Pyometra alters the redox status and expression of estrogen and progesterone receptors in the uterus of domestic cats

Abstract

Objectives The aim of this study was to evaluate the expression profile of sex steroid receptors and redox mediators in the uterus of domestic cats with pyometra. Methods Twelve cats were used and divided into groups: (1) non-gestational healthy diestrus (n = 7) and (2) pyometra (n = 5). The plasma profiles of estradiol and progesterone (P4) as well as uterine expression levels of estradiol alpha (ERα), progesterone (PR) and androgen (AR) receptors, of the antioxidant enzymes superoxide dismutase 1 (SOD1), catalase and glutathione peroxidase 1 (GPX1), and of the oxidative damage marker 8-hydroxy-2′-deoxyguanosine (8-OHdG) were evaluated. Results Cats with pyometra showed higher plasma P4 levels and increased uterine messenger RNA (mRNA) and protein expression of ERα and PR, mainly in the glandular epithelium for ERα and in stromal and myometrial cells for PR. In addition, there was an increase in 8-OHdG immunostaining and GPX1 mRNA and protein expression in cats with pyometra compared with those in non-gestational diestrus, while catalase showed a reduction in endometrial immunostaining in cats with pyometra. There were no differences in uterine AR and SOD1 expression between the groups. Conclusion and relevance The findings of this study showed that pyometra is associated with oxidative stress in the uterus of domestic cats and alterations of the profile of sex steroid receptors, especially ERα and PR, and of antioxidant enzymes, suggesting that changes in these mediators may play a role with the etiopathogenesis of this disease.

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

“…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]. Thus, this paper reviews the current knowledge about the modulation and expression profiles of hormonal, immunological, redox, and growth mediators in the uterus, ovary, and placenta of domestic cats throughout the estrous cycle and during pregnancy.…”

“…In addition, a positive correlation between the genes SOD1 and progesterone (PR) receptor was observed in the uterus of these animals, suggesting that SOD1 expression may be modulated by P 4 . In the subsequent study, de Jesus Nascimento et al [30] showed a trend of increasing the SOD1 gene in uterine samples of cats with pyometra, which showed an increase in P 4 concentration. This study also demonstrated that pyometra reduces the endometrial expression of CAT, positively regulates the gene and protein expression of GPX1, and increases the expression of 8-hydroxyl-2'-deoxyguanosine (8-OhdG), which is an indicator of oxidative DNA damage [179].…”

“…Several hormonal, immunological, redox, and growth mediators are fundamental in the morphophysiology of the female genital system and participate in various processes of the reproductive cycle and pregnancy [58][59][60][61]. Thus, changes in the expression of these mediators have been observed in several pathological conditions in both women and animals, such as recurrent abortion [62,63], preeclampsia [64,65], premature birth [66,67], and pyometra [14,[28][29][30], which can not only result in subfertility or infertility but also cause the death of the individual.…”