Estradiol and testosterone modulate the tissue-specific expression of ghrelin, ghs-r, goat and nucb2 in goldfish.

BERTUCCI JI; BLANCO AM; CANOSA LF; UNNIAPPAN S

GENERAL AND COMPARATIVE ENDOCRINOLOGY

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 2016 vol. 228 p. 17 - 23

0016-6480

Abstract Ghrelin, and nesfatin-1 (encoded bynucleobindin2/nucb2) are twometabolic peptides with multiple biological effects in vertebrates. While sexsteroids are known to regulate endogenous ghrelin and NUCB2 in mammals, suchactions by steroids in fish remain unknown. This study aimed to determinewhether estradiol (E2) and testosterone (T) affects the expression ofpreproghrelin, ghrelin/growth hormone secretagogue receptor (GHS-R), ghrelinO-acyl transferase (GOAT) and NUCB2 in goldfish (Carassius auratus). First, a dose-response assay was performed inwhich fish were intraperitoneally (ip) implanted with pellets containing 25, 50or 100 µg/g body weight (BW) of E2 or T. It was found that sex steroids (100µg/g BW) administered for 2.5 days achieved the highest E2 or T in circulation.In a second experiment, fish were ip implanted with pellets containing 100 µg/gBW of E2, T or without hormone (control). RT-qPCR analyses at 2.5 dayspost-administration show that gut preproghrelin and GOAT expression was upregulatedby both E2 and T treatments, while the same effect was observed for GHS-R onlyin the pituitary. Both treatments also reduced hypothalamic preproghrelin mRNAexpression. NUCB2 expression was increased in the forebrain of T treated groupand reduced in the gut and pituitary under both treatments. These results showfor the first time a modulation of preproghrelinand nucb2/nesfatin-1 by sex steroidsin fish. The interaction between sex steroids and genes implicated in bothmetabolism and reproduction might help meeting the reproduction dependentenergy demands in fish.