MR has a post on eggs where he mentions oxidized cholesterol that everyone should read and here's a new study I came across:
Biochem Biophys Res Commun. 2010 Jan 29;392(1):58-62. Epub 2010 Jan 6.
StarD4-mediated translocation of 7-hydroperoxycholesterol to isolated mitochondria: deleterious effects and implications for steroidogenesis under oxidative stress conditions.
Korytowski W, Rodriguez-Agudo D, Pilat A, Girotti AW.
Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
Abstract
StAR family proteins, including StarD4, play a key role in steroidogenesis by transporting cholesterol (Ch) into mitochondria for conversion to pregnenolone. Using a model system consisting of peroxidized cholesterol (7 alpha-OOH)-containing liposomes as donors, we showed that human recombinant StarD4 accelerates 7 alpha-OOH transfer to isolated liver mitochondria, and to a greater extent than Ch transfer. StarD4 had no effect on transfer of non-oxidized or peroxidized phosphatidylcholine, consistent with sterol ring specificity. StarD4-accelerated 7 alpha-OOH transfer to mitochondria resulted in greater susceptibility to free radical lipid peroxidation and loss of membrane potential than in a non-StarD4 control. The novel implication of these findings is that in oxidative stress states, inappropriate StAR-mediated trafficking of peroxidized Ch in steroidogenic tissues could result in damage and dysfunction selectively targeted to mitochondria. Copyright © 2010 Elsevier Inc. All rights reserved.
PMID: 20059974 [PubMed - indexed for MEDLINE]PMCID: PMC2829839 [Available on 2011/1/29]
