Angiotensin II promotes selective uptake of high density lipoprotein cholesterol esters in bovine adrenal glomerulosa and human adrenocortical carcinoma cells through induction of scavenger receptor class B type I

Article Article scientifique Article Angiotensin II promotes selective uptake of high density lipoprotein cholesterol esters in bovine adrenal glomerulosa and human adrenocortical carcinoma cells through induction of scavenger receptor class B type I eng 2001 author Cherradi Nadia 98323 author Bideau Sar Martine 57989 author Arnaudeau Serge 508253 author Demaurex Nicolas 0000-0002-9933-6772 24642 author James Richard William 26359 author Azhar Salman author Capponi Alessandro Mario 24743 4540-4549 10.1210/en.142.10.4540 11564720 0013-7227 Angiotensin II is one of the main physiological regulators of aldosterone biosynthesis in the zona glomerulosa of the adrenal cortex. The hormone stimulates intracellular cholesterol mobilization to the mitochondrion for steroid biosynthesis. Here we have examined whether angiotensin II also modulates exogenous lipoprotein cholesterol ester supply to the steroidogenic machinery and whether this control is exerted on the selective transport of high density lipoprotein-derived cholesterol ester to intracellular lipid droplets through the scavenger receptor class B type I. In bovine adrenal glomerulosa and human NCI H295R adrenocortical carcinoma cells, high density lipoprotein stimulated steroid production. Angiotensin II pretreatment for 24 h potentiated this response. Fluorescence microscopy of cellular uptake of reconstituted high density lipoprotein containing a fluorescent cholesterol ester revealed an initial, time-dependent narrow labeling of the cell membrane followed by an intense accumulation of the fluorescent cholesterol ester within lipid droplets. At all time points, labeling was more pronounced in cells that had been treated for 24 h with angiotensin II. Fluorescence incorporation into cells was prevented by a monoclonal antibody directed against apolipoprotein A-I. Upon quantitative fluorometric determination, cholesterol ester uptake in angiotensin II-treated bovine cells was increased to 175 +/- 15% of controls after 2 h and to 260 +/- 10% after 4 h of exposure to fluorescent high density lipoprotein. The amount of scavenger receptor class B type I protein detected in cells treated with angiotensin II for 24 h reached 203 +/- 12% of that measured in control cells (n = 3, P < 0.01). In contrast, low density lipoprotein receptors were only minimally affected by angiotensin II treatment. This increase in scavenger receptor class B type I protein was associated with a 3-fold induction of scavenger receptor class B type I mRNA, which could be prevented by actinomycin D but not by cycloheximide. Similar results were obtained in the human adenocarcinoma cell line H295R. These observations show that angiotensin II regulates the scavenger receptor class B type I-mediated selective transport of lipoprotein cholesterol ester across the cell membrane as a major source of precursor for mineralocorticoid biosynthesis in both human and bovine adrenal cells. Adrenal Cortex Neoplasms/metabolism Adrenocortical Carcinoma/metabolism Angiotensin II/metabolism/pharmacology Animals Antigens, CD36/metabolism Biological Transport/drug effects Cattle Cells, Cultured Cholesterol Esters/metabolism Humans Lipoproteins, HDL/metabolism Membrane Proteins Receptors, Immunologic Receptors, Lipoprotein Receptors, Scavenger Scavenger Receptors, Class B Signal Transduction/drug effects Zona Glomerulosa/metabolism Dewey 612 Dewey 616 134 Département de physiologie cellulaire et métabolisme 21C 56 Département de médecine 221 false 958 Médecine interne générale et pédiatrie ambulatoires 968 168 Signaux intracellulaires 210 Endocrinology 142 10 c0a88b99-644d-49e3-9aba-d7c047e16c44 Article (Published version) Public Angiotensin II Promotes....pdf 1328032 application/pdf openAccess Faculté de médecine / Section de médecine fondamentale / Département de physiologie cellulaire et métabolisme Faculté de médecine / Section de médecine clinique / Département de médecine

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Angiotensin II promotes selective uptake of high density lipoprotein cholesterol esters in bovine adrenal glomerulosa and human adrenocortical carcinoma cells through induction of scavenger receptor class B type I	Endocrinology			2001	629	366

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