title: The protein kinase a pathway regulates CYP17 expression and androgen production in the human placenta.
abstract: BACKGROUND
  Our previous work demonstrated that the human placenta expresses CYP17 and is capable of de novo production of C-19 steroids; thus, it has intrinsic capacity to generate estrogens without fetal or maternal steroid precursors.
  
  
  OBJECTIVE
  Our objective was to elucidate the regulation of CYP17 expression and androgen production in the human trophoblasts.
  
  
  METHODS
  Fresh placentas and JEG-3 cells were used for all experiments. CYP17 mRNA analysis was performed via RT-PCR, and steroid products were quantified using RIA. To assess protein kinase A (PKA) pathway involvement, a pharmacological approach was used with forskolin (FSK) (10 μM), an activator, and H89 (10 μM), an inhibitor of the PKA pathway.
  
  
  RESULTS
  FSK treatment amplified CYP17 mRNA levels in both cell types when compared with basal, with levels increasing over time, peaking at 72 h, and appearing more robust in primary cells; this difference ranged from 2- to 10-fold and was statistically significant at all time points. Meanwhile, H89 reduced CYP17 levels and blunted the effect of FSK when the treatments were combined. Similarly, FSK treatment significantly increased 17α-hydroxyprogesterone concentration in both cell cultures, and H89 blunted that effect as well.
  
  
  CONCLUSIONS
  We confirm again that the human trophoblast expresses CYP17 and is able to generate estrogen precursors. We demonstrate that this process is regulated, at least in part, by the cAMP/PKA pathway.
authors: Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75235-9032, USA.
authors: Julian C
authors: JC
authors: Escobar
authors: Bruce R
authors: BR
authors: Carr
mesh_terms: D000728:Androgens / Q000096:biosynthesis*; D002460:Cell Line; D002478:Cells, Cultured; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D010920:Placenta / Q000166:cytology / Q000378:metabolism*; D011247:Pregnancy; D015398:Signal Transduction / Q000502:physiology*; D013254:Steroid 17-alpha-Hydroxylase / Q000235:genetics / Q000378:metabolism*
chemical_list: D000728:Androgens; D013254:Steroid 17-alpha-Hydroxylase; D017868:Cyclic AMP-Dependent Protein Kinases