Ceramide Enhances Cholesterol Efflux to Apolipoprotein A-I by Increasing the Cell Surface Presence of ATP-binding Cassette Transporter A1

摘要: It is widely accepted that functional ATP-binding cassette transporter A1 (ABCA1) critical for the formation of nascent high density lipoprotein particles. However, cholesterol pool(s) and cellular signaling processes utilized by ABCA1-mediated pathway remain unclear. Sphingomyelin maintains a preferential interaction with in membranes, its catabolites, especially ceramide, are potent molecules could play role ABCA1 regulation or function. To study potential ceramide this process, we treated variety cell lines 20 microM C2-ceramide examined apolipoprotein-mediated efflux to lipid-free apoA-I. We found expressing displayed 2-3-fold increases Cell not were unaffected ceramide. further characterized effect Chinese hamster ovary cells. Ceramide treatment did cause significant cytotoxicity apoptosis affect non-apolipoprotein acceptors. Raising endogenous levels increased Using surface biotinylation method, total at plasma membrane treatment. Also enhanced binding fluorescently labeled apoA-I These data suggest may increase content ABCA1, leading efflux.