title: Lipoprotein (a) up-regulates the expression of the plasminogen activator inhibitor 2 in human blood monocytes.
abstract: Elevated plasma lipoprotein (a) (Lp[a]) and cardiac events show a modest but significant association in various clinical studies. However, the influence of high Lp(a) on the gene expression in blood monocytes as a major cell involved in atherogenesis is poorly described. To identify genes influenced by elevated serum Lp(a), the gene expression was analyzed on a complementary DNA microarray comparing monocytes from a patient with isolated Lp(a) hyperlipidemia and coronary heart disease with monocytes from a healthy blood donor with low Lp(a). By using this approach, numerous genes were found differentially expressed in patient-versus-control monocytes. Verification of these candidates by Northern blot analysis or semiquantitative polymerase chain reaction in monocytes from additional patients with Lp(a) hyperlipidemia and healthy blood donors with elevated Lp(a) confirmed a significant induction of plasminogen activator inhibitor type 2 (PAI-2) messenger RNA (mRNA) in monocytes from male, but not from female, individuals with high Lp(a), indicating that this observation is gender specific. This led also to increased intracellular and secreted PAI-2 protein in monocytes from male probands with Lp(a) hyperlipidemia. Plasminogen activator inhibitor type 1 (PAI-1) mRNA was found suppressed only in the patients' monocytes and not in healthy probands with high Lp(a) levels. Purified Lp(a) induced PAI-2 mRNA and protein and reduced PAI-1 expression in monocytes isolated from various controls. The finding that PAI-2 is elevated in monocytes from male patients with isolated Lp(a) hyperlipidemia and male healthy probands with high Lp(a) and that purified Lp(a) up-regulates PAI-2 in control monocytes in vitro indicate a direct, but gender-specific, effect of Lp(a) for the induction of PAI-2 expression.
authors.affiliation: Institute for Clinical Chemistry and Laboratory Medicine, University of Regensburg, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Buechler
authors.forename: H
authors.initials: H
authors.lastname: Ullrich
authors.forename: M
authors.initials: M
authors.lastname: Ritter
authors.forename: M
authors.initials: M
authors.lastname: Porsch-Oezcueruemez
authors.forename: K J
authors.initials: KJ
authors.lastname: Lackner
authors.forename: S
authors.initials: S
authors.lastname: Barlage
authors.forename: S O
authors.initials: SO
authors.lastname: Friedrich
authors.forename: G M
authors.initials: GM
authors.lastname: Kostner
authors.forename: G
authors.initials: G
authors.lastname: Schmitz
mesh_terms: D000328:Adult; D000368:Aged; D015152:Blotting, Northern; D002478:Cells, Cultured; D003327:Coronary Disease / Q000097:blood; D005260:Female; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects; D014644:Genetic Variation; D006801:Humans; D006951:Hyperlipoproteinemias / Q000097:blood* / Q000235:genetics; D007249:Inflammation; D017270:Lipoprotein(a) / Q000494:pharmacology / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000378:metabolism*; D009203:Myocardial Infarction / Q000097:blood; D020411:Oligonucleotide Array Sequence Analysis; D017395:Plasminogen Activator Inhibitor 1 / Q000096:biosynthesis / Q000235:genetics; D017396:Plasminogen Activator Inhibitor 2 / Q000096:biosynthesis* / Q000235:genetics; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis; D011956:Receptors, Cell Surface / Q000096:biosynthesis / Q000235:genetics; D055293:Receptors, Urokinase Plasminogen Activator; D012727:Sex Characteristics
chemical_list: D017270:Lipoprotein(a); C524898:PLAUR protein, human; D017395:Plasminogen Activator Inhibitor 1; D017396:Plasminogen Activator Inhibitor 2; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator