Membrane organization determines barrier properties of endothelial cells and short-chain sphingolipid-facilitated doxorubicin influx

• Published in: Biochimica et biophysica acta 2014-09, Vol.1841 (9), p.1301-1307
• Main Authors: van Hell, A.J., Klymchenko, A., Gueth, D.M., van Blitterswijk, W.J., Koning, G.A., Verheij, M.
• Format: Article
• Language: English
• Subjects: Animals; Antibiotics, Antineoplastic - metabolism; Aorta - cytology; Aorta - metabolism; Apical basolateral polarization; Biological Transport; Bovine aortic endothelial cells; Cancer therapy; Cattle; Dogs; Doxorubicin; Doxorubicin - metabolism; Drug delivery; Endothelial Cells - cytology; Endothelial Cells - metabolism; Endothelium, Vascular - cytology; Endothelium, Vascular - metabolism; Life Sciences; Madin Darby Canine Kidney Cells; Membrane Lipids - chemistry; Membrane Microdomains - chemistry; Membranes, Artificial; Organ Specificity; Vasculature
• ISSN: 1388-1981; 0006-3002; 1879-2618
• DOI: 10.1016/j.bbalip.2014.06.006

The endothelial lining and its outer lipid membrane are the first major barriers drug molecules encounter upon intravenous administration. Our previous work identified lipid analogs that counteract plasma membrane barrier function for a series of amphiphilic drugs. For example, short-chain sphingolipids (SCS), like N-octanoyl-glucosylceramide, effectively elevated doxorubicin accumulation in tumor cells, both in vitro and in vivo, and in endothelial cells, whereas other (normal) cells remained unaffected. We hypothesize here that local membrane lipid composition and the degree of lipid ordering define SCS efficacy in individual cells. To this end, we study the differential effect of SCS on bovine aortic endothelial cells (BAEC) in its confluent versus proliferative state, as a model system. While their (plasma membrane) lipidome stays remarkably unaltered when BAECs reach confluency, their lipids segregate to form apical and basolateral domains. Using probe NR12S, we reveal that lipids in the apical membrane are more condensed/liquid-ordered. SCS preferentially attenuate the barrier posed by these condensed membranes and facilitate doxorubicin influx in these particular membrane regions. We confirm these findings in MDCK cells and artificial membranes. In conclusion, SCS-facilitated drug traversal acts on condensed membrane domains, elicited by confluency in resting endothelium. •Drug influx is defined by polarization of cultured endothelial cells.•Plasma membrane lipid composition is unaltered when cells polarize.•Lipids organize into a condensed apical membrane, preventing doxorubicin influx.•Short-chain lipid analogs facilitate drug influx over condensed membranes.