Granulosa cell proliferation is inhibited by PGE2 in the primate ovulatory follicle

Trans 10, cis 12-conjugated linoleic acid reduced reproductive ability by disrupting the estrus cycle in female mice

As a positional and geometrical isomer of linoleic acid, trans 10, cis 12 conjugated linoleic acid (t10c12-CLA) reduces white fat by reducing food intake, modulating lipid metabolism, and stimulating energy expenditure. However, the t10c12-CLA products are mostly mixtures, making it difficult to obtain accurate results. Studies are needed to investigate the effects of pure t10c12-CLA on animals and humans. In this study, we used the biallelic transgenic (tg) mice, which could produce t10c12-CLA itself, to investigate the effects of pure t10c12-CLA on female reproductive ability. The results showed that the body and relative ovary weights had no significant difference between tg and wild-type (wt) littermates at ages 3 or 10 weeks. While the fecundity test found that tg mice had a significantly longer first litter time (32.0 ± 4.70 days vs. 21.3 ± 2.31 days, P<0.05), and a significantly lower number of litters (4.75 ± 2.75 vs. 6.67 ± 0.57, P<0.05) when compared with wt mice during continuous mating within seven months. Hormone profiles showed that serum estradiol levels did not change in tg mice; however, significantly (P<0.05) decreased progesterone and increased prostaglandin E2 levels were observed in tg mice compared with those of wt mice. Hematoxylin-eosin staining showed no pathological characteristics in tg ovaries, except for the increased atresia follicles (P<0.05). Moreover, the tg mice had a significantly more extended diestrus period than the wt mice (48.4 ± 6.38% vs. 39.6 ± 3.81%, P<0.05). In summary, t10c12-CLA could affect serum progesterone and prostaglandin E2 levels, lead to a disordered estrus cycle, and impact the reproductive performance of female mice. This study provided theoretical and biosafety recommendations for applying t10c12-CLA in female mammals.

The SLC19A1-AS/miR-1343/WNT11 axis is a novel positive regulatory ceRNA network governing goat granulosa cell proliferation

Long noncoding RNAs (lncRNAs), as competitive endogenous RNAs (ceRNAs), can directly or indirectly affect the proliferation and apoptosis of granulosa cells by regulating microRNA (miRNA) pathways. A ceRNA network of the SLC19A1-AS-miR-1343-WNT11 axis was constructed via comprehensive transcriptome sequencing of ovaries from goats with various fertility levels to further elucidate the function and regulatory mechanism of SLC19A1-AS in modulating miR-1343 and WNT11 during granulosa cell proliferation and apoptosis. Subsequent validation experiments were conducted in vitro using granulosa cells. In these experiments, we performed RNA immunoprecipitation (RIP) and identified SLC19A1-AS as a ceRNA in goat granulosa cells that promoted proliferation. Through bioinformatics prediction, luciferase reporter gene assays, and RNA pulldown assays, we confirmed that SLC19A1-AS acts as a sponge for miR-1343, preventing its binding to WNT11 mRNA and thereby increasing the expression of WNT11. This interaction also influenced the proliferation and apoptosis of granulosa cells. Our study systematically validated the biological function of the lncRNA-miRNA-mRNA ceRNA network in goat ovaries and revealed the potential regulatory mechanism by which SLC19A1-AS functions as a ceRNA in granulosa cells. These findings are expected to provide an important experimental foundation for further elucidating the physiological regulatory network of the ovary and contributing to reproductive health in goats.

Luteinizing hormone-like and follicle-stimulating hormone-like activities of equine chorionic gonadotropin β-subunit mutants in cells expressing rat luteinizing hormone/chorionic gonadotropin receptor and rat follicle-stimulating hormone receptor

To identify the specific region of eCG involved in FSH-like activity, the following mutant expression vectors were constructed targeting the amino acid residues 102–104 of the eCG β-subunit: single mutants, eCGβV102G/α, eCGβF103P/α, and eCGβR104K/α; double mutants, eCGβV102G;F103P/α, eCGβV102G;R104K/α, and eCGβF103P;R104K/α; triple mutant, eCGβV102G;F103P;R104K/α. The LH-like and FSH-like activities of eCG mutants were examined in CHO-K1 cells expressing rat LH/CG receptor and rat FSH receptor. The levels of eCGβV102G/α, eCGβR104K/α, and eCGβV102G;R104K/α in the culture supernatant were markedly lower than those of eCGβ/α-wt. The other mutants and rec-eCGβ/α-wt were efficiently secreted into the culture supernatant. The LH-like activities of eCGV104G/α, eCGβV102G;R104K/α, and eCGβF103P;R104K/α were approximately 61%, 52%, and 54%, respectively, of those of eCG-wt. The Rmax values of the mutants were 58.9%–78.8% those of eCG-wt with eCGβR104K/α exhibiting the lowest value. The FSH-like activities of single mutants were only 16%–20% of those of eCG-wt. Additionally, the FSH-like activity of double mutants was less than 10% of that of eCG-wt. In particular, the FSH-like activities of βV102G;R104K/α and βF103P;R104K/α were 2.5–2.9% of that of eCG-wt. These results suggest that the amino acid residues 102–104 of the eCG β-subunit are dispensable and that the residue 104 of the eCG β-subunit plays a pivotal role in signal transduction through the rat FSH receptor. Thus, these mutants may aid future studies on eCG interactions with mammalian FSH receptors in vitro and in vivo.