Differential activation of neuropeptide FF receptors by gonadotropin-inhibitory hormone peptides in the European sea bass

Neuropeptide FF (NPFF) and gonadotropin-inhibitory hormone (GnIH) are thought to be paralogous, a recent study has revealed that both NPFF GnIH peptides can activate the receptor (GnIHR, also called NPFFR1) in European sea bass ( Dicentrarchus labrax ). However, whether bind (NPFFR2) is still yet unknown this species. Accordingly, we further investigated potential interactions between NPFFR2 (two forms present bass, namely NPFFR2-1 NPFFR2-2) on intracellular signaling pathways. Neither GnIH1 nor GnIH2 had any effect basal CRE-luc activity, while forskolin-stimulated activity was significantly reduced when COS-7 cells expressing NPFFR2-2 were challenged with these two peptides. NPAF inhibited forskolin-induced via their cognate receptors. An evident stimulation of SRE-luc observed transfected treated NPAF, whereas no effect, except slight but significant increase elicited by 1000 nM NPFFR2-2. Moreover, only exerted an inhibitory action NFAT-RE-luc NPFFR2-1. None or altered ERK phosphorylation levels Our results provide new evidence may exert functions partially NPFFR2, PKA, PKC Ca 2+ routes mediators.