title: Regulation of endothelial MAPK/ERK signalling and capillary morphogenesis by low-amplitude electric field.
abstract: Low-amplitude electric field (EF) is an important component of wound-healing response and can promote vascular tissue repair; however, the mechanisms of action on endothelium remain unclear. We hypothesized that physiological amplitude EF regulates angiogenic response of microvascular endothelial cells via activation of the mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway. A custom set-up allowed non-thermal application of EF of high (7.5 GHz) and low (60 Hz) frequency. Cell responses following up to 24 h of EF exposure, including proliferation and apoptosis, capillary morphogenesis, vascular endothelial growth factor (VEGF) expression and MAPK pathways activation were quantified. A db/db mouse model of diabetic wound healing was used for in vivo validation. High-frequency EF enhanced capillary morphogenesis, VEGF release, MEK-cRaf complex formation, MEK and ERK phosphorylation, whereas no MAPK/JNK and MAPK/p38 pathways activation was observed. The endothelial response to EF did not require VEGF binding to VEGFR2 receptor. EF-induced MEK phosphorylation was reversed in the presence of MEK and Ca(2+) inhibitors, reduced by endothelial nitric oxide synthase inhibition, and did not depend on PI3K pathway activation. The results provide evidence for a novel intracellular mechanism for EF regulation of endothelial angiogenic response via frequency-sensitive MAPK/ERK pathway activation, with important implications for EF-based therapies for vascular tissue regeneration.
authors.affiliation: Biomedical Engineering, SEEBME, University of Cincinnati, 2901 Woodside Drive, Cincinnati, OH 45221-0012, USA.
authors.forename: Abdul Q
authors.initials: AQ
authors.lastname: Sheikh
authors.forename: Toloo
authors.initials: T
authors.lastname: Taghian
authors.forename: Bryan
authors.initials: B
authors.lastname: Hemingway
authors.forename: Hongkwan
authors.initials: H
authors.lastname: Cho
authors.forename: Andrei B
authors.initials: AB
authors.lastname: Kogan
authors.forename: Daria A
authors.initials: DA
authors.lastname: Narmoneva
mesh_terms: D000818:Animals; D017209:Apoptosis; D002118:Calcium / Q000378:metabolism; D002196:Capillaries / Q000166:cytology / Q000254:growth & development*; D049109:Cell Proliferation; D002478:Cells, Cultured; D004574:Electromagnetic Fields; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005786:Gene Expression Regulation; D048670:MAP Kinase Kinase 4 / Q000378:metabolism; D020935:MAP Kinase Signaling System; D051379:Mice; D009024:Morphogenesis; D018919:Neovascularization, Physiologic; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D019908:Proto-Oncogene Proteins c-raf / Q000378:metabolism; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis
chemical_list: D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse; D019869:Phosphatidylinositol 3-Kinases; D019908:Proto-Oncogene Proteins c-raf; D048049:Extracellular Signal-Regulated MAP Kinases; D048670:MAP Kinase Kinase 4; D002118:Calcium