Intracellular trafficking of recycling apolipoprotein E in Chinese hamster ovary cells

Nicole A. Braun, Peter J. Mohler, Karl H. Weisgraber, Alyssa H. Hasty, MacRae F. Linton, Patricia G. Yancey, Ru Su Yan, Sergio Fazio, Larry L. Swift

    Research output: Contribution to journalArticle

    13 Scopus citations

    Abstract

    We have investigated apolipoprotein E (apoE) recycling in Chinese hamster ovary (CHO) cells, a peripheral cell that does not produce lipoproteins or express apoE. Using a pulse-chase protocol in which cells were pulsed with 125I-apoE-VLDL and chased for different periods, ∼30% of the apoE internalized during the pulse was resecreted within a 4 h chase in a relatively lipid-free state. The addition of lysosomotropic agents or brefeldin A had no effect on apoE recycling. Unlike previous results with hepatocytes and macrophages, neither apoA-I nor upregulation of ABCA1 stimulated apoE recycling. However, cyclodextrin, which extracts cholesterol from plasma membrane lipid rafts, increased recycling. Confocal studies revealed that apoE, internalized during a 1 h pulse, colocalizes with early endosomal antigen-1, Rab5, Rab11a, and lysobisphosphatidic acid but not with lysosomal-associated membrane protein-1. Colocalization of apoE and Rab11a persisted even after cells had been chased for 1 h, suggesting a pool of apoE within the endosomal recycling compartment (ERC). Our data suggest that apoE recycling in CHO cells is linked to cellular cholesterol removal via the ERC and phospholipid-containing acceptors in a pathway alternative to the ABCA1-apoA-I axis.

    Original languageEnglish (US)
    Pages (from-to)1176-1186
    Number of pages11
    JournalJournal of lipid research
    Volume47
    Issue number6
    DOIs
    StatePublished - Jun 2006

    Keywords

    • ATP binding cassette transporter A1
    • Cholesterol efflux
    • Early endosomes
    • Rab11a
    • Rab5
    • Recycling endosomes
    • β-cyclodextrin

    ASJC Scopus subject areas

    • Biochemistry
    • Endocrinology
    • Cell Biology

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  • Cite this

    Braun, N. A., Mohler, P. J., Weisgraber, K. H., Hasty, A. H., Linton, M. F., Yancey, P. G., Yan, R. S., Fazio, S., & Swift, L. L. (2006). Intracellular trafficking of recycling apolipoprotein E in Chinese hamster ovary cells. Journal of lipid research, 47(6), 1176-1186. https://doi.org/10.1194/jlr.M500503-JLR200