title: Shock Wave Enhances Angiogenesis through VEGFR2 Activation and Recycling.
abstract: Although low-energy shock wave (SW) is adopted to treat ischemic diseases because of its pro-angiogenic properties, the underlying mechanism remains unclear. This study aimed at testing whether SW-induced angiogenesis may be through endothelial vascular endothelial growth factor receptor 2 (VEGFR2) signaling and trafficking. Phosphorylation of VEGFR2-Akt-eNOS axis and production of nitric oxide (NO) were determined in human umbilical vein endothelial cells (HUVECs) treated with SW. Carotid artery in ob/ob mice was treated with SW before evaluation with sprouting assay. Critical limb ischemia was induced in ob/ob mice to evaluate blood flow recovery after SW treatment. Tube formation and migration assays were also performed with/without SW treatment in the presence/absence of SU5416 (VEGFR2 kinase inhibitor) and siRNA-driven silencing of VEGFR2. Chloroquine was used for disrupting endosome, and Rab11a controlling slow endocytic recycling was silenced with siRNAin vitro. Following SW treatment, augmented ligand-independent phosphorylation in VEGFR2-Akt-eNOS axis and endogenous NO production, increased cellular migration and tube formation, elevated sprouting of carotid artery and blood flow in ischemic limb in ob/ob mice were noted. Moreover, SU5416 and VEGFR2 silencing both inhibited SW-induced angiogenesis. SW-induced angiogenesis, which was accompanied by increased VEGFR2 protein expression without transcriptional change, was suppressed by chloroquine and Rab11a silencing. We concluded that SW enhanced angiogenesis via ligand-independent activation of VEGFR2 and further prolonged through endosome-to-plasma membrane recycling in endothelial cells.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, 83301, Taiwan.
authors.forename: Tien-Hung
authors.initials: TH
authors.lastname: Huang
authors.affiliation: Department of Emergency Medicine, E-Da Hospital, I-Shou University School of Medicine for International Students, Kaohsiung, 82445, Taiwan.
authors.forename: Cheuk-Kwan
authors.initials: CK
authors.lastname: Sun
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, 83301, Taiwan.
authors.forename: Yi-Ling
authors.initials: YL
authors.lastname: Chen
authors.affiliation: Center for Shockwave Medicine and Tissue Engineering, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, 83301, Taiwan.|Department of Orthopedic Surgery, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, 83301, Taiwan.
authors.forename: Ching-Jen
authors.initials: CJ
authors.lastname: Wang
authors.affiliation: Department of Orthopedic Surgery, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, 83301, Taiwan.
authors.forename: Tsung-Cheng
authors.initials: TC
authors.lastname: Yin
authors.affiliation: Department of Orthopedic Surgery, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, 83301, Taiwan.
authors.forename: Mel S
authors.initials: MS
authors.lastname: Lee
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, 83301, Taiwan.|Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, 83301, Taiwan.|Center for Shockwave Medicine and Tissue Engineering, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, 83301, Taiwan.|Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, 40402, Taiwan.|Department of Nursing, Asia University, Taichung, 41354, Taiwan.
authors.forename: Hon-Kan
authors.initials: HK
authors.lastname: Yip
keywords: VEGFR2; angiogenesis; endocytic recycling; endothelial cell; shock wave