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Updated: Sep 26, 2026

Live-Cell Förster Resonance Energy Transfer Imaging of Metabolically Regulated Akt Activation Dynamics in HepG2 Cells
Published on: May 23, 2025
Hepatocyte growth factor activates endothelial nitric oxide synthase by Ca(2+)- and phosphoinositide
Kennedy Makondo1, Kazuhiro Kimura, Naoki Kitamura
1Laboratory of Biochemistry, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
Abstract:
Hepatocyte growth factor (HGF) causes endothelium-dependent vasodilation, but its relation to endothelial nitric oxide synthase (eNOS) activity remains to be elucidated. Treatment of bovine aortic endothelial cells with HGF increased eNOS activity within minutes, accompanied by an increase of activity-related site-specific phosphorylation of eNOS. The phosphorylation was completely abolished by pretreatment of the cells with a phosphoinositide 3-kinase (PI3K) inhibitor (wortmannin) and by transfection of dominant-negative Akt, and the enzyme activity was inhibited by wortmannin. In addition, eNOS activity and phosphorylation were abolished by pretreatment of the cells with an intracellular Ca(2+)-chelator, bis-(o-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid tetrakis(acetoxymethyl ester) (BAPTA/AM), with a suppression of Akt phosphorylation. These results suggest that HGF stimulates eNOS activity by a PI3K/Akt-dependent phosphorylation in a Ca(2+)-sensitive manner in vascular endothelial cells.
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