| Lipid synthesis and secretion in HepG2 cells is not affected by ACTH. | |
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MedLine Citation:
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PMID: 20478061 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Apolipoprotein B (apoB) containing lipoproteins, i.e. VLDL, LDL and Lp(a), are consequently lowered by ACTH treatment in humans. This is also seen as reduced plasma apoB by 20-30% and total cholesterol by 30-40%, mostly accounted for by a decrease in LDL-cholesterol. Studies in hepatic cell line (HepG2) cells showed that apoB mRNA expression is reduced in response to ACTH incubation and is followed by a reduced apoB secretion, which may hypothesize that ACTH lowering apoB containing lipoproteins in humans may be mediated by the inhibition of hepatic apoB synthesis. This was recently confirmed in vivo in a human postprandial study, where ACTH reduced transient apoB48 elevation from the small intestine, however, the exogenic lipid turnover seemed unimpaired. In the present study we investigated if lipid synthesis and/or secretion in HepG2 cells were also affected by pharmacological levels of ACTH to accompany the reduced apoB output. HepG2 cells were incubated with radiolabelled precursors ([14C]acetate and [3H]glycerol) either before or during ACTH stimuli. Cellular and secreted lipids were extracted with chloroform:methanol and separated by the thin layer chromatography (TLC), and [14C]labelled cholesterol and cholesteryl ester and [3H]labelled triglycerides and phospholipids were quantitated by the liquid scintillation counting. It demonstrated that ACTH administration did not result in any significant change in neither synthesis nor secretion of the studied lipids, this regardless of presence or absence of oleic acid, which is known to stabilize apoB and enhance apoB production. The present study suggests that ACTH lowers plasma lipids in humans mainly mediated by the inhibition of apoB synthesis and did not via the reduced lipid synthesis. |
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Authors:
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Maria Skoog; Maria Berggren-Söderlund; Peter Nilsson-Ehle; Ning Xu |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2010-05-17 |
Journal Detail:
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Title: Lipids in health and disease Volume: 9 ISSN: 1476-511X ISO Abbreviation: Lipids Health Dis Publication Date: 2010 |
Date Detail:
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Created Date: 2010-06-07 Completed Date: 2010-08-20 Revised Date: 2010-09-28 |
Medline Journal Info:
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Nlm Unique ID: 101147696 Medline TA: Lipids Health Dis Country: England |
Other Details:
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Languages: eng Pagination: 48 Citation Subset: IM |
Affiliation:
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Section of Clinical Chemistry & Pharmacology, Institute of Laboratory Medicine, Lunds University, S-22185 Lund, Sweden. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adrenocorticotropic Hormone
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pharmacology* Apolipoproteins B / biosynthesis Cholesterol / analysis Cholesterol Esters / analysis Hep G2 Cells Humans Lipids / biosynthesis*, secretion Radioactive Tracers Triglycerides / analysis |
| Chemical | |
Reg. No./Substance:
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0/Apolipoproteins B; 0/Cholesterol Esters; 0/Lipids; 0/Radioactive Tracers; 0/Triglycerides; 57-88-5/Cholesterol; 9002-60-2/Adrenocorticotropic Hormone |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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