Mutual Interactions Between GnRH and Kisspeptin in GnRH- and Kiss-1-Expressing Immortalized Hypothalamic Cell Models

• Published in: Reproductive sciences (Thousand Oaks, Calif.) Calif.), 2021-12, Vol.28 (12), p.3380-3389
• Main Authors: Kanasaki, Haruhiko, Tumurbaatar, Tuvshintugs, Tumurgan, Zolzaya, Oride, Aki, Okada, Hiroe, Kyo, Satoru
• Format: Article
• Language: English
• Subjects: Animals; Cell Line, Transformed; Cells, Cultured; Embryology; Female; Fetus; Gene Expression Regulation, Developmental - physiology; Gonadotropin-Releasing Hormone - metabolism; Hypothalamus - cytology; Hypothalamus - growth & development; Hypothalamus - metabolism; Kisspeptins - metabolism; Medicine; Medicine & Public Health; Obstetrics/Perinatology/Midwifery; Protein Binding - physiology; Rats; Reproductive Endocrinology; Original Article; Reproductive Medicine
• ISSN: 1933-7191; 1933-7205
• DOI: 10.1007/s43032-021-00695-z

Kisspeptin and gonadotropin-releasing hormone (GnRH) are central regulators of the hypothalamic-pituitary-gonadal axis and control female reproductive functions. Recently established mHypoA-50 and mHypoA-55 cells are immortalized hypothalamic neuronal cell models that originated from the anteroventral periventricular nucleus (AVPV) and arcuate nucleus (ARC) regions of the mouse hypothalamus, respectively. mHypoA-50 or mHypoA-55 cells were stimulated with kisspeptin-10 (KP10) and GnRH, after which the expression of kisspeptin and GnRH was determined. Primary cultures of fetal rat brain cells were also examined. mHypoA-50 and mHypoA-55 cells expressed mRNA for Kiss-1 (which encodes kisspeptin) and GnRH as well as receptors for kisspeptin and GnRH. We found that Kiss-1 mRNA expression was significantly increased in mHypoA-50 AVPV cells by KP10 and GnRH stimulation. Kisspeptin protein expression was also increased by KP10 and GnRH stimulation in these cells. In contrast, GnRH expression was unchanged in mHypoA-50 AVPV cells by KP10 and GnRH stimulation. In mHypoA-55 ARC cells, kisspeptin expression was also significantly increased at the mRNA and protein levels by KP10 and GnRH stimulation; however, GnRH expression was also upregulated by KP10 and GnRH stimulation in these cells. KP10 and estradiol (E2) both increased Kiss-1 gene expression in mHypoA-50 AVPV cells, but combined stimulation with KP10 and E2 did not potentiate their individual effects on Kiss-1 gene expression. On the other hand, E2 did not increase Kiss-1 gene expression in mHypoA-55 ARC cells, and the KP10-induced increase of Kiss-1 gene expression was inhibited in the presence of E2 in these cells. KP10 and GnRH significantly increased c-Fos protein expression in the mHypoA-50 AVPV and mHypoA-55 ARC cell lines. In primary cultures of fetal rat neuronal cells, KP10 significantly increased Kiss-1 gene expression, whereas GnRH significantly increased GnRH gene expression. We found that kisspeptin and GnRH affected Kiss-1- and GnRH-expressing hypothalamic cells and modulated Kiss-1 and/or GnRH gene expression with a concomitant increase in c-Fos protein expression. A mutual- or self-regulatory system might be present in Kiss-1 and/or GnRH neurons in the hypothalamus.