Development of a novel fluorescent ligand of growth hormone secretagogue receptor based on the N-Terminal Leap2 region

BARRILE, FRANCO; CABRAL, AGUSTINA; CANTEL, SONIA; DENOYELLE, SÉVERINE; RAINGO, JESICA; DE FRANCESCO, PABLO N.; MUSTAFÁ, EMILIO R.; MARY, SOPHIE; MARIE, JACKY; PERELLÓ, MARIO; M'KADMI, CÉLINE; GARCÍA ROMERO, GUADALUPE; DAMIAN, MARJORIE; BANÈRES, JEAN-LOUIS; FEHRENTZ, JEAN-ALAIN

MOLECULAR AND CELLULAR ENDOCRINOLOGY.

ELSEVIER IRELAND LTD

Año: 2019 vol. 498

0303-7207

Liver-expressed antimicrobial peptide 2 (LEAP2) was recently recognized as an endogenous ligand for the growth hormone secretagogue receptor (GHSR), which also is a receptor for the hormone ghrelin. LEAP2 blocks ghrelin-induced activation of GHSR and inhibits GHSR constitutive activity. Since fluorescence-based imaging and pharmacological analyses to investigate the biology of GHSR require reliable probes, we developed a novel fluorescent GHSR ligand based on the N-terminal LEAP2 sequence, hereafter named F-LEAP2. In vitro, F-LEAP2 displayed binding affinity and inverse agonism to GHSR similar to LEAP2. In a heterologous expression system, F-LEAP2 labeling was specifically observed in the surface of GHSR-expressing cells, in contrast to fluorescent ghrelin labeling that was mainly observed inside the GHSR-expressing cells. In mice, centrally-injected F-LEAP2 reduced ghrelin-induced food intake, in a similar fashion to LEAP2, and specifically labeled cells in GHSR-expressing brain areas. Thus, F-LEAP2 represents a valuable tool to study the biology of GHSR in vitro and in vivo.