c‐fos and estrogen receptor gene expression pattern in the rat uterine epithelium during the estrous cycle

Abstract

Different studies in ovariectomized estrogen treated animals support the idea that cfos plays a role in the proliferation of uterine epithelial cells. However, these studies invite us to reassess the role played by c-fos in epithelial cell types of the endometrium during the estrous cycle. The present study was undertaken to determine the c-fos and estrogen receptor (ER) gene expression pattern in the rat uterine epithelium during the estrous cycle in which natural and cyclic changes of steroid hormones occur, and correlate these changes with the proliferation status of this cellular types. Proliferation was assessed during the estrous cycle using bromodeoxyuridine incorporation to DNA. ERa and b proteins were assessed by immunohistochemistry. The regulation of c-fos gene expression in the uterus of intact animals during the estrous cycle was evaluated using both in situ hybridization and immunohistochemistry. Estradiol (E 2 ) and progesterone (P 4 ) plasma levels were assessed by radioimmunoassay. The results indicated that luminal (LE) and glandular epithelia (GE) presented maximal proliferation during the metestrus (M) and the diestrus (D) days. However, during the proestrus (P) day only LE presented proliferation, and during the estrus (E) day only the stromal cells proliferated. A marked immunostaining for ERa was detected in both LE and GE cells during the early phases of the cycle but diminished on the P and the E day. In contrast, ERb was undetectable in both epithelia during all stages of the cycle. The highest cfos mRNA level was detected in both epithelia on the M day, followed by a significant reduction during the other days of the cycle. The highest protein content was observed on the M and D days, and the minimal value was detected on the E day. The c-Fos protein level in LE was increased during M and D days, presenting a high correlation with the cellular proliferation pattern of this cell type. In conclusion, the overall results indicate that c-Fos protein presented a good correlation with uterine epithelial cell proliferation of LE. In the case of GE, the same tendency was observed, although no significant correlation was found. Both in LE and GE, c-fos mRNA did not strictly correlate with its protein levels. c-fos seems to have a postranscriptional regulation in uterine epithelial cells during the rat's estrous cycle. Mol. Reprod. Dev. 64: 379-388,

Regulation of the immunoexpression of aquaporin 9 by ovarian hormones in the rat oviductal epithelium

“…On the other hand, P 4 administered after priming with E 2 or P 4 may trigger a mechanism to activate AQP translation. Similar posttranscriptional mechanisms have been proposed to occur in the estrous cycle-dependent expression of c-Fos in the rat uterine epithelium (36). Also, a posttranscriptional regulation of the E 2 -and P 4 -dependent expression of microtubule-associated protein-2 Fig.…”

Analysis of spatial and temporal expression patterns of bone morphogenetic protein family members in the rat uterus over the estrous cycle

“…Consistent with this idea is the expression of PR in the periluminal stroma (Ohta et al 1993). In the case of function, it is notable that DII is characterized by the highest rates of apoptosis in the endometrial epithelial cells (Spornitz et al 1994, Burroughs et al 2000, Mendoza-Rodríguez et al 2003. This, coupled with the ability of BMP-2 to cause apoptosis in target cells (Macias et al 1997, Song et al 1998, Kimura et al 2000, Hay et al 2001, Kawamura et al 2002, raises the possibility that the temporal pattern of BMP-2 expression could have a role in the regulation of epithelial apoptosis/proliferation during the cycle.…”

“…In normal cycling rodents (Katsuda et al 1999, Pelletier et al 2000, Wang et al 2000, Andersson et al 2001, Mendoza-Rodríguez et al 2003 and humans (Mertens et al 2001, Punyadeera et al 2003, ER is the dominant subtype expressed in the uterus, being localized to the epithelium, stroma, myometrium and some blood vessels. By comparison, ER is more weakly expressed.…”

Perfil de glicosaminoglicanos sulfatados no útero de camundongas durante o ciclo estral

“…Este achado muito provavelmente relaciona-se ao fato de que é nesta fase que se encontram aumentados os níveis de progesterona, sendo que ao seu final inicia-se o aumento do estradiol. De fato, sabe-se que é o diestro a fase em que ocorre maior proliferação dos epitélios luminal e glandular 17 .…”

“…Na área experimental, acreditamos que pesquisas realizadas em animais nas diferentes fases do ciclo estral permitiriam elucidar a ação dos hormônios esteróides (estrogênio e progesterona) sobre os componentes da matriz extracelular para podermos compreender melhor as patologias do trato reprodutivo [13][14][15][16][17] .…”