title: Metformin, but not thiazolidinediones, inhibits plasminogen activator inhibitor-1 production in human adipose tissue in vitro.
abstract: Biguanides and thiazolidinediones (TZDs), which are primarily used as anti-diabetic drugs, are also associated with other beneficial effects on cardiovascular risk factors such as reduced plasma plasminogen activator inhibitor-1 (PAI-1) concentration in both diabetic and non-diabetic obese subjects. Since human adipose tissue is of importance for the production of PAI-1, the aim of the present study was to investigate the possible direct effects of these anti-diabetic agents on PAI-1 mRNA and secretion by human adipose tissue. Adipose tissue was obtained from biopsies taken from the subcutaneous abdominal depot. Adipose tissue fragments, isolated mature adipocytes, and preadipocytes were incubated in vitro with metformin and various TZDs. Metformin (0.1 - 10 mM) dose-dependently decreased PAI-1 production (and PAI-1 mRNA) under both basal (43 % inhibition at 10 mM, p < 0.05) and interleukin-1beta (IL-1beta)-stimulated conditions where the levels were inhibited by 47.8 % at 1 mM metformin (p < 0.05) and by 100 % at 10 mM (p < 0.01). None of the TZDs tested (PPAR-gamma agonists: troglitazone, pioglitazone, or ciglitazone) had any effects on PAI-1 production. Moreover, no effects on PAI-1 production were observed using various PPAR-alpha agonists such as 5, 8, 11, 14-eicosatetraynoic acid (ETYA), Wy14643 and fenofibrate. Our findings indicate no direct effects of TZDs on PAI-1 secretion, whereas metformin was able to directly inhibit PAI-1 production in human adipose tissue.
authors.affiliation: Department of Endocrinology and Metabolism C, Aarhus Amtssygehus, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: G
authors.initials: G
authors.lastname: He
authors.forename: S B
authors.initials: SB
authors.lastname: Pedersen
authors.forename: J M
authors.initials: JM
authors.lastname: Bruun
authors.forename: A S
authors.initials: AS
authors.lastname: Lihn
authors.forename: B
authors.initials: B
authors.lastname: Richelsen
mesh_terms: D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism; D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism*; D000328:Adult; D002478:Cells, Cultured; D002839:Chromans / Q000494:pharmacology*; D046508:Culture Techniques; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007700:Kinetics; D008687:Metformin / Q000494:pharmacology*; D000077205:Pioglitazone; D017395:Plasminogen Activator Inhibitor 1 / Q000096:biosynthesis*; D018160:Receptors, Cytoplasmic and Nuclear / Q000819:agonists; D020133:Reverse Transcriptase Polymerase Chain Reaction; D045162:Thiazolidinediones / Q000494:pharmacology*; D014157:Transcription Factors / Q000819:agonists; D000077288:Troglitazone
chemical_list: D002839:Chromans; D007004:Hypoglycemic Agents; D017395:Plasminogen Activator Inhibitor 1; D018160:Receptors, Cytoplasmic and Nuclear; D045162:Thiazolidinediones; D014157:Transcription Factors; D008687:Metformin; D000077288:Troglitazone; D000077205:Pioglitazone