Effects of Kiss2 on the Expression of Gonadotropin Genes in the Pituitary of Nile Tilapia (<i>Oreochromis niloticus</i>).
Park. Jin Woo JW; Kim. Jung-Hyun JH; Kwon. Joon Yeong JY
Key Findings
- High kisspeptin (>0.1 µM) for 3 h boosted fshβ mRNA but not lhβ in tilapia pituitary.
- At 0.1 µM, kisspeptin raised both fshβ and lhβ mRNA after 6 h exposure.
- LHRH alone increased both hormone genes more strongly, and adding kisspeptin gave no extra benefit.
Practical Outcomes
- For human biohackers, the results don’t translate into a clear, actionable protocol. It shows kisspeptin can affect reproductive hormone signals, but the optimal dose, timing, and relevance to people remain unknown, so more research is needed before practical use.
Summary
The study tested kisspeptin‑10 on fish pituitary tissue and found it can modestly raise the gene activity for reproductive hormones (FSH and LH) under specific doses and timing, but the effects are weaker and more complicated than expected, especially compared to the classic hormone LHRH.
Abstract
Kisspeptin, expressed mainly in the hypothalamus, stimulates gonadotropin-releasing hormone neurons to facilitate reproduction. In some model animals, the kisspeptin is also expressed in the pituitary. Recently, a pathway has been suggested in which kisspeptin acts directly on the pituitary to secretion of gonadotropin in mammals. In the present study, pituitaries of the Nile tilapia (<i>Oreochromis niloticus</i>) were cultured at different concentrations of kisspeptin-10 (Kp-10, FNYNPLSLRF) for 3 hours to observe the effect of kisspeptin on the expression of follicle-stimulating hormone β subunit (<i>fshβ</i>) gene and luteinizing hormone β subunit (<i>lhβ</i>) gene. Pituitary tissues were cultured with 0.1 μM of Kp-10, luteinizing hormone releasing hormone (LHRH), or LHRH+Kp-10 for 3, 6, 12, and 24 hours to investigate changes in the expression of <i>fshβ</i> and <i>lhβ</i> mRNA. Pituitaries cultured with high concentration of Kp-10 more than 0.1 μM for 3 hours exhibited a significant increase of <i>fshβ</i> mRNA expression, but not <i>lhβ</i> mRNA. The expression of both <i>fshβ</i> and <i>lhβ</i> mRNA increased after 6 hours in 0.1 μM of Kp-10 medium in comparison with that in the control medium. Tissues cultured in the LHRH medium however exhibited increased expression of both genes not only at 6 but also 12 hours. There were no significant differences of <i>fshβ</i> and <i>lhβ</i> gene expression in tissues cultured with LHRH+KP-10 medium compared with the control. These results suggested that although kisspeptin plays an important role in <i>fshβ</i> and <i>lhβ</i> expression in the pituitary of Nile tilapia, its action is far more complicated than expected.
Study Information
pubmed
2020
2020-09-30T00:00:00.000Z
10.12717/dr.2020.24.3.149