The Effects of Phytoestrogen Genistein on Steroidogenesis and Estrogen Receptor Expression in Porcine Granulosa Cells of Large Follicles

Abstract

NYNCA A., SADOWSKA A., ORLOWSKA K., JABLONSKA M., CIERESZKO R.E. 2015. The effects of phytoestrogen genistein on steroidogenesis and estrogen receptor expression in porcine granulosa cells of large follicles. Folia Biologica (Kraków) 63: 119-128. Genistein is a biologically active isoflavone with estrogenic or antiestrogenic activity which can be found in a variety of soy products. Since in pigs diet soy is the main source of protein, genistein may affect the reproductive/endocrine systems in these animals. Genistein has been shown to alter porcine ovarian and adrenal steroidogenesis but the mechanism of this action is still not clear. It is known that genistein binds to both estrogen receptor alpha (ERá) and estrogen receptor beta (ERâ), although it has a higher affinity to ERâ. Moreover, this phytoestrogen was demonstrated to posses the activity of protein tyrosine kinase (PTK)inhibitor. The aim of the study was to examine the in vitro effects of genistein on: (1) progesterone (P " ) and estradiol (E ) secretion by porcine luteinized granulosa cells harvested from large follicles, and (2) the mRNA and protein expression of ERá and ERâ in these cells.In addition, to verify the role of PTKdependent mechanisms possibly involved in genistein biological action, we tested the effects of lavendustin C, the nonsteroidal PTK inhibitor, on granulosa cell steroidogenesis. Genistein significantly inhibited P " and did not affect E secretion by porcine luteinized granulosa cells isolated from large follicles. Lavendustin C did not affect basal steroids secretion by examined cells. Genistein did not alter ERá but increased ERâ mRNA levels in the cultured porcine granulosa cells. In contrast to medium follicles, the expression of ERâ protein was unaffected by genistein in granulosa cells of large follicles. To conclude, the soy phytoestrogen genistein acts directly on the porcine ovary to decrease progesterone production and to increase the expression of ERâ mRNA.Moreover, genistein-induced changes in follicular steroidogenesis and granulosal sensitivity to estrogens in pigs may depend on maturity of the follicles.

Genistein exposure inhibits growth and alters steroidogenesis in adult mouse antral follicles

“…It is likely that our results differ from previous studies largely due to species differences in the effects of genistein on sex steroid hormone levels. Most previous studies were conducted with pigs (Gregoraszczuk et al , 1999; Nynca and Ciereszko, 2006; Tiemann et al , 2007; Basini et al , 2010; Nynca et al , 2015) or human cells (Whitehead et al , 2002; Lacey et al , 2005), whereas our study was conducted in mice. Further, our results likely differ from the other study conducted in mice (Jefferson et al , 2005) because of the differences in study design, such as in vitro vs in vivo experiments and pre-pubertal vs adult, non-pregnant exposure timing, as well as the differences in genistein concentrations.…”

“…One study indicates that neonatal genistein exposure (50 mg/kg/day) does not affect serum levels of progesterone or testosterone when measured before puberty and during pregnancy in mice (Jefferson et al , 2005). Additionally, genistein exposure (1, 18.5, and 185 μM) inhibits FSH-stimulated and basal progesterone levels in cultured porcine granulosa cells (Nynca and Ciereszko, 2006; Basini et al , 2010)), LH-stimulated progesterone secretion in porcine luteinized granulosa cells (0.5-50 μM; (Nynca et al , 2015)), and prolactin-stimulated progesterone secretion in porcine thecal cells (45 μM; (Gregoraszczuk et al , 1999)). Furthermore, genistein exposure (50 μM) inhibits the ability of primary porcine granulosa cells to produce progesterone (Tiemann et al , 2007).…”

The isoflavone daidzein directly affects porcine ovarian cell functions and modifies the effect of follicle‐stimulating hormone

“…The key biological active molecule of soya is the isoflavone daidzein, which possesses antioxidant (Ruiz‐Larrea et al., ; Choi and Kim, ) and oestrogenic activities (Cederroth et al., ). Daidzein binds oestrogen receptors α and β (ER α and ER β ) (Mense et al., ) and affects receptor expression (Nynca et al., , ). Daidzein treatment reduced progesterone (P4) release (Tiemann et al., ; Nynca et al., , ), but it did not affect estradiol production by porcine ovarian granulosa cells (Tiemann et al., ; Nynca et al., , ) or porcine Cumulus oophorus cells (Galeati et al., ).…”

“…Daidzein binds oestrogen receptors α and β (ER α and ER β ) (Mense et al., ) and affects receptor expression (Nynca et al., , ). Daidzein treatment reduced progesterone (P4) release (Tiemann et al., ; Nynca et al., , ), but it did not affect estradiol production by porcine ovarian granulosa cells (Tiemann et al., ; Nynca et al., , ) or porcine Cumulus oophorus cells (Galeati et al., ). Daidzein also increased the proliferation of human ovarian cancer cells (Schmitt et al., ) and chicken embryonic ovarian germ cells (Liu et al., ).…”

2,3,7,8-Tetrachlorodibenzo-p-dioxin alters steroid secretion but does not affect cell viability and the incidence of apoptosis in porcine luteinised granulosa cells

“…Ovarian morphology and follicular size were evaluated (Akins and Morrissette, 1968), and GCs were isolated from medium (3-6 mm) and preovulatory (≥ 8 mm) follicles (Nynca et al, 2009). Cell viability was determined by 0.4% trypan blue dye exclusion (≥ 97%) and the cells were resuspended in incubation medium: Eagle's medium with 10% calf serum (CS; Biomed, Lublin, Poland), 0.05 mg/ml gentamicin and 60 U/ml nystatin.…”