Lipid accumulation and lysosomal pathways contribute to dysfunction and apoptosis of human endothelial cells caused by 7-oxysterols
2011 (English)In: Biochemical and Biophysical Research Communications - BBRC, ISSN 0006-291X, E-ISSN 1090-2104, Vol. 409, no 4, 711-716 p.Article in journal (Refereed) Published
Endothelial dysfunction and cell death play an important role in pathogenesis of atherosclerosis. 7-Oxysterols, the major cytotoxic component found in oxidized low-density lipoprotein, are toxic to endothelial cells. However, the pathways and molecular mechanism involved in the process remain incompletely understood. In this study, we first investigate whether 7 beta-hydroxycholesterol (7 beta OH) or 7-ketocholesterol (7keto) induces apoptosis of human endothelial cell line (HUVEC-CS). We then examine possible involved pathways by focusing on cellular lipid, lysosomal pathways, cellular oxidative stress and mitochondrial pathways. Our results for the first time showed that 7-oxysterols induced apoptotic cell death of HUVEC-CS after 24 h, which was preceded by early lipid accumulation (6 h) and lysosomal membrane permeabilization (6-12 h). Afterward, levels of reactive oxygen species, mitochondrial membrane permeabilization, and lysosomal cathepsin were increased assayed by immuno-cytochemistry and blotting. Notably, the exposure to 7 beta OH or 7keto induced expressions and secretion of isoforms of von Willebrand factor (VWF). We conclude that apoptosis of HUVEC-CS induced by 7 beta OH or 7keto mediates by early lysosomal lipid accumulation and oxidative lysosomal pathways, which results in induction and release of VWF. The results suggest the cell death induced by 7-oxysterols may contribute to endothelial dysfunction and atherothrombosis.
Place, publisher, year, edition, pages
Elsevier Science B.V., Amsterdam , 2011. Vol. 409, no 4, 711-716 p.
Atherosclerosis; Apoptosis; Oxidized lipids; Oxidative stress
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-69855DOI: 10.1016/j.bbrc.2011.05.071ISI: 000292358500021OAI: oai:DiVA.org:liu-69855DiVA: diva2:433432