title: LDL but not HDL increases adiponectin release of primary human adipocytes.
abstract: Adipocytes in obesity have inappropriately low cholesterol while adiponectin release is reduced. Cholesterol shortage may contribute to low adiponectin and 3T3-L1 cells treated with lovastatin have diminished adiponectin in cell supernatants. LDL and HDL deliver cholesterol to adipocytes. LDL but not HDL increases adiponectin in cell supernatants of primary human adipocytes. The effect of LDL is not blocked by receptor associated protein suggesting that members of the LDL-receptor family are not involved. To evaluate whether these in vitro observations translate into changes in systemic adiponectin, adiponectin was measured in serum of three patients before, immediately after and 3d after LDL-apheresis. Whereas circulating lipoproteins are reduced immediately after apheresis adiponectin is not changed. Therefore, acute lowering of lipoproteins does not affect systemic adiponectin also excluding that plenty of adiponectin is bound to lipoprotein particles. Accordingly, levels of adiponectin in purified lipoproteins are quite low. Familial hypobetalipoproteinemia (FHBL) is a rare disorder associated with low plasma LDL. Serum adiponectin is, however, similar compared to healthy controls. Thus, neither LDL nor HDL directly contributes to circulating adiponectin concentrations.
authors.affiliation: Department of Internal Medicine I, Regensburg University Hospital, D-93042 Regensburg, Germany.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Krautbauer
authors.forename: Markus
authors.initials: M
authors.lastname: Neumeier
authors.forename: Kristina
authors.initials: K
authors.lastname: Eisinger
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Hader
authors.forename: Ashraf
authors.initials: A
authors.lastname: Dada
authors.forename: Gerd
authors.initials: G
authors.lastname: Schmitz
authors.forename: Charalampos
authors.initials: C
authors.lastname: Aslanidis
authors.forename: Christa
authors.initials: C
authors.lastname: Buechler
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D052242:Adiponectin / Q000378:metabolism*; D000328:Adult; D000818:Animals; D000924:Anticholesteremic Agents / Q000494:pharmacology; D008076:Cholesterol, HDL / Q000494:pharmacology*; D008078:Cholesterol, LDL / Q000494:pharmacology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D006995:Hypobetalipoproteinemias / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D008074:Lipoproteins / Q000378:metabolism; D008148:Lovastatin / Q000494:pharmacology; D008297:Male; D051379:Mice; D008875:Middle Aged
chemical_list: D052242:Adiponectin; D000924:Anticholesteremic Agents; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D008074:Lipoproteins; D008148:Lovastatin
keywords: Familial hypobetalipoproteinemia; LDL apheresis; Lipoprotein