Referenced in: none

Automatically associated channels: TRP , TRPV , TRPV1

Title: Transient receptor potential vanilloid type 1 is vital for (-)-epigallocatechin-3-gallate mediated activation of endothelial nitric oxide synthase.

Authors: Bei-Chia Guo, Jeng Wei, Kuo-Hui Su, An-Na Chiang, Jin-Feng Zhao, Hsiang-Ying Chen, Song-Kun Shyue, Tzong-Shyuan Lee

Journal, date & volume: Mol Nutr Food Res, 2015 Apr , 59, 646-57

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/25581901

Abstract
Epigallocatechin-3-gallate (EGCG), the most abundant catechin of green tea, has beneficial effects on physiological functions of endothelial cells (ECs), yet the detailed mechanisms are not fully understood. In this study, we investigated the role of transient receptor potential vanilloid type 1 (TRPV1), a ligand-gated nonselective calcium channel, in EGCG-mediated endothelial nitric oxide (NO) synthase (eNOS) activation and angiogenesis.In ECs, treatment with EGCG time-dependently increased the intracellular level of Ca(2+) . Removal of extracellular calcium (Ca(2+) ) by EGTA or EDTA or inhibition of TRPV1 by capsazepine or SB366791 abrogated EGCG-increased intracellular Ca(2+) level in ECs or TRPV1-transfected HEK293 cells. Additionally, EGCG increased the phsophorylation of eNOS at Ser635 and Ser1179, Akt at Ser473, calmodulin-dependent protein kinase II (CaMKII) at Thr286 and AMP-activated protein kinase (AMPK) at Thr172, all abolished by the TRPV1 antagonist capsazepine. EGCG-induced NO production was diminished by pretreatment with LY294002 (an Akt inhibitor), KN62 (a CaMKII inhibitor), and compound C (an AMPK inhibitor). Moreover, blocking TRPV1 activation prevented EGCG-induced EC proliferation, migration, and tube formation, as well as angiogenesis in Matrigel plugs in mice.EGCG may trigger activation of TRPV1-Ca(2+) signaling, which leads to phosphorylation of Akt, AMPK, and CaMKII; eNOS activation; NO production; and, ultimately, angiogenesis in ECs.