title: Aberrant claudin-4 transcript levels in eutopic endometrium of women with idiopathic infertility and minimal endometriosis.
abstract: BACKGROUND
  Claudin-4 (CLDN4) is a transmembrane protein, responsible for cellular contact and organization. A different expression of claudin 4 in the endometrium, depending on the menstrual cycle and with peak at the aim of the 'implantation window', has been observed. CLDN4 is believed to play an important role in embryo implantation.
  
  
  OBJECTIVE
  The aim of the study was to compare the mRNA CLDN4 expression levels in two subgroups of infertile women (idiopathic infertility or minimal endometriosis) and compare them to fertile controls.
  
  
  METHODS
  The study included 36 women with idiopathic infertility and 24 with minimal endometriosis. The control group comprised 26 women. Eutopic endometrium samples were collected with a Pipelle device during the implantation window. Firstly mRNA was extracted from the endometrium and reverse transcribed into cDNA. Real time PCR was used for the assessment of relative expression levels.
  
  
  RESULTS
  The observed transcription level of CLDN4 did not differ statistically between the studied groups, but was significantly higher when compared to controls.
  
  
  CONCLUSIONS
  Exceedingly high levels of CLDN4 might negatively influence fertility rates.
authors.affiliation: Department of Gynecology and Obstetrics, Division of Reproduction, Poznan University of Medical Sciences, Poland.
authors.forename: Mateusz
authors.initials: M
authors.lastname: Mikołajczyk
authors.forename: Przemysław
authors.initials: P
authors.lastname: Wirstlein
authors.forename: Jana
authors.initials: J
authors.lastname: Skrzypczak
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D062506:Claudin-4 / Q000235:genetics* / Q000378:metabolism; D004715:Endometriosis / Q000235:genetics* / Q000378:metabolism; D004717:Endometrium / Q000378:metabolism*; D005260:Female; D005298:Fertility / Q000235:genetics; D020869:Gene Expression Profiling; D006801:Humans; D007247:Infertility, Female / Q000235:genetics* / Q000378:metabolism; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics; D055815:Young Adult
chemical_list: D062506:Claudin-4; D012333:RNA, Messenger