Spatial and temporal expression profile of sex steroid receptors and antioxidant enzymes in the maternal-fetal interface of domestic cats

Molecular Factors Involved in the Reproductive Morphophysiology of Female Domestic Cat (Felis catus)

“…In the placenta, while ERα and PR were not observed in the trophoblast, the decidual giant cells showed intense expression at the end of pregnancy. In contrast, AR expression was observed in all placental cell types, with higher immunolabeling in mid-pregnancy compared to late pregnancy [27]. Interestingly, the decidual cells also more intensely express the genes encoding the steroidogenic acute regulatory protein (StAR) and 3βhydroxysteroid dehydrogenase/isomerase (3βHSD) enzymes in mid-to-late gestation [87], and domestic cat placental homogenates are able to produce P 4 , showing that the placenta acts as an additional source of P 4 during the final third of gestation [87,88].…”

“…In addition, in this study, the immunolabeling area of AR and PR did not differ in the uterus of pregnant and non-pregnant cats. However, the PR gene expression was higher in mid-pregnancy in relation to late pregnancy and the non-gestational diestrus, while no variations were observed in AR gene expression [27]. Interestingly, increased cytoplasmic immunolabeling of AR and reduced nuclear labeling in the luminal and glandular epithelium was observed in pregnant cats compared to nonpregnant cats, suggesting that pregnancy in cats alters the intracellular localization of AR since the receptor was translocated from the nucleus to the cytoplasm [27].…”

“…However, until recently, it was unknown whether pregnancy itself could influence the uterine expression of these receptors. In this regard, the study by de Jesus Nascimento et al [27] showed that ERα is upregulated in the endometrium and myometrium of domestic cats in mid-pregnancy when compared to the endometrium of cats in late pregnancy or in the non-gestational diestrus. In addition, in this study, the immunolabeling area of AR and PR did not differ in the uterus of pregnant and non-pregnant cats.…”

“…These hormones are called sex steroids and are mainly estrogens and P 4 , which also act on the organs of the female genital tract through their ER and PR receptors, respectively. However, recent studies in humans and other animal species have also demonstrated the importance of androgens, through signaling with their receptor (AR), in uterine morphophysiology [81,82], thus also suggesting its participation in the reproductive physiology of cats [25,27]. In the female cat, receptor expression for sex steroids has been well-documented in the uterus [25,83,84], in the ovary [84,85], and in the placenta [27].…”

“…Although the morphological changes and clinical signs that occur during the estrous cycle and pregnancy are well known, little is known about the molecular mechanisms involved in the reproductive physiology of this animal species. Studies conducted in the last decade with domestic cats have shown that several growth, hormonal, immunological, and redox factors are expressed differently in the uterus and ovary throughout the reproductive cycle [14,[18][19][20][21][22][23][24][25], as well as in the placenta throughout pregnancy [18,19,26,27]. Moreover, these studies show that changes in the expression of some of these factors are involved in the reproductive alterations observed in pyometra [14,[28][29][30] and in feline immunodeficiency virus (FIV) infection [31][32][33][34].…”