title: Molecular mechanisms of the angiogenic effects of low-energy shock wave therapy: roles of mechanotransduction.
abstract: We have previously demonstrated that low-energy extracorporeal cardiac shock wave (SW) therapy improves myocardial ischemia through enhanced myocardial angiogenesis in a porcine model of chronic myocardial ischemia and in patients with refractory angina pectoris. However, the detailed molecular mechanisms for the SW-induced angiogenesis remain unclear. In this study, we thus examined the effects of SW irradiation on intracellular signaling pathways in vitro. Cultured human umbilical vein endothelial cells (HUVECs) were treated with 800 shots of low-energy SW (1 Hz at an energy level of 0.03 mJ/mm(2)). The SW therapy significantly upregulated mRNA expression and protein levels of vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS). The SW therapy also enhanced phosphorylation of extracellular signal-regulated kinase 1/2 (Erk1/2) and Akt. Furthermore, the SW therapy enhanced phosphorylation of caveolin-1 and the expression of HUTS-4 that represents β1-integrin activity. These results suggest that caveolin-1 and β1-integrin are involved in the SW-induced activation of angiogenic signaling pathways. To further examine the signaling pathways involved in the SW-induced angiogenesis, HUVECs were transfected with siRNA of either β1-integrin or caveolin-1. Knockdown of either caveolin-1 or β1-integrin suppressed the SW-induced phosphorylation of Erk1/2 and Akt and upregulation of VEGF and eNOS. Knockdown of either caveolin-1 or β1-integrin also suppressed SW-induced enhancement of HUVEC migration in scratch assay. These results suggest that activation of mechanosensors on cell membranes, such as caveolin-1 and β1-integrin, and subsequent phosphorylation of Erk and Akt may play pivotal roles in the SW-induced angiogenesis.
authors.affiliation: Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan; and Department of Innovative Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Hatanaka
authors.affiliation: Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan; and Department of Innovative Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan ito-kenta@cardio.med.tohoku.ac.jp.
authors.forename: Kenta
authors.initials: K
authors.lastname: Ito
authors.affiliation: Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan; and.
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Shindo
authors.affiliation: Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan; and.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Kagaya
authors.affiliation: Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan; and.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Ogata
authors.affiliation: Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan; and.
authors.forename: Kumiko
authors.initials: K
authors.lastname: Eguchi
authors.affiliation: Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan; and.
authors.forename: Ryo
authors.initials: R
authors.lastname: Kurosawa
authors.affiliation: Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan; and Department of Innovative Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Shimokawa
mesh_terms: D043925:Angiogenesis Inducing Agents / Q000627:therapeutic use*; D000818:Animals; D051242:Caveolin 1 / Q000378:metabolism; D002460:Cell Line; D019220:High-Energy Shock Waves / Q000627:therapeutic use*; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D019012:Integrin beta1 / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000502:physiology; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D009389:Neovascularization, Pathologic / Q000378:metabolism* / Q000503:physiopathology*; D018919:Neovascularization, Physiologic / Q000502:physiology*; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D010766:Phosphorylation / Q000502:physiology; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D013552:Swine; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D043925:Angiogenesis Inducing Agents; D051242:Caveolin 1; D019012:Integrin beta1; D042461:Vascular Endothelial Growth Factor A; D052250:Nitric Oxide Synthase Type III; D051057:Proto-Oncogene Proteins c-akt
keywords: angiogenesis; caveolin-1; mechanotransduction; shock wave; β1-integrin