β2-Glycoprotein I Inhibits Vascular Endothelial Growth Factor-Induced Angiogenesis by Suppressing the Phosphorylation of Extracellular Signal-Regulated Kinase 1/2, Akt, and Endothelial Nitric Oxide Synthase

Abstract

Angiogenesis is the process of new blood vessel formation, and it plays a key role in various physiological and pathological conditions. The β2-glycoprotein I (β2-GPI) is a plasma glycoprotein with multiple biological functions, some of which remain to be elucidated. This study aimed to identify the contribution of 2-GPI on the angiogenesis induced by vascular endothelial growth factor (VEGF), a pro-angiogenic factor that may regulate endothelial remodeling, and its underlying mechanism. Our results revealed that β2-GPI dose-dependently decreased the VEGF-induced increase in endothelial cell proliferation, using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and the bromodeoxyuridine (BrdU) incorporation assays. Furthermore, incubation with both β2-GPI and deglycosylated β2-GPI inhibited the VEGF-induced tube formation. Our results suggest that the carbohydrate residues of β2-GPI do not participate in the function of anti-angiogenesis. Using in vivo Matrigel plug and angioreactor assays, we show that β2-GPI remarkably inhibited the VEGF-induced angiogenesis at a physiological concentration. Moreover, β2-GPI inhibited the VEGF-induced phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), Akt, and endothelial nitric oxide synthase (eNOS). In summary, our in vitro and in vivo data reveal for the first time that β2-GPI inhibits the VEGF-induced angiogenesis and highlights the potential for β2-GPI in anti-angiogenic therapy.

Aspalatone Prevents VEGF‐Induced Lipid Peroxidation, Migration, Tube Formation, and Dysfunction of Human Aortic Endothelial Cells

“…Growth factors such as VEGF bind to its receptors VEGFR1 and VEGFR2 and activate downstream signaling pathways of oxidative stress mediated various kinases such as p38MAPK, AKT, and JNK, which are important regulators of endothelial cell activation [ 56 , 57 ]. Chiu et al have shown that β 2-glycoprotein-I prevents VEGF-induced HAEC growth as well as migration by regulating the activation of ERK1/2 and AKT [ 58 ]. Further, Shu et al have shown that vasostatin prevents endothelial cell growth by activation of caspase-3 and downregulation of eNOS in HUVEC cells [ 59 ].…”

Structural and functional characterization of β2‐glycoprotein I domain 1 in anti‐melanoma cell migration

“…[12][13][14][15] We showed previously that purified β 2 -GPI inhibits cell migration, proliferation, and angiogenesis in human aortic endothelial cells. [9][10][11] However, the role of natural β 2 -GPI in tumor development remains unknown. The present study showed that β 2 -GPI is a negative regulator of cell migration, proliferation, and invasion in melanoma cells.…”

“…Western blot analysis was carried out as previously described. 11 In brief, cells were lysed in RIPA buffer and cell extracts were separated by centrifugation at 12 000 g for 20 minutes at 4°C. Nuclear extracts were prepared for analysis of nuclear p50 and p65 levels.…”

“…We previously showed that β 2 -GPI plays an essential role in the suppression of vascular endothelial cell growth, cell migration, and angiogenesis under the regulation of nuclear factor-kappa B (NF-кB) signaling and vascular endothelial growth factor (VEGF)-mediated phosphorylation of VEGFR2, ERK1/2 and Akt pathways. [9][10][11] It is well established that abnormal cell migration and proliferation are closely related to carcinogenesis. [12][13][14][15] Furthermore, many studies have reported that inhibition of cell migration decreases tumor growth in multiple cancers.…”

Estudo do efeito da beta 2-glicoproteína I no desenvolvimento da rede vascular de membrana corioalantóica de embriões de galinha

“…A ação sobre a angiogênese é apenas uma parte das funções fisiológicas descritas para a β 2 GPI e a multiplicidade de seus efeitos reitera as vias de sinalização intracelular como prováveis alvos bioquímicos para sua função. Diversos autores relataram o efeito da proteína sobre a angiogênese, tanto in vitro quanto in vivo (Rakic et al, 2003;Beecken et al, 2006;Sakai et al, 2007;Nakagawa et al, 2009;Passam et al, 2010b;Machado et al, 2013;Chiu et al, 2016). A abordagem utilizada neste trabalho não permitiu atribuir uma via alvo específico para os efeitos anti-angiogênicos da proteína.…”