Ghrelin induces clock gene expression in the liver of goldfish in vitro via protein kinase C and protein kinase A pathways

• DOI: 10.1242/jeb.144253
• Publication Date: 2017-01-27T01:10:33Z
• Authors: Aída Sánchez-Bretaño; Ayelén M. Blanco; Ángel L. Alonso-G...; María J. Delgado; Olivier Kah; Esther Isorna
• Keywords: MAP3K7; MAP2K7; ASK1; c-Raf

The liver is the most important link between circadian system and metabolism. As a food-entrainable oscillator, hepatic clock needs to be entrained by food-related signals. objective of present study was investigate possible role ghrelin (an orexigenic peptide mainly synthesized in gastrointestinal tract) as an endogenous synchronizer oscillator teleosts. To achieve this aim, we first examined presence receptors goldfish. Then, regulation gene expression goldfish studied. Finally, involvement phospholipase C/protein kinase C (PLC/PKC) adenylate cyclase/protein A (AC/PKA) intracellular signalling pathways investigated. Ghrelin receptor transcripts, ghs-r1a, are majority cells. induced mRNA positive (gbmal1a, gclock1a) negative (gper genes) elements main loop molecular machinery, well grev-erbα (auxiliary loop) cultured liver. These effects were blocked, at least part, antagonist. Incubation with PLC inhibitor (U73122), PKC activator (phorbol 12-myristate 13-acetate) (chelerythrine chloride) demonstrated that PLC/PKC pathway mediates such actions. Experiments AC (forskolin) PKA (H89) showed could due activation PKA. Taken together, results show for time vertebrates direct action on genes support hormone temporal messenger entrainment functions.