptor 2 (VEGFR2) internalization and downstream signaling. To explore the structural components of EMCN that are necessary for its function and the molecular mechanism of EMCN in VEGF-induced endothelial functions, we generated a series of mouse EMCN truncation mutants and examined their ability to rescue VEGF-induced endothelial functions in human primary endothelial cells (EC) in which endogenous EMCN had been knocked down using siRNA. Expression of the mouse full-length EMCN (FL EMCN) and the extracellular domain truncation mutants ∆21-81 EMCN and ∆21-121 EMCN, but not the shortest mutant ∆21-161 EMCN, successfully rescued the VEGF-induced EC migration, tube formation, and proliferation. ∆21-161 EMCN failed to interact with VEGFR2 and did not facilitate VEGFR2 internalization. Deletion of COSMC (C1GalT1C1) revealed that the abundant mucin-type O-glycans were not required for its VEGFR2-related functions. Mutation of the two N-glycosylation sites on ∆21-121 EMCN abolished its interaction with VEGFR2 and its function in VEGFR2 internalization. These results reveal ∆21-121 EMCN as the minimal extracellular domain sufficient for VEGFR2-mediated endothelial function and demonstrate an important role for N-glycosylation in VEGFR2 interaction, internalization, and angiogenic activity.

scholarly journals Molecular cloning of CD68, a human macrophage marker related to lysosomal glycoproteins

Blood ◽  
1993 ◽  
Vol 81 (6) ◽  
pp. 1607-1613 ◽  
Author(s):  
CL Holness ◽  
DL Simmons
Keyword(s):  
Extracellular Domain ◽  
Integral Membrane Protein ◽  
Human Macrophage ◽  
Cdna Clones ◽  
Type I ◽  
Cos Cells ◽  
Transmembrane Glycoprotein ◽  
Macrophage Marker ◽  
Glycosylation Sites ◽  
Low Levels

CD68 is a 110-Kd transmembrane glycoprotein of unknown function highly expressed by human monocytes and tissue macrophages. We have isolated cDNA clones encoding CD68 from a U937 cDNA library by transient expression in COS cells and panning with the anti-CD68 monoclonal antibodies (MoAbs) Y2/131, Y1/82A, EBM11, and Ki-M6. CD68 transcripts are constitutively present in the promonocyte cell line U937 and are upregulated by phorbol myristic acid (PMA). By contrast, CD68 transcripts are absent or present at very low levels in many hematopoietic lines including KG1, CEM, and K562, but can be induced by exposure to PMA. The cDNA sequence predicts a type I integral membrane protein of 354 residues with a heavily glycosylated extracellular domain of 298 residues containing nine potential N-linked glycosylation sites and numerous potential O-linked glycosylation sites. The extracellular domain consists of two distinct regions separated by an extended proline hinge: a membrane-distal mucin-like domain containing short peptide repeats and consisting of 54% serine and threonine residues; and a membrane proximal domain that has significant sequence homology to a family of lysosomal/plasma membrane shuttling proteins known as the lamp 1 group. CD68 is a member of a growing family of hematopoietic mucin-like molecules, including leukosialin/CD43, the stem cell antigen CD34, and the lymph node high endothelial ligand for L-selectin GlyCAM-1.

scholarly journals Molecular cloning of CD68, a human macrophage marker related to lysosomal glycoproteins

Blood ◽  
1993 ◽  
Vol 81 (6) ◽  
pp. 1607-1613 ◽  
Author(s):  
CL Holness ◽  
DL Simmons
Keyword(s):  
Extracellular Domain ◽  
Integral Membrane Protein ◽  
Human Macrophage ◽  
Cdna Clones ◽  
Type I ◽  
Cos Cells ◽  
Transmembrane Glycoprotein ◽  
Macrophage Marker ◽  
Glycosylation Sites ◽  
Low Levels

Abstract CD68 is a 110-Kd transmembrane glycoprotein of unknown function highly expressed by human monocytes and tissue macrophages. We have isolated cDNA clones encoding CD68 from a U937 cDNA library by transient expression in COS cells and panning with the anti-CD68 monoclonal antibodies (MoAbs) Y2/131, Y1/82A, EBM11, and Ki-M6. CD68 transcripts are constitutively present in the promonocyte cell line U937 and are upregulated by phorbol myristic acid (PMA). By contrast, CD68 transcripts are absent or present at very low levels in many hematopoietic lines including KG1, CEM, and K562, but can be induced by exposure to PMA. The cDNA sequence predicts a type I integral membrane protein of 354 residues with a heavily glycosylated extracellular domain of 298 residues containing nine potential N-linked glycosylation sites and numerous potential O-linked glycosylation sites. The extracellular domain consists of two distinct regions separated by an extended proline hinge: a membrane-distal mucin-like domain containing short peptide repeats and consisting of 54% serine and threonine residues; and a membrane proximal domain that has significant sequence homology to a family of lysosomal/plasma membrane shuttling proteins known as the lamp 1 group. CD68 is a member of a growing family of hematopoietic mucin-like molecules, including leukosialin/CD43, the stem cell antigen CD34, and the lymph node high endothelial ligand for L-selectin GlyCAM-1.

scholarly journals Islet vascularization is regulated by primary endothelial cilia via VEGF-A-dependent signaling

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Yan Xiong ◽  
M Julia Scerbo ◽  
Anett Seelig ◽  
Francesco Volta ◽  
Nils O'Brien ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Primary Cilia ◽  
Capillary Density ◽  
Vegf Receptor ◽  
Vascular Endothelial ◽  
Downstream Signaling ◽  
Vegfr2 Signaling ◽  
And Migration ◽  
Endothelial Growth Factor

Islet vascularization is essential for intact islet function and glucose homeostasis. We have previously shown that primary cilia directly regulate insulin secretion. However, it remains unclear whether they are also implicated in islet vascularization. At eight weeks, murine Bbs4-/-islets show significantly lower intra-islet capillary density with enlarged diameters. Transplanted Bbs4-/- islets exhibit delayed re-vascularization and reduced vascular fenestration after engraftment, partially impairing vascular permeability and glucose delivery to β-cells. We identified primary cilia on endothelial cells as the underlying cause of this regulation, via the vascular endothelial growth factor-A (VEGF-A)/VEGF receptor 2 (VEGFR2) pathway. In vitro silencing of ciliary genes in endothelial cells disrupts VEGF-A/VEGFR2 internalization and downstream signaling. Consequently, key features of angiogenesis including proliferation and migration are attenuated in human BBS4 silenced endothelial cells. We conclude that endothelial cell primary cilia regulate islet vascularization and vascular barrier function via the VEGF-A/VEGFR2 signaling pathway.

scholarly journals Tetramethylpyrazine Ameliorates Peritoneal Angiogenesis by Regulating VEGF/Hippo/YAP Signaling

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaolin Zhu ◽  
Yun Shan ◽  
Manshu Yu ◽  
Jun Shi ◽  
Lei Tang ◽  
...  
Keyword(s):  
Nuclear Translocation ◽  
Vascular Endothelial Cells ◽  
Tube Formation ◽  
Vegf Receptor ◽  
Vascular Endothelial ◽  
Peritoneal Fibrosis ◽  
Peritoneal Mesothelial Cells ◽  
Downstream Signaling ◽  
Vegfr2 Signaling ◽  
Golgi Network

Angiogenesis of human peritoneal vascular endothelial cells (HPVECs), linked to vascular endothelial growth factor (VEGF)/VEGF receptor 2 (VEGFR2) signaling, is a complication of peritoneal fibrosis (PF). Hippo/YAP signaling interacts with VEGF/VEGFR2 signaling, but the effect on peritoneal angiogenesis and PF has not been studied. We tested VEGF/Hippo/YAP inhibition by tetramethylpyrazine (TMP) in PF mice and HPVECs. This treatment ameliorated peritoneal dialysis (PD)–induced angiogenesis and PF. In mice, PF was associated with upregulation of VEGF, and TMP ameliorated submesothelial fibrosis, perivascular bleeding, and Collagen I abundance. In HPVECs, angiogenesis occurred due to human peritoneal mesothelial cells (HPMCs)–conditioned medium, and TMP alleviated HPVECs migration, tube formation, and YAP nuclear translocation. YAP knockdown PF mouse and HPVEC models were established to further confirm our finding. YAP deletion attenuated the PD-induced or VEGF-induced increase in angiogenesis and PF. The amount of CYR61 and CTGF was significantly less in the YAP knockdown group. To study the possibility that TMP could benefit angiogenesis, we measured the HPVECs migration and tube formation and found that both were sharply increased in YAP overexpression; TMP treatment partly abolished these increases. As well, the amount of VEGFR localized in the trans-Golgi network was lower by double immunofluorescence; VEGFR and its downstream signaling pathways including p-ERK, p-P38, and p-Akt were more in HPVECs with YAP overexpression. Overall, TMP treatment ameliorated angiogenesis, PF, and peritoneum injury. These changes were accompanied by inhibition of VEGF/Hippo/YAP.

Effects of the Indazolylpyrimidine GW786034 on Angiogenesis and MM Cell Growth: Therapeutic Implications.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2452-2452
Author(s):  
Klaus Podar ◽  
Melissa Simoncini ◽  
Steven Le Gouill ◽  
Yu-Tzu Tai ◽  
Shaji Kumar ◽  
...  
Keyword(s):  
Cell Growth ◽  
Tumor Cells ◽  
Dendritic Cell Maturation ◽  
Vegf Receptor ◽  
Therapeutic Implications ◽  
Downstream Signaling ◽  
Branching Points ◽  
And Migration ◽  
Vegfr Inhibitor ◽  
Endothelial Growth Factor

Abstract Vascular endothelial growth factor (VEGF) and its receptors play an important role in the pathogenesis of multiple myeloma (MM). Specifically, VEGF, which is present in the MM bone marrow (BM) microenvironment, induces neovascularization; triggers tumor cell growth, survival, and migration; inhibits dendritic cell maturation; and induces osteoclastogenesis. Therefore, the VEGF receptor provides a potential novel therapeutic target in MM. Previous studies showed that GW654652, a pan VEGFR inhibitor, inhibits growth and migration of MM tumor cells (Podar et al. Blood. 2004; 103:3473–3479.). Here we describe the effects of GW786034, a derivative of GW654652, on MM cells to support its potential clinical evaluation in MM patients. GW786034 inhibits VEGF- triggered Flt-1 phosphorylation and activation of downstream signaling molecules, induces concentration-dependent MM cell and HUVEC apoptosis, and inhibits VEGF- triggered MM cell migration. Specifically, GW786034 induces cleavage of caspase-8 and PARP, but not caspase-9, and induces downregulation of the pro-apoptotic molecules survivin, cIAP1, 2, and Mcl-1. Furthermore, GW786034 decreases proliferation of MM cells induced by their adhesion to BMSCs, and inhibits VEGF-induced upregulation of ICAM-1 and VCAM-1, thereby abrogating their adhesion to HUVECs. Consistent with these results, GW786034 inhibited both tubuli formation and accumulation of tumor cells at vascular branching points in a Matrigel tube forming assay. Finally, GW786034 sensitizes both MM cells alone and tumor cells bound to BMSCs or HUVECs to melphalan and bortezomib. Taken together, these studies support clinical evaluations of GW786034 either alone or in combination with other agents in MM patients.

Carbon monoxide inhibits sprouting angiogenesis and vascular endothelial growth factor receptor-2 phosphorylation

2015 ◽  
Vol 113 (02) ◽  
pp. 329-337 ◽  
Author(s):  
Peter W. Hewett ◽  
Takeshi Fujisawa ◽  
Samir Sissaoui ◽  
Meng Cai ◽  
Geraldine Gueron ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Carbon Monoxide ◽  
Growth Factor ◽  
Umbilical Vein ◽  
Growth Factor Receptor ◽  
Tube Formation ◽  
Vegf Receptor ◽  
Vascular Endothelial ◽  
Sprouting Angiogenesis ◽  
Endothelial Growth Factor

SummaryCarbon monoxide (CO) is a gaseous autacoid known to positively regulate vascular tone; however, its role in angiogenesis is unknown. The aim of this study was to investigate the effect of CO on angiogenesis and vascular endothelial growth factor (VEGF) receptor-2 phosphorylation. Human umbilical vein endothelial cells (HUVECs) were cultured on growth factor-reduced Matrigel and treated with a CO-releasing molecule (CORM-2) or exposed to CO gas (250 ppm). Here, we report the surprising finding that exposure to CO inhibits vascular endothelial growth factor (VEGF)-induced endothelial cell actin reorganisation, cell proliferation, migration and capillary-like tube formation. Similarly, CO suppressed VEGF-mediated phosphorylation of VEGFR-2 at tyrosine residue 1175 and 1214 and basic fibroblast growth factor- (FGF-2) and VEGF-mediated Akt phosphorylation. Consistent with these data, mice exposed to 250 ppm CO (1h/day for 14 days) exhibited a marked decrease in FGF-2-induced Matrigel plug angiogenesis (p<0.05). These data establish a new biological function for CO in angiogenesis and point to a potential therapeutic use for CO as an anti-angiogenic agent in tumour suppression.

scholarly journals Vascular Endothelial Growth Factor Induces Branching Morphogenesis/Tubulogenesis in Renal Epithelial Cells in a Neuropilin-Dependent Fashion

2005 ◽  
Vol 25 (17) ◽  
pp. 7441-7448 ◽  
Author(s):  
Anil Karihaloo ◽  
S. Ananth Karumanchi ◽  
William L. Cantley ◽  
Shivalingappa Venkatesha ◽  
Lloyd G. Cantley ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Epithelial Cells ◽  
Neutralizing Antibodies ◽  
Branching Morphogenesis ◽  
Tube Formation ◽  
Vegf Receptor ◽  
Vascular Endothelial ◽  
Renal Epithelial Cell ◽  
Endothelial Growth Factor

ABSTRACT Vascular endothelial growth factor (VEGF) is well characterized for its role in endothelial cell differentiation and vascular tube formation. Alternate splicing of the VEGF gene in mice results in various VEGF-A isoforms, including VEGF-121 and VEGF-165. VEGF-165 is the most abundant isoform in the kidney and has been implicated in glomerulogenesis. However, its role in the tubular epithelium is not known. We demonstrate that VEGF-165 but not VEGF-121 induces single-cell branching morphogenesis and multicellular tubulogenesis in mouse renal tubular epithelial cells and that these morphogenic effects require activation of the phosphatidylinositol 3-kinase (PI 3-K) and, to a lesser degree, the extracellular signal-regulated kinase and protein kinase C signaling pathways. Further, VEGF-165-stimulated sheet migration is dependent only on PI 3-K signaling. These morphogenic effects of VEGF-165 require activation of both VEGF receptor 2 (VEGFR-2) and neuropilin-1 (Nrp-1), since neutralizing antibodies to either of these receptors or the addition of semaphorin 3A (which blocks VEGF-165 binding to Nrp-1) prevents the morphogenic response and the phosphorylation of VEGFR-2 along with the downstream signaling. We thus conclude that in addition to endothelial vasculogenesis, VEGF can induce renal epithelial cell morphogenesis in a Nrp-1-dependent fashion.

scholarly journals Capillary Morphogenesis gene 2 mediates multiple pathways of growth factor-induced angiogenesis by regulating endothelial cell chemotaxis

2019 ◽  
Author(s):  
Lorna Cryan ◽  
Tsz-Ming Tsang ◽  
Jessica Stiles ◽  
Lauren Bazinet ◽  
Sai Lun Lee ◽  
...  
Keyword(s):  
Growth Factor ◽  
Corneal Neovascularization ◽  
Tube Formation ◽  
Vegf Receptor ◽  
Vascular Endothelial ◽  
The Novel ◽  
Capillary Morphogenesis ◽  
Pathological Angiogenesis ◽  
Endothelial Tube Formation ◽  
Endothelial Growth Factor

AbstractPathological angiogenesis contributes to diseases as varied as cancer and corneal neovascularization. The vascular endothelial growth factor (VEGF) - VEGF receptor 2 (KDR/VEGFR2) axis has been the major target for treating pathological angiogenesis. However, VEGF-targeted therapies exhibit reduced efficacy over time, indicating that new therapeutic strategies are needed. Therefore, identifying new targets that mediate angiogenesis is of great importance. Here, we report that one of the anthrax toxin receptors, capillary morphogenesis gene 2 (ANTXR2/CMG2), plays an important role in mediating angiogenesis induced by both bFGF and VEGF. Inhibiting physiological ligand binding to CMG2 results in significant reduction of corneal neovascularization, endothelial tube formation and cell migration. We also report the novel finding that CMG2 mediates angiogenesis by regulating the direction of endothelial chemotactic migration without affecting overall cell motility.

scholarly journals Piceatannol, a Natural Analog of Resveratrol, Exerts Anti-angiogenic Efficiencies by Blockage of Vascular Endothelial Growth Factor Binding to Its Receptor

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3769 ◽  
Author(s):  
Wei-Hui Hu ◽  
Diana Kun Dai ◽  
Brody Zhong-Yu Zheng ◽  
Ran Duan ◽  
Tina Ting-Xia Dong ◽  
...  
Keyword(s):  
Umbilical Vein ◽  
Underlying Mechanism ◽  
Tube Formation ◽  
Vegf Receptor ◽  
Cancer Proliferation ◽  
In Vivo Models ◽  
Downstream Signaling ◽  
Natural Analog

Piceatannol is also named as trans-3,4,3′,5′-tetrahydroxy-stilbene, which is a natural analog of resveratrol and a polyphenol existing in red wine, grape and sugar cane. Piceatannol has been proved to possess activities of immunomodulatory, anti-inflammatory, antiproliferative and anticancer. However, the effect of piceatannol on VEGF-mediated angiogenesis is not known. Here, the inhibitory effects of piceatannol on VEGF-induced angiogenesis were tested both in vitro and in vivo models of angiogenesis. In human umbilical vein endothelial cells (HUVECs), piceatannol markedly reduced the VEGF-induced cell proliferation, migration, invasion, as well as tube formation without affecting cell viability. Furthermore, piceatannol significantly inhibited the formation of subintestinal vessel in zebrafish embryos in vivo. In addition, we identified the underlying mechanism of piceatannol in triggering the anti-angiogenic functions. Piceatannol was proposed to bind with VEGF, thus attenuating VEGF in activating VEGF receptor and blocking VEGF-mediated downstream signaling, including expressions of phosphorylated eNOS, Erk and Akt. Furthermore, piceatannol visibly suppressed ROS formation, as triggered by VEGF. Moreover, we further determined the outcome of piceatannol binding to VEGF in cancer cells: piceatannol significantly suppressed VEGF-induced colon cancer proliferation and migration. Thus, these lines of evidence supported the conclusion that piceatannol could down regulate the VEGF-mediated angiogenic functions with no cytotoxicity via decreasing the amount of VEGF binding to its receptors, thus affecting the related downstream signaling. Piceatannol may be developed into therapeutic agents or health products to reduce the high incidence of angiogenesis-related diseases.

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