Ghrelin modulates gene and protein expression of digestive enzymes in the intestine and hepatopancreas of goldfish (Carassius auratus) via the GHS-R1a: Possible roles of PLC/PKC and AC/PKA intracellular signaling pathways.
Blanco, A. M., Bertucci, J. I., Sanchez-Bretano, A., Delgado, M. J., Valenciano, A. I. and Unniappan, S.
Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, S7N 5B4 Saskatoon, Saskatchewan, Canada; Departamento de Fisiologia (Fisiologia Animal II), Facultad de Biologia, Universidad Complutense de Madrid, Jose Antonio Novais 12, 28040 Madrid, Spain. Electronic address: ayelenmelisablanco@ucm.es.
Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, S7N 5B4 Saskatoon, Saskatchewan, Canada; Instituto de Investigaciones Biotecnologicas-Instituto Tecnologico Chascomus, Avenida Intendente Marinos Km. 8,2, 7130 Chascomus, Buenos Aires, Argentina. Electronic address: jbertucci@intech.gov.ar.
Department of Pharmacology and Toxicology, and Neuroscience Institute, Morehouse School of Medicine, 720 Westview Drive, GA 30310 Atlanta, GA, United States. Electronic address: asanchez@msm.edu.
Departamento de Fisiologia (Fisiologia Animal II), Facultad de Biologia, Universidad Complutense de Madrid, Jose Antonio Novais 12, 28040 Madrid, Spain. Electronic address: mjdelgad@bio.ucm.es.
Departamento de Fisiologia (Fisiologia Animal II), Facultad de Biologia, Universidad Complutense de Madrid, Jose Antonio Novais 12, 28040 Madrid, Spain. Electronic address: aivalenciano@bio.ucm.es.
Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, S7N 5B4 Saskatoon, Saskatchewan, Canada. Electronic address: suraj.unniappan@usask.ca.
Ghrelin, a multifunctional gut-brain hormone, is involved in the regulation of gastric functions in mammals. This study aimed to determine whether ghrelin modulates digestive enzymes in goldfish (Carassius auratus). Immunofluorescence microscopy found colocalization of ghrelin, GHS-R1a and the digestive enzymes sucrase-isomaltase, aminopeptidase A, trypsin and lipoprotein lipase in intestinal and hepatopancreatic cells. In vitro ghrelin treatment in intestinal and hepatopancreas explant culture led to a concentration- and time-dependent modulation (mainly stimulatory) of most of the digestive enzymes tested. The ghrelin-induced upregulations of digestive enzyme expression were all abolished by preincubation with the GHS-R1a ghrelin receptor antagonist [D-Lys3]-GHRP-6, and most of them by the phospholipase C inhibitor U73122 or the protein kinase A inhibitor H89. This indicates that ghrelin effects on digestive enzymes are mediated by GHS-R1a, partly by triggering the PLC/PKC and AC/PKA intracellular signaling pathways. These data suggest a role for ghrelin on digestive processes in fish.
Molecular and Cellular Endocrinology 442: 165-181 (2017)