Advanced Search

Journal Navigation

Journal Home

Subscriptions

Archive

Contact Us

Table of Contents

CiteULike is a free service for managing and discovering scholarly references - click here to get started.

Sign In to gain access to subscriptions and/or personal tools.
International Journal of Toxicology
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to Saved Citations
Right arrow Download to citation manager
Right arrow Add to My Marked Citations
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Right arrow Citing Articles via Scopus
Google Scholar
Right arrow Articles by Ryan, L.
Right arrow Articles by O’Brien, N. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Ryan, L.
Right arrow Articles by O’Brien, N. M.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

Articles

Involvement of Calcium in 7β-Hydroxycholesterol and Cholesterol-5β,6β-Epoxide-Induced Apoptosis

L. Ryan
Y. C. O’Callaghan
N. M. O’Brien

Department of Food and Nutritional Sciences, University College Cork, Ireland

Correspondence: Address correspondence to Dr. N. M. O’Brien, Nutritional Sciences, Department of Food and Nutritional Sciences, University College Cork, Cork, Ireland. E-mail:nob{at}ucc.ie

Oxidized low-density lipoprotein (oxLDL) is believed to play a central role in the development of atherosclerosis. The induction of apoptosis in cells of the arterial wall is a critical event in the development of atheroma. 7β-Hydroxycholesterol (7β-OH) and cholesterol-5β,6β-epoxide (β-epoxide) are components of oxLDL and have previously been shown to be potent inducers of apoptosis. The exact mechanism through which these oxysterols induce apoptosis remains to be fully elucidated. A perturbation of intra-cellular calcium homeostasis has been found to trigger apoptosis in many experimental systems. The aim of the present study was to determine the involvement of calcium signaling in 7β-OH and β-epoxide–induced apoptosis. To this end, the authors employed the calcium channel blockers verapamil and nifedipine and inhibitors of calpain activation, ALLM and ALLN. Verapamil protected against the decrease in viability induced by 7β-OH whereas nifedipine had a protective effect in both 7β-OH and β-epoxide–treated cells, though these compounds did not restore viability to control levels. Verapamil, nifedipine, and ALLM prevented apoptosis induced by β-epoxide. None of the compounds employed in the current study protected against 7β-OH–induced apoptosis. Our results implicate calcium signaling in the apoptotic pathway induced by β-epoxide and also highlight differences between apoptosis induced by 7β-OH and β-epoxide.

Key Words: Apoptosis • Calcium • Cholesterol-5β • 6β-Epoxide • 7β-Hydroxycholesterol • U937 Cells

International Journal of Toxicology, Vol. 25, No. 1, 35-39 (2006)
DOI: 10.1080/10915810500488387
Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?


This article has been cited by other articles:


Home page
 International Journal of ToxicologyHome page
S. Lordan, J. J. Mackrill, and N. M. O'Brien
Involvement of Fas Signalling in 7{beta}-Hydroxycholesterol-and Cholesterol-5{beta},6{beta}-Epoxide-Induced Apoptosis
International Journal of Toxicology, May 1, 2008; 27(3): 279 - 285.
[Abstract] [Full Text] [PDF]