Activating CD137 Signaling Promotes Sprouting Angiogenesis via Increased VEGFA Secretion and the VEGFR2/Akt/eNOS Pathway

Combination of antiangiogenesis and immunotherapy may be an effective strategy for treatment of solid tumors. Our previous work reported that activation of CD137 signaling promotes intraplaque angiogenesis. A number of studies have demonstrated that vascular endothelial growth factor receptor 2 (VEG...

Full description

Saved in:
Bibliographic Details
Main Authors: Bo Li, Yue Zhang, Runting Yin, Wei Zhong, Rui Chen, Jinchuan Yan
Format: Article
Language:English
Published: Wiley 2020-01-01
Series:Mediators of Inflammation
Online Access:http://dx.doi.org/10.1155/2020/1649453
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1832551679233359872
author Bo Li
Yue Zhang
Runting Yin
Wei Zhong
Rui Chen
Jinchuan Yan
author_facet Bo Li
Yue Zhang
Runting Yin
Wei Zhong
Rui Chen
Jinchuan Yan
author_sort Bo Li
collection DOAJ
description Combination of antiangiogenesis and immunotherapy may be an effective strategy for treatment of solid tumors. Our previous work reported that activation of CD137 signaling promotes intraplaque angiogenesis. A number of studies have demonstrated that vascular endothelial growth factor receptor 2 (VEGFR2) is a key target for angiogenesis. However, it is unknown whether CD137-mediated angiogenesis is related to VEGFR2. In this study, we investigated the effect of CD137 on the VEGFR2 expression and explored the underlying mechanisms of CD137-mediated angiogenesis. Knock-out of CD137 in ApoE-/- mice significantly decreased neovessel density in atherosclerotic plaques. CD137 silencing or inhibition attenuated endothelial cell (ECs) proliferation, migration, and tube formation. We found activation of CD137 signaling for increased VEGFR2 transcription and translation steadily. Moreover, CD137 signaling activated phosphorylated VEGFR2 (Tyr1175) and the downstream Akt/eNOS pathway, whereas neutralizing CD137 signaling weakened the activation of VEGFR2 and the downstream Akt/eNOS pathway. The aortic ring assay further demonstrated that CD137 signaling promoted ECc sprouting. Inhibition of VEGFR2 by siRNA or XL184 (cabozantinib) and inhibition of downstream signaling by LY294002 (inhibits AKT activation) and L-NAME (eNOS inhibitor) remarkably abolished proangiogenic effects of CD137 signaling both in vitro and ex vivo. In addition, the condition medium from CD137-activated ECs and vascular endothelial growth factor A (VEGFA) had similar effects on ECs that expressed high VEGFR2. Additionally, activating CD137 signaling promoted endothelial secretion of VEGFA, while blocking CD137 signaling attenuated VEGFA secretion. In conclusion, activation of CD137 signaling promoted sprouting angiogenesis by increased VEGFA secretion and the VEGFR2/Akt/eNOS pathway. These findings provide a basis for stabilizing intraplaque angiogenesis through VEGFR2 intervatioin, as well as cancer treatment via combination of CD137 agonists and specific VEGFR2 inhibitors.
format Article
id doaj-art-73a14c3bbdab430dbb252894616ee9f3
institution Kabale University
issn 0962-9351
1466-1861
language English
publishDate 2020-01-01
publisher Wiley
record_format Article
series Mediators of Inflammation
spelling doaj-art-73a14c3bbdab430dbb252894616ee9f32025-02-03T06:00:48ZengWileyMediators of Inflammation0962-93511466-18612020-01-01202010.1155/2020/16494531649453Activating CD137 Signaling Promotes Sprouting Angiogenesis via Increased VEGFA Secretion and the VEGFR2/Akt/eNOS PathwayBo Li0Yue Zhang1Runting Yin2Wei Zhong3Rui Chen4Jinchuan Yan5Department of Cardiology, Affiliated Hospital of Jiangsu University, Zhenjiang, ChinaDepartment of Cardiology, Affiliated Hospital of Jiangsu University, Zhenjiang, ChinaDepartment of Cardiology, Affiliated Hospital of Jiangsu University, Zhenjiang, ChinaDepartment of Cardiology, Affiliated Hospital of Jiangsu University, Zhenjiang, ChinaDepartment of Cardiology, Affiliated Hospital of Jiangsu University, Zhenjiang, ChinaDepartment of Cardiology, Affiliated Hospital of Jiangsu University, Zhenjiang, ChinaCombination of antiangiogenesis and immunotherapy may be an effective strategy for treatment of solid tumors. Our previous work reported that activation of CD137 signaling promotes intraplaque angiogenesis. A number of studies have demonstrated that vascular endothelial growth factor receptor 2 (VEGFR2) is a key target for angiogenesis. However, it is unknown whether CD137-mediated angiogenesis is related to VEGFR2. In this study, we investigated the effect of CD137 on the VEGFR2 expression and explored the underlying mechanisms of CD137-mediated angiogenesis. Knock-out of CD137 in ApoE-/- mice significantly decreased neovessel density in atherosclerotic plaques. CD137 silencing or inhibition attenuated endothelial cell (ECs) proliferation, migration, and tube formation. We found activation of CD137 signaling for increased VEGFR2 transcription and translation steadily. Moreover, CD137 signaling activated phosphorylated VEGFR2 (Tyr1175) and the downstream Akt/eNOS pathway, whereas neutralizing CD137 signaling weakened the activation of VEGFR2 and the downstream Akt/eNOS pathway. The aortic ring assay further demonstrated that CD137 signaling promoted ECc sprouting. Inhibition of VEGFR2 by siRNA or XL184 (cabozantinib) and inhibition of downstream signaling by LY294002 (inhibits AKT activation) and L-NAME (eNOS inhibitor) remarkably abolished proangiogenic effects of CD137 signaling both in vitro and ex vivo. In addition, the condition medium from CD137-activated ECs and vascular endothelial growth factor A (VEGFA) had similar effects on ECs that expressed high VEGFR2. Additionally, activating CD137 signaling promoted endothelial secretion of VEGFA, while blocking CD137 signaling attenuated VEGFA secretion. In conclusion, activation of CD137 signaling promoted sprouting angiogenesis by increased VEGFA secretion and the VEGFR2/Akt/eNOS pathway. These findings provide a basis for stabilizing intraplaque angiogenesis through VEGFR2 intervatioin, as well as cancer treatment via combination of CD137 agonists and specific VEGFR2 inhibitors.http://dx.doi.org/10.1155/2020/1649453
spellingShingle Bo Li
Yue Zhang
Runting Yin
Wei Zhong
Rui Chen
Jinchuan Yan
Activating CD137 Signaling Promotes Sprouting Angiogenesis via Increased VEGFA Secretion and the VEGFR2/Akt/eNOS Pathway
Mediators of Inflammation
title Activating CD137 Signaling Promotes Sprouting Angiogenesis via Increased VEGFA Secretion and the VEGFR2/Akt/eNOS Pathway
title_full Activating CD137 Signaling Promotes Sprouting Angiogenesis via Increased VEGFA Secretion and the VEGFR2/Akt/eNOS Pathway
title_fullStr Activating CD137 Signaling Promotes Sprouting Angiogenesis via Increased VEGFA Secretion and the VEGFR2/Akt/eNOS Pathway
title_full_unstemmed Activating CD137 Signaling Promotes Sprouting Angiogenesis via Increased VEGFA Secretion and the VEGFR2/Akt/eNOS Pathway
title_short Activating CD137 Signaling Promotes Sprouting Angiogenesis via Increased VEGFA Secretion and the VEGFR2/Akt/eNOS Pathway
title_sort activating cd137 signaling promotes sprouting angiogenesis via increased vegfa secretion and the vegfr2 akt enos pathway
url http://dx.doi.org/10.1155/2020/1649453
work_keys_str_mv AT boli activatingcd137signalingpromotessproutingangiogenesisviaincreasedvegfasecretionandthevegfr2aktenospathway
AT yuezhang activatingcd137signalingpromotessproutingangiogenesisviaincreasedvegfasecretionandthevegfr2aktenospathway
AT runtingyin activatingcd137signalingpromotessproutingangiogenesisviaincreasedvegfasecretionandthevegfr2aktenospathway
AT weizhong activatingcd137signalingpromotessproutingangiogenesisviaincreasedvegfasecretionandthevegfr2aktenospathway
AT ruichen activatingcd137signalingpromotessproutingangiogenesisviaincreasedvegfasecretionandthevegfr2aktenospathway
AT jinchuanyan activatingcd137signalingpromotessproutingangiogenesisviaincreasedvegfasecretionandthevegfr2aktenospathway