Elevation of cyclic AMP in human skin fibroblasts results in increased capacity for HDL binding.
Pre-incubation of cultured human skin fibroblasts, lung fibroblasts and vascular smooth muscle cells, for 24 h with cAMP-elevating agents resulted in a significant increase (40-60%) of the cells' capacity to bind HDL. The increase was due to enhancement of the maximal binding capacity of a high affinity saturable site which binds HDL in preference to LDL. The effect was dependent upon the concentration of the cAMP-elevating agents and required more than 4 h to become evident. Cyclic AMP-mediated elevation of HDL binding occurred in cells with access to an exogenous source of cholesterol, which could be the physiological donor LDL or non-lipoprotein in origin. The observed effects were not subsequent to changes in cellular balance of cholesterol to cholesterol ester and were not due to inhibition of cellular proliferation.
Middleton
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A
Department of Biochemistry, University of Nottingham Medical School, Queen's Medical Centre, UK.
Middleton
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B
D002478:Cells, Cultured; D002784:Cholesterol / Q000378:metabolism / Q000494:pharmacology; D002788:Cholesterol Esters / Q000378:metabolism; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism* / Q000494:pharmacology; D005347:Fibroblasts / Q000378:metabolism*; D006801:Humans; D008075:Lipoproteins, HDL / Q000378:metabolism*; D008168:Lung / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000378:metabolism; D012867:Skin / Q000378:metabolism*
D002788:Cholesterol Esters; D008075:Lipoproteins, HDL; D005576:Colforsin; D002784:Cholesterol; D000242:Cyclic AMP