Apigenin, a plant-derived flavone, activates transient receptor potential vanilloid 4 cation channel
Article first published online: 10 APR 2012
© 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society
British Journal of Pharmacology
Special Issue: Themed Section: Secretin Family (Class B) G Protein-Coupled Receptors - from Molecular to Clinical Perspectives. Guest Editors: David R Poyner and Debbie L Hay
Volume 166, Issue 1, pages 349–358, May 2012
How to Cite
Ma, X., He, D., Ru, X., Chen, Y., Cai, Y., Bruce, I. C., Xia, Q., Yao, X. and Jin, J. (2012), Apigenin, a plant-derived flavone, activates transient receptor potential vanilloid 4 cation channel. British Journal of Pharmacology, 166: 349–358. doi: 10.1111/j.1476-5381.2011.01767.x
- Issue published online: 10 APR 2012
- Article first published online: 10 APR 2012
- Accepted manuscript online: 3 NOV 2011 05:12AM EST
- Received; 14 May 2011; Revised; 14 October 2011; Accepted; 18 October 2011
- endothelial cell;
BACKGROUND AND PURPOSE Transient receptor potential vanilloid 4 (TRPV4) is a Ca2+-permeable channel with multiple modes of activation. Apigenin is a plant-derived flavone, which has potential preventive effects on the development of cardiovascular disease. We set out to explore the effects of apigenin on TRPV4 channel activity and its role in vasodilatation.
EXPERIMENTAL APPROACH The effects of apigenin (0.01–30 µM) on TPRV4 channels were investigated in HEK293 cells over-expressing TRPV4, rat primary cultured mesenteric artery endothelial cells (MAECs) and isolated small mesenteric arterial segments using whole-cell patch clamp, fluorescent Ca2+ imaging, intracellular recording and pressure myography.
KEY RESULTS Whole-cell patch clamp and fluorescent Ca2+ imaging in HEK cells over-expressing TRPV4 showed that apigenin concentration-dependently stimulated the TRPV4-mediated cation current and Ca2+ influx. In MAECs, apigenin stimulated Ca2+ influx in a concentration-dependent manner. These increases in cation current and Ca2+ influx were markedly inhibited by TRPV4-specific blockers and siRNAs. Furthermore, pressure myography and intracellular recording in small third-order mesenteric arteries showed that apigenin dose-dependently evoked smooth muscle cell membrane hyperpolarization and subsequent vascular dilatation, which were significantly inhibited by TRPV4-specific blockers. TRPV4 blocker or charybdotoxin (200 nM) plus apamin (100 nM) diminished the apigenin-induced dilatation.
CONCLUSION AND IMPLICATIONS This is the first study to demonstrate the selective stimulation of TRPV4 by apigenin. Apigenin was found to activate TRPV4 channels in a dose-dependent manner in HEK cells over-expressing TRPV4 and in native endothelial cells. In rat small mesenteric arteries, apigenin acts on TRPV4 in endothelial cells to induce EDHF-mediated vascular dilatation.