Up-Regulatory Effects of Curcumin on Large Conductance Ca2+-Activated K+ Channels.

Bibliographic Details
Title: Up-Regulatory Effects of Curcumin on Large Conductance Ca2+-Activated K+ Channels.
Authors: Qijing Chen, Jie Tao, Hongya Hei, Fangping Li, Yunman Wang, Wen Peng, Xuemei Zhang
Source: PLoS ONE, Vol 10, Iss 12, p e0144800 (2015)
Publisher Information: Public Library of Science (PLoS), 2015.
Publication Year: 2015
Collection: LCC:Medicine
LCC:Science
Subject Terms: Medicine, Science
More Details: Large conductance Ca2+-activated potassium channels (BK) are targets for research that explores therapeutic means to various diseases, owing to the roles of the channels in mediating multiple physiological processes in various cells and tissues. We investigated the pharmacological effects of curcumin, a compound isolated from the herb Curcuma longa, on BK channels. As recorded by whole-cell patch-clamp, curcumin increased BK (α) and BK (α+β1) currents in transfected HEK293 cells as well as the current density of BK in A7r5 smooth muscle cells in a dose-dependent manner. By incubating with curcumin for 24 hours, the current density of exogenous BK (α) in HEK293 cells and the endogenous BK in A7r5 cells were both enhanced notably, though the steady-state activation of the channels did not shift significantly, except for BK (α+β1). Curcumin up-regulated the BK protein expression without changing its mRNA level in A7r5 cells. The surface expression and the half-life of BK channels were also increased by curcumin in HEK293 cells. These effects of curcumin were abolished by MG-132, a proteasome inhibitor. Curcumin also increased ERK 1/2 phosphorylation, while inhibiting ERK by U0126 attenuated the curcumin-induced up-regulation of BK protein expression. We also observed that the curcumin-induced relaxation in the isolated rat aortic rings was significantly attenuated by paxilline, a BK channel specific blocker. These results show that curcumin enhances the activity of the BK channels by interacting with BK directly as well as enhancing BK protein expression through inhibiting proteasomal degradation and activating ERK signaling pathway. The findings suggest that curcumin is a potential BK channel activator and provide novel insight into its complicated pharmacological effects and the underlying mechanisms.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 1932-6203
Relation: https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0144800&type=printable; https://doaj.org/toc/1932-6203
DOI: 10.1371/journal.pone.0144800&type=printable
DOI: 10.1371/journal.pone.0144800
Access URL: https://doaj.org/article/4ce8ff6b3cf941b6bfc432938548b9bd
Accession Number: edsdoj.4ce8ff6b3cf941b6bfc432938548b9bd
Database: Directory of Open Access Journals
More Details
ISSN:19326203
DOI:10.1371/journal.pone.0144800&type=printable
Published in:PLoS ONE
Language:English