Direct observation of cargo transfer from HDL particles to the plasma membrane

Birgit Plochberger, Markus Axmann, Clemens Röhrl, Julian Weghuber, Mario Brameshuber, Benedikt K. Rossboth, Sandra Mayr, Robert Ros, Robert Bittman, Herbert Stangl, Gerhard J. Schütz

Research output: Contribution to journalArticle

3 Scopus citations

Abstract

Background and aims: Exchange of cholesterol between high-density lipoprotein (HDL) particles and cells is a key process for maintaining cellular cholesterol homeostasis. Recently, we have shown that amphiphilic cargo derived from HDL can be transferred directly to lipid bilayers. Here we pursued this work using a fluorescence-based method to directly follow cargo transfer from HDL particles to the cell membrane. Methods: HDL was either immobilized on surfaces or added directly to cells, while transfer of fluorescent cargo was visualized via fluorescence imaging. Results: In Chinese hamster ovary (CHO) cells expressing the scavenger receptor class B type 1 (SR-B1), transfer of amphiphilic cargo from HDL particles to the plasma membrane was observed immediately after contact, whereas hydrophobic cargo remained associated with the particles; about 60% of the amphiphilic cargo of surface-bound HDL was transferred to the plasma membrane. Essentially no cargo transfer was observed in cells with low endogenous SR-B1 expression. Interestingly, transfer of fluorescently-labeled cholesterol was also facilitated by using an artificial linker to bind HDL to the cell surface. Conclusions: Our data hence indicate that the tethering function of SR-B1 is sufficient for efficient transfer of free cholesterol to the plasma membrane.

Original languageEnglish (US)
Pages (from-to)53-59
Number of pages7
JournalAtherosclerosis
Volume277
DOIs
StatePublished - Oct 2018

Keywords

  • Cholesterol
  • HDL
  • Single molecule microscopy
  • transfer

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

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    Plochberger, B., Axmann, M., Röhrl, C., Weghuber, J., Brameshuber, M., Rossboth, B. K., Mayr, S., Ros, R., Bittman, R., Stangl, H., & Schütz, G. J. (2018). Direct observation of cargo transfer from HDL particles to the plasma membrane. Atherosclerosis, 277, 53-59. https://doi.org/10.1016/j.atherosclerosis.2018.08.032