MON-012 The Direct Effect of Kisspeptin on Human Ovarian Granulosa Cells to Regulate Steroidogenesis

Abstract

Kisspeptin has a central role to stimulate the hypothalamic-pituitary-gonadal (HPG) axis. Furthermore, a previous study has suggested that kisspeptin might have a peripheral role in follicular development (1). This study aimed to 1) explore the effect of kisspeptin on CYP19A1 (aromatase) mRNA expression in human granulosa cells and aromatase concentrations in the supernatant; and 2) investigate the effect of kisspeptin on FSHR mRNA expression in human granulosa cells. In this study, human granulosa-like tumor cell line (KGN) (n=3) was incubated for 24 hours with FSH (10-8 M); FSH with IGF-1 (10-8 M); different doses of kisspeptin including 1, 10, 100, 1,000, and 10,000 nM; FSH with different doses of kisspeptin; and FSH with IGF-1 together with different doses of kisspeptin. FSH treatment alone or FSH with IGF-1 did not increase CYP19A1 mRNA expression when compared to control. Interestingly, kisspeptin treatment at the doses of 100 nM (P=0.028), 1,000 nM (P=0.005), and 10,000 nM (P=0.009) in the presence of FSH together with IGF-1 enhanced CYP19A1 mRNA expression when compared with control. Furthermore, FSH or FSH with IGF-1 or FSH with all doses of kisspeptin or FSH with IGF-1 together with all doses of kisspeptin increased aromatase concentrations in the supernatant when compared to control (P<0.01 all). Surprisingly, kisspeptin at the dose of 10,000 nM with FSH or FSH together with IGF-1 statistically increased aromatase concentrations in the supernatant when compared with FSH treatment alone or FSH with IGF-1 treatment (P<0.01 all). FSHR mRNA expression was comparable between control and all treatments. As a result, kisspeptin combined with FSH and IGF-1 could enhance CYP19A1 mRNA expression in human granulosa cells and the high dose of kisspeptin (10,000 nM) might be able to augment aromatase secretion in the supernatant. These results suggest that kisspeptin might enhance aromatase expression and secretion, which probably leads to enhance estrogen synthesis. Further studies regarding kisspeptin treatment on estrogen synthesis or secretion in human granulosa cells should be confirmed. Reference: (1) Fernandois D, et al. J Endocrinol. 2016;228(3):161-70.