title: Altered expression of claudin-3 and claudin-4 in ectopic endometrium of women with endometriosis.
abstract: OBJECTIVE
  To investigate the expression of claudin-3 and claudin-4 in the eutopic and ectopic endometrium of women with endometriosis and to evaluate the role of claudin-3 and claudin-4 in the pathogenesis of endometriosis.
  
  
  METHODS
  Cross-sectional measurement of gene expression levels of claudin-3 and claudin-4 on endometriotic tissue.
  
  
  METHODS
  Academic.
  
  
  METHODS
  Thirty-five patients with endometriosis and 35 healthy women who were free of endometriosis were recruited for the study.
  
  
  METHODS
  Expression of claudin-3 and claudin-4 were investigated with immunohistochemical analysis, Western blot, and real-time polymerase chain reaction. Morphologic change of tight junction was also observed in different kinds of endometria.
  
  
  METHODS
  The expression levels of claudin-3 and claudin-4 in epithelial cells from 35 ectopic endometrial tissues, 27 eutopic endometrial tissues from women with endometriosis, and 35 normal endometrial tissues from women without endometriosis.
  
  
  RESULTS
  Expression of claudin-3 and claudin-4 was significantly lower in the ectopic endometriotic tissue than in the eutopic endometrium from women with endometriosis and normal controls at both the messenger RNA and protein levels. No significant difference was found between eutopic endometrium from women with endometriosis and normal endometrium from women without endometriosis.
  
  
  CONCLUSIONS
  Down-regulated expression of claudin-3 and claudin-4 in ectopic endometrium suggests that claudin-3 and claudin-4 might play a pathogenic role in the formation of endometriosis.
authors.affiliation: Department of Obstetrics and Gynecology, China-Japan Friendship Hospital, Beijing, People's Republic of China. changpanxiaoyu@163.com
authors.forename: Xiao-Yu
authors.initials: XY
authors.lastname: Pan
authors.forename: Xue
authors.initials: X
authors.lastname: Li
authors.forename: Zhan-Ping
authors.initials: ZP
authors.lastname: Weng
authors.forename: Bo
authors.initials: B
authors.lastname: Wang
mesh_terms: D000328:Adult; D002828:Choristoma / Q000378:metabolism*; D062465:Claudin-3; D062506:Claudin-4; D003430:Cross-Sectional Studies; D004715:Endometriosis / Q000378:metabolism* / Q000473:pathology; D004717:Endometrium / Q000737:chemistry*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000032:analysis* / Q000235:genetics / Q000502:physiology; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis; D019108:Tight Junctions / Q000473:pathology
chemical_list: C568122:CLDN3 protein, human; C568157:CLDN4 protein, human; D062465:Claudin-3; D062506:Claudin-4; D008565:Membrane Proteins; D012333:RNA, Messenger