Qi-Hong Wu1, Yu Ma1, Cheng-Chao Ruan1,2,3, Yan Yang1,3, Xin-He Liu1, Qian Ge1,3, Ling-Ran Kong1,3, Ji-Wei Zhang4, Chen Yan1,3, Ping-Jin Gao5,2,3. 1. State Key Laboratory of Medical Genomics, Shanghai Key Laboratory of Hypertension, Department of Hypertension, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China. 2. Laboratory of Vascular Biology and Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences and Shanghai Jiao Tong University School of Medicine, Shanghai, China. 3. Shanghai Institute of Hypertension, Shanghai 200025, China. 4. Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200127, China. 5. State Key Laboratory of Medical Genomics, Shanghai Key Laboratory of Hypertension, Department of Hypertension, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China; gaopingjin@sibs.ac.cn.
Abstract
OBJECTIVE: Osteoglycin (OGN) has been noted for its implication in cardiovascular disease in recent studies. However, the relationship between OGN and angiogenesis remains unknown. Therefore, we aimed to investigate the effect of OGN on ischaemia-induced angiogenesis and to address the underlying mechanisms. METHODS AND RESULTS: The expression of OGN was decreased in a limb ischaemia mouse model. OGN knockout (KO) mice were used to further understand the role of OGN after ischaemia. The perfusion recovery rate after femoral artery ligation was higher in OGN KO mice than in wild-type (WT) mice. The capillary density in the gastrocnemius muscle of the ischaemic limb was also higher in OGN KO mice. Moreover, ex vivo aortic ring explants from OGN KO mice exhibited stronger angiogenic sprouting than those from WT mice. In human umbilical vein endothelial cells (HUVECs), OGN knockdown enhanced endothelial cell (EC) activation, including tube formation, proliferation, and migration. In contrast, OGN overexpression inhibited HUVEC activation. Mechanistic studies revealed that OGN associates with vascular endothelial growth factor receptor 2 (VEGFR2) and negatively regulates the interaction of vascular endothelial growth factor (VEGF) and VEGFR2, thereby negatively modulating the activation of VEGFR2 and its downstream signalling pathways. Consistently, the pro-angiogenic effect of OGN KO was abrogated by VEGFR2 inhibition, supporting the critical role of VEGFR2 signalling in OGN-mediated regulation of angiogenic function. CONCLUSIONS: OGN plays a critical role in negatively regulating ischaemia-induced angiogenesis by inhibiting VEGF-VEGFR2 signalling and thereby attenuating EC tube formation, proliferation, and migration. Thus, OGN may be a novel therapeutic target for ischaemic vascular diseases. Published on behalf of the European Society of Cardiology. All rights reserved.
OBJECTIVE:Osteoglycin (OGN) has been noted for its implication in cardiovascular disease in recent studies. However, the relationship between OGN and angiogenesis remains unknown. Therefore, we aimed to investigate the effect of OGN on ischaemia-induced angiogenesis and to address the underlying mechanisms. METHODS AND RESULTS: The expression of OGN was decreased in a limb ischaemiamouse model. OGN knockout (KO) mice were used to further understand the role of OGN after ischaemia. The perfusion recovery rate after femoral artery ligation was higher in OGN KO mice than in wild-type (WT) mice. The capillary density in the gastrocnemius muscle of the ischaemic limb was also higher in OGN KO mice. Moreover, ex vivo aortic ring explants from OGN KO mice exhibited stronger angiogenic sprouting than those from WT mice. In human umbilical vein endothelial cells (HUVECs), OGN knockdown enhanced endothelial cell (EC) activation, including tube formation, proliferation, and migration. In contrast, OGN overexpression inhibited HUVEC activation. Mechanistic studies revealed that OGN associates with vascular endothelial growth factor receptor 2 (VEGFR2) and negatively regulates the interaction of vascular endothelial growth factor (VEGF) and VEGFR2, thereby negatively modulating the activation of VEGFR2 and its downstream signalling pathways. Consistently, the pro-angiogenic effect of OGN KO was abrogated by VEGFR2 inhibition, supporting the critical role of VEGFR2 signalling in OGN-mediated regulation of angiogenic function. CONCLUSIONS:OGN plays a critical role in negatively regulating ischaemia-induced angiogenesis by inhibiting VEGF-VEGFR2 signalling and thereby attenuating EC tube formation, proliferation, and migration. Thus, OGN may be a novel therapeutic target for ischaemic vascular diseases. Published on behalf of the European Society of Cardiology. All rights reserved.