title: Differential expression and localization of CFTR and ENaC in mouse endometrium during pre-implantation.
abstract: Interaction between the cystic fibrosis transmembrane conductance regulator (CFTR), a CAMP-activated Cl- channel, and epithelial Na+ channel (ENaC) has been proposed as the major mechanism regulating uterine fluid absorption and secretion. Differential expression of these ion channels may give rise to dynamic changes in the fluid environment affecting various reproductive events in the female reproductive tract. This study investigated the expression and localization of CFTR and ENaC during the pre-implantation period. Semi-quantitative reverse transcriptase polymerase chain reaction and immunohistochemistry were used to study the expression and localization of CFTR and ENaC in uteri collected from mature superovulated female mice. RT-PCR showed maximal ENaC and CFTR expression on day 3 after mating. Maximal immunoreactivity was also observed for both ENaC and CFTR on day 3 after mating. However, ENaC was immunolocalized to the apical membrane of both luminal and glandular epithelia, while CFTR was predominantly found in the stromal cells rather than the epithelial cells. Differential expression and localization of CFTR and ENaC provide a molecular mechanism by which maximal fluid absorption can be achieved immediately prior to implantation, to ensure the immobilization of the blastocyst necessary for implantation.
authors.affiliation: Epithelial Cell Biology Research Center, Department of Physiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR.
authors.forename: Jian Zhi
authors.initials: JZ
authors.lastname: Yang
authors.forename: Louis Chukwuemeka
authors.initials: LC
authors.lastname: Ajonuma
authors.forename: Lai Ling
authors.initials: LL
authors.lastname: Tsang
authors.forename: Sun Yee
authors.initials: SY
authors.lastname: Lam
authors.forename: Dewi Kenneth
authors.initials: DK
authors.lastname: Rowlands
authors.forename: Lok Sze
authors.initials: LS
authors.lastname: Ho
authors.forename: Chen Xi
authors.initials: CX
authors.lastname: Zhou
authors.forename: Yiu Wa
authors.initials: YW
authors.lastname: Chung
authors.forename: Hsiao Chang
authors.initials: HC
authors.lastname: Chan
mesh_terms: D000818:Animals; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000032:analysis / Q000235:genetics* / Q000378:metabolism*; D010064:Embryo Implantation; D004717:Endometrium / Q000166:cytology / Q000378:metabolism*; D053503:Epithelial Sodium Channels; D005260:Female; D005786:Gene Expression Regulation; D007150:Immunohistochemistry; D051379:Mice; D008813:Mice, Inbred ICR; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D015222:Sodium Channels / Q000032:analysis / Q000235:genetics* / Q000378:metabolism*; D014599:Uterus / Q000378:metabolism / Q000502:physiology / Q000648:ultrastructure
chemical_list: D053503:Epithelial Sodium Channels; D012333:RNA, Messenger; D015222:Sodium Channels; D019005:Cystic Fibrosis Transmembrane Conductance Regulator