scholarly journals The Nucleolar Protein Nucleophosmin Is Physiologically Secreted by Endothelial Cells in Response to Stress Exerting Proangiogenic Activity Both In Vitro and In Vivo

2021 ◽  
Vol 22 (7) ◽  
pp. 3672
Author(s):  
Anna Di Carlo ◽  
Sara Beji ◽  
Silvia Palmerio ◽  
Mario Picozza ◽  
Marco D’Agostino ◽  
...  

Nucleophosmin (NPM), a nucleolar multifunctional phosphoprotein, acts as a stress sensor in different cell types. NPM can be actively secreted by inflammatory cells, however its biology on endothelium remains unexplored. In this study, we show for the first time that NPM is secreted by human vein endothelial cells (HUVEC) in the early response to serum deprivation and that NPM acts as a pro-inflammatory and angiogenic molecule both in vitro and in vivo. Accordingly, 24 h of serum starvation condition induced NPM relocalization from the nucleus to cytoplasm. Interestingly, NPM was increasingly excreted in HUVEC-derived conditioned media in a time dependent fashion upon stress conditions up to 24 h. The secretion of NPM was unrelated to cell necrosis within 24 h. The treatment with exogenous and recombinant NPM (rNPM) enhanced migration as well as the Intercellular Adhesion Molecule 1 (ICAM-1) but not Vascular cell adhesion protein 1 (VCAM-1) expression and it did not affect cell proliferation. Notably, in vitro tube formation by Matrigel assay was significantly increased in HUVEC treated with rNPM compared to controls. This result was confirmed by the in vivo injection of Matrigel plug assay upon stimulation with rNPM, displaying significant enhanced number of functional capillaries in the plugs. The stimulation with rNPM in HUVEC was also associated to the increased expression of master genes regulating angiogenesis and migration, including Vascular Endothelial Growth Factor-A (VEGF-A), Hepatocyte Growth Factor (HGF), Stromal derived factor-1 (SDF-1), Fibroblast growth factor-2 (FGF-2), Platelet Derived Growth Factor-B (PDGF-B), and Matrix metallopeptidase 9 (MMP9). Our study demonstrates for the first time that NPM is physiologically secreted by somatic cells under stress condition and in the absence of cell necrosis. The analysis of the biological effects induced by NPM mainly related to a pro-angiogenic and inflammatory activity might suggest an important autocrine/paracrine role for NPM in the regulation of both phenomena.

Blood ◽  
2005 ◽  
Vol 105 (6) ◽  
pp. 2343-2349 ◽  
Author(s):  
Kui Zhu ◽  
Mohammed Asif Amin ◽  
Yuanyuan Zha ◽  
Lisa A. Harlow ◽  
Alisa E. Koch

AbstractThe 4A11 antigen is a unique cytokine-inducible antigen up-regulated on rheumatoid arthritis (RA) synovial endothelial cells (ECs) compared with normal ECs. Previously, we showed that in soluble form, this antigen, Lewisy-6/H-5-2 (Ley/H) or its glucose analog, 2-fucosyl lactose (H-2g), induced the expression of EC intercellular adhesion molecule-1 (ICAM-1) and leukocyte-endothelial adhesion through the Janus kinase 2 (JAK2)–signal transducer and activator of transcription 3 (STAT3) pathway. Currently, we show that H-2g induces release of EC angiogenic basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF), an effect inhibited by decoy nuclear factor κB (NFκB) oligodeoxynucleotide (ODN). JAK2 and phosphoinositide-3 kinase (PI3K) are 2 upstream kinases of NFκB activated by H-2g, as confirmed by an inhibitor of kappa B kinase (IKKβ) assay. In vitro, H-2g induces vascular sprouting in the rat aortic ring model, whereas blockade of JAK2, PI3K, or NFκB inhibits sprouting. Likewise, in the in vivo mouse Matrigel plug angiogenesis assay, chemical inhibitors and antisense or decoy ODNs of JAK2, PI3K, or NFκB decrease angiogenesis, confirming the importance of these pathways in H-2g–induced EC signaling. The critical role of Ley/H involvement in angiogenesis and its signaling pathways may provide new targets for therapy of diseases characterized by pathologic neovascularization.


2020 ◽  
Vol 9 (2) ◽  
pp. 400 ◽  
Author(s):  
Lamiaa Shalaby ◽  
Menaka Thounaojam ◽  
Amany Tawfik ◽  
Junnan Li ◽  
Khaled Hussein ◽  
...  

ADAM17, a disintegrin and metalloproteinase 17, is a transmembrane metalloproteinase that regulates bioavailability of multiple membrane-bound proteins via ectodomain shedding. ADAM17 activity was shown to contribute to a number of vascular pathologies, but its role in the context of diabetic retinopathy (DR) is not determined. We found that expression and enzymatic activity of ADAM17 are upregulated in human diabetic postmortem retinas and a mouse model of streptozotocin-induced diabetes. To further investigate the contribution of ADAM17 to vascular alterations associated with DR, we used human retinal endothelial cells (HREC) treated with ADAM17 neutralizing antibodies and exposed to glucidic stress and streptozotocin-induced endothelial ADAM17 knockout mice. Evaluation of vascular permeability, vascular inflammation, and oxidative stress was performed. Loss of ADAM17 in endothelial cells markedly reduced oxidative stress evidenced by decreased levels of superoxide, 3-nitrotyrosine, and 4-hydroxynonenal and decreased leukocyte-endothelium adhesive interactions in vivo and in vitro. Reduced leukostasis was associated with decreased vascular permeability and was accompanied by downregulation of intercellular adhesion molecule-1 expression. Reduction in oxidative stress in HREC was associated with downregulation of NAD(P)H oxidase 4 (Nox4) expression. Our data suggest a role for endothelial ADAM17 in DR pathogenesis and identify ADAM17 as a potential new therapeutic target for DR.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Samir Sissaoui ◽  
Stuart Egginton ◽  
Ling Ting ◽  
Asif Ahmed ◽  
Peter W. Hewett

AbstractPlacenta growth factor (PlGF) is a pro-inflammatory angiogenic mediator that promotes many pathologies including diabetic complications and atherosclerosis. Widespread endothelial dysfunction precedes the onset of these conditions. As very little is known of the mechanism(s) controlling PlGF expression in pathology we investigated the role of hyperglycaemia in the regulation of PlGF production in endothelial cells. Hyperglycaemia stimulated PlGF secretion in cultured primary endothelial cells, which was suppressed by IGF-1-mediated PI3K/Akt activation. Inhibition of PI3K activity resulted in significant PlGF mRNA up-regulation and protein secretion. Similarly, loss or inhibition of Akt activity significantly increased basal PlGF expression and prevented any further PlGF secretion in hyperglycaemia. Conversely, constitutive Akt activation blocked PlGF secretion irrespective of upstream PI3K activity demonstrating that Akt is a central regulator of PlGF expression. Knock-down of the Forkhead box O-1 (FOXO1) transcription factor, which is negatively regulated by Akt, suppressed both basal and hyperglycaemia-induced PlGF secretion, whilst FOXO1 gain-of-function up-regulated PlGF in vitro and in vivo. FOXO1 association to a FOXO binding sequence identified in the PlGF promoter also increased in hyperglycaemia. This study identifies the PI3K/Akt/FOXO1 signalling axis as a key regulator of PlGF expression and unifying pathway by which PlGF may contribute to common disorders characterised by endothelial dysfunction, providing a target for therapy.


1996 ◽  
Vol 316 (3) ◽  
pp. 703-707 ◽  
Author(s):  
Ralf BIRKENHÄGER ◽  
Bernard SCHNEPPE ◽  
Wolfgang RÖCKL ◽  
Jörg WILTING ◽  
Herbert A. WEICH ◽  
...  

Vascular endothilial growth factor (VEGF) and placenta growth factor (PIGF) are members of a dimeric-growth-factor family with angiogenic properties. VEGF is a highly potent and specific mitogen for endothelial cells, playing a vital role in angiogenesis in vivo. The role of PIGF is less clear. We expressed the monomeric splice forms VEGF-165, VEGF-121, PIGF-1 and PlGF-2 as unfused genes in Escherichia coli using the pCYTEXP expression system. In vitro dimerization experiments revealed that both homo- and hetero-dimers can be formed from these monomeric proteins. The dimers were tested for their ability to promote capillary growth in vivo and stimulate DNA synthesis in cultured human vascular endothelial cells. Heterodimers comprising different VEGF splice forms, or combinations of VEGF/PlGF splice forms, showed mitogenic activity. The results demonstrate that four different heterodimeric growth factors are likely to have as yet uncharacterized functions in vivo.


2000 ◽  
Vol 279 (5) ◽  
pp. H2241-H2248 ◽  
Author(s):  
Hiroshi Saito ◽  
Cam Patterson ◽  
Zhaoyong Hu ◽  
Marschall S. Runge ◽  
Ulka Tipnis ◽  
...  

Interleukin (IL)-6 reportedly has negative inotropic and hypertrophic effects on the heart. Here, we describe endotoxin-induced IL-6 in the heart that has not previously been well characterized. An intraperitoneal injection of a bacterial lipopolysaccharide into C57BL/6 mice induced IL-6 mRNA in the heart more strongly than in any other tissue examined. Induction of mRNA for two proinflammatory cytokines, IL-1β and tumor necrosis factor (TNF)-α, occurred rapidly before the induction of IL-6 mRNA and protein. Although stimulation of isolated rat neonatal myocardial cells with IL-1β or TNF-α induced IL-6 mRNA in vitro, nonmyocardial heart cells produced higher levels of IL-6 mRNA upon stimulation with IL-1β. In situ hybridization and immunohistochemical analyses localized the IL-6 expression primarily in nonmyocardial cells in vivo. Endotoxin-induced expression of cardiac IL-1β, TNF-α, and intercellular adhesion molecule 1 was augmented in IL-6-deficient mice compared with control mice. Thus cardiac IL-6, expressed mainly by nonmyocardial cells via IL-1β action during endotoxemia, is likely to suppress expression of proinflammatory mediators and to regulate itself via a negative feedback mechanism.


2018 ◽  
Vol 24 (3) ◽  
pp. 278-287 ◽  
Author(s):  
Shengnan Zhao ◽  
Minglu Liang ◽  
Yilong Wang ◽  
Ji Hu ◽  
Yi Zhong ◽  
...  

The vascular endothelium is a continuous layer of flat polygonal cells that are in direct contact with the blood and participate in responses to inflammation. Chrysin is a flavonoid compound extracted from plants of the genus Asteraceae with a wide range of pharmacological activities and physiological activities. Here, we studied the effects of chrysin on the regulation of the proadhesion and pro-inflammatory phenotypes of the endothelium both in vitro and in vivo. Our results revealed that chrysin strongly inhibited Tohoku Hospital Pediatrics-1 (THP-1) cell adhesion to primary human umbilical vein endothelial cells and concentration-dependently attenuated interleukin 1β-induced increases in intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and E-selectin messenger RNA levels and ICAM-1 and VCAM-1 protein levels. Previous studies reported that nuclear factor κB (NF-κB) is important in the inflammatory response in endothelial cells, particularly in regulating adhesion molecules, and our data shed light on the mechanisms whereby chrysin suppressed endothelial inflammation via the NF-κB signaling pathway. In addition, our in vivo findings demonstrated the effects of chrysin in the permeability and inflammatory responses of the endothelium to inflammatory injury. Taken together, we conclude that chrysin inhibits endothelial inflammation both in vitro and in vivo, which could be mainly due to its inhibition of NF-κB signaling activation. In conclusion, chrysin may serve as a promising therapeutic candidate for inflammatory vascular diseases.


Blood ◽  
1990 ◽  
Vol 76 (12) ◽  
pp. 2583-2593 ◽  
Author(s):  
SS Evans ◽  
DB Lee ◽  
T Han ◽  
TB Tomasi ◽  
RL Evans

Abstract Interferon (IFN)-alpha inhibits DNA synthesis stimulated by low molecular weight B-cell growth factor (BCGF) in hairy cells in vitro, suggesting that the therapeutic efficacy of IFN-alpha in hairy cell leukemia (HCL) involves growth inhibition of malignant B cells. Evidence that the 16-Kd cell surface protein Leu-13 mediates an antiproliferative signal in T lymphocytes and is IFN-inducible in endothelial cells prompted us to examine the expression and functional role of this molecule in leukemic B cells. Leu-13 density, determined by flow cytometry, was upregulated in vitro and in vivo by IFN-alpha on malignant B cells from patients with HCL, chronic lymphocytic leukemia, and prolymphocytic leukemia. Monoclonal anti-Leu-13 triggered homotypic aggregation of leukemic B cells via an adhesion pathway that was not inhibited by antibodies to leukocyte function associated antigen-1 (LFA- 1) or intercellular adhesion molecule-1 (ICAM-1). Moreover, anti-Leu-13 potentiated the inhibitory effects of IFN-alpha on BCGF-stimulated DNA synthesis, assessed by [3H]-thymidine and [3H]-deoxyadenosine incorporation into DNA. These results indicate that Leu-13 is part of a novel IFN-inducible signaling pathway which may modify the growth and adhesive properties of leukemic B cells under physiologic or therapeutic conditions.


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