Selective uptake of high density lipoprotein-associated cholesterylesters by differentiated Ob1771 adipocytes is modulated by endogenous and exogenous lipoprotein lipase.
The present study aimed at investigating mechanisms of selective uptake of HDL3-associated cholesterylesters (HDL3-CEs) by differentiated Ob1771 adipocytes. Our findings indicate that Ob1771 cells are capable of pronounced selective uptake of HDL3-CEs in 2.6-fold excess of HDL3 holoparticle uptake. Selective uptake of HDL3-CEs into a releasable pool (presumably located in the cellular plasma membrane) was temperature insensitive while prominent internalization into a non-releasable and subsequent hydrolysis in a non-chloroquine sensitive compartment occurred at 37 degrees C. Release of membrane bound endogenous LPL by heparin resulted in decreased HDL3 holoparticle, total CE and selective CE uptake. Accordingly, the addition of exogenous LPL to the culture medium resulted in increased holoparticle, total CE and selective CE uptake.
Schorsch
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F
Karl-Franzens University Graz, Department of Medical Biochemistry, Austria.
Malle
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E
Sattler
W
W
D017667:Adipocytes / Q000166:cytology / Q000378:metabolism*; D000818:Animals; D002454:Cell Differentiation; D002738:Chloroquine / Q000494:pharmacology; D002788:Cholesterol Esters / Q000378:metabolism / Q000493:pharmacokinetics*; D006801:Humans; D006868:Hydrolysis; D008071:Lipoprotein Lipase / Q000378:metabolism* / Q000494:pharmacology; D008075:Lipoproteins, HDL / Q000378:metabolism* / Q000493:pharmacokinetics; D008247:Lysosomes / Q000187:drug effects; D051379:Mice; D013696:Temperature
D002788:Cholesterol Esters; D008075:Lipoproteins, HDL; D002738:Chloroquine; D008071:Lipoprotein Lipase