Nesfatin-1 regulates the hypothalamo-pituitary-ovarian axis of fish.
Nesfatin-1 is an anorexigen in goldfish. In the present study, we provide novel data indicating the presence and regulatory effects of nesfatin-1 on the hypothalamo-pituitary-ovarian (HPO) axis of goldfish. Nucleobindin-2 (NUCB2)/nesfatin-1-like immunoreactive (ir) cells are present in the hypothalamus and in the pituitary, suggesting a hypophysiotropic role for nesfatin-1. NUCB2/nesfatin-1-like ir cells colocalize gonadotropin-releasing hormone (GnRH) in the nucleus lateralis tuberis posterioris and the nucleus anterior tuberis of the goldfish hypothalamus. The presence of nesfatin-1 with GnRH in these two nuclei implicated in pituitary hormone release suggests a role for nesfatin-1 on gonadotropin secretion. A single i.p. injection of synthetic goldfish nesfatin-1 (50 ng/g body wt) resulted in an acute decrease (∼75%) in the expression of hypothalamic chicken GnRH-II and salmon GnRH mRNAs at 15 min postinjection in goldfish. Meanwhile, pituitary luteinizing hormone (LH) beta and follicle-stimulating hormone beta mRNAs were also inhibited (∼80%), but only at 60 min postinjection. Nesfatin-1 administration also resulted in a significant reduction (∼60%) in serum LH levels at 60 min postadministration. Nesfatin-1-like immunoreactivity was also found in the follicle cells, but not the oocytes, in zebrafish and goldfish ovaries. Incubation of zebrafish follicles with nesfatin-1 resulted in a significant reduction in basal germinal vesicle breakdown (∼50%) during the oocyte maturation. In addition, nesfatin-1 also attenuated the stimulatory effects of maturation-inducing hormone on germinal vesicle breakdown. Together, the current results indicate that nesfatin-1 is a metabolic hormone with an inhibitory tone on fish reproduction. Nesfatin-1 appears to elicit this suppressive effect through actions on all three tissues in the fish HPO axis.
Laboratory of Integrative Neuroendocrinology, Department of Biology, York University, Toronto, Ontario, Canada.
Ronald
R
Gonzalez
Erin
E
Shepperd
Vetri
V
Thiruppugazh
Sneha
S
Lohan
Caleb L
CL
Grey
John P
JP
Chang
Suraj
S
Unniappan
D000818:Animals; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology*; D005260:Female; D005399:Fishes / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D005640:Follicle Stimulating Hormone / Q000097:blood / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006054:Goldfish / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D007987:Gonadotropin-Releasing Hormone / Q000235:genetics / Q000378:metabolism; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism; D007986:Luteinizing Hormone / Q000097:blood / Q000235:genetics / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology*; D000080866:Nucleobindins; D010053:Ovary / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D010902:Pituitary Gland / Q000187:drug effects / Q000378:metabolism; D015027:Zebrafish / Q000235:genetics / Q000378:metabolism / Q000502:physiology
D002135:Calcium-Binding Proteins; D004268:DNA-Binding Proteins; D009419:Nerve Tissue Proteins; D000080866:Nucleobindins; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone