Control of the expression of human neuropeptide Y by leptin: in vitro studies

Neuropeptide Y (NPY) participates in the regulation of reproduction and foo d intake. The adipose-secreted hormone, leptin, has also been involved in t hese processes, and has been shown to exert its effects in part by controll ing NPY synthesis and release at the hypothalamic level. In the present stu dy, we utilized the SH-SY5Y human neuroblastoma cell line, to study the lep tin-NPY interrelationships. SH-SY5Y cells were found to express leptin rece ptors (RT-PCR and Western blot analyses). A 24-h treatment with leptin at d ifferent concentrations did not affect NPY gene expression, but resulted in a stimulation of NPY release. This stimulated secretion was blocked by the combined treatment with leptin and the muscarinic agonist carbachol or the phorbol ester TPA. Leptin and carbachol also caused an increased intracell ular content of NPY. In conclusion, the SH-SY5Y human neuroblastoma cell li ne appears to be a suitable in vitro model for studying the pharmacological effects of leptin on the biosynthesis and secretion of NPY. (C) 2001 Elsev ier Science Inc. All rights reserved.