Donate Help Contact The AHA Sign In Home
American Heart Association
Arteriosclerosis, Thrombosis, and Vascular Biology
Search: search_blue_button Advanced Search
« Previous Article | Table of Contents | Next Article »
Arteriosclerosis, Thrombosis, and Vascular Biology. 1985;5:45-54

This Article
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowRequest Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Aulinskas, T. H.
Right arrow Articles by van der Westhuyzen, D. R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Aulinskas, T. H.
Right arrow Articles by van der Westhuyzen, D. R.

Arteriosclerosis, Vol 5, 45-54, Copyright © 1985 by American Heart Association

ARTICLES

Retro-endocytosis of low density lipoprotein by cultured human skin fibroblasts

TH Aulinskas, JF Oram, EL Bierman, GA Coetzee, W Gevers and DR van der Westhuyzen

A fraction of the low-density lipoprotein (LDL) internalized by cells via receptor-mediated endocytosis follows a short-circuit pathway, termed "retro-endocytosis," that results in the rapid exocytosis of ligand. Results from the current study suggest that retro-endocytosis of LDL in human fibroblasts is caused by resurfacing of endocytotic vesicles that contain both free and receptor-bound ligand, resulting in discharge of vesicular contents and in spontaneous dissociation of LDL from its receptor. The bulk of the released LDL particles had the same size, density, and immunogenic properties as native LDL, indicating that they were discharged intact. Some of the retro-endocytosed LDL was larger than native LDL, and some exhibited altered sedimentation properties. When fusion of endosomes with lysosomes was inhibited by chilling cells to 18 degrees C, the proportion of intracellular LDL subsequently released was unaffected, suggesting that retro-endocytosis does not require lysosomal participation. Furthermore, the shorter the internalization phase the greater was the proportion of LDL subsequently released, suggesting that LDL was discharged from compartments formed early in endocytosis. Retro-endocytosis of LDL was stimulated by agents that neutralize acid intracellular compartments, such as ionophores (monensin) and weak bases (chloroquine and methylamine). Monensin increased the proportion of intracellular LDL released, suggesting that it had a direct effect on retro-endocytosis. The effect of weak bases appeared to be secondary to their ability to promote cellular accumulation of undegraded LDL. Thus, retro- endocytosis of LDL becomes a major pathway when intracellular compartments fail to maintain a low pH or where the intracellular concentration of LDL reaches abnormal levels.


This article has been cited by other articles:


Home page
 J. Biol. Chem.Home page
T. A. Pagler, S. Rhode, A. Neuhofer, H. Laggner, W. Strobl, C. Hinterndorfer, I. Volf, M. Pavelka, E. R. M. Eckhardt, D. R. van der Westhuyzen, et al.
SR-BI-mediated High Density Lipoprotein (HDL) Endocytosis Leads to HDL Resecretion Facilitating Cholesterol Efflux
J. Biol. Chem., April 21, 2006; 281(16): 11193 - 11204.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
P. C. N. Rensen, M. C. Jong, L. C. van Vark, H. van der Boom, W. L. Hendriks, T. J. C. van Berkel, E. A. L. Biessen, and L. M. Havekes
Apolipoprotein E Is Resistant to Intracellular Degradation in Vitro and in Vivo. EVIDENCE FOR RETROENDOCYTOSIS
J. Biol. Chem., March 17, 2000; 275(12): 8564 - 8571.
[Abstract] [Full Text] [PDF]

Home page
 J. Cell Sci.Home page
J Heeren, W Weber, and U Beisiegel
Intracellular processing of endocytosed triglyceride-rich lipoproteins comprises both recycling and degradation
J. Cell Sci., January 2, 1999; 112(3): 349 - 359.
[Abstract] [PDF]


ATVB Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search
Copyright © 1985 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited.