title: Expression of human leukocyte antigen-G during normal placentation and in preeclamptic pregnancies.
abstract: OBJECTIVE
  This study was undertaken to investigate the expression pattern of human leukocyte antigen-G (HLA-G) during normal placentation and determine whether altered expression of HLA-G is associated with severe preeclampsia.
  
  
  METHODS
  We investigated HLA-G protein levels in first (n = 27), second (n = 7), and third trimester placentas (n = 10) from normal pregnancies, and determined HLA-G levels in term placentas from normal (n = 15) and severe preeclamptic pregnancies (n = 14) using real-time RT-PCR and western blot analysis.
  
  
  RESULTS
  In normal placentas, HLA-G protein expression reached a peak level at gestational weeks 6 and 7, then gradually decreased from week 8 to third trimester (p < 0.05). In preeclamptic placentas, both HLA-G mRNA and protein levels were decreased significantly in comparison with normal term placentas (p < 0.05).
  
  
  CONCLUSIONS
  HLA-G may contribute to placentation during early and mid-term pregnancy, and participate in maintaining gestation during term pregnancy. The reduced level of HLA-G may be associated with pathogenesis of preeclampsia.
authors.affiliation: Department of Obstetrics and Gynecology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, PR China. xiaomingzhu1981@hotmail.com
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Zhu
authors.forename: Tao
authors.initials: T
authors.lastname: Han
authors.forename: Guowu
authors.initials: G
authors.lastname: Yin
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Wang
authors.forename: Yuanqing
authors.initials: Y
authors.lastname: Yao
mesh_terms: D000328:Adult; D002824:Chorionic Villi / Q000378:metabolism*; D005260:Female; D059951:HLA-G Antigens / Q000378:metabolism*; D006801:Humans; D010929:Placentation; D011225:Pre-Eclampsia / Q000378:metabolism*; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D012333:RNA, Messenger / Q000378:metabolism; D055815:Young Adult
chemical_list: D059951:HLA-G Antigens; D012333:RNA, Messenger