LacZ expression in Fut2-LacZ reporter mice reveals estrogen-regulated endocervical glandular expression during estrous cycle, hormone replacement, and pregnancy

Abstract

The secretor gene (FUT2) encodes an alpha(1,2)fucosyltransferase (E.C. 2.4.1.69) that elaborates alpha(1,2)fucose residues on mucosal epithelium and secreted mucins. Though uterine alpha(1,2)fucosylated glycans have been proposed to be involved in embryo adhesion, mice with a homozygous null mutation of Fut2 displayed normal fertility. To help develop alternative hypotheses for function, the cell type and regulation of Fut2 expression during the estrous cycle, hormone replacement, and pregnancy was examined in Fut2-LacZ reporter mice containing targeted replacement of Fut2 with bacterial lacZ. LacZ expression in the reproductive tract of Fut2-LacZ mice is most prominent in the glandular epithelium of the endocervix during estrus and pregnancy. Nuclear LacZ expression identifies cell-specific expression of Fut2 in mucus-secreting cells of the endocervix, uterine glands, foveolar pit and chief cells of the stomach, and goblet cells of the colon. In ovariectomized Fut2-LacZ mice, estradiol treatment stimulates X-gal staining in endocervix and uterus but does not affect expression in stomach and colon. Northern blot analysis in wild-type mice shows 15-fold elevations of Fut2 steady-state mRNA with estradiol treatment, whereas Fut1 varies little. Fut2 levels in the glandular stomach and distal colon remain constant, and uterine Fut2 levels vary eightfold during the estrous cycle. These data represent the first demonstration of a glycosyltransferase gene under tissue-specific hormonal regulation in a LacZ reporter mouse model. Endocervical expression of Fut2 in estrus and pregnancy may modify cervical mucus barrier properties from microbial infection analogous to the potential role of mucosal glycans in humans.

Characterisation of mouse interferon-induced transmembrane protein-1 gene expression in the mouse uterus during the oestrous cycle and pregnancy

“…The general protocol used for ovariectomy was adapted from that described by Domino and Hurd (2004). Briefly, four different hormones were injected into OVX mice as follows: 10 mg kg À1 oestradiol (Sigma-Aldrich Korea), 30 mg kg À1 P4 (Sigma-Aldrich Korea), 160 IU kg À1 hCG and 160 IU kg À1 PMSG.…”

Blood Groups in Infection and Host Susceptibility

“…Animal studies also support Secretor as a protective host factor against Candida vaginitis. FUT2 is expressed by endocervical glands and ectocervical squamous cells, which synthesize mucins bearing Le b and H-active epitopes (225,226). In FUT2-null mice, there is a selective loss of H-active mucins, although mucins with Le a and Le X activity are still synthesized and secreted (226).…”

“…This increase could be eliminated by intravaginal administration of H-active mucins or by surgical removal of the cervix through hysterectomy (227). It is important to note that FUT2 is upregulated by estrogen (225)(226)(227)(228): Estrogen is required for Candida proliferation and adhesion in vivo, possibly through modulation of host-microbe interactions (226,229).…”

Immunoregulation of fetal and anti-paternal immune responses

“…In the FRT, estradiol drives the proliferation of uterine and vaginal epithelial cells [19] also the expression of mucin genes and secretion of mucus from goblet cells [20]. During estrus in mice the vagina is thought to be an immunosuppressive site [21], however, the frequencies of MHC II positive macrophages and DC in the estrous vagina and uteri are as high or higher than during diestrous [22,23].…”