Direct Current Electric Field Stimulates Nitric Oxide Production and Promotes NO-Dependent Angiogenesis: Involvement of the PI3K/Akt Signaling Pathway

Abstract

Electric fields (EFs) promote angiogenesis in vitro and in vivo. These results indicate the feasibility of the application of EFs to modulate angiogenesis. Nitric oxide (NO) derived from endothelial nitric oxide synthase (eNOS) is an important regulator of angiogenesis. However, the role of direct current EFs in eNOS activity and expression in association with angiogenesis of endothelial cells has not been investigated. In the present study, we stimulated human umbilical vein endothelial cells (HUVECs) with EFs and evaluated the activity and expression of eNOS. EFs induced significant phosphorylation of eNOS, upregulation of the expression of eNOS protein, and an increase in NO production from HUVECs. L-NAME, a specific inhibitor of eNOS, abolished EF-induced HUVEC angiogenesis. EFs stimulated Akt activation. Inhibition of PI3K activity inhibited EF-mediated Akt and eNOS activation and inhibited NO production in the endothelial cells. Moreover, EFs stimulated HUVEC proliferation and enhanced the S phase cell population of the cell cycle. We conclude that EFs stimulate eNOS activation and NO production via a PI3K/Akt-dependent pathway. Thus, activation of eNOS appears to be one of the key signaling pathways necessary for EF-mediated angiogenesis. These novel findings suggest that NO signaling may have an important role in EF-mediated endothelial cell function.

Analysis of the Differential Gene and Protein Expression Profiles of Corneal Epithelial Cells Stimulated with Alternating Current Electric Fields

“…The application of DC EFs is known to significantly increase the activation of AKT and impact the PI3K/AKT pathway, which plays an important role in cell survival, growth, migration, and metabolism [46]. Further, DC-induced activation of the PI3K/AKT pathway was also reported in different cell types, including neural progenitor cells [47], Schwann cells [48], and human umbilical vein endothelial cells (HUVEC) [49], as well as in ocular cells, including the corneal epithelium [6,50]. Activation of the MAPK signaling pathway is also reported through the application of EFs in neuronal cells [51,52], fibroblasts, HUVEC [53], and corneal epithelial cells [6].…”

Bioelectric Potential in Next-Generation Organoids: Electrical Stimulation to Enhance 3D Structures of the Central Nervous System

“…In particular, EFs have been identified to regulate pathways involving phosphatase and kinase activity. Numerous reports have confirmed the ability of EFs to induce activation of Akt, and signal transduction of the PI3K pathway ( Arocena et al, 2010 ; Meng et al, 2011 ; Wang et al, 2013 ; Dong et al, 2019 ; Yang et al, 2019 ; Wei et al, 2020 ). Additionally, multiple studies have identified various electrical field parameters to increase production of nitric oxide (NO) both in vivo and in vitro ( Petrofsky et al, 2007 ; Kim et al, 2013 ; Trivedi et al, 2013 ; Wei et al, 2020 ).…”

“…Bioelectric signals are reported to influence angiogenesis, the formation of blood vessels within existing vasculature. Electric field-induced angiogenesis has been identified in endothelial cells receiving electrical stimulation ( Wei et al, 2020 ). Blood flow increases in response to electrical fields, and blood flow alone causes a change in electric field potential ( Petrofsky et al, 2007 ; Trivedi et al, 2013 ).…”

The Role of the BH4 Cofactor in Nitric Oxide Synthase Activity and Cancer Progression: Two Sides of the Same Coin

“…Angiogenesis is maintained by the overproduction of proangiogenic factors, including growth factors, matrix proteinases, and extracellular matrix molecules [100,102]. Different approaches have already shown that eNOS-derived NO signaling in endothelial cells is a critical mechanism of vascular homeostasis, mediating angiogenesis and contributing to increased cell proliferation and migration of endothelial cells and consequently to tumor progression [103][104][105]. Since eNOS activity requires BH4 as a cofactor for NO production, it was shown that the maintenance of its bioavailability is essential for angiogenesis by many groups using different technical procedures [60,61,106,107].…”