title: Insulin stimulation of Akt/PKB phosphorylation in the placenta of preeclampsia patients.
abstract: OBJECTIVE
  Preeclampsia is a multi-systemic disease and one of the most frequent severe health problems during pregnancy. Binding of insulin triggers phosphorylation and activates cytoplasmic substrates such as phosphatidylinositol 3 kinase (PI3K). Phosphorylation of membrane phosphoinositide 2 (PIP2) to phosphoinositide 3 (PIP3) by PI3K starts Akt/PKB activation. Defects in phosphorylation of the insulin receptor and its substrates have an important role in insulin resistance. Studies have shown that insulin resistance is associated with preeclampsia and its pathophysiology. The aim here was to investigate insulin stimulation of the Akt/PKB pathway in the placenta, in normal and preeclampsia parturients.
  
  
  METHODS
  Cross-sectional study in a tertiary public university hospital.
  
  
  METHODS
  Placentas were collected from 12 normal and 12 preeclampsia patients. These were stimulated and analyzed using Western blot to quantify the Akt/PKB phosphorylation.
  
  
  RESULTS
  The insulin stimulation was confirmed through comparing the stimulated group (1.14 ± 0.10) with the non-stimulated group (0.91 ± 0.08; P < 0.001). The phosphorylation of Akt/PKB did not differ between the placenta of the normal patients (1.26 ± 0.16) and those of the preeclampsia patients (1.01 ± 0.11; P = 0.237).
  
  
  CONCLUSIONS
  In vitro insulin stimulation of the human placenta has been well established. There was no difference in Akt/PKB phosphorylation, after stimulation with insulin, between placentas of normal and preeclampsia patients. Nevertheless, it cannot be ruled out that the Akt/PKB signaling pathway may have a role in the pathophysiology of preeclampsia, since the substrates of Akt/PKB still need to be investigated.
authors.affiliation: Biological Sciences (Physiology), Molecular, Endocrine and Tumor Biology Laboratory and Department of Gynecology and Obstetrics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Gustavo Dias
authors.initials: GD
authors.lastname: Ferreira
authors.forename: Rafael Bueno
authors.initials: RB
authors.lastname: Orcy
authors.forename: Sérgio Hofmeister
authors.initials: SH
authors.lastname: Martins-Costa
authors.forename: José Geraldo Lopes
authors.initials: JG
authors.lastname: Ramos
authors.forename: Ilma Simoni
authors.initials: IS
authors.lastname: Brum
authors.forename: Helena von Eye
authors.initials: Hv
authors.lastname: Corleta
authors.forename: Edison
authors.initials: E
authors.lastname: Capp
mesh_terms: D000328:Adult; D015153:Blotting, Western; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004789:Enzyme Activation; D005260:Female; D006801:Humans; D007328:Insulin / Q000494:pharmacology*; D007333:Insulin Resistance / Q000502:physiology; D010766:Phosphorylation; D010920:Placenta / Q000187:drug effects* / Q000201:enzymology; D011225:Pre-Eclampsia / Q000201:enzymology*; D011247:Pregnancy; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D007328:Insulin; D051057:Proto-Oncogene Proteins c-akt