X-Ray fluorescence imaging and other analyses identify selenium and GPX1 as important in female reproductive function

Abstract

Studies of selenium (Se) status indicate that Se is necessary for fertility but how precisely is not known. We aimed to show that Se was important in bovine female reproductive function. The elemental distribution in the bovine ovary (n = 45 sections) was identified by X-ray fluorescence (XRF) imaging. Se was consistently localized to the granulosa cell layer of large (>10 mm) healthy follicles. Inductively Coupled Plasma - Mass Spectrometry revealed tenfold higher Se in the bovine follicle wall compared to corpora lutea. Gene expression analysis of selenoprotein genes GPX1, GPX3, VIMP and SELM in bovine granulosa cells revealed that only GPX1 was significantly up-regulated in large healthy follicles compared to the small healthy or atretic follicles (P < 0.05). Western immunoblotting identified GPX1 protein in bovine granulosa cells of large healthy follicles, but not of small healthy follicles. To assess if GPX1 was important in human follicles, cumulus cells from women undergoing IVF/ICSI with single embryo transfer were collected. Oocytes and embryos were cultured and transferred independently in 30 patients undergoing elective single embryo transfer. Gene expression of GPX1 was significantly higher in human cumulus cells from cumulus-oocyte complexes yielding a pregnancy (P < 0.05). We present the first XRF imaging of mammalian ovaries showing that Se is consistently localized to the granulosa cells of large healthy follicles. We conclude that Se and selenoproteins are elevated in large healthy follicles and may play a critical role as an antioxidant during late follicular development.

Dietary Selenium Supplementation Ameliorates Female Reproductive Efficiency in Aging Mice

“…Dietary deficiency of essential trace elements such as Se has been shown to impair the mammalian reproductive physiology [9,10,28]. In a well-known previous study on 112 patients undergoing in vitro fertilization (IVF) procedures, Paszkowski and colleagues [29] reported that detectable traces of Se were observed in human follicular fluid, and it was shown that subjects with idiopathic infertility had significantly lower Se levels compared to those who were suffering from known causes of infertility.…”

“…However, despite past evidence of Se implication in female fertility and reproduction, there are more studies focusing on the role of Se in male reproduction [10]. There is still a comparative dearth of adequately powered mechanistic and functional studies elucidating the wider implications of Se and selenoproteins in female fertility and reproduction [9,28]. Available evidence highlights that studies focusing on role of Se as an essential trace element in female reproduction are mainly focused on human pregnancy [30] and related complications such as pre-eclampsia [31], miscarriage and preterm birth [9,32], intrauterine growth restriction [33], small-for-gestational age newborns [34], pregnancy-induced hypertension [35], and pregnancy-related autoimmune thyroid disease [36].…”

“…It was shown that Se was implicated in regulating the physiology of uterine smooth muscles potentially via modulating the expression of Selenon, Selenot, and Selenow [41,42], and the G protein Rho (RhoA)/Rho kinase (ROCK) signaling pathway in mice [43]. However, only recently have researchers paid attention to potential role of Se in ovarian physiology and embryo development [9,28,[44][45][46][47][48][49][50]. Interestingly, when exploring the mainstream literature, with the exclusion of one study reporting the beneficial effects of Se supplementation on sperm parameters in aging mice [51], no study has yet elucidated how Se might ameliorate the reproductive function in aging mammalian models, let alone the aged females.…”

2015 Atomic Spectrometry Update – a review of advances in X-ray fluorescence spectrometry and their applications

“…Ceko et al 386 aimed to show that Se is important in the bovine female reproductive function. This state-of-the-art paper included as well as nomenclature, denitions, as examples of calibration strategies with analytical calibration procedures.…”

Maximum‐likelihood approaches reveal signatures of positive selection in BMP15 and GDF9 genes modulating ovarian function in mammalian female fertility

“…However, the oocyte development within the follicular structure involves uninterrupted two‐way dialogs between the oocyte and cumulus complex, as well as the other somatic cells in the follicles, such as the granulosa and theca cells (Wigglesworth et al., 2013). The granulosa cells are important components of the follicular environment for the achievement of oocyte capability, ovulation, and fertilization as they regulate the expression of luteinizing hormone receptor (LHR), production of estradiol and progesterone, Inhibin A and B secretion, and production of several transcripts vital proteins (Ceko et al., 2014; Hatzirodos et al., 2014). The bone morphogenetic protein 15 and growth differentiation factor 9, belong to the TGF‐β superfamily, act on the granulosa cells to regulate oocyte growth and differentiation.…”