title: Isolation of basal membrane proteins from BeWo cells and their expression in placentas from fetal growth-restricted pregnancies.
abstract: BACKGROUND
  The syncytiotrophoblast, a key barrier between the mother and fetus, is a polarized epithelium composed of a microvillus and basal membrane (BM). We sought to characterize BM proteins of BeWo cells in relation to hypoxia and to investigate their expression in placentas from pregnancies complicated by fetal growth restriction (FGR).
  
  
  METHODS
  We isolated the BM fraction of BeWo cells by the cationic colloidal silica method and identified proteins enriched in this fraction by mass spectrometry. We evaluated the effect of hypoxia on the expression and intracellular localization of identified proteins and compared their expression in BM fractions of FGR placentas to those from normal pregnancies.
  
  
  RESULTS
  We identified BM proteins from BeWo cells. Among BM proteins, we further characterized heme oxygenase-1 (HO-1), voltage-dependent anion channel-1 (VDAC1), and ribophorin II (RPN2), based on their relevance to placental biology. Hypoxia enhanced the localization of these proteins to the BM of BeWo cells. HO-1, VDAC1, and RPN2 were selectively expressed in the human placental BM fraction. C-terminally truncated HO-1 was identified in placental BM fractions, and its BM expression was significantly reduced in FGR placentas than in normal placentas. Interestingly, a truncated HO-1 construct was predominantly localized in the BM in response to hypoxia and co-localized with VDAC1 in BeWo cells.
  
  
  CONCLUSIONS
  Hypoxia increased the BM localization of HO-1, VDAC1, and RPN2 proteins. FGR significantly reduced the expression of truncated HO-1, which was surmised to co-localize with VDAC1 in hypoxic BeWo cells.
authors.affiliation: Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Soo-Young
authors.initials: SY
authors.lastname: Oh
authors.affiliation: Samsung Biomedical Research Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Jae Ryoung
authors.initials: JR
authors.lastname: Hwang
authors.affiliation: Samsung Biomedical Research Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Yoonna
authors.initials: Y
authors.lastname: Lee
authors.affiliation: Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Suk-Joo
authors.initials: SJ
authors.lastname: Choi
authors.affiliation: Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Jung-Sun
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Jong-Hwa
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Magee-Womens Research Institute, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh, Pittsburgh, USA.
authors.forename: Yoel
authors.initials: Y
authors.lastname: Sadovsky
authors.affiliation: Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea. Electronic address: crroh@skku.edu.
authors.forename: Cheong-Rae
authors.initials: CR
authors.lastname: Roh
mesh_terms: D001485:Basement Membrane / Q000737:chemistry* / Q000378:metabolism / Q000473:pathology; D002478:Cells, Cultured; D005260:Female; D005317:Fetal Growth Retardation / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008565:Membrane Proteins / Q000302:isolation & purification* / Q000378:metabolism*; D010920:Placenta / Q000737:chemistry / Q000378:metabolism* / Q000473:pathology; D011247:Pregnancy
chemical_list: D008565:Membrane Proteins
keywords: Basal membrane; BeWo cells; Fetal growth restriction; Heme oxygenase-1; Hypoxia; Trophoblast; Voltage-dependent anion channel 1