IMBICE   05372
INSTITUTO MULTIDISCIPLINARIO DE BIOLOGIA CELULAR
Unidad Ejecutora - UE
artículos
Título:
Ghrelin Gene-Related Peptides
Autor/es:
GIOVAMBATTISTA , ANDRÉS; GAILLARD, ROLF; SPINEDI, EDUARDO
Revista:
Vitamins and Hormones
Editorial:
Academic Press
Referencias:
Lugar: Estados Unidos; Año: 2008 vol. 77 p. 171 - 205
ISSN:
0083-6729
Resumen:
It is known that ghrelin and des-n-octanoyl (desacyl) ghrelin modulate food
intake and adipogenesis in vivo. However, desacyl ghrelin represents the
majority of ghrelin forms found in the circulation. The present study explored
whether ghrelin gene-derived compounds could modulate, in vitro, adipocyte
endocrine function and preadipocyte differentiation. Retroperitoneal (RP) adipocytes
were cultured in the absence or presence of either ghrelin or desacyl
ghrelin and in combination with either inhibitors of protein synthesis, insulin,
dexamethasone (DXM), or GHSR1a antagonist. The results indicate that both
ghrelin forms possess a direct leptin-releasing activity (LRA) on RP adipocytes
and significantly enhanced adipocyte ob mRNA expression. These activities
were related and unrelated to the activation of GHSR1a after coincubation
with ghrelin and desacyl ghrelin, respectively. Moreover, desacyl ghrelin facilitated
RP preadipocyte differentiation. Desacyl ghrelin enhanced cell lipid content,
and PPARg2, and LPL mRNAs expression. The LRAs developed by different
substances tested followed a rank order: ghrelin > desacyl ghrelin ¼ insulin _
DXM. Additionally, desacyl ghrelin was able to enhance medium glucose consumption
by mature adipocytes in culture. These data strongly support that
adipogenesis and adipocyte function are processes directly and positively
modulated by ghrelin gene-derived peptides, thus further indicating that,
besides their effects on food intake, ghrelin gene-derived peptides could play
an important role on adiposity for maintaining homeostasis.