pISSN 1226-4512 eISSN 2093-3827

Article

home Article View

Original Article

Korean J Physiol Pharmacol 2019; 23(5): 345-356

Published online September 1, 2019 https://doi.org/10.4196/kjpp.2019.23.5.345

Copyright © The Korean Journal of Physiology & Pharmacology.

Docosahexaenoic acid reduces adenosine triphosphate-induced calcium influx via inhibition of store-operated calcium channels and enhances baseline endothelial nitric oxide synthase phosphorylation in human endothelial cells

Thom Thi Vu1,2,*, Peter Dieterich1, Thu Thi Vu3,4, and Andreas Deussen1

1Department of Physiology, Medical Faculty Carl Gustav Carus, Technical University Dresden, Dresden 01307, Germany, 2Department of Basic Sciences in Medicine and Pharmacy, School of Medicine and Pharmacy, Vietnam National University, Hanoi 100000, Vietnam, 3Faculty of Biology, VNU University of Science, Hanoi 100000, Vietnam, 4Dinh Tien Hoang Institute of Medicine, Hanoi 100000, Vietnam

Correspondence to:*Thom Thi Vu, E-mail: thomtbk5@gmail.com

Received: May 16, 2019; Revised: July 12, 2019; Accepted: July 15, 2019

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Docosahexaenoic acid (DHA), an omega-3-fatty acid, modulates multiple cellular functions. In this study, we addressed the effects of DHA on human umbilical vein endothelial cell calcium transient and endothelial nitric oxide synthase (eNOS) phosphorylation under control and adenosine triphosphate (ATP, 100 µM) stimulated conditions. Cells were treated for 48 h with DHA concentrations from 3 to 50 µM. Calcium transient was measured using the fluorescent dye Fura-2-AM and eNOS phosphorylation was addressed by western blot. DHA dose-dependently reduced the ATP stimulated Ca2+-transient. This effect was preserved in the presence of BAPTA (10 and 20 µM) which chelated the intracellular calcium, but eliminated after withdrawal of extracellular calcium, application of 2-aminoethoxy-diphenylborane (75 µM) to inhibit store-operated calcium channel or thapsigargin (2 µM) to delete calcium store. In addition, DHA (12 µM) increased ser1177/thr495 phosphorylation of eNOS under baseline conditions but had no significant effect on this ratio under conditions of ATP stimulation. In conclusion, DHA dose-dependently inhibited the ATP-induced calcium transient, probably via store-operated calcium channels. Furthermore, DHA changed eNOS phosphorylation suggesting activation of the enzyme. Hence, DHA may shift the regulation of eNOS away from a Ca2+ activated mode to a preferentially controlled phosphorylation mode.

Keywords: Adenosine triphosphate, Calcium, Docosahexaenoic acid, Human umbilical vein endothelial cell, Store-operated calcium channels