title: Dysregulation of placental endothelial lipase in obese women with gestational diabetes mellitus.
abstract: OBJECTIVE
  This study addressed the hypothesis that placental endothelial lipase (EL) expression is affected by pregnancies complicated by obesity and gestational diabetes mellitus (GDM).
  
  
  METHODS
  EL expression in placental tissues from pregnancies complicated by obesity, GDM, or obesity combined with GDM (obese-GDM) was analyzed by quantitative RT-PCR. Moreover, primary placental cells were isolated and treated with insulin, glucose, leptin, or tumor necrosis factor (TNF)-α, and EL expression was measured. Inhibitors of nuclear factor (NF)-κB or mitogen-activated protein kinase (MAPK) signaling were used to detect potential pathways of EL regulation in primary placental endothelial cells (ECs).
  
  
  RESULTS
  In placentas from obese-GDM pregnancies, EL expression was upregulated by 1.9-fold (P < 0.05) compared with lean pregnancies, whereas obesity or GDM alone had no significant effect. Analyses of metabolic parameters in maternal venous and umbilical venous plasma revealed significantly increased insulin and leptin as well as slightly increased glucose and TNF-α values in the obese and obese-GDM groups. Cell culture experiments identified TNF-α and leptin, but not glucose or insulin, as regulators of EL expression in ECs. Induction of EL expression by these mediators occurred in a para/endocrine manner, since only leptin and TNF-α receptors, but not the cytokines themselves, were expressed in ECs. Inhibitor experiments suggested that TNF-α and leptin-mediated upregulation of EL may occur via two different routes. Whereas TNF-α induced EL upregulation in ECs by activation of the NF-κB pathway, leptin did not stimulate NF-κB or MAPK signaling pathways in these cells.
  
  
  CONCLUSIONS
  Metabolic inflammation with high leptin and locally increased TNF-α concentrations at the fetal-placental interface regulates placental EL expression.
authors.affiliation: Institute of Cell Biology, Histology and Embryology, Center for Molecular Medicine, Medical University of Graz, Graz, Austria. martin.gauster@medunigraz.at
authors.forename: Martin
authors.initials: M
authors.lastname: Gauster
authors.forename: Ursula
authors.initials: U
authors.lastname: Hiden
authors.forename: Mireille
authors.initials: M
authors.lastname: van Poppel
authors.forename: Sasa
authors.initials: S
authors.lastname: Frank
authors.forename: Christian
authors.initials: C
authors.lastname: Wadsack
authors.forename: Sylvie
authors.initials: S
authors.lastname: Hauguel-de Mouzon
authors.forename: Gernot
authors.initials: G
authors.lastname: Desoye
mesh_terms: D000328:Adult; D002478:Cells, Cultured; D016640:Diabetes, Gestational / Q000201:enzymology*; D042783:Endothelial Cells / Q000201:enzymology / Q000378:metabolism; D005260:Female; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D020738:Leptin / Q000378:metabolism; D008049:Lipase / Q000235:genetics / Q000378:metabolism*; D009765:Obesity / Q000150:complications / Q000201:enzymology*; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D040081:Protein Array Analysis; D054411:Receptors, Leptin; D018124:Receptors, Tumor Necrosis Factor; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D015854:Up-Regulation; D055815:Young Adult
chemical_list: D020738:Leptin; D054411:Receptors, Leptin; D018124:Receptors, Tumor Necrosis Factor; D014409:Tumor Necrosis Factor-alpha; C410382:LIPG protein, human; D008049:Lipase