Expression and effect of resistin on bovine and rat granulosa cell steroidogenesis and proliferation

Abstract

Resistin, initially identified in adipose tissue and macrophages, was implicated in insulin resistance. Recently, its mRNA was found in hypothalamo-pituitary axis and rat testis, leading us to hypothesize that resistin may be expressed in ovary. In this study, we determined in rats and cows 1) the characterization of resistin in ovary by RT-PCR, immunoblotting, and immunohistochemistry and 2) the effects of recombinant resistin (10, 100, 333, and 667 ng/ml)GIGF1 (76 ng/ml) on steroidogenesis, proliferation, and signaling pathways of granulosa cells (GC) measured by enzyme immunoassay, [3 H]thymidine incorporation, and immunoblotting respectively. We observed that resistin mRNA and protein were present in several bovine and rat ovarian cells. Nevertheless, only bovine GC abundantly expressed resistin mRNA and protein. Resistin treatment decreased basal but not IGF1-induced progesterone (P!0.05; whatever the dose) and estradiol (P!0.005; for 10 and 333 ng/ml) production by bovine GC. In rats, resistin (10 ng/ml) increased basal and IGF1-induced progesterone secretion (P!0.0001), without effect on estradiol release. We found no effect of resistin on rat GC proliferation. Conversely, in cows, resistin increased basal proliferation (P!0.0001; for 100-667 ng/ml) and decreased IGF1-induced proliferation of GC (P!0.0001; for 10-333 ng/ml) associated with a decrease in cyclin D2 protein level (P!0.0001). Finally, resistin stimulated AKT and p38-MAPK phosphorylation in both species, ERK1/2-MAPK phosphorylation in rats and had the opposite effect on the AMPK pathway (P!0.05). In conclusion, our results show that resistin is expressed in rat and bovine ovaries. Furthermore, it can modulate GC functions in basal state or in response to IGF1 in vitro.

Resistin is a survival factor for porcine ovarian follicular cells

“…The first indication that resistin was involved in the regulation of the female reproductive system may be the discovery that resistin was expressed in rat ovaries throughout the oestrous cycle and was elevated in animals with induced ovarian cysts (Jones et al 2009). Subsequent study demonstrated resistin expression in ovarian cells of bovine (Maillard et al 2011), pigs , humans (Niles et al 2012, Reverchon et al 2013b) and the vespertilionid bat (Singh et al 2015). We demonstrated that both gonadotropins and steroid hormones significantly stimulated, while insulin growth factor type 1 (IGF1) and a synthetic agonist of PPARg reduced resistin expression and secretion by cultured porcine ovarian follicles, indicating that ovarian resistin expression can be regulated by several factor (Rak-Mardyła & Drwal 2015.…”

“…We demonstrated that both gonadotropins and steroid hormones significantly stimulated, while insulin growth factor type 1 (IGF1) and a synthetic agonist of PPARg reduced resistin expression and secretion by cultured porcine ovarian follicles, indicating that ovarian resistin expression can be regulated by several factor (Rak-Mardyła & Drwal 2015. Moreover, resistin ovarian expression is a species difference, with both granulosa and thecal cell expression in the cow, but only thecal cell expression in the rat (Maillard et al 2011). These species differences likely account for the differences in steroidogenesis observed.…”

The effect of nutrition and metabolic status on the development of follicles, oocytes and embryos in ruminants

“…Resistin is also present in the bovine ovaries (Table 1). Furthermore, human recombinant resistin decreases basal but not IGF-I-induced progesterone and oestradiol production by the bovine granulosa cells (Maillard et al, 2011). Spicer et al (2011), have also observed that resistin preferentially inhibited steroidogenesis in the granulosa cells from small follicles and inhibited proliferation of the granulosa cells from large follicles, suggesting that the ovarian response to resistin is altered during follicular development.…”

Adiponectine et résistine

“…Certains variants et haplotypes identifiés sont associés à des tailles de portées plus grandes, un plus petit nombre de porcelets mort-nés et momifiés, et un intervalle sevrage-oestrus plus court [31]. La résistine est présente dans le liquide folliculaire, l'ovocyte, les cellules de la thèque et le corps jaune chez la rate et la vache [32]. Contrairement à la rate, elle est retrouvée dans les cellules de la granulosa production des stéroïdes par les cellules de la thèque en réduisant l'expression des récepteurs de la LH et des enzymes CYP11a1 (cytochrome P450, famille 11, sous-famille a, polypeptide 1) et CYP17a1 (cytochrome P450, famille 17, sous-famille a, polypeptide 1) [28].…”

“…Dans les cellules de thèques humaines en culture, la résistine augmente l'expression de la 17-α-hydroxylase en présence de forskoline et/ou de forskoline + insuline, suggérant un rôle de la résistine dans la production d'androgènes [33]. Chez la vache et la rate, la résistine module différemment la steroïdogenèse et la prolifération des cellules de la granulosa en réponse à l'IGF-1, suggérant un effet dépendant de l'espèce [32].…”