Ciliated epithelial-specific and regional-specific expression and regulation of the estrogen receptor-beta2 in the fallopian tubes of immature rats: a possible mechanism for estrogen-mediated transport process in vivo.
Several ERbeta isoforms have been identified in human and rodent tissues, but it is unclear whether each isoform has distinctly different cellular targeting characteristics and physiological functions. We have investigated the intracellular localization and regulatory patterns for ERbeta isoforms in rat fallopian tubes. Western blot analysis reveals that two ERbeta isoforms corresponding to ERbeta1 and ERbeta2 are expressed in rat fallopian tubes. However, ERbeta2 is the predominant form of ERbeta in this tissue. High-resolution confocal imaging and immunohistochemical analysis provide ample evidence that ERbeta expression is limited almost exclusively to the ciliated epithelial cells, in contrast to ERalpha, which is widely distributed. Furthermore, within the ciliated epithelial cells, ERbeta is colocalized with beta-tubulin IV at stem portion of the cilia. We show that ERbeta2 protein expression is tightly regulated by E(2) or DPN in a time-dependent manner without changes in ERbeta1 expression. These estrogenic effects are inhibited by an ER antagonist, ICI 182,780. In addition, significant alteration of ERbeta immunoreactivity is detected only histologically in the ampullary region. Since the cilia are considered an essential determinant of tubal transport, we further demonstrate that E(2)- or DPN-induced ERbeta2 activation is associated with alterations in tubal protein expression crucial for the regulation of calcium-dependent ciliary beating. Given the coordinated regulation and interaction of ER and progesterone receptor in the cilia, we hypothesize that tubal ERbeta2 may facilitate the estrogen-mediated transport process by processing protein-protein interaction under physiological and/or pathological conditions. We show for the first time that a previously unrecognized localization of ERbeta isoform in rat fallopian tubes can combine with estrogen to individually control the expression of ER beta-isoforms in normal target tissues.
Shao
Ruijin
R
Instiute of Neuroscience and Physiology, The Sahlgrenska Academy at Gothenburg University, SE-41390 Gothenburg, Sweden. ruijin.shao@fysiologi.gu.se
Weijdegård
Birgitta
B
Fernandez-Rodriguez
Julia
J
Egecioglu
Emil
E
Zhu
Changlian
C
Andersson
Niklas
N
Thurin-Kjellberg
Ann
A
Bergh
Christina
C
Billig
Håkan
H
D000818:Animals; D002923:Cilia / Q000378:metabolism; D004848:Epithelium / Q000378:metabolism*; D004958:Estradiol / Q000494:pharmacology*; D047629:Estrogen Receptor beta / Q000235:genetics* / Q000378:metabolism*; D005187:Fallopian Tubes / Q000378:metabolism*; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D009928:Organ Specificity; D011374:Progesterone / Q000494:pharmacology; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D012741:Sexual Maturation / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects; D014018:Tissue Distribution
D047629:Estrogen Receptor beta; D020033:Protein Isoforms; D011374:Progesterone; D004958:Estradiol