title: The expression and post-transcriptional regulation of FSTL1 transcripts in placental trophoblasts.
abstract: BACKGROUND
  Follistatin-like-1 (FSTL1) is a widely expressed secreted protein with diverse but poorly understood functions. Originally described as a pro-inflammatory molecule, it has recently been reported to play a role in signaling pathways that regulate development and homeostasis. Distinctively, FSTL1 harbors within its 3'-UTR the sequence encoding microRNA-198 (miR-198), shown to be inversely regulated relative to FSTL1 expression and to exhibit opposite actions on cellular processes such as cell migration. We sought to investigate the expression of FSTL1 and to assess its interplay with miR-198 in human trophoblasts.
  
  
  METHODS
  We used a combination of northern blot analyses, quantitative PCR, small RNA sequencing, western blot and immunohistochemistry to characterize FSTL1 and miR-198 expression in placental trophoblasts. We also used reporter assays to examine the post-transcriptional regulation of FSTL1 and assess its putative regulation by miR-198.
  
  
  RESULTS
  We detected the expression of FSTL1 transcript in both the human extravillous trophoblast line HTR-8/SVneo and in primary term human villous trophoblasts. We also found that the expression of FSTL1 was largely restricted to extravillous trophoblasts. Hypoxia enhanced the expression of FSTL1 protein in cultured primary villous trophoblasts. Interestingly, we did not detect any evidence for expression or function of mature miR-198 in human trophoblasts.
  
  
  CONCLUSIONS
  Our data indicate that placental FSTL1 is expressed particularly in extravillous trophoblasts. We also found no evidence for placental expression of miR-198, or for its regulation of FSTL1, implying that the post-transcriptional regulation of FSTL1 by miR-198 is tissue specific.
authors.affiliation: Magee-Womens Research Institute, University of Pittsburgh, PA, USA; Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh, PA, USA.
authors.forename: Jean-Francois
authors.initials: JF
authors.lastname: Mouillet
authors.affiliation: Magee-Womens Research Institute, University of Pittsburgh, PA, USA; Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh, PA, USA.
authors.forename: Takuya
authors.initials: T
authors.lastname: Mishima
authors.affiliation: Magee-Womens Research Institute, University of Pittsburgh, PA, USA; Instituto de Ciencias Biologicas, Universidade Federal de Alfenas (UNIFAL-MG), Alfenas, MG, Brazil.
authors.forename: Andrea Mollica do Amarante
authors.initials: AM
authors.lastname: Paffaro
authors.affiliation: Magee-Womens Research Institute, University of Pittsburgh, PA, USA; Department of Pathology, University of Pittsburgh, PA, USA.
authors.forename: Tony W
authors.initials: TW
authors.lastname: Parks
authors.affiliation: Magee-Womens Research Institute, University of Pittsburgh, PA, USA.
authors.forename: Judy A
authors.initials: JA
authors.lastname: Ziegler
authors.affiliation: Magee-Womens Research Institute, University of Pittsburgh, PA, USA; Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh, PA, USA.
authors.forename: Tianjiao
authors.initials: T
authors.lastname: Chu
authors.affiliation: Magee-Womens Research Institute, University of Pittsburgh, PA, USA; Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh, PA, USA; Department of Microbiology and Molecular Genetics, University of Pittsburgh, PA, USA. Electronic address: ysadovsky@mwri.magee.edu.
authors.forename: Yoel
authors.initials: Y
authors.lastname: Sadovsky
mesh_terms: D002460:Cell Line; D038702:Follistatin-Related Proteins / Q000378:metabolism*; D006801:Humans; D000860:Hypoxia / Q000378:metabolism; D035683:MicroRNAs / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D014327:Trophoblasts / Q000378:metabolism*
chemical_list: D038702:Follistatin-Related Proteins; C535221:MIRN198 microRNA, human; D035683:MicroRNAs; C448799:FSTL1 protein, human
keywords: FSTL1; Hypoxia; Trophoblasts; miR-198