Inhibition of store-operated Ca(2+) channels prevent ethanol-induced intracellular Ca(2+) increase and cell injury in a human hepatoma cell line.

Abstract

Elevated intracellular Ca(2+) content is implicated in ethanol-induced hepatocyte apoptosis and necrosis. Extracellular Ca(2+) influx has been suggested to play a role in this process. However, the exact Ca(2+)-permeable channel involved in the plasma membrane is still unclear. This study investigated the role of store-operated calcium entry (SOCE) in ethanol-induced cytosolic free Ca(2+) concentrations ([Ca(2+)](i)) increase and hepatotoxicity. Ethanol (25-800mM) dose-dependently increased [Ca(2+)](i) content and hepatocyte damage in HepG2 cells. 2-aminoethoxydiphenyl borate (2-APB), the proved efficient antagonist of SOCs, dose-dependently suppressed the ethanol (200nM)-increased [Ca(2+)](i) content and protected against ethanol-induced viability loss and transaminase leakage. Exposure to 200mM ethanol for 24h significantly upregulated the mRNA and protein expression of calcium release-activated calcium channel protein 1 (CRACM1, Orai1) and stromal interaction molecule 1 (STIM1), the two main molecular constituents of SOCs, which was sustained for at least 72h. In addition, small interfering RNA knockdown of STIM1 attenuated the ethanol-increased [Ca(2+)](i) content and hepatotoxicity. Taken together, these data indicate that the Ca(2+) channel of SOCE may be involved in the pathogenesis of ethanol-induced intracellular Ca(2+) elevation and consequent hepatocyte damage.

• Authors: Huimin Liu, Xiaoqing Jia, Zheng Luo, Hui Guan, Hong Jiang, Xuehui Li, Ming Yan
• Journal: Toxicology letters (Toxicol Lett) Vol. 208 Issue 3 Pg. 254-61 (Feb 05 2012) ISSN: 1879-3169 [Electronic] Netherlands
• PMID: 22119170 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Chemical References

• Boron Compounds
• Calcium Channel Blockers
• Calcium Channels
• Membrane Proteins
• Neoplasm Proteins
• ORAI1 Protein
• ORAI1 protein, human
• RNA, Messenger
• RNA, Small Interfering
• STIM1 protein, human
• Stromal Interaction Molecule 1
• Ethanol
• 2-aminoethoxydiphenyl borate
• Calcium

Topics

• Blotting, Western
• Boron Compounds (pharmacology)
• Calcium (metabolism)
• Calcium Channel Blockers (pharmacology)
• Calcium Channels (genetics, metabolism)
• Cell Survival (drug effects)
• Drug Interactions
• Ethanol (antagonists & inhibitors, toxicity)
• Hep G2 Cells
• Hepatocytes (drug effects, metabolism, pathology)
• Humans
• Liver Diseases, Alcoholic (metabolism, pathology)
• Membrane Proteins (genetics, metabolism)
• Neoplasm Proteins (genetics, metabolism)
• ORAI1 Protein
• RNA, Messenger (chemistry, genetics)
• RNA, Small Interfering (pharmacology)
• Real-Time Polymerase Chain Reaction
• Reverse Transcriptase Polymerase Chain Reaction
• Stromal Interaction Molecule 1